[Information] Shirutoku Report No. 106 # Introduction to Principle Verification

Explaining the airflow when a fan is placed inside the sealed enclosure of electronic equipment using fluid simulation results!

★★Shirutoku Report: Useful Information You Can Benefit From★★ When using a fan or blower to circulate air within a space, you may have specific goals such as wanting to direct airflow to a particular area or to circulate air throughout the entire space. However, if the placement of the fan is done solely based on intuition, it may not achieve those objectives. In this report, we will introduce the importance of considering not only the outlet side of the fan but also the inlet side when using fans or blowers to circulate or ventilate air inside a room or electronic devices. [Contents] ■ Considering fan placement based on airflow ■ How to prevent short circuits ■ Taking the inlet side into account for fans and blowers *For more details, please refer to the PDF document or feel free to contact us.

• Ventilation and Exhaust

Introducing the fluid analysis model images and the wind speed distribution (analysis results) when the window is opened, using diagrams!

★★Shirutoku Report: Useful Information You Can Benefit From★★ At WTI, we offer thermal design services that include predicting component temperatures and proposing heat dissipation measures, with ventilation being one of the effective strategies for heat dissipation. In today's life, the importance of ventilating offices and rooms is increasing, and the fundamental approach to ventilating electronic devices and rooms is the same. Therefore, this time we will introduce methods to ensure airflow entry and exit when ventilating. [Contents] ■ Ventilation by opening windows ■ Ventilation using fans ■ Ventilation in thermal design *For more details, please refer to the PDF document or feel free to contact us.

• Other contract services

Check if only a specific function performs as intended! Here is a simple example.

★★Shirutoku Report: Useful Information You Can Benefit From★★ At WTI, we conduct design and development tailored to our customers' needs, and this time we will discuss principle verification. Here, principle verification refers to the confirmation of basic operations and characteristics before starting the full-scale product design. When there is a request for new development and it is believed that there may be technical challenges, we may suggest starting with principle verification. [Contents] ■ About Principle Verification ■ Confirmation of whether the MOSFET for inrush current prevention functions as intended *For more details, please refer to the PDF document or feel free to contact us.

• Other contract services

It's important to select parts suitable for their intended use! Engineers with ample design experience provide the service!

★★Shirutoku Report: Useful Information You Should Know★★ Recently, with the proliferation of mobile devices, there has been remarkable progress in the miniaturization and increased capacity of ceramic capacitors. However, when using ceramic capacitors, it is essential to have a good understanding of their characteristics. In particular, those with high dielectric constants can have significant variations in capacitance due to temperature and applied voltage, so caution is necessary. This time, we will focus on the often-overlooked factor of "shock" and introduce important points to consider when using ceramic capacitors. [Contents] ■ Important Points to Consider When Using Ceramic Capacitors *For more details, please refer to the PDF document or feel free to contact us.

• Capacitor
• Other contract services

It has been well received for being able to automatically measure and judge, thereby reducing the burden on operators!

★★Shirutoku Report: Useful Information You Should Know★★ Our company offers custom measurement services, proposing the construction of testing environments tailored to our customers' needs. We accommodate not only general evaluations such as semiconductors but also a wide range of special measurements, including high-sensitivity measurements, large currents, and high voltages. This time, we would like to introduce a transistor sorting inspection system that was developed in response to such requests. It is especially recommended for customers who are struggling with the need for custom evaluations but cannot make capital investments. [Contents] ■ Transistor Sorting Inspection System *For more details, please refer to the PDF document or feel free to contact us.

• Transistor
• Software (middle, driver, security, etc.)
• Other contract services

An important factor related to the safety and reliability of equipment! Let me introduce you to insulation.

★★Shirutoku Report: Useful Information You Should Know★★ This time, I would like to discuss the basics of "insulation" in power supply design. In power supply design, insulation is primarily used to ensure the safety of equipment and to prevent malfunctions caused by noise, making it an important factor related to the safety and reliability of devices that use the power supply. Please take a moment to read it. [Contents] ■ Types of Insulation ■ Explanation ■ Examples of Application Locations *For more details, please refer to the PDF document or feel free to contact us.

• Insulation Tester

If you are having trouble with timing constraints that we are introducing this time, please feel free to contact us!

★★Shirutoku Report: Useful Information You Can Benefit From★★ This time, I would like to convey that timing verification is extremely important in FPGA design. We have included images of long wiring between flip-flops. Please take a moment to read it. [Contents] ■Timing verification is extremely important in FPGA design ■Images of long wiring between flip-flops *For more details, please refer to the PDF document or feel free to contact us.

• Development support tools (ICE, emulators, debuggers, etc.)

Important tools! Here are the two major challenges in thermal simulation.

★★Shirutoku Report: Useful Information You Should Know★★ The Structural Design Department is broadly divided into simulation (thermal, stress) and mechanism design, and I am in charge of thermal simulation. I started with almost no knowledge of heat. Through daily learning, the simulation that visualizes the invisible "heat" is an important tool for solving and preventing various thermal issues, and I am currently learning its fundamentals. There are two major challenges in thermal simulation. Let me explain the reasons. [Contents] ■ Two Challenges in Thermal Simulation ■ Temperature Distribution Diagram Around Heat Sources (Simulation Results) *For more details, please refer to the PDF document or feel free to contact us.

• simulator

What criteria should be used for selecting components? Introducing the selection criteria for LNA!

★★Shirutoku Report: Useful Information You Should Know★★ One of the important components that affects the receiving characteristics of wireless communication is the LNA (Low Noise Amplifier). We often receive requests from customers asking, "What criteria should we use to select this component?" Therefore, this time, we will discuss the selection criteria for LNA. Please take a moment to read it. [Contents] ■(1) Selection of devices considering power-saving requirements ■(2) Selection focusing on NF and P1dB ■(3) Selection focusing on Gain and IP3 *For more details, please refer to the PDF document or feel free to contact us.

• Other electronic parts

I will talk about the noise countermeasures in the evaluation of power converters!

★★Shirutoku Report: Useful Information You Can Benefit From★★ The current task is the evaluation of "power conditioners" (hereinafter referred to as power conditioners). When we talk about "evaluation of power conditioners," there are various types of evaluations, but this time I would like to discuss the noise countermeasures implemented in our recent work. Please take a moment to read it. [Contents] ■ Causes of Noise Generation ■ Noise Countermeasure Component "Core (Core Material of the Coil)" *For more details, please refer to the PDF document or feel free to contact us.

• Other electronic parts

No application or notification for a license is necessary! We will also introduce the wireless equipment test purchase.

★★Shirutoku Report: Useful Information You Should Know★★ This time, I will talk about weak radio waves. Weak radio waves are wireless signals that emit only extremely weak radio waves, so there are no restrictions on their use or transmission time, and there is no need to apply for or notify a license. However, the electric field strength (the strength of the radio wave) must be lower than the specified level. For more details, please take a look. 【Contents】 ■ What are weak radio waves? ■ Wireless equipment test purchase *For more information, please refer to the PDF document or feel free to contact us.

• others

Communication standards for IoT devices using LPWA technology! I will talk about the differences between "LTE-M" and "NB-IoT."

★★Shirutoku Report: Useful Information You Can Benefit From★★ Recently, we received inquiries about the differences between "LTE-M" and "NB-IoT," which are communication standards for IoT devices using LPWA (Low Power Wide Area) technology. We will discuss "Why is the performance not as specified in the data sheet?" and "How to ensure performance according to design values/data sheets." Please take a moment to read it. [Contents] ■ Why is the performance not as specified in the data sheet? ■ How to ensure performance according to design values/data sheets ■ Antenna simulation analysis service (If you have issues with antennas...) ■ Lastly *For more details, please refer to the PDF document or feel free to contact us.

• antenna

Various tasks such as confirming the operation of circuit functions and checking component ratings! The evaluation of power converters also includes assessments related to circuits.

★★Shirutoku Report: Useful Information You Should Know★★ This time, I will talk about the voltage detection circuit, which plays an important role in the functions of power converters. The evaluation of power converters includes assessments related to the circuit, such as confirming the operation of circuit functions and checking component ratings. Please take a moment to read it. 【Contents】 ■ Voltage detection points ■ About the voltage detection circuit *For more details, please refer to the PDF document or feel free to contact us.

• others

This explains the overview of transfer functions and illustrates the transfer function when incorporating phase compensation with diagrams!

★★Shirutoku Report: Useful Information You Should Know★★ This time, I would like to continue discussing the topic related to transfer functions that I briefly touched on last time. A transfer function, as mentioned in the title, is knowledge necessary for the design of power supply control circuits. Phase compensation can also be considered a control circuit in terms of controlling circuit oscillation. We have also included a simple overview of transfer functions. Please take a moment to read it. [Contents] ■ Overview of Transfer Functions ■ Transfer Functions with Phase Compensation Incorporated *For more details, please refer to the PDF document or feel free to contact us.

• power supply

5th Generation mobile communication system! Introducing features and high-frequency amplifiers for 5G.

★★Shirutoku Report: Useful Information You Should Know★★ This time, I would like to talk about "5G" and "high-frequency amplifiers," which are part of a communication standard. I will introduce what "5G" is, its features, and high-frequency amplifiers for 5G. Please take a moment to read it. 【Contents】 ■ What is 5G? ■ Features of 5G ■ High-frequency amplifiers for 5G *For more details, please refer to the PDF document or feel free to contact us.

• others

The performance of MOSFETs is compared using a performance index called FoM! Measurement conditions vary by manufacturer.

★★Shirutoku Report: Useful Information You Should Know★★ SiC MOSFETs have the characteristic of high voltage resistance compared to Si, while also having low resistance. Leveraging this feature, many products are seen replacing high-voltage IGBTs with SiC MOSFETs. This time, I would like to talk about MOSFETs. If you want to know about SiC diodes, please refer to Shirutoku Report No. 12. 【Contents】 ■Comparison examples of Si-MOSFET, IGBT, and SiC-MOSFET ■Do not compare only based on ON resistance ■When replacing with SiC, be careful to change the drive voltage as well *For more details, please refer to the PDF document or feel free to contact us.

• diode

Create a behavior model for driving a simple inverter FET! I will explain step by step.

★★Shirutoku Report: Useful Information You Can Benefit From★★ Spice simulation typically uses models provided by manufacturers or models extracted from actual measurements. However, as the scale becomes too large, it can lead to slow analysis speeds or errors that prevent operation. This can result in situations where you only want to check trends, but end up spending more time than expected investigating the manufacturer's models because they won't run. This time, I will discuss the "behavior model," which can be used when you want to grasp trends simply in circuit simulation. [Contents] ■ (1) Creating a PWM signal ■ (1-1) Creating the modulated signal ■ (1-2) Creating the carrier signal ■ (1-3) Creating the original PWM signal *For more details, please refer to the PDF document or feel free to contact us.

• Other electronic parts

The results of the simulation can vary greatly depending on the accuracy of the model used! Explanation using diagrams and graphs!

★★Shirutoku Report: Useful Information You Can Benefit From★★ Last time, we created the base PWM signal, so this time we will add the necessary dead time for actual operation and try driving the inverter circuit with the generated signal. We have provided clear explanations using diagrams and graphs, so please take a moment to read through it. 【Contents】 ■ (2) Adding Dead Time ■ (3) Using It in the Inverter Circuit *For more details, please refer to the PDF document or feel free to contact us.

• Other electronic parts

"What are we measuring?" "Is the performance of the equipment being used appropriate?" It is necessary to carefully consider these!

★★Shirutoku Report: Useful Information You Can Benefit From★★ When observing signal waveforms, most of you probably use an oscilloscope. Today, I will talk about whether the waveforms you see on that oscilloscope are truly accurate. Please take a moment to read this. 【Contents】 ■ About the oscilloscope itself ■ About general passive probes ■ How to connect the oscilloscope's GND *For more details, please refer to the PDF document or feel free to contact us.

• Other electronic parts

If you make the minimum necessary settings, communication can surprisingly be easy! I have confirmed that communication can be established with various settings.

★★Shirutoku Report: Useful Information You Should Know★★ CAN FD (CAN with Flexible Data Rate) is a communication protocol that extends the specifications of the CAN (Classic CAN: Controller Area Network) protocol, enabling higher communication speeds and accommodating larger data volumes compared to traditional CAN. This document explains the actual implementation of CAN FD communication using the AURIX microcontroller from Infineon, utilizing an evaluation board (TriBoard). We encourage you to read it. 【Contents】 ■ Structure of the communicating bits ■ CAN FD communication ■ Secondary sample point ■ Surprisingly easy to communicate *For more details, please refer to the PDF document or feel free to contact us.*

• Other electronic parts

There are no radio waves that directly interfere with 920MHz specific low-power radio devices!

★★Shirutoku Report: Useful Information You Can Benefit From★★ Following Shirutoku No. 79, this is the second installment on improving communication distance. In the previous issue, we introduced how reviewing the installation height of antennas in relation to the Fresnel zone can extend communication distance. This time, we would like to consider measures against interference waves. 【Contents】 ■ Radio waves can sometimes become interference waves ■ Tips for countermeasures ■ High-frequency (RF) and wireless design contracting services *For more details, please refer to the PDF document or feel free to contact us.*

• Wireless LAN

You cannot obtain the technical standards conformity certification (Giteki) as it is? Let me explain the reason!

★★Shirutoku Report: Useful Information You Should Know★★ Recently, many customers have expressed a desire to obtain Technical Standards Conformity Certification (Giteki) to use or sell imported Wi-Fi products domestically. However, imported Wi-Fi products are not adjusted for the Japanese market, and in most cases, they cannot obtain Technical Standards Conformity Certification (Giteki) even if tested as they are. Let me explain the reasons. [Contents] ■ The transmission power is too high ■ The usable frequencies are different ■ It is necessary to comply with Japan-specific DFS patterns *For more details, please refer to the PDF document or feel free to contact us.

• Other network tools

Simulation of how the size of the ground affects antenna characteristics!

★★Shirutoku Report: Useful Information You Should Know★★ This time, we will introduce a comparison of radiation efficiency by changing the ground area of a monopole chip antenna. We will cover the "introduction," as well as the "monopole antenna" and the "relationship between the radiation efficiency of monopole chip antennas and ground area." Please take a moment to read it. [Contents] ■ Introduction (Frequency bands of 4G and LTE-Advanced and multi-band antennas) ■ Monopole Antenna (The ground is also part of the antenna) ■ Relationship between the radiation efficiency of monopole chip antennas and ground area *For more details, please refer to the PDF document or feel free to contact us.

• others

The differences in usage are mobility, FOTA, communication speed, and more! I will talk about the differences!

★★Shirutoku Report: Useful Information You Should Know★★ Recently, we received inquiries about the differences between "LTE-M" and "NB-IoT," which are communication standards for IoT devices using LPWA (Low Power Wide Area) technology. Both "LTE-M" and "NB-IoT" are IoT communication services that utilize mobile phone networks, and they operate in the same frequency band. Please take a moment to read through this. [Contents] ■ LTE-M and NB-IoT ■ Both utilize mobile phone networks... ■ Differences in usage... *For more details, please refer to the PDF document or feel free to contact us.*

• others

By simply reviewing the installation height of the antenna, there is a possibility of significantly improving the communication distance!

★★Shirutoku Report: Useful Information You Should Know★★ In the case of 920MHz low-power wireless modules, which have relatively good communication distance and decent speed, the transmission output is limited to 20mW or less. A line-of-sight distance of about 5 km is possible. However, in practice, it is often the case that the range is only a few hundred meters. This document explains the factors that reduce communication distance. Please take a moment to read it. 【Contents】 ■ Factors that reduce communication distance ■ Football-shaped space ■ Significantly improving communication distance *For more details, please refer to the PDF document or feel free to contact us.*

• Wireless LAN

It is necessary to realize a stable system that "achieves the required functionality" while "not stopping operation"!

★★Shirutoku Report: Useful Information You Should Know★★ There is no need to reiterate the definition of "IoT," as it has already permeated our lives. In the market, there are many inexpensive gadgets available that allow for development simply by connecting to a PC, creating an environment where anyone can easily work on IoT devices as part of summer vacation projects. While IoT devices have become so easy to develop, what challenges arise when it comes to commercialization and productization? We will introduce the essential embedded technologies for IoT development. 【Contents】 (1) The performance of IoT devices that cannot be achieved by just combining devices (2) The necessity of power-saving for IoT devices, which is essential for energy efficiency, utility expansion, and large-scale applications (3) Other challenges that need to be addressed *For more details, please refer to the PDF document or feel free to contact us.*

• Development support tools (ICE, emulators, debuggers, etc.)

LED lighting can control the amount of light through current! Its ability to achieve a wide range of dimming is a key feature.

★★Shirutoku Report: Useful Information You Should Know★★ I am engaged in power supply circuit design and encounter a wide variety of power supplies on a daily basis. There are various control methods for power supplies, but the two types that are most commonly seen are: (1) Constant voltage power supply, which controls to maintain a constant voltage value (2) Constant current power supply, which controls to maintain a constant current value This time, I would like to talk about (2) the constant current power supply. [Contents] ■1. (Pseudo) constant current drive of LEDs using a constant voltage power supply ■2. Constant current drive of LEDs *For more details, please refer to the PDF document or feel free to contact us.

• power supply
• LED Module

Caution is needed! It is important to properly address metastability measures during the design phase!

★★Shirutoku Report: Useful Information You Should Know★★ Digital circuits consist of synchronous circuits that are synchronized with a clock and asynchronous circuits that are not. In synchronous circuits, flip-flops (FF) used have timing specifications such as setup time (tSU) and hold time (tH) established as requirements for stable operation between the clock and input signals. This time, we will explain the handling of asynchronous input signals, which require caution in digital circuit design such as FPGA. 【Contents】 ■ Factors that cause logical circuits to malfunction ■ Measures to prevent impact on circuit operation ■ The number of flip-flops needs to be optimized ■ It is important to properly implement metastability measures during the design phase *For more details, please refer to the PDF materials or feel free to contact us.*

• others

It is important to consider impedances not shown in the circuit diagram and to collaborate with the customer to address them!

★★Shirutoku Report: Useful Information You Should Know★★ We are engaged in the development of chargers for Li-ion batteries. In addition to the Li-ion battery, the charger is connected to an inverter as part of the entire system, which requires resistance to noise voltage generated by these components. This time, we will discuss the resistance to noise voltage applied externally to the output terminals of this charger. 【Contents】 ■ It is also necessary not to resonate with noise ■ Confirm characteristics with an impedance analyzer ■ Consideration of impedances not shown in the circuit diagram is also necessary *For more details, please refer to the PDF document or feel free to contact us.*

• power supply

When connecting multiple LEDs, there are several connection methods! Here are the key points to consider!

★★Shirutoku Report: Useful Information You Should Know★★ LED lighting is now used in various places, including home lighting, streetlights, and display backlights. When using LEDs for lighting, it is often necessary to drive multiple units simultaneously to meet brightness specifications. In such cases, the question arises as to how to combine and connect them in series and parallel. Are you aware of the characteristics that differ based on the connection method? I would like to explain the advantages and disadvantages of LED series and parallel connections. [Contents] ■ Series Connection ■ Parallel Connection ■ Advantages and Disadvantages *For more details, please refer to the PDF document or feel free to contact us.*

• LED Module

With a large-signal model of a transistor, it is possible to design considering large-signal characteristics such as output power and efficiency!

★★Shirutoku Report: Useful Information You Can Benefit From★★ In this document, I would like to discuss the design of high-frequency amplification circuits. High-frequency amplification circuits are composed of amplification elements, matching circuits, and bias circuits. I will explain in order: "Selection of amplification elements," "Design of matching circuits," and "Design of bias circuits." Please take a moment to read it. [Contents] ■ Selection of amplification elements ■ Design of matching circuits ■ Design of bias circuits *For more details, please refer to the PDF document or feel free to contact us.

• Circuit board design and manufacturing

An important issue to be aware of in the development of high-frequency amplifiers is "not to oscillate"!

★★Shirutoku Report: Useful Information You Should Know★★ Indicators that represent the performance of high-frequency amplifiers include output power, gain, and efficiency, and development is progressing to meet the required performance for each. However, aside from these performance metrics, there is an important issue to be aware of in high-frequency amplifier development: "avoiding oscillation." This document explains that addressing oscillation is also crucial in high-frequency amplifier development. Please take a moment to read it. 【Contents】 ■Methods to Suppress Gain *For more details, please refer to the PDF document or feel free to contact us.

• Amplifier

In simple terms, it means "You cannot transmit radio waves without obtaining a license as a radio station or acquiring a technical conformity mark!"

★★Shirutoku Report: Useful Information You Should Know★★ Have you ever seen the "Technical Standards Conformity Certification" mark? This is a mark given to products that have received certification known as "Giteki" for short. This time, I would like to talk about the frequently asked questions regarding obtaining Giteki certification. Please take a moment to read it. 【Contents】 ■ What is Technical Standards Conformity Certification? (What is Giteki?) ■ What is the difference between Giteki and construction design certification? ■ How should I apply for Giteki? ■ What are the benefits of requesting Giteki application from a design company? *For more details, please refer to the PDF document or feel free to contact us.

• others

Are you having trouble with sound? Here are some points to consider for designing high sound quality (low noise).

★★Shirutoku Report: Useful Information You Can Benefit From★★ In this document, I would like to talk about audio design (high sound quality). Recently, we haven't been hearing the term Hi-Fi (high fidelity, high reproducibility) as much. Perhaps it's because the term Wi-Fi has become so common that it has become confusing... Or could it be that high-resolution audio has taken the place of Hi-Fi as the term for high sound quality? 【Contents】 ■ Definition of Good Sound ■ Design Points to Be Careful About *For more details, please refer to the PDF document or feel free to contact us.*

• others

By verifying the validity of work from a design perspective, we ensure the quality of the product!

I am engaged in the development and design of mobile communication devices. In this document, I will focus on the "modification" work within that context. "Modification" in the development and design field involves identifying issues from prototype evaluations and incorporating the countermeasures back into the prototype (essentially reworking it). There are points to be cautious about in terms of both the work process and the design aspects during "modification." Please take a moment to read through it. [Contents] ■ Points to consider for soldering work ■ Design considerations *For more details, please refer to the PDF document or feel free to contact us.

• Solder
• Prototype Services
• others

We propose communication standards that suit your needs! Introducing the applications of specific low-power radio (Tokushou) stations, etc.

★★Shirutoku Report: Useful Information You Should Know★★ Do you know about specific low-power radio? It is often referred to as "Tokusho" for short. In this document, we will introduce this topic. We cover "Uses of Specific Low-Power Radio (Tokusho)" and "Wireless Communication Circuit Design Services," so please take a moment to read through it. [Contents] ■ What is Specific Low-Power Radio (Tokusho)? ■ Various Standards for Specific Low-Power Radio (Tokusho) ■ Introduction to Wireless Communication Circuit Design Services *For more details, please refer to the PDF document or feel free to contact us.*

• Wireless LAN
• others

I think it is important to have a good understanding of the circuit in order to effectively use a circuit simulator!

★★Shirutoku Report: Useful Information You Should Know★★ In the field of high frequency, the use of circuit simulation is essential for circuit design. This document introduces the utilization of high frequency circuit simulators. We explain using figures such as "Examples of Circuit Simulation Results for Matching Circuits," so please take a moment to read it. [Contents] ■ Examples of Circuit Simulation Results for Matching Circuits, etc. *For more details, please refer to the PDF document or feel free to contact us.*

• Other FA equipment
• simulator
• others

What should I prepare for the application for technical standards conformity certification? Information on necessary documents for the application is provided.

★★Shirutoku Report: Useful Information You Should Know★★ In this document, we would like to provide detailed information about "Technical Compliance" (Giteki), which has seen an increase in inquiries. We will explain what is required for a Giteki application using the example of a Bluetooth (BLE) module application. We also include the benefits of requesting a Giteki application from a design company, so please take a moment to read through it. 【Contents】 ■ What is required for a Giteki application... ■ What are the benefits of requesting a Giteki application from a design company? *For more details, please refer to the PDF document or feel free to contact us.*

• others

Achieving a flat temperature characteristic by combining negative and positive temperature characteristics!

★★Shirutoku Report: Useful Information You Can Benefit From★★ You may casually use linear regulators and DC-DC converters, but when you turn on the power, they provide the desired output voltage as if it were a given. Have you ever wondered, "Why is that voltage output so stable?" In this report, we will introduce the reference voltage sources found in power ICs such as linear regulators and DC-DC converters. Please take a moment to read it. [Contents] ■ Discussion on Reference Voltage Sources ■ An Example of a Bandgap Reference Circuit ■ Detailed Explanation *For more details, please refer to the PDF document or feel free to contact us.*

• converter
• Other power sources

The issue of noise in ADCs and its countermeasures! The important point is to handle it skillfully!

★★Shirutoku Report: Useful Information You Should Know★★ In this report, we will introduce the A/D converter related components mounted on the microcontroller of the control board, which is central to power control. The importance of noise countermeasures for the ADC used in circuits is extremely high, as deviations in conversion values due to noise can adversely affect subsequent control. We will discuss the noise issues related to ADCs and their countermeasures, so please take a moment to read it. 【Contents】 ■ (1) About ADCs mounted on microcontrollers ■ (2) The issue of input noise in ADCs ■ (3) Specific examples of noise countermeasures for ADCs *For more details, please refer to the PDF document or feel free to contact us.

• converter
• Control Panel

The breakers lined up in the distribution board are of different types according to their purposes!

★★Shirutoku Report: Useful Information You Should Know★★ The Power Supply Design Department designs various types of switching power supplies, such as AC-DC converters and DC-AC inverters, and conducts various evaluations and tests specific to power supplies. Among these tests, there are rigorous assessments known as "abnormal tests," which evaluate safety in the event of component failures. One of the important devices that protects evaluation equipment during such harsh tests is the "circuit breaker." Many may be more familiar with the term "breaker." In this report, we will introduce this breaker. [Contents] ■ Ampere Breaker: Maintains the current value contracted with the power company ■ Leakage Breaker: Protects commercial systems held by households and power companies from accidents ■ Safety Breaker: Maintains the current value for each circuit (each room) *For more details, please refer to the PDF document or feel free to contact us.

• Circuit breakers and switches

To keep the lamp lit stably, it is necessary to control the power output according to the condition of the lamp!

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces the features of ballast power control. The ballast power supply refers to a device that stabilizes the discharge state of lamps, which are light sources such as car headlights and LCD projectors. Unlike general power supplies that operate under constant voltage or constant current, to keep the lamp lit stably, it is necessary to understand the lighting characteristics of each type of lamp and control the power output according to the lamp's condition. [Contents] ■ Example of lighting characteristics of ultra-high pressure mercury lamps used in LCD projectors ■ Fast control is required ■ Emits light at the necessary brightness ■ Control of the switching operation itself *For more details, please refer to the PDF document or feel free to contact us.

• Other power sources
• power supply

In the manufacturing field, production equipment using the once-popular PC98 from over 20 years ago is still in active use!

★★Shirutoku Report: Useful Information You Can Benefit From★★ This report introduces measures for dealing with equipment failures related to PC98. A customer consulted us about a printer connected to their PC98, which is used to control testing equipment, that has broken down and is unable to print data. They were seeking a solution. Our company also responds to issues related to aging tools, devices, and equipment surrounding production facilities, as well as measures for failure prevention and extension of lifespan, so please feel free to consult us if you have any problems. 【Contents】 ■ Customer Consultation ■ Specific Measures ■ Construction of the Measures System *For more details, please refer to the PDF document or feel free to contact us.

• Industrial PCs
• Desktop PC

Our company is capable of simulating the 3D conversion of CAD drawings and structural diagrams, extracting the contributing elements.

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces the ideals and realities of circuit diagrams. Circuit diagrams feature electronic components such as capacitors, inductors, transistors, diodes, and resistors, each treated as ideal elements. However, in real circuits, there are not only these elements but also parasitic components such as capacitive, inductive, and resistive elements, which can cause various adverse effects and hinder the intended operation of the designer. Our company has many engineers who are well-versed in parasitic components and can perform circuit design accordingly, so if you are interested, please feel free to contact us. [Contents] ■ Parasitic Capacitance ■ Parasitic Inductance ■ Parasitic Resistance *For more details, please refer to the PDF document or feel free to contact us.

• Other semiconductors
• connector

Even parasitic impedance not shown in the circuit diagram can be detected by a professional!

★★Shirutoku Report: Useful Information You Can Benefit From★★ In this report, we will introduce an important invisible element, "impedance," in addition to parasitic components that are not visible on circuit diagrams. Impedance refers to AC resistance and is often specified as 50Ω for single-ended and 100Ω for differential. In high-frequency circuit design, impedance becomes a critical issue. Even parasitic impedance that is not shown in the circuit diagram can be discerned by professionals. If you are interested, please feel free to contact us. 【Contents】 ■ An example of a circuit diagram created with LT-spice *For more details, please refer to the PDF document or feel free to contact us.

• Other semiconductors
• connector

How should switching evaluation be conducted? Explanation using diagrams and photos.

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces the switching evaluation of power semiconductors such as power devices and power modules. The ideal switching operation is a state where there is no delay time in current and voltage when switching ON/OFF, meaning there is no occurrence of power loss. However, during the switching operation of power devices, some delay time inevitably occurs. Our company has engineers with expertise in switching evaluation, so if you require evaluation of various power devices, please feel free to consult us. 【Contents】 ■ IGBT Module Measurement Circuit Examples ■ IGBT Module Measurement Environment Examples *For more details, please refer to the PDF document or feel free to contact us.

• Capacitor
• Other semiconductors

I will talk about a method to quantitatively verify the magnitude of circuit inductance.

★★Shirutoku Report: Useful Information You Should Know★★ In this report, we will introduce a method to quantitatively confirm the magnitude of circuit inductance. When improving the measurement environment for switching evaluation of power semiconductors, it is sometimes necessary to reconsider the wiring. However, without a quantitative understanding of the magnitude of the circuit inductance in the measurement system, improvements can be difficult. By using the measured circuit inductance values during simulations, results closer to the actual measured waveforms can be obtained. 【Contents】 ■ Methods for Improving Circuit Inductance ■ IGBT Module Measurement Circuit Example ■ How to Confirm Circuit Inductance *For more details, please refer to the PDF document or feel free to contact us.*

• Capacitor
• Other semiconductors

An insulated circuit that requires careful attention for noise countermeasures. Here is an example of a method to stabilize the ground.

★★Shirutoku Report: Useful Information You Should Know★★ In this report, we will introduce the requirements for insulation and noise countermeasures. In electrical circuits, insulation may be used for safety reasons, such as preventing electric shocks, or to avoid unexpected current destruction. Common items we handle include communication interfaces like LAN and insulated power supplies. It is common to use optocouplers or transformers for the transmission of signals and power across insulated sections. If you are having trouble with noise countermeasures, please feel free to contact us. 【Contents】 ■ Insulation and Noise Countermeasures *For more details, please refer to the PDF document or feel free to contact us.*

• transformer
• power supply
• LAN/Optical cable

Why is it called "distribution constant," and what is being distributed? An introduction to distribution constant circuits.

★★Shirutoku Report: Useful Information You Can Benefit From★★ This report introduces distributed constant circuits. We will explain distributed constant circuits, where the distance and dimensions of wiring and components are finite and the signal transmission time is also finite, in contrast to concentrated constant circuits, which are the opposite concept where the distance of wiring is zero, using diagrams. Please take a moment to read it. 【Contents】 ■ Concentrated Constant Circuits ■ Distributed Constant Circuits *For more details, please refer to the PDF document or feel free to contact us.*

• Other electronic measuring instruments

For those who have grown tired of the same lighting patterns every year, we introduce illumination control using Arduino.

★★Shirutoku Report: Useful Information You Can Benefit From★★ This report introduces illumination control using Arduino. For those who want to "add or change their favorite lighting patterns," we present examples of DIY projects using microcontrollers and modules that have simple and convenient features. Please take a moment to read it. 【Contents】 ■ Equipment Used ■ Procedure *For more details, please refer to the PDF document or feel free to contact us.*

• LED Module
• Other process controls

I created a custom project using samples with the goal of illuminating the lights. Here is an introduction to the screen display and button operation.

★★Shirutoku Report: Useful Information You Can Benefit From★★ This report is a continuation of the discussion on controlling illumination with Arduino from Shirutoku Report No. 58, and this time we have incorporated screen display and button operation. We will explain the LCD display method and button operation method along with actual photos. Our company undertakes the development of various embedded devices and IoT devices using a variety of microcontrollers. If you have any inquiries, please feel free to contact us. [Contents] ■ LCD Display Method ■ Button Operation Method *For more details, please refer to the PDF document or feel free to contact us.

• LED Module
• Other process controls

We also support tests in accordance with various standards such as certification. Here, we introduce the main evaluation and testing items for switching power supplies and their implementation details.

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces electrical evaluations related to switching power supplies. The evaluation of power supply circuits is characterized by the inclusion of many aspects that confirm safe operation (ensuring there are no hazards). There are also specific contents that may be unfamiliar to those not involved in power supply design or evaluation, so we would like to take this opportunity to explain. 【Contents】 ■Electrical characteristic evaluation ■Component rating confirmation ■Abnormal testing ■Temperature rise testing ■Immunity testing ■Reliability testing *For more details, please refer to the PDF document or feel free to contact us.

• Switching Power Supply

Introducing circuit verification using 'SPICE' as a countermeasure for problems arising from changes in component characteristics.

★★Shirutoku Report: Useful Information You Can Benefit From★★ This report focuses on circuit verification using "SPICE," which allows for various validations. Using a filter as an example, we will present a verification designed to reduce the number of components by modifying the configuration, ensuring that the attenuation characteristics match at 10MHz, illustrated with diagrams. Our company also conducts validity checks of designs through simulations based on customer requests. We encourage you to read on. 【Contents】 ■ Examples of circuit verification using SPICE ■ One-point advice ■ Meaning of commands *For more details, please refer to the PDF document or feel free to contact us.*

• Contract measurement

Introduction of the evaluation content for power converter assessments, such as certification testing of developed products and performance evaluations of products!

★★Shirutoku Report: Useful Information You Can Benefit From★★ A power conditioner (power con) is an inverter device that converts renewable energy, such as solar power, into commercial alternating current used in households. This report includes evaluations of certification tests for developed products, performance evaluations of products, and system tests of products, all related to power con assessments. Additionally, we introduce the "lightning surge test," which applies a voltage equivalent to lightning to confirm durability. We encourage you to read it. 【Contents】 ■ Certification test evaluations for developed products ■ Performance evaluations of products ■ System tests of products ■ Information on lightning surge tests *For more details, please refer to the PDF document or feel free to contact us.

• power supply
• inverter
• Other contract services

Introducing circuit diagrams and features of insulated switching power supplies, such as forward and flyback methods!

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces representative methods of isolated switching power supplies that use transformers among the circuit types of switching power supplies. It includes circuit diagrams and features of the Forward method, Flyback method, Push-Pull method, and Full Bridge method. Please take a moment to read it. [Contents] ■ Forward Method ■ Flyback Method ■ Push-Pull Method ■ Full Bridge Method *For more details, please refer to the PDF document or feel free to contact us.

• power supply
• Switching Power Supply
• Other contract services

A convenient data analysis tool that anyone can use, takes no time, and has no mistakes!

★★Shirutoku Report: Useful Information You Can Benefit From★★ How do you compile data collected from various measuring instruments into reports during evaluation analysis? Many of you might be manually and patiently rearranging data or creating graphs. When the volume becomes enormous, it can take a lot of time and be inefficient. If there are mistakes, you might have to start all over again. It would be great to have something that anyone can use, doesn’t take much time, and doesn’t lead to errors. That’s why we want to introduce our company’s 'Data Analysis Tool.' For more details, please take a moment to read on. [Contents] ■ Data Analysis Tool provided by Wave Technology *For more information, please refer to the PDF document or feel free to contact us.*

• Other analyses

Implemented using a measurement method called feedback method! Introducing the basic circuit for measuring microcurrents.

★★Shirutoku Report: Useful Information You Can Benefit From★★ This report introduces the examination of microcurrent measuring devices. Previously, I created a microcurrent measuring device for work. There are various methods for measuring microcurrents, but the method used this time is called the "feedback method." I will explain the basic circuit of this method. For more details, please be sure to read on. 【Contents】 ■ Target performance of microcurrent measuring devices ■ Basic principles of microcurrent measurement ■ Determining the measurement range ■ Selection of OP amps ■ Phase compensation capacitors ■ Conclusion *For more details, please refer to the PDF document or feel free to contact us.

• Other measurement, recording and measuring instruments

"What is V2H?" "What can be done with V2H?" Published! An explanation of how to utilize electric vehicles at home.

★★Shirutoku Report: Useful Information You Can Benefit From★★ In recent years, our company has seen an increase in automotive-related operations and is involved with a vehicle-to-home (V2H) electric vehicle charging and discharging system. V2H stands for "Vehicle to Home," which is an abbreviation for a system that allows the use of an electric vehicle's battery at home. This report will introduce V2H. [Contents] ■ What is V2H? ■ What can you do with V2H? *For more details, please refer to the PDF document or feel free to contact us.*

• power supply
• Secondary Cells/Batteries
• Power storage device

Efficient power supply using SiC devices! A brief introduction to the types and features of diodes.

★★Shirutoku Report: Useful Information You Should Know★★ By changing semiconductor materials from Si to SiC (silicon carbide), the breakdown voltage of Schottky Barrier Diodes (SBD) has improved, making them usable in DC/DC converters for PCS. While performance improves with SiC, cost issues had previously hindered its adoption. However, in the last year or two, cost challenges have been addressed, leading to increased opportunities for use. This report will briefly explain the types and characteristics of diodes. 【Contents】 ■ Types and Characteristics of Diodes *For more details, please refer to the PDF document or feel free to contact us.*

• power supply
• diode

Key points to consider in power supply design! Here are some points for beginners to keep in mind when designing.

★★Shirutoku Report: Useful Information You Should Know★★ The "power supply" is an essential component in electrical circuits. The "power supply" has functions such as converting voltage levels and transforming alternating current (AC) to direct current (DC). Among these, I would like to discuss the frequently used "DC-DC converter." A "DC-DC converter" is a device that converts direct current into direct current at different voltage levels. While detailed design methods can be referenced in specialized books, this report introduces key points for beginners when designing. [Contents] ■ Key Points in Circuit Design *For more details, please refer to the PDF document or feel free to contact us.*

• power supply
• Circuit board design and manufacturing

If you have any concerns, whether related to new designs or responses to production discontinuation, please feel free to consult with us.

★★Shirutoku Report: Useful Information You Should Know★★ Power supply equipment must satisfy the lifespan of products with components such as electrolytic capacitors, phototransistors (optical communication devices), and relays. There are many instances where lifespan verification is conducted through lifespan calculations and electrical evaluations. This report introduces examples of electrical evaluations. [Contents] ■Electrolytic Capacitors ■Phototransistors *For more details, please refer to the PDF document or feel free to contact us.*

• Other inspection equipment and devices

Be cautious of inductance that does not appear in the circuit diagram! A problem unique to the field of power electronics.

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces the circuit operation of power converters. A power converter is a device that converts the direct current (DC) generated by solar panels into alternating current (AC) for commercial power systems. As an example, we have included a configuration diagram that only describes the power circuit in a transformerless method. Please take a moment to read it. 【Featured Content】 ■ About the circuit operation of power converters - Chopper circuit - Inverter circuit ■ Have you ever experienced issues such as the device not operating even though it was built according to the circuit diagram, or switching elements failing immediately? *For more details, please refer to the PDF document or feel free to contact us.

• inverter

Avalanche surrender, UIS test circuits and waveforms, etc.! An explanation of the avalanche tolerance testing of power MOSFETs.

★★Shirutoku Report: Useful Information You Should Know★★ The avalanche rating measured in avalanche testing refers to the amount of energy that a power device can withstand before it begins to conduct current rapidly and ultimately fails when a voltage exceeding its breakdown voltage is applied. This report explains avalanche breakdown, UIS test circuits, and waveforms using diagrams. To verify whether there are any issues in the event that the device enters avalanche mode, it is necessary to investigate the avalanche rating of power MOSFETs when designing power electronics circuits. [Contents] ■ Image of avalanche breakdown ■ Test circuit and waveform for measuring avalanche rating *For more details, please refer to the PDF document or feel free to contact us.

• Other measurement, recording and measuring instruments
• Contract Inspection
• Other contract services

Explaining the transient thermal resistance of devices using diagrams! Calculations will be performed using a MOSFET with appropriate parameters as an example.

★★Shirutoku Report: Useful Information You Should Know★★ This report is a continuation of the avalanche rating test of MOSFETs discussed in Shirutoku Report No. 52. We will explain the relationship between the device's transient thermal resistance and the losses and time during avalanche operation using diagrams and graphs. When selecting a device, comparing devices measured under different conditions is not very meaningful. It is recommended to measure in an environment as close to actual operation as possible, rather than relying solely on data sheet values. 【Contents】 ■ Transient thermal resistance of the device ■ Relationship between losses and time during avalanche operation ■ Graph of Tj and time *For more details, please refer to the PDF document or feel free to contact us.

• Other measurement, recording and measuring instruments
• Contract Inspection
• Other contract services

The power converter, which plays the role of bridging electricity, is the key to the system! Introducing the battery-compatible system.

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces battery-compatible systems. Using solar power generation as an example, we explain the combinations of system operations over the course of a single day. By setting the operating modes for each product, we can explore various conditions under which the battery charges/discharges, whether it operates when buying from (or selling to) the grid, and other diverse operational patterns. 【Contents】 ■ Battery-Compatible Systems ・Nighttime ・Morning (Evening) ・Daytime *For more details, please refer to the PDF document or feel free to contact us.

• power supply
• Other power sources
• Other contract services

The communication device accesses the power company's server to obtain information! Introducing the mechanism and evaluation of the output control function.

★★Shirutoku Report: Useful Information You Should Know★★ In recent years, the rapid increase in solar power generation has disrupted the balance between supply and demand, raising concerns that supply (generation) may exceed demand. This report covers the output control function. When electricity supply is expected to exceed demand, power companies need to reduce the generation of renewable energy. 【Contents】 ■ What is the output control function? ■ Mechanism of the output control function - Information is registered on servers owned by each power company - Communication devices access the power company's server to obtain information - Information is sent to the power converter for control ■ Evaluation of the output control function *For more details, please refer to the PDF document or feel free to contact us.*

• Other process controls
• Other energy equipment
• Other services

Correct knowledge of phase is essential for power supply design! Here’s an example to enhance circuit operation stability.

★★Shirutoku Report: Useful Information You Should Know★★ Phase compensation in power circuits is a technique that controls the phase shifts caused by the capacitors (C) and inductors (L) implemented on power boards, ensuring stable operation of the circuit. In this report, we will introduce examples of voltage and current phases and the transfer function of feedback circuits using diagrams. If the phase remains shifted, the control to lower the output voltage may inversely affect it, potentially causing the output voltage to rise indefinitely and lead to oscillation. We encourage you to read it. 【Contents (Excerpt)】 ■ Voltage and Current Phases ■ An Example of the Transfer Function of Feedback Circuits ■ Stability Confirmation Using Board Wires ■ Changes in Board Bode Plots with Phase Compensation Added *For more details, please refer to the PDF document or feel free to contact us.

• power supply
• Other power sources
• Other contract services

Explanation on how to reduce output variation in circuits with characteristic variability!

★★Shirutoku Report: Useful Information You Should Know★★ Feedback refers to the process of "returning" or "reverting," and it is a control method that operates the output according to a target by returning the output to the input side for control. This report explains feedback control, which is closely related to power circuits, and open-loop control. Power circuits can experience significant changes in characteristics when various loads are connected externally or when the input voltage fluctuates greatly, making feedback control very important. [Contents] ■ Open-loop Control ■ Feedback Control *For more details, please refer to the PDF document or feel free to contact us.*

• power supply
• Switching Power Supply
• Other contract services

Selection of ICs with Ioff functionality is necessary! Explanation of support for external interfaces and other related matters.

★★Shirutoku Report: Useful Information You Should Know★★ This report explains the important Ioff function during partial power down. "Partial" means "some" or "partial," and partial power down refers to a state where the power is turned off partially. During partial power down, it is necessary to be cautious during design, as there will be a mix of circuit blocks that are powered on and those that are powered off. [Contents] ■ Points to note during partial power down ■ Support for partial power down in external interfaces ■ Pull-up resistors *For more details, please refer to the PDF document or feel free to contact us.

• power supply
• Other power sources

If you understand phase compensation, you won't be afraid of power supply oscillation! An explanation of power supply performance.

★★Shirutoku Report: Useful Information You Should Know★★ When evaluating power supplies, you may have experienced "oscillation at low temperatures!" In such cases, it is necessary to diagnose the power supply's frequency characteristics more quantitatively and implement countermeasures. This report explains the performance of power supplies using diagrams and graphs, without using mathematical formulas, to provide a conceptual image. We encourage you to read it. 【Contents】 ■ Negative Feedback Circuit ■ Bode Plot (Gain Plot, Phase Plot) *For more details, please refer to the PDF document or feel free to contact us.*

• power supply
• Other power sources
• Other contract services

Whether it's a microcontroller or an FPGA, we will introduce the key points of system design!

★★Shirutoku Report: Useful Information You Can Benefit From★★ When developing a new product, many people have experienced the dilemma of whether to use a microcontroller or an FPGA for processing. Additionally, a common conversation is whether to process with software or hardware. In this report, we will discuss the key points of system design. For more details, please take a moment to read through it. [Contents] ■ Efficiency in System Design ■ Image of Processing Speed *For more information, please refer to the PDF document or feel free to contact us.*

• Software (middle, driver, security, etc.)
• Other embedded systems (software and hardware)

Explanation of the types and uses of substrates! In particular, we will introduce the types of rigid substrates.

★★Shirutoku Report: Useful Information You Can Benefit From★★ The design values and finished values for wiring widths and layer spacing differ depending on the type of circuit board and manufacturing methods (such as subtractive methods, semi-additive methods, etc.). In this report, we will introduce the different types of circuit boards available. Additionally, WTI offers various types of circuit board design and prototyping services. Please feel free to reach out to us. 【Contents】 ■ Types of Circuit Boards and Their Applications *For more details, please refer to the PDF document or feel free to contact us.*

• Printed Circuit Board
• Circuit board design and manufacturing
• Prototype Services

Promoting development design! Custom measurement and interface circuits.

★★Shirutoku Report: Useful Information You Can Benefit From★★ This report introduces the utilization of "interface circuits" that make measurement convenient, which is being worked on by the Custom Technology Division. Our company occasionally prepares original "interface circuits" with high versatility, and this time we are featuring one of those examples. Proposing solutions to our customers' challenges is a hallmark of our services. We look forward to hearing from those who are interested. 【Contents (Excerpt)】 ■ Providing services centered around custom measurement ■ What is an interface circuit? ■ Image of the configuration of an interface circuit (analog isolation circuit board) ■ Production board for interface circuits (analog isolation circuit board) *For more details, please refer to the PDF document or feel free to contact us.

• Other Connectors
• Other inspection equipment and devices
• Contract measurement

A simple explanation using MOSFET as an example! Introducing power cycle testing to evaluate durability.

★★Shirutoku Report: Useful Information You Can Benefit From★★ Suddenly, do you all know about "reliability testing"? In brief, it is a collective term for various tests that evaluate the reliability (performance, durability, safety, failure rate, etc.) of a product. The main objectives are to confirm whether the performance meets the design specifications and to assess whether it meets market quality requirements. In this report, we will introduce one of the durability tests for power devices, known as the "power cycle test." For more details, please take a moment to read on. 【Contents】 ■ Short Power Cycle Test (Reference: JEITA-ED-4701/601 602) ■ Long Power Cycle Test (Reference: JEITA-ED-4701/603) *For more details, please refer to the PDF document or feel free to contact us.

• Other inspection equipment and devices
• Contract Inspection
• Other contract services

Explaining the basics of sensor control! If you're considering automating measurements, please give it a try.

★★Shirutoku Report: Useful Information You Can Benefit From★★ When you want to "check characteristics while changing a certain parameter," "automatic measurement" is convenient. In this report, I would like to briefly explain how to perform "instrument control" necessary for automatic measurement. For more details, please be sure to read on. 【Contents】 ■ Automatic Measurement / Step 1: Connect the PC and the measuring instrument ■ Automatic Measurement / Step 2: Prepare the control library ■ Automatic Measurement / Step 3: Send commands to control the measuring instrument ■ Common Commands *For more details, please refer to the PDF document or feel free to contact us.

• Other measurement, recording and measuring instruments

Create the rules in the R-Table and the predicted values of state-action pairs in the Q-Table! Introducing the Q-Learning algorithm.

★★Shirutoku Report: Useful Information You Can Benefit From★★ The most challenging aspect I encountered while developing programs was the implementation of algorithms. There are many interesting algorithms, and recently I had the opportunity to explore Q-Learning, which is a type of reinforcement learning related to machine learning. I created a program (Cheese Puzzle Simulator) to demonstrate it. Q-Learning is one of the algorithms in reinforcement learning and is utilized in various fields, from autonomous driving to fintech. In this report, I would like to briefly introduce the Q-Learning algorithm. For more details, please feel free to read on. [Contents] ■Challenges ■Explanations *For more information, please refer to the PDF document or feel free to contact us.*

• Software (middle, driver, security, etc.)
• Other embedded systems (software and hardware)
• others

The thermal stress caused by temperature changes is greater than expected! It is important to consider expansion and contraction in the design.

★★Shirutoku Report: Useful Information You Can Benefit From★★ In daily life, we don't often think about it, but when the temperature of an object changes, thermal expansion and contraction occur. The magnitude of this expansion and contraction varies depending on the properties of each material (coefficient of linear expansion). In this report, we will discuss the thermal stress caused by this thermal expansion and contraction. For more details, please take a moment to read it. 【Contents】 ■ Simple thermal warping calculation tool for laminated boards *For more information, please refer to the PDF document or feel free to contact us.*

• Stress Analysis
• others

Essential thermal resistance of semiconductors for thermal analysis! Introducing typical thermal resistances and their formulas.

★★Shirutoku Report: Useful Information You Should Know★★ In recent years, while products have been miniaturizing, thermal issues have continued to worsen, and we have seen an increasing trend in inquiries from customers regarding thermal analysis. The content of these inquiries varies, but in this report, we will briefly explain the thermal resistance of semiconductors, which is essential for thermal analysis. For more details, please take a moment to read through it. [Contents] ■Typical thermal resistances and their formulas *For more information, please refer to the PDF document or feel free to contact us.*

• Other semiconductors
• Other analyses
• others

Explaining the points to note for multi-channel automatic measurement! Using a switch expands the range of automatic measurement!

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces the multi-channelization of automatic measurement. "Multi-channelization" refers to the process of enabling a measurement device that originally has only one channel to measure multiple points with a single trigger by continuously connecting switch circuits. Through multi-channelization, challenges such as "wanting to automatically measure a large number of samples at once" and "unable to perform automatic measurement due to the need to switch connections" can be resolved. For more details, please take a moment to read. 【Contents】 ■ Multi-channelization of automatic measurement ■ Principles of multi-channel automatic measurement ■ Points to note for multi-channel automatic measurement ■ Conclusion *For more information, please refer to the PDF document or feel free to contact us.

• Other measurement, recording and measuring instruments

Improved quality of circuit board design! Published the design rule setting items for circuit board design!

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces DRC. DRC stands for Design Rule Check, which is a function of PCB CAD that verifies whether the design adheres to the set design rules and can automatically detect violations of those rules. The advent of PCB CAD has reduced labor costs and improved the quality of PCB design. While DRC is very convenient, it is crucial to correctly set the design rules for the PCB CAD to accurately identify rule violations. For more details, please take a look. 【Contents】 ■ About DRC - Items for setting design rules in PCB design *For more information, please refer to the PDF document or feel free to contact us.*

• Printed Circuit Board
• Other CAD
• Other CAD related software

Consideration to meet product specifications! Examples of component layout taking electrical characteristics into account are included!

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces considerations for component placement. It is rare to use a circuit board in isolation; it is often housed in a case or connected to other devices. In component placement considerations, we first position components that cannot be moved structurally, such as connectors and switches. For other components, we proceed with the placement while paying attention to structural placement constraints (height limitations of components, prohibited areas for placement and wiring). For more details, please take a moment to read through. 【Contents】 ■ Consideration of structural constraints in component placement ■ Placement considerations based on electrical characteristics ■ Wiring considerations *For more information, please refer to the PDF document or feel free to contact us.

• Printed Circuit Board
• Other electronic parts

Automatic control with control programs! We are presenting the benefits of automatically controlling measuring instruments.

★★Shirutoku Report: Useful Information You Can Benefit From★★ In this report, we would like to introduce the automatic control of measurement devices related to optical devices. To confirm the functionality of optical devices, multiple characteristics such as optical output, light reception sensitivity, and frequency characteristics are measured and evaluated. To evaluate these characteristics, a variety of measurement devices are used, including DC power supplies, temperature controllers, and optical component analyzers. For more details, please be sure to read on. 【Contents】 ■Automatic Control of Measurement Devices 　・Benefits of Automatically Controlling Measurement Devices *For more information, please refer to the PDF document or feel free to contact us.*

• Piezoelectric Devices
• Other measurement, recording and measuring instruments

A structure in which electrodes are provided on the substrate, solder balls are formed on top, and are joined to the electrodes on the package side!

★★Shirutoku Report: Useful Information You Should Know★★ In this report, we will discuss the analysis methods for "BGA packages." "BGA" stands for "Ball Grid Array," which is a type of package for integrated circuits (ICs). In simple terms, it is a surface mount package that has electrodes (lands) on the substrate, with solder balls formed on top to connect to the electrodes on the package side. For more details, please take a look. [Contents] ■ About BGA Packages ■ Dyeing Analysis ■ Cross-Section Polishing *For more information, please refer to the PDF document or feel free to contact us.*

• Contract Analysis
• Other analyses
• Contract Analysis

Particularly common requests! Circuit board design for small, high-density implementations used in IoT devices and wearable devices!

★★Shirutoku Report: Useful Information You Should Know★★ In WTI's circuit board design, we handle various types of board designs, including large-scale circuits, multilayer wiring boards, high-density mounting boards, and flexible printed circuits (FPC). Particularly in demand are the designs for small, high-density mounting boards used in IoT devices and wearable devices. To reduce the size of products and lower the cost of boards, it is common to adopt BGA packages for microcontrollers and FPGAs. This report discusses 'BGA Board Design.' We encourage you to read it. [Contents] ■ About BGA Board Design *For more details, please refer to the PDF document or feel free to contact us.*

• Board to Board Connectors
• Board to Cable Connector
• Circuit board design and manufacturing

Introducing common questions regarding screw structures in waterproof design and points to consider during their examination!

★★Shirutoku Report: Useful Information You Should Know★★ When designing for waterproofing, many people tend to focus solely on the gasket parts of the enclosure. In fact, the screw areas require even more attention than the main waterproof sections. In this report, we discuss the screw structures in waterproof design and the points to consider that are frequently asked about. Please take a moment to read it. 【Contents】 ■ Services we have received inquiries about ■ Frequently asked questions - What specifications should be applied for waterproof screws? - What is the most important point to be cautious about when using waterproof screws? *For more details, please refer to the PDF document or feel free to contact us.

• Waterproof Connector

We are collaborating to solve our customers' problems by utilizing FPGAs!

★★Shirutoku Report: Useful Information You Should Know★★ In this report, we will focus on the response to the discontinuation of parts using "FPGA." This is not about replacing the parts themselves with "FPGA," but rather introducing designs that implement measures for the discontinuation of LCD panel production using "FPGA." If you need designs such as "I want to perform data processing for high-speed serial communication with FPGA" or "I want to process signals from sensors with FPGA and transfer data," please feel free to contact us. 【Contents】 ■ Solutions with "FPGA"!? *For more details, please refer to the PDF document or feel free to contact us.*

• Board to Board Connectors
• Circuit board design and manufacturing
• Control Panel

The concept of distributed constant circuits is becoming necessary! An explanation of characteristic impedance and substrate design.

★★Useful Information Report: Knowledge is Power★★ This report introduces the "characteristic impedance (wiring impedance)" of printed circuit boards. With the recent increase in the speed of digital signals, the design of digital circuit boards now requires the concept of distributed constant circuits rather than lumped constant circuits, making it essential to consider the characteristic impedance of the board in the design. So, how do we determine the characteristic impedance of a printed circuit board? [Contents] ■ Characteristic Impedance of Printed Circuit Boards *For more details, please refer to the PDF document or feel free to contact us.*

• Printed Circuit Board
• Circuit board design and manufacturing
• Prototype Services

Why do optical semiconductors fail? Let me explain a bit more about failures caused by light!

★★Shirutoku Report: Useful Information You Can Benefit From★★ What kind of semiconductor failures come to mind when you think of them? First, you might think of damage caused by static electricity, right? Of course, optical semiconductors can also fail due to static electricity, but they can also fail due to light itself. In this report, we will explain a bit more about failures caused by light. [Contents] ■Failures Caused by Light *For more details, please refer to the PDF document or feel free to contact us.*

• diode
• Other semiconductors
• Semiconductor inspection/test equipment

How is a metal casing made? A brief introduction to processing methods and design techniques.

★★Shirutoku Report: Useful Information You Can Benefit From★★ Without further ado, I will talk about the metal enclosures I am currently involved in developing. There are various processing methods for creating metal enclosures, and the design approach changes depending on the processing method. This report briefly introduces the representative processing methods and design approaches for metal enclosures. [Contents] ■ Press bending processing ■ Deep drawing processing ■ Die casting *For more details, please refer to the PDF document or feel free to contact us.

• Mold Design
• Processing Contract

The method is super easy! Just search for Wi-Fi signals and display the obtained data on the screen!

★★Useful Information Report: Knowledge is Gained★★ This report introduces a board called M5stack, which is equipped with a Wi-Fi module called "ESP32," along with practical examples of its use. The creation process is super simple: it searches for Wi-Fi signals and displays the acquired data on the screen. That's all there is to it. Please take a moment to read it. 【Contents】 ■How to Make a Simple Wi-Fi Checker ・Recipe *For more details, please refer to the PDF document or feel free to contact us.

• Other inspection equipment and devices

Responding to various customer inquiries based on the experience and knowledge gained from previous design and evaluation.

★★Shirutoku Report: Useful Information You Can Benefit From★★ Our company is involved in the development of semiconductor package mounting technology and mounting reliability technology. We mainly focus on packages known as BGA (Ball Grid Array). In this report, we will introduce the daisy chain sample used for evaluating the mounting reliability of semiconductor packages. [Contents] ■ Daisy chain sample for identifying breakage locations ■ Daisy chain sample for identifying breakage locations - Case studies from customer inquiries *For more details, please refer to the PDF document or feel free to contact us.*

• Other semiconductors
• Circuit board design and manufacturing

Knowing the configuration (types) of substrate data can prevent unexpected schedule delays.

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces the composition (types) of circuit board data. We provide a diagram outlining the general flow from circuit board design to manufacturing. Our company can convert Gerber data into our CAD data (CR5000BD) for design purposes when revisions to existing circuit boards are necessary, such as for the development of similar models or for dealing with discontinued parts (EOL, discon). If you need design work that utilizes existing design assets, please feel free to contact us. 【Main Circuit Board Design CAD (Excerpt)】 ■CR5000BD (Zuken) - Circuit board CAD data file extension: .pcb/.rul - Cover data file extension: .phl/.phd ■CR8000DF (Zuken) - Circuit board CAD data file extension: .dsgn - Cover data file extension: fph/fpl *For more details, please refer to the PDF document or feel free to contact us.

• Circuit board design and manufacturing

Introducing programming using OTA with ESP32 via Wi-Fi!

★★Shirutoku Report Useful Information You Should Know★★ The ESP32 is a microcontroller that integrates Wi-Fi and Bluetooth, manufactured by Espressif Systems, a wireless chip maker based in Shanghai. OTA stands for Over The Air, which allows programming to be written via wireless networks such as Wi-Fi, mobile data communication, and Bluetooth. In this report, we attempted programming using OTA on the ESP32 microcontroller, and we will introduce the details of that experience. [Contents] ■ What is ESP32 ■ What is OTA ■ Boards Used ■ Writing the Program *For more details, please refer to the PDF document or feel free to contact us.

• LED Module
• Other information systems

It is important to be aware of thermal issues from the early stages of design! Introducing preventive diagnostics for thermal problems.

★★Shirutoku Report: Useful Information You Should Know★★ The required performance of developed products is increasing year by year, leading to a more challenging thermal situation due to the need to make products thinner and smaller, as well as the addition of circuit functions (such as communication functions), which increases heat sources. In response, our company has decided to offer a service to assess the presence of thermal issues and the difficulty of thermal design early in the design process (preventive diagnosis of thermal issues). This report explains "Product Performance Requirements and Thermal Issues" and "Contents of Preventive Diagnosis of Thermal Issues." [Contents] ■ About Thermal Simulation ■ Product Performance Requirements and Thermal Issues ■ Contents of Preventive Diagnosis of Thermal Issues *For more details, please refer to the PDF document or feel free to contact us.

• Other contract services

Questions and Solutions! Key Points to Keep in Mind When Developing Waterproof Products

★★Shirutoku Report: Useful Information You Should Know★★ In this report, we introduce the most frequently asked questions from customers regarding the development of waterproof products and their solutions. You may have come across the terms "waterproof specifications IPX5, 6, 7" in various product fields. Waterproof specifications have become a standard feature in smartphones, and as a result, the demand for waterproof functionality is increasingly being sought in consumer products as a whole. We provide answers and key points to questions such as "What are the structural differences between waterproof and non-waterproof products?" and "What does the evaluation of waterproof products entail?" We encourage you to read through it. 【Contents (Excerpt)】 ■Question: What are the structural differences between waterproof and non-waterproof products? ■Question: I want to have a certain level of waterproof performance, but I would rather prioritize design and production costs. In such cases, what level of protection rating is achievable? ■Question: What does the evaluation of waterproof products entail? *For more details, please refer to the PDF document or feel free to contact us.

• Circuit board design and manufacturing

It is also possible to reduce high manufacturing initial costs! Here are some tips for reducing the cost of printed circuit boards.

★★Shirutoku Report: Useful Information You Should Know★★ Printed circuit boards (PCBs) are relatively expensive components among electronic devices, and depending on the quality of the design, the use of the board may change, which can impact costs. You might consider searching for inexpensive PCB manufacturers overseas and adopting them, but the factors that significantly affect the cost of printed circuit boards are "board structure/layer count" and "board size." This report focuses on "board size" and introduces tips for reducing PCB costs. [Contents] ■ Tips for Reducing Costs Based on Board Size *For more details, please refer to the PDF document or feel free to contact us.*

• Printed Circuit Board

A suitable structural examination is necessary due to the mounted components and wiring density! An explanation of the structure of the substrate.

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces the "Structure of PCBs." It includes topics such as "Classification by PCB Structure," "Conductor Materials and Solder Resist," and "The Importance of Initial Considerations in PCB Structure." Our company is also capable of PCB design starting from initial considerations, including PCB structure. If you have any concerns, please feel free to reach out to us. 【Contents】 ■ Classification by PCB Structure ■ Conductor Materials and Solder Resist ■ The Importance of Initial Considerations in PCB Structure ■ About Flexible PCBs *For more details, please refer to the PDF document or feel free to contact us.*

• Printed Circuit Board

The grounding (GND) of the antenna is important! Things to be careful about when designing an antenna.

★★Shirutoku Report: Useful Information You Should Know★★ This report introduces the "antenna," which is essential for communication devices. We describe the antennas commonly used in wireless communication devices along with their features. Our company provides support services to address improvements in antenna communication distance, so if you have any inquiries or would like to consult with us, please feel free to contact us. 【Contents】 ■ Antennas used in wireless communication devices ■ Grounding (GND) is important for antennas! ■ Be cautious with the substrate when using pattern antennas! ■ Check the finish once the substrate is completed! ■ Pay attention to the area around the antenna! ■ Strategies for improving antenna communication distance *For more details, please refer to the PDF document or feel free to contact us.*

• antenna

Content to be confirmed in structural evaluation! Explanation of drop tests and waterproof tests.

★★Shirutoku Report: Useful Information You Can Benefit From★★ This report introduces typical evaluations (drop tests, waterproof tests) conducted in the development and design of mobile communication devices. The drop test is the first test performed to confirm the strength of the casing. The waterproof test is based on protection grades related to waterproofing defined by IEC (International Electrotechnical Commission) and JIS (Japanese Industrial Standards), and it is necessary to select a testing method that suits the product's purpose. In addition to structural evaluations, there are other tests such as pressure tests and key press tests, and WTI is capable of handling various tests. If you have any inquiries about what we can do, please feel free to reach out to us. [Contents] ■ Drop Test ■ Waterproof Test *For more details, please refer to the PDF document or feel free to contact us.*

• Impact Test
• others

Could a substitute capacitor cause performance issues? Please contact us if you are having trouble with EOL.

★★Shirutoku Report: Useful Information You Can Benefit From★★ I mainly design matching circuits for high-frequency power amplifiers used in commercial radio equipment. In this report, I will share my experiences regarding the discontinuation of capacitors (EOL: End Of Life). For more details, please take a moment to read on. 【Contents】 ■ Recent EOL situation ■ Alternative capacitors may lead to performance issues!? *For more information, please refer to the PDF document or feel free to contact us.*

• Capacitor
• High frequency/microwave parts

It is relatively easy to build a system! Here are some examples of the adoption of microcurrent detection systems.

★★Shirutoku Report: Useful Information You Can Benefit From★★ The "Custom Measurement Service" is a service that provides the functions required in your research and development environment in the form of a tailor-made "custom measurement system." Are you thinking, "But a tailor-made system seems too high-end..."? At WTI, we can relatively easily build a system by collaborating with partner companies and combining it with existing equipment. In this report, we will introduce this service based on case studies. For more details, please be sure to read on. [Contents] ■Case Study: Partner Company A *For more information, please refer to the PDF document or feel free to contact us.*

• Other electronic measuring instruments
• Evaluation Board
• Other contract services

Introducing the analysis of rubber products! Please feel free to consult us if you are having trouble with structural design or analysis.

★★Shirutoku Report: Useful Information You Should Know★★ The Structural Design Department primarily focuses on "structural design of metal and plastic enclosures using CAD" and "front-loading development using thermal fluid simulation/structural simulation technologies." *There are various names for structural analysis, structural CAE, stress analysis, FEM analysis, etc. In this report, we will briefly introduce our efforts in structural simulation and then discuss the analysis of rubber products (which are useful in waterproof design, among other applications). For more details, please take a moment to read through it. [Contents] ■ Efforts in Structural Simulation ■ Analysis of Rubber Products (Useful in Waterproof Design, etc.) *For more information, please refer to the PDF document or feel free to contact us.

• Structural Analysis
• Stress Analysis

Customization suitable for the measurement environment is also available! Introducing the automatic measurement system with curve tracer.

★★Shirutoku Report: Useful Information You Should Know★★ What kind of measuring instruments do you use when evaluating the electrical characteristics of semiconductors like MOSFETs and bipolar transistors? While there are dedicated testers, curve tracers are also convenient for easy evaluation. However, when using a curve tracer, have you ever thought, "There are so many evaluation items, manual operation is a hassle..." or "There are so many evaluations, it would be great if I could operate it more easily..."? If these needs can be met, you will be freed from the enormous evaluation time. Therefore, we would like to introduce the 'Automatic Measurement System for Curve Tracers.' For more details, please take a look. [Contents] ■ Automatic Measurement System for Curve Tracers *For more information, please refer to the PDF document or feel free to contact us.

• Semiconductor inspection/test equipment
• Other electronic measuring instruments
• Other inspection equipment and devices

Developing with a focus on reliability/quality! Here are some key points for creating embedded software.

★★Shirutoku Report: Useful Information You Can Benefit From★★ In this report, we will discuss the key points when creating embedded software (firmware), specifically about ensuring real-time performance: "Creating it to flow continuously." At WTI, we undertake numerous embedded software development projects for our clients, focusing on reliability and quality, including the principle of "flowing continuously." If you are facing challenges in software development, please contact WTI. [Contents] ■ Busy Signal ■ Sequential Operation ■ Post-Change Flow *For more details, please refer to the PDF document or feel free to contact us.*

• Software (middle, driver, security, etc.)
• Other embedded systems (software and hardware)

Please try to utilize interrupt functions to create embedded software that is "always flowing"!

★★Shirutoku Report: Useful Information You Should Know★★ The Software Design Department creates a lot of embedded software to control dedicated circuit boards. In this report, we will discuss the key points to consider when creating embedded software. The key point when creating embedded software is to ensure real-time performance: "create it to flow continuously." For more details, please take a moment to read through. [Contents] ■ Key Points When Creating Embedded Software *For more information, please refer to the PDF document or feel free to contact us.*

• Software (middle, driver, security, etc.)
• Other embedded systems (software and hardware)

High efficiency and miniaturization are possible! Designing switching power supplies requires know-how.

★★Shirutoku Report: Useful Information You Should Know★★ The power supply circuits handled by the Power Supply Design Department come in various circuit configurations, but if broadly classified, most of them fall under the category of switching power supplies. In this report, we will discuss the characteristics of switching power supplies. For more details, please take a moment to read through it. 【Contents】 ■ Advantages ■ Disadvantages *For more information, please refer to the PDF document or feel free to contact us.*

• Other electronic parts
• Switching Power Supply

If you are having trouble with heat, such as retrofitting heat measures or additional heat measures, please feel free to contact us!

★★Shirutoku Report: Useful Information You Can Benefit From★★ We mainly engage in the design of enclosures for outdoor installed products. Through this work, we often hear customers say, "It's hot, what should I do?" In this report, we will answer what to do in such cases. For more details, please take a moment to read. 【Contents】 ■The answer is "Just cool it down." *For more information, please refer to the PDF document or feel free to contact us.*

• Other electronic parts
• Other temperature and humidity measuring instruments

Achieving longer battery life and miniaturization! Introducing the development of IoT devices equipped with wireless modules.

★★Shirutoku Report: Useful Information You Can Benefit From★★ Creating IoT devices with wireless communication capabilities from scratch presents several technically challenging issues. As a means to more easily achieve wireless communication functionality, there is the option of mounting a wireless module on a circuit board. In this report, we will introduce wireless modules. For more details, please take a moment to read through it. 【Contents】 ■ What is a Wireless Module *For more information, please refer to the PDF document or feel free to contact us.*

• Other electronic parts
• Other services

JOHNAN has released a video that clearly explains the implementation technology for stretchable films, which are expected to be utilized in wearable devices and medical equipment. In the video, you can see how the film, which has excellent elasticity, stretches and contracts. Please check our high technological capabilities and the flexible characteristics that are useful for product development. We hope this will help you generate new ideas in product development. ▼You can watch the video here [Link to the implementation page for stretchable films] https://www.johnan.com/dms/mounting/filmdevic/stretchable/

Thank you very much for your continued support. We sincerely apologize for the inconvenience, but our company will be closed for summer vacation during the following period. 【Closure Period】 From Saturday, August 9, 2025, to Thursday, August 14, 2025. We will resume normal business operations on Friday, August 15. We appreciate your understanding during this time and apologize for any inconvenience caused.

"Because it's an invisible place, we won't overlook it." Japan's climate is characterized by high temperatures and humidity, and particularly after typhoons and heavy rains, the conditions can be harsh for homes. It's not just the roofs and exterior walls that are affected by rain and wind. The area beneath the floor is actually the most susceptible and often overlooked point. This time, we will explain the "checkpoints for under the floor" that should be confirmed after a typhoon or heavy rain, the "responses" if abnormalities are found, and measures for preventing recurrence. [Table of Contents] ■ Why is underfloor checking necessary? ■ Checkpoints to confirm after a typhoon or heavy rain ■ Responses when damage is discovered ■ Points for preventing recurrence ■ Suggestions from Seihou Products ■ Summary Please be sure to read the [related materials] and [related links]. ↓ ↓ ↓

Explosion-proof motors available in stock We will deliver within 7 days to meet your delivery schedule. 【What is an explosion-proof motor?】 In factories and plants, flammable gases and vapors are present. When these mix with air and come into contact with an ignition source, an explosion or fire can occur. This motor is designed with measures to eliminate such ignition sources. 【Available stock models】 ■ Pressure-resistant explosion-proof motors, explosion-proof grade d2G4 - Foot-mounted type, output 0.4 to 3.7 kW, 4 poles - Flange type, output 0.4 to 0.75 kW, 4 poles ■ Increased safety explosion-proof motors, explosion-proof grade eG3 - Foot-mounted type, output 0.2 to 0.75 kW, 2 and 4 poles - Flange type, output 0.2 to 0.75 kW, 2 and 4 poles

As part of the "Hometown Ibara Future Creation Human Resource Development Project," we welcomed local elementary and middle school students to the special summer program "Ibara Job Exploration Tour 2025," a collaboration between the Ibara City Chamber of Commerce and the Corporate Branding Committee. We conducted a presentation that clearly and enjoyably introduced how our technology supports society, allowing the children to learn about the appeal of manufacturing and the significance of working while interacting with actual devices and products. Through this initiative, we hope to deepen our connection with the community and nurture the curiosity of the children who will carry the future. We sincerely thank everyone who participated, as well as all those involved in planning and organizing the event.