DENKI OTAKU Video Summaries

AIに回路図設計とファームウェア作成を任せて、自作キーボード用の基板を実際に発注・実装・動作確認まで行う様子を紹介します。JLCPCBで発注した6層基板と組み立て済み部品の費用、AIが選んだ部品の意図、起動後に判明したキー不具合の原因と対処まで、実際のプロセスを追って解説します。

■ 基板の発注とコスト
- JLCPCBの6層基板の価格設定や割引クーポン、pad-on-via 仕様についての案内
- 5枚の基板と部品・実装・送料を含めた総額と1枚あたりのコスト
- 100×100mmの6層基板5枚の価格は36.8ドル

■ AIが選んだ部品と設計の解説
- 60%レイアウトのキーボードマトリクスと表面実装部品の構成
- RP2040・外部フラッシュ・レギュレーター・水晶発振器の役割と価格
- メモリ内蔵型RP2354を使えば部品代を抑えられる点の比較
- スイッチ選定で、AIが実績のある部品を優先した経緯

■ 動作確認とトラブルシューティング
- PCへの接続とファームウェア書き込み、実際のタイピング確認
- 特定の列のキーが反応しない原因の切り分けと回路図上の確認
- 締めくくり：AIに任せてよい回路の範囲や、指示の出し方の学び

自作キーボードやPCB設計に興味がある方、AIをハードウェア開発に使う際の進め方や注意点を知りたい方は、発注から試作・検証までの流れを1つの実例として確認できます。部品選定の見極め方やトラブル時の切り分け方も、今後の自作プロジェクトの参考になります。

I tested AI-assisted circuit and PCB design by having it produce a complete keyboard PCB, from component selection to layout, in about two hours. I share the full workflow, including the environment setup, the revisions I requested, and the areas where manual review was still needed.

■ Environment Setup and First Test
- Claude Code and EasyEDA's AI skill package from GitHub, working folder on OneDrive
- Simple battery-powered LED circuit as a trial run

■ Keyboard PCB Design
- Choosing a 60% keyboard with number keys and selecting the RP2040 microcontroller
- Tactile switches, diodes, and surrounding circuit components
- Layout revisions: QWERTY check, silkscreen labels, 180-degree rotation, footprint and outline adjustments
- Auto-routing results, component placement tuning, and manual adjustments

■ Manufacturing and Sponsor
- Ordering five assembled PCBs through EasyEDA and JLCPCB, totaling $66 with shipping
- JLCPCB flexible PCB options, with boards starting at $2 for 500x100mm

■ What Comes Next
- Keyboard firmware work carried out entirely through Claude Code

This is aimed at electronics makers and hobbyists who want to see a practical, start-to-finish example of AI-assisted design and where human intervention still applies. Watching gives you a concrete sense of the workflow, the tools involved, and what to prepare before trying it yourself. A follow-up showing the assembled keyboard in operation is planned, so results can be checked there as well.

A professional-grade Hioki DT4282 (roughly $300–400) and an affordable AstroAI multimeter (about $25) are put side by side to reveal how much difference price makes. The comparison covers design, specs, usability, and real voltage and current measurements, using a benchtop DMM as a reference.

■ Design and Build Quality
- Weight, back magnet, lead storage grooves, and kickstand handling (including with insulating gloves)
- Battery compartment design, battery types, and cover fastening
- Test lead flexibility, probe tip covers, and contact points

■ Features and Display
- Backlight operation and readability
- Input jacks, error-prevention mechanism, and rotating dial behavior
- 6,000-count vs. 60,000-count displays, digit loss, and 6.5-digit benchtop displays
- Measurement functions and a check of operation on rechargeable NiMH cells

■ Performance Measurements
- DC/AC voltage accuracy and response time in auto and manual ranges
- Frequency limits for voltage and current readings
- DC/AC current, resistance, capacitance, and transistor hFE

■ Internal Teardown
- Component count and circuit design of both units

The video suits anyone choosing a first multimeter or weighing a budget purchase against a premium one. Viewing it helps you understand where differences in accuracy, response speed, and build show up in practice, so you can decide which class of device matches your electronics work and how to plan your purchase.

Taiyo Electric Industry's new PX211 temperature-controlled soldering iron is put to the test alongside the digital PX280 and the long-selling PX201. This hands-on comparison covers heating speed, temperature accuracy, soldering performance on a copper board and through-hole/surface-mount components, plus disassembly and build details.

■ Model Lineup and Positioning
- Overview of the Goot PX201, PX280, and PX211
- Differences in heater-to-tip gap, tip shape, dial size, temperature range, and power

■ PX280 vs PX211 Comparison
- Body size, grip thickness, and cable guide
- Digital features: 1°C adjustments, sleep and auto-shutdown, real-time tip temperature display
- Optional heat-resistant tip cap

■ Comparison with Other Manufacturers
- Specs comparison with the Hakko FX600 and its relationship to the FX600D

■ Performance Testing
- Heat-up time and measured tip temperature at 350°C
- Soldering on a bare copper board and the effect of tip thermal mass
- Through-hole and surface-mount soldering with various tips (C type, 3BC, right-angle, D type)

■ Disassembly and Conclusion
- Internal PCB, analog control circuit, and replaceable ceramic heater

Viewers choosing among temperature-controlled soldering irons will gain a practical basis for comparing analog and digital models, understanding how tip selection affects results, and deciding which model fits their workflow and budget. The description includes product links for reference.

Here I examine a ground loop isolator purchased on Amazon and verify what it actually does. Through circuit experiments and measurements, I look at how ground loop noise is generated, whether an isolator suppresses it, and how to build a functional one from scratch.

■ Ground Loop Noise Basics
- Internal structure of an isolator and the role of its transformer
- How a noise loop forms between the grounds of two devices
- Experiment injecting noise between GND-A and GND-B
■ Examining the Purchased Unit
- Resistance measurements between terminals
- Inspection of the internal wiring
■ Building an Isolator from Scratch
- PCB from JLCPCB; components from Akizuki and DigiKey
- Rubycon PMLCAP capacitor and an added high-pass filter
- Assembly and enclosure
■ Verification and Measurements
- Audible comparison with and without the isolator
- Waveform observation under 50 Hz and 40 kHz noise
- Noise reduction across frequencies
- Frequency response and phase characteristics of the finished unit

This is aimed at audio engineers, DIY electronics enthusiasts, and anyone troubleshooting humming noise in an audio setup. Watching gives you a clear picture of how ground loop noise travels through a circuit, how much an isolator can actually remove at different frequencies, and what goes into a home-built version.

This video explores whether NFC (Near Field Communication), known mainly for data exchange at 13.56 MHz, can serve as a practical power source. Using ROHM's NFC wireless charging ICs (ML7671 transmitter / ML7670 receiver), the presenter measures real power delivery inside a radio anechoic chamber and builds a working smart band powered entirely without a battery.

■ NFC Power Transfer Fundamentals
- Electromagnetic induction explained with coil and magnet demonstrations
- Qi charging vs NFC charging: frequency, power level, coil size, and data capability

■ ROHM NFC Wireless Charging ICs
- ML7671 (transmitter) and ML7670 (receiver) evaluation boards, PCB-patterned coils, antenna design and matching support
- Commercial example: SOXAI RING 2 smart ring using the same ICs
- Measured power delivery: stable 150–200 mW, peaking around 250 mW under ideal conditions

■ Smart Band Demo & Data Communication
- Smart band running microcontroller, accelerometer, and display on wireless power alone
- Battery-integrated operation, mirroring accelerometer data to a receiver display via NFC
- Simultaneous power + data considerations, ML7661/ML7660 alternatives, and NFC tag functionality

If you are an electronics engineer, embedded developer, or hobbyist interested in wirelessly powering small wearables, this hands-on experiment shows what NFC wireless charging can realistically deliver today and which components and constraints to consider. Watch it to understand the trade-offs between Qi and NFC and how to evaluate these ICs for your own designs.

I demonstrate how voltage travels through a circuit the same way a wave moves through a medium, using a custom wave machine alongside a PCB containing a 25-meter-long copper trace. Physical wave behavior and measured electrical waveforms are compared side by side to make the invisible movement of voltage easier to visualize.

■ Wave Machine Demonstrations
- Reflection and transmission at a free end
- Reflection and transmission at a fixed end
- How medium changes cause partial reflection

■ Electric Circuit Experiments
- Pulse propagation along a 50Ω characteristic-impedance trace
- Voltage measurements at 25%, 50%, 75% and the end of the line
- Open-ended, short-circuited, and impedance-matched terminations

■ Advanced Wave Behavior
- Superposition of waves launched from both ends of the trace
- Wave independence after collision
- Opposite-polarity signals canceling at the midpoint

Aimed at electronics learners, students, and engineers who work with high-speed signals, the presentation connects wave theory with practical circuit behavior. Viewers gain an intuitive understanding of signal reflection, impedance matching, and how to read oscilloscope waveforms in terms of wave propagation.

This video examines Belkin's BoostCharge Pro 67W USB charger, which is marketed as using zero standby power, and measures how much standby power it actually draws compared with chargers from Anker, CIO, UGREEN, and Apple. It also covers the charger's internal circuit design, its power conversion efficiency, thermal behavior, and the conditions under which the standby power figure changes.

■ Standby Power Measurements
- Test setup using a clean-sine-wave AC power supply and a power meter
- Measured standby power of the Belkin charger and several other brand chargers
- Annual electricity cost comparison based on Tokyo Electric Power rates
■ Efficiency and Thermal Performance
- Why power conversion efficiency matters more than standby power in daily use
- Conversion efficiency measurement and thermal camera readings
- Thermal throttling test under continuous maximum output
■ Standby Power With and Without a USB Cable
- Repeat measurements with a USB cable connected, including cables with and without an eMarker chip
- Comparison across other chargers when a cable is plugged in
■ Teardown and Circuit Analysis
- Internal structure, thermal compound, and graphite sheet placement
- Flyback converter architecture and the Renesas, Dialog, and Intersil components inside
- How the flyback controller and PD controller work together to reduce standby power

This content is suited to viewers interested in USB charger design, low-power electronics, or energy-saving hardware. Watching it provides a basis for evaluating charger standby power and efficiency figures, along with practical considerations when choosing and using a charger.

This presentation explains intelligent power modules (IPMs) from the ground up: what they contain, how they compare with discrete power semiconductors and conventional power modules, and how they are applied in real inverter circuits. It also shows a practical build of a three-phase inverter based on an IPM that is used to drive a motor, covering both the advantages and the limitations of the approach.

■ IPM Fundamentals
- Where IPMs are used, including household appliances such as air conditioners, refrigerators, and washing machines
- Package variety and the specifications of the Fuji Electric P633A series IPM (650 V, 10 A)
- Internal structure: power semiconductors (IGBTs), integrated gate drive circuits, and built-in protection functions
■ Comparison with Alternatives
- Discrete power semiconductors and their need for separate drive circuits
- Non-intelligent power modules, including 2-in-1 and 6-in-1 configurations
- Advantages of integration and drawbacks such as limited flexibility for series/parallel connection and fixed drive characteristics
■ Practical Build and Motor Test
- A three-phase inverter circuit designed around the IPM and driven by a microcontroller
- Motor operation using a 200 V DC supply, plus the role of switching frequency in controlling motor noise

This is aimed at electronics learners, hobbyists, and engineers who are considering an IPM for an inverter project. Viewers will gain an understanding of what an IPM integrates, when it is a suitable choice, and what to check before selecting one, and can use that knowledge to plan their own inverter build.

This video examines reported malfunctions in the SwitchBot Plug Mini smart plug by collecting about ten defective units and investigating their internal circuits. The analysis traces the symptoms back to a specific component and compares older and newer production batches.

■ Failure Symptoms and Inspection
- Reported issues such as failure to power on and repeated relay switching
- Serial number batches listed for official replacement
- Visual inspection of opened units and comparison with a working unit

■ Circuit-Level Analysis
- Reverse-engineered power supply circuit and the role of the smoothing capacitor
- Operating waveforms, ripple current, and voltage drops around the Wi-Fi module
- Measured capacitance and ESR of failed capacitors, and causes of deterioration
- Degradation stages and the symptoms each stage produces

■ Batch Comparison and Summary
- Capacitor type differences between 2023 and 2024 production units
- Overview of possible contributing factors and the video's closing remarks

本作は、電子機器の故障解析や回路設計に関心のある方、スマートプラグを長期利用している方に向いています。内部構造の確認から実測データの観察まで一連の流れを追えるため、故障の仕組みや部品劣化への着眼点を学べます。購入前のモデルチェンジ確認や、交換対象シリアル番号の照合にも役立ちます。

e-POWER is Nissan's series hybrid system, in which the engine only generates electricity and never drives the wheels directly. This teardown explains the system's operating modes, its efficiency characteristics, and the internal circuit of the inverter that makes it possible.

■ Series Hybrid System Overview
- System configuration: engine, generator motor, two inverters, battery, and drive motor
- Operating modes: EV driving, regenerative braking, battery charging, combined power supply, engine-driven power
- Thermal efficiency advantage and high-speed fuel-efficiency characteristics, with comparisons to Toyota and Honda hybrid systems and WLTC fuel-economy figures
■ Inverter Structure
- External inspection: battery terminals, motor/generator busbars, coolant ports, and back side
- Film capacitor and laminated busbar structure, including insulation methods compared with the Prius and IONIQ 5
- Two stacked control boards, power semiconductor modules, and current sensors
■ Circuit and Current Flow
- Overall circuit diagram and power flow in each mode
- Regenerative braking on long descents and the engine braking mechanism
■ Component Details
- Capacitor, busbars, microcontroller, gate drivers, IGBT module, resolver IC, and current sensors
- Coolant channel design and component standardization across both channels

Engineers, EV and hybrid technicians, electronics enthusiasts, and anyone curious about vehicle power electronics will gain a clear picture of how a series hybrid inverter is structured and how each part contributes to its operation. The step-by-step disassembly also offers practical reference for those considering their own teardowns.

The internal structure of the power control unit (inverter) removed from a 5th-generation Toyota Prius ZVW60 is disassembled and examined section by section, with comparisons to the 4th-generation design. The breakdown covers the exterior, control circuit board, power stage, and 12V DC/DC converter, showing which components and layouts changed between generations.

■ Exterior and Structure Overview
- External terminals, wiring harness fuse rating, and coolant inlet/outlet paths
- Overall internal layout: control board, inverter module, inductor, DC/DC converter
- Difference in coolant channel placement compared with the 4th generation

■ Control Circuit Board
- Microcontroller and custom IC configuration on the board
- Gate driver circuit, floating power supply, and insulation distance on the PCB
- Change from contact sockets to soldered power card leads

■ Power Stage and Generational Differences
- Power cards, laminated bus bar, inductor, film capacitor, and water-cooled heat sink
- Power card count and bidirectional converter configuration vs. the 4th generation
- Motor output figures of the 4th and 5th generation models

■ 12V DC/DC Converter
- Single-board structure with surface-mounted power semiconductors
- Circuit configuration, busbar thickness, and secondary-side rectification

This content is suited to viewers interested in hybrid and EV power electronics, engineers, and automotive technicians. Watching it provides an understanding of how a hybrid power control unit is laid out internally and which design changes were introduced in the latest generation.

TO-247-4 is a four-lead version of the common TO-247 power semiconductor package, featuring an additional Kelvin terminal that separates the gate drive path from the main current path. I compare the switching performance of a three-lead TO-247 and a four-lead TO-247-4 using a double pulse test board.

■ Package Basics and Theory
- Differences between the 3-lead TO-247 and the 4-lead TO-247-4
- Role of the Kelvin terminal (driver source) in isolating gate drive from main current
- How parasitic capacitance and inductance affect MOSFET switching speed
- Internal package structure: lead frame, bonding wires, and parasitic elements

■ Double Pulse Test Experiment
- Test board design with gate driver circuit, current probe points, and air-core inductor
- Switching loss measurement using both three-terminal and four-terminal configurations
- Comparison of switching waveforms and loss values between the two packages
- Effect of switching speed increase on voltage overshoot and ringing

■ Practical Considerations
- Why Kelvin terminal packages are commonly used with SiC MOSFETs
- Impact of faster switching on main circuit parameter design
- Recommendations for gate driver and main circuit design when using four-terminal packages

電力電子機器の設計に携わる方や、パッケージ構成がスイッチング特性に与える影響を理解したい方に向けて、パッケージの基本構造から実験結果までを段階的に解説しています。理論と実測の両面から、四端子パッケージを設計に取り入れる際の考慮点が把握できます。

Boost converterの構成部品から動作原理、ダーティ比と出力電圧の関係、実機での波形測定までを順を追って解説します。インダクタに蓄えられたエネルギーが出力電圧を上げている様子を、計算と実験の両面から確認できる内容です。

■ 回路の構成と動作原理
- コイル、MOSFET、ダイオード、電解コンデンサ、負荷からなるブーストコンベンタ回路の構成
- スイッチのオン/オフ時の電流経路と、インダクタ電流が増減する仕組み
- コンデンサの充放電とダイオードによる逆流防止の役割

■ ダーティ比と出力電圧
- Ton・Toff・ダーティ比の定義と出力電圧の計算式
- ダーティ比を変えた場合の出力電圧の変化を数値で確認
- ダーティ比を1に近づけた場合の回路の挙動と部品にかかる負荷

■ 実験と測定
- 入力電圧やダーティ比を変えたときの出力電圧の実測
- スイッチ電圧とインダクタ電流の波形観測
- スイッチング周波数を下げたときのリップルとインダクタの磁気飽和
- 積層コア間に紙を挟むなどしたインダクタの磁気飽和対策の比較

■ 連続電流モードと不連続電流モード
- 不連続電流モードが生じる条件と、計算式が適用できない点
- ブースト回路を使った力率改善回路などの応用例

電源回路や電子回路を学びたい学生、DC-DCコンベンタの設計や力率改善回路に関わる技術者を対象としています。回路の各部の挙動と実測波形を対比できるため、ブーストコンベンタの動作理解と部品選定時の留意点を整理できます。

マザーボードのCPU電源部を構成するVRMとフェーズ数が、電圧供給の安定性や発熱にどう関係するかを、回路の動作原理から自作した多フェーズ回路を使った実測実験まで一貫して検証します。バッコンバータの基礎、多フェーズ化の利点と欠点、制御方法による違いまでを順を追って整理しています。

■ 基礎解説
- VRM（電圧レギュレータモジュール）とフェーズ数の定義、実物マザーボード上の構成確認
- VRMの正体であるバッコンバータの動作原理とダーティサイクル

■ フェーズ数の効果
- 電力負荷の分散、発熱低減、電圧安定化などの利点と、部品数・コスト・実装面積などの考慮点

■ 実験と制御方法
- 1相／4相運転時の温度とリプル電圧の実測比較
- 従来制御とインターリーブ制御の出力波形比較（パワーレールプローブによる計測）

PC自作や電源回路に関心のある方、マザーボード選びでフェーズ数の意味を把握したい方に向けています。視聴後は、フェーズ数がもたらす効果と制御方法の役割を踏まえて製品を比較できるようになります。まず基本原理を押さえたうえで、実験パートの計測結果を確認することをおすすめします。