🔌 Diode Types Explorer

Session 3: Semiconductors & Diodes

Rectifier Diode

Converts AC to DC (Rectification)

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✓ Forward Bias

Conducts current when positive voltage applied to anode. Electrons flow from cathode to anode through the load.

✗ Reverse Bias

Blocks current when negative voltage applied to anode. Only small leakage current flows.

Types of Rectifier Diodes

Standard Rectifier
Fast Recovery
Schottky

Key Characteristics

Forward voltage drop: 0.7V (Silicon)
High current handling capability
Used in power supplies and rectification

🚗 Applications in Electric Vehicles

1
AC-DC conversion in charging systems
2
Battery charging circuits
3
Power supply rectification
4
Onboard charger circuits
📈

Zener Diode

Voltage Regulation (Maintains constant voltage)

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✓ Forward Bias

Operates like a normal diode, conducting current in forward direction.

⚡ Reverse Breakdown

Conducts at specific breakdown voltage (Zener voltage). Maintains constant voltage across terminals.

Types of Zener Diodes

Low voltage (<5V)
High voltage (>5V)

Key Characteristics

Operates in reverse breakdown region
Maintains constant voltage
Available in various Zener voltages (2.4V to 200V)

🚗 Applications in Electric Vehicles

1
Voltage regulation in BMS
2
Overvoltage protection circuits
3
Reference voltage generation
4
Sensor signal conditioning
💡

Light Emitting Diode (LED)

Converts electrical energy to light

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💡 Forward Bias

Emits light when forward biased through electron-hole recombination. Photons released as visible light.

✗ Reverse Bias

No light emission, blocks current like standard diode.

Types of LEDs

Standard LED
RGB LED
High-power LED
OLED

Key Characteristics

Forward voltage: 2-3.5V (color dependent)
Low current operation: 10-20mA
Long lifespan: 25,000-50,000 hours
High energy efficiency

🚗 Applications in Electric Vehicles

1
Vehicle lighting (headlights, taillights)
2
Dashboard indicators
3
Charge status displays
4
Interior ambient lighting
👁️

Photodiode

Converts light to electrical current

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✓ Forward Bias

Normal diode operation - conducts current regardless of light.

☀️ Reverse Bias (Photoconductive)

Generates current proportional to light intensity. Used in light sensing applications.

Types of Photodiodes

PN Photodiode
PIN Photodiode
Avalanche Photodiode

Key Characteristics

Linear response to light intensity
Fast response time
Spectral sensitivity varies by material
Low dark current

🚗 Applications in Electric Vehicles

1
Ambient light sensors
2
Solar panel monitoring
3
Rain detection sensors
4
Proximity detection systems

📚 Semiconductor Basics Review

P-Type Semiconductor

  • Doped with Group III elements (Boron, Aluminum)
  • Creates excess holes
  • Holes are majority carriers
  • Positive charge carriers dominate

N-Type Semiconductor

  • Doped with Group V elements (Phosphorus, Arsenic)
  • Creates excess electrons
  • Electrons are majority carriers
  • Negative charge carriers dominate

P-N Junction

  • Formed by joining P and N materials
  • Creates depletion region at junction
  • Basis of all diode operation
  • Allows current in one direction only
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