Product quality inspection

Measure the resistance between electrodes. Put the multimeter in the R×100 or R×1K block, and test according to the six different connection methods of the red and black test pens. Among them, the forward resistance values of the emitter junction and the collector junction are relatively low, and the resistance values measured by the other four connection methods are all very high, ranging from several hundred thousand ohms to infinity. But whether it is low resistance or high resistance, the inter-electrode resistance of the silicon triode is much larger than the inter-electrode resistance of the germanium triode.

The value of the penetration current ICEO of the chip transistor is approximately equal to the product of the multiple β of the tube and the reverse current ICBO of the collector junction. ICBO increases rapidly with the increase of ambient temperature, and the increase of ICBO will inevitably lead to the increase of ICEO. The increase of the ICEO will directly affect the stability of the pipe work, so the pipe with the small ICEO should be used as much as possible in use.

product category

Divided into two types according to polarity: one is NPN type triode, which is the most commonly used one, and the other is PNP type triode.

According to the material, it is divided into two types: one is silicon triode, which is the most commonly used one, and the other is germanium triode, which was used more in the past.

The triode is divided into two types according to the working frequency: one is a low-frequency triode, which is mainly used in places where the working frequency is relatively low; the other is a high-frequency triode, which is mainly used in places where the working frequency is relatively high.

According to the power, it is divided into three types: one is low-power triode, its output power is smaller; one is medium-power triode, its output power is larger; the other is high-power triode, its output power can be very large , mainly used for high power output occasions.

According to the purpose, it is divided into: amplifying tube and switching tube.