Welcome to Lesson 5! 🎉
レッスン5へようこそ！
In this lesson, you will learn about electrical systems in vehicles, including circuits, components, and safety procedures.
このレッスンでは、回路、部品、安全手順など、車両の電気システムについて学びます。
✓ Electrical circuit fundamentals
✓ Key electrical components
✓ Wiring and connections
✓ Troubleshooting techniques
✓ Safety procedures
This lesson takes approximately 5-6 hours to complete, including the quiz at the end.
Electrical Circuit Basics ⚡
電気回路の基礎
An electrical circuit is a closed loop that allows electricity to flow from a power source through conductors to a load and back.
電気回路は、電源から導体を通って負荷に流れ、戻ってくる閉じたループです。
電源 → 負荷 → 戻り経路
• Power Source (Battery) | 電源（バッテリー）
• Conductors (Wires) | 導体（ワイヤー）
• Load (Lights, Motors) | 負荷（ライト、モーター）
• Control Devices (Switches) | 制御装置（スイッチ）
• Protection Devices (Fuses) | 保護装置（ヒューズ）
Types of Circuits 🔌
回路の種類
In a series circuit, if one component fails, the entire circuit stops. In a parallel circuit, other components continue to work.
Ohm’s Law ⚡
オームの法則
Ohm’s Law is the fundamental relationship between voltage, current, and resistance in an electrical circuit.
I = Current (Amperes) | 電流
R = Resistance (Ohms) | 抵抗
If a circuit has 12V and 2A current:
R = V ÷ I = 12 ÷ 2 = 6 Ohms
Understanding Voltage 🔋
電圧の理解
Voltage is the electrical pressure that pushes electrons through a circuit. It’s measured in Volts (V).
電圧は電子を回路に押し通す電気的な圧力です。ボルト（V）で測定されます。
High voltage systems in hybrid and electric vehicles require special training and safety procedures!
Understanding Current ⚡
電流の理解
Current is the flow of electrons through a conductor. It’s measured in Amperes (A) or Amps.
電流は導体を通る電子の流れです。アンペア（A）で測定されます。
電子は負から正へ流れる
• Headlights: 10-15A | ヘッドライト
• Starter Motor: 150-300A | スターターモーター
• Radio: 1-2A | ラジオ
• Power Windows: 10-20A | パワーウィンドウ
Understanding Resistance Ω
抵抗の理解
Resistance opposes the flow of current. It’s measured in Ohms (Ω).
抵抗は電流の流れに対抗します。オーム（Ω）で測定されます。
Unwanted resistance (corrosion, loose connections) causes voltage drops and circuit problems!
The Battery 🔋
バッテリー
The battery stores electrical energy and provides power to start the engine and run accessories when the engine is off.
• Voltage: 12.6V (fully charged) | 電圧
• CCA (Cold Cranking Amps): 400-800A | 低温始動電流
• Reserve Capacity: 60-120 min | 予備容量
• Amp-Hours (Ah): 40-100Ah | アンペア時
The Alternator ⚡
オルタネーター（発電機）
The alternator generates electricity while the engine runs, charging the battery and powering electrical systems.
The Starter Motor 🔧
スターターモーター
The starter motor cranks the engine to begin the combustion process. It draws high current (150-300A) for a short time.
• Solenoid: Engages starter gear | ソレノイド
• Armature: Rotating part | アーマチュア
• Pinion Gear: Meshes with flywheel | ピニオンギア
• Brushes: Transfer current | ブラシ
Fuses and Circuit Protection 🛡️
ヒューズと回路保護
Fuses protect circuits by melting and breaking the circuit when current exceeds safe levels.
Never replace a fuse with a higher amperage rating – this can cause fires!
Relays 🔀
リレー
A relay is an electromagnetic switch that allows a small current to control a larger current circuit.
• Headlights | ヘッドライト
• Fuel Pump | 燃料ポンプ
• Horn | ホーン
• Cooling Fan | 冷却ファン
• Starter | スターター
Automotive Wiring 🔌
自動車配線
Proper wiring is essential for safe and reliable electrical systems. Wire gauge (thickness) must match the current requirements.
• 18 AWG: Small loads (1-5A) | 小負荷
• 16 AWG: Medium loads (5-10A) | 中負荷
• 14 AWG: Larger loads (10-15A) | 大負荷
• 12 AWG: High loads (15-20A) | 高負荷
• 10 AWG: Very high loads (20-30A) | 超高負荷
Lower gauge number = thicker wire = more current capacity
Wire Color Codes 🎨
配線カラーコード
Wire colors help identify circuit functions. While colors vary by manufacturer, some are standard.
Always refer to the vehicle’s wiring diagram – colors can vary between manufacturers!
Electrical Connectors 🔗
電気コネクター
Connectors join wires and components. Proper connection is critical for reliable operation.
Grounding Systems ⏚
接地システム
The vehicle body serves as the ground (negative) path back to the battery. Good grounds are essential!
• Corrosion at ground points | 接地点の腐食
• Loose ground connections | 緩い接地接続
• Paint under ground terminal | 端子下の塗料
• Damaged ground straps | 損傷した接地ストラップ
Using a Multimeter 📊
マルチメーターの使用
A multimeter is the most important tool for electrical diagnosis. It measures voltage, current, and resistance.
Voltage Drop Testing 📉
電圧降下テスト
Voltage drop testing finds unwanted resistance in a circuit while current is flowing.
Ground circuits should be ≤ 0.1V | 接地回路は0.1V以下
1. Set meter to DC Volts
2. Connect across the component/connection
3. Operate the circuit
4. Read voltage drop
Troubleshooting Steps 🔍
トラブルシューティング手順
Follow a systematic approach to diagnose electrical problems efficiently.
1. Verify the complaint | 症状を確認
2. Check the basics | 基本を確認（ヒューズ、接続）
3. Consult wiring diagrams | 配線図を参照
4. Test with multimeter | マルチメーターでテスト
5. Isolate the problem | 問題を特定
6. Repair and verify | 修理と確認
Always check the simple things first – 80% of electrical problems are loose connections or blown fuses!
Common Electrical Problems ⚠️
一般的な電気の問題
Electrical Safety ⚡🛡️
電気安全
Working with electrical systems requires proper safety precautions to prevent injury and damage.
• Disconnect battery before working | 作業前にバッテリーを外す
• Wear safety glasses | 保護メガネを着用
• Remove jewelry | アクセサリーを外す
• Use insulated tools | 絶縁工具を使用
• Never work on wet surfaces | 濡れた場所で作業しない
• Batteries produce hydrogen gas – explosive!
• Always disconnect negative terminal first
• Reconnect positive terminal first
Lesson Summary 📝
レッスンのまとめ
• Ohm’s Law: V = I × R
• Circuit Types: Series, Parallel, Series-Parallel
• Key Components: Battery, Alternator, Starter
• Protection: Fuses, Relays, Circuit Breakers
• Testing: Multimeter, Voltage Drop Test
• Safety: Always disconnect battery first!
You’ve completed all the learning content! The next slides contain a 10-question quiz to test your knowledge. You need 70% (7/10) to pass.
📝 Lesson 5 Quiz
レッスン5クイズ
Test your knowledge with 10 multiple-choice questions.
• 10 multiple-choice questions
• Passing score: 70% (7/10 correct)
• You can review your answers after completion
• Take your time and read carefully
Click “Next” to begin the quiz. Good luck!
「次へ」をクリックしてクイズを開始します。頑張ってください！
問題1: ヒューズの主な機能は何ですか？
問題2: オームの法則の公式は？
問題3: 完全に充電された12Vバッテリーの電圧は？
問題4: オルタネーターでACをDCに変換する部品は？
問題5: 直列回路で1つの部品が故障するとどうなりますか？
問題6: ほとんどの回路で許容される最大電圧降下は？
問題7: どちらのワイヤーゲージがより多くの電流を扱えますか？
問題8: リレーの目的は何ですか？
問題9: どの色のワイヤーが通常接地/負極を示しますか？
問題10: 電気システムで作業する前に必ず行うべきことは？
📊 Calculating Your Results…
結果を計算中…
スコアを計算しています
結果を計算中…
Continue with the next lessons in Module 5 to master electrical systems!
