How is the thermal resistance of rectifier bridge generated

The thermal resistance of a rectifier bridge refers to the thermal resistance between the heat generated by the rectifier bridge components during operation and their heat dissipation conditions. A rectifier bridge typically consists of four diodes, used to convert alternating current into direct current.

When the rectifier bridge is working, the current passing through the diode will cause the resistor to heat up. Due to the resistance of electronic components and the power generated when powered on, rectifier bridges generate a certain amount of heat. These heat will be dissipated into the surrounding environment through the outer surface of the rectifier bridge.

Thermal Resistance is a characteristic that describes thermal conductivity and measures a material's ability to conduct heat. The thermal resistance of a rectifier bridge refers to the ratio between the heat (power) generated by the rectifier bridge per unit area and the temperature difference between its surface temperature.

In practical applications, resistors are usually added before connecting the rectifier bridge, mainly for the following reasons:

1. Current limitation: Resistors can limit the input current of the rectifier bridge to prevent damage to the rectifier bridge and other circuit components caused by excessive current. Especially in terms of initial start-up or overcurrent protection, this resistor can provide certain current limitation and protection functions.

2. Voltage distribution: Adding resistors can achieve the distribution of input voltage to the rectifier bridge. For example, if the input voltage of the rectifier bridge is higher than the required voltage value, the voltage division ratio can be adjusted by adding resistors to adapt to the required voltage range.

3. Voltage balance: In some special cases, the voltage distribution of each diode in the rectifier bridge may be uneven, resulting in different voltages borne by each diode. By adding appropriate resistors, the balance of rectifier bridge voltage can be achieved, ensuring that the voltage distribution of each diode is relatively uniform.

4. Suppress high-frequency noise: Due to the switching behavior of the rectifier bridge during operation, some high-frequency noise may be generated. By adding appropriate resistors, it can help suppress noise currents and oscillations, improve the stability and anti-interference ability of the overall circuit.