BU407 NPN Power Transistor (150V-7A)

⚡ BU407 – NPN Power Transistor

(High-voltage NPN Bipolar Junction Transistor – BJT)

📌 General Description

The BU407 is an NPN silicon power transistor designed for high-voltage, high-speed switching applications, such as horizontal deflection circuits in CRT displays, inverters, power supplies, and motor drivers. It can handle high collector voltages and moderate current, with decent switching speed.

⚙️ Key Specifications

📦 Package – TO-220 Pinout

       ________
      |        |
Base | 1      | Collector (Tab)
      | 2      |
Emitter | 3   |
      --------

🧪 Features

• High collector voltage handling (up to 150V)
• Moderate current (up to 4A)
• Fast switching capability
• Rugged TO-220 package with good thermal dissipation
• Suitable for flyback converters and CRT deflection

🛠️ Typical Applications

• CRT monitor horizontal deflection
• High-voltage switching
• Inverter circuits
• Motor driver circuits
• Flyback converters

🔧 Usage Notes

• Requires proper base drive for fast switching (often via a resistor and diode for turn-off speed).
• Use a heatsink when operating at high current or continuous power.
• Add a snubber circuit (RC or diode) to protect against voltage spikes in inductive loads.

✅ Advantages

• Reliable and robust for high-voltage work
• Still available from multiple manufacturers
• Handles decent power and voltage