How to select a general small power triode and a high power triode?

The article explores how to select a general small power triode and a high power triode

1.The selection of general small power triode

When the triode is selected, it is necessary to make clear that the frequency of the electronic circuit is about how much. In the engineering design, the characteristic frequency of the triode is 3 times that of the actual working frequency. Therefore, the characteristic frequency of triode can be chosen according to this requirement.

The selection of the small power triode BVCEO can be determined according to the power supply voltage of the circuit. In general, as long as the BVCEO of the triode is larger than the maximum voltage of the power supply in the circuit. When the load of the triode is inductive load, such as transformer, coil and so on, the selection of BVCEO value should be careful. The induction voltage on the inductive load may reach 2~8 times of the power supply voltage.

Generally, the Icm of the small power triode is between 30~50mA. Generally speaking, the small signal circuit can not be considered. But for relays and tubes that drive high power speakers, we must calculate carefully. Of course, first of all, we need to know how much the current of the relay, so as to determine the IcM of the transistor.

2. The selection of high power triode.

For the high power triode, as long as it is not a high frequency emission circuit, it is not necessary to consider the characteristic frequency of the triode .

For the electrode emitter reverse breakdown voltage of the tri electrode, and the limit parameter of BV-CEO is the same as that of the small power triode. The choice of the maximum allowable current Icm of the collector is also calculated according to the load condition of the triode. The maximum allowable dissipative power PcM of the triode collector is an important consideration in the high power triode. It is important to note that the high power triode must have a good radiator.

Even a forty or fifty watt high-power triode can only withstand two or three watts of power dissipation without a radiator. The choice of high-power triode should also be left with sufficient allowance. In addition, when choosing the high-power triode, it should consider its installation conditions to decide whether to choose plastic or metal encapsulated tubes.

If you get a transistor and you can't find its parameters, you can guess its parameters according to its shape. At present, the small power triode is most commonly seen in the TO- 92 encapsulation pipe, and also partly in the metal shell package. Their PcCM is usually between 100~500mW, and the maximum is no more than 1W. Their Icm is usually between 50~ 500mA, and the maximum is no more than 1. 5A. Other parameters are not well judged.

This article is from Allicdata Electronics Limited.