What is a power transistor? The basic structure, characteristics, working principle, applications, driving protection, installation points, circuit analysis, and development history of power transistors 4

7、 Circuit analysis:

Power transistors are commonly used in power amplification and switch control circuits. In a power amplifier circuit, the input terminal of a power transistor receives a low-power signal and outputs a high-power signal after amplification. In switch control circuits, power transistors are used to control the switching state of the circuit and achieve the switching function of the circuit.

The circuit analysis of power  transistors be made using the following formula:

1. Voltage calculation: Voltage refers to the potential difference between the two ends of a power transistor, which can be calculated using Ohm's law. That is, V=I * R, where V is voltage, I is current, and R is resistance.

2. Current calculation: Current refers to the flow of charge through a power transistor, which can be calculated using Ohm's law. That is, I=V/R, where I is current, V is voltage, and R is resistance.

3. Power calculation: Power refers to the energy conversion rate of a power transistor per unit time, which can be calculated using a power formula. That is, P=V * I, where P is power, V is voltage, and I is current.

8、 Development history:

The development history of power transistors can be traced back to the late 1940s and early 1950s. At that time, transistors had already replaced electronic tubes as key components in electronic devices. However, early transistors were not suitable for high-power applications such as power amplifiers and switching power supplies.