Transformer

Transformer is a device that uses the principle of electromagnetic induction to change the AC voltage, and the main components are primary coils, secondary coils and iron cores (magnetic cores). The main functions are: voltage conversion, current conversion, impedance conversion, isolation, voltage regulation (magnetic saturation transformer). According to the use can be divided into: power transformers and special transformers (electric furnace transformer, rectifier, power frequency test transformer, voltage regulator, mine transformer, audio transformer, medium frequency transformer, high frequency transformer, impact transformer, instrument transformer, electronic transformer, reactor, transformer, etc.). The circuit symbol is often used as the beginning of the number T. Example: T01, T201, etc.

The appearance characteristics of the heat sink mainly have the following points:

(1) The shape of the heat sink can be flat plate type, or it can be a variety of profiles, which is aluminum material.

(2) The heat sink is set on the shell of the power amplifier tube and fixed on the power amplifier integrated circuit with screws. According to these characteristics, the heat sink can be easily found on the circuit board.

Fin action

When the power amplifier tube is working, the collector should produce a lot of heat, if the heat is not dissipated in time, it will greatly affect its dissipated power PCM, the light affects the output power of the device, and the heavy damages the device. This is because there is a thermal resistance in the transistor, which affects the dissipation of this heat. For this reason, in some cases with large output power, the power amplifier tube and power amplifier integrated circuit are installed with heat sinks to help them dissipate heat. After the heat sink is added, the thermal resistance of the power amplifier tube will be greatly reduced, and the heat of the collector is easily dispersed to the space, so that the junction temperature of the power amplifier tube is not too high. Conversely, after the heat sink is added, the thermal resistance of the triode is reduced, and the power amplifier triode can withstand greater dissipation power at the same ambient temperature, which is why the heat sink is added.

At present, there are two kinds of heat sinks for transformers: the first is used as a chip radiator, which is generally used as a high-quality cold-rolled steel plate (ST13). The other is a heat sink for corrugated oil tank, and the material is 08AL steel plate. The latter has a better radiator expansion coefficient and is commonly used as a fully sealed transformer tank.