晶体三极管(英文).doc

TransistorTransistor in a circuit commonly used Q add numerals, such as: Q17 said Numbers for 17 of the transistor.Characteristics: the transistor (hereinafter referred to as transistor) is interior contains two PN junction, and has the ability of special device amplification.It points NPN type and PNP type two kinds, the two types of triode from work characteristics can be mutually make up, the so-called OTL circuit of the pipe is a PNP type and NPN type matching use.Telephone the commonly used PNP transistor: type A92, 9015 models, NPN transistor: type A42, 9014, 9018, 9013 9012 etc, models.Patch trioderiode principle of workTransistor is a kind of control components, mainly used to control the current size, with total emitter after method for example (signal input from base, from collector output, emitter grounding), when there is a base voltage UB slight change, base current IB will then have a small change, by base current IB control, collector current IC will have a very big change, base current IB, the greater the collector current IC is bigger also, conversely, base current smaller, collector current also smaller, namely base current control collector current changes. But the collector current changes than base current change much, this is triode amplifying function. The variation of IC with IB changes the ratio of the amount called transistor magnifacation beta (beta = IC/ IB, said variation. , transistor magnifacation beta generally in decades to hundreds of times.Transistor in boosting signals, the first to enter the on-state, i.e. to first set up suitable static robustly, also called build bias, otherwise will magnify distortion.In the collector and the power audion indirect a resistor, can be current amplification convert voltage amplifier: when base voltage UB rises, IB greaten, IC becomes larger, IC in collector resistance RC pressure drop is bigger also, so triode collector voltage UC can be reduced, and the higher the UB, UC will be lower, and UC = UB.Triode applications:Basic amplifying circuitTriode swi