What is a power transistor? The basic structure, characteristics, working principle, applications, driving protection, installation points, circuit analysis, and development history of power transistors 2

3、 Working principle:

The working principle of power transistors is the same as that of ordinary transistors, based on the conduction and cutoff characteristics of PN junctions. When the voltage between the base emitter is greater than the turn-on voltage (usually 0.6V), the power transistor is in a conducting state; When the voltage between the base emitter is less than the turn-on voltage, the power transistor is in the off state.

4、 Application:

Power transistors are widely used in various power amplification and control circuits, including:

1. Power amplifier: used to amplify power signals and provide them to other circuits.

2. AC motor driver: used to control the speed and direction of the electric motor.

3. Power switch: used to switch high-power loads, such as lights, power tools, etc.

4. Inverter: Used to convert DC power into AC power and control the speed of AC motors.

5. Inverter: converts direct current into alternating current for solar power generation, wind power generation, etc.

5、 Drive protection:

In order to ensure the normal operation and lifespan of power transistors, appropriate driving protection is required. Common driving protection methods include overcurrent protection, over temperature protection, and overvoltage protection.