Els tres elèctrodes del tiristor es poden distingir per un multímetre
El tres elèctrodes de un tiristor regular es pot mesurar usant un multímetre amb un ohm rang de R × 100. As nosaltres tots sabem, hi ha un un pN unxió entre tiristors G i K, que és equivalent a un díode. G és el pol positiu i K és el pol negatiu. Per tant, d'acord al_mètode de prova díodes, trobar dos del tres pols i mesurar el seu endavant i inversa resistència. Quan la resistència és petita, la sonda negra del multímetre és connectada al_pol de control G, la sonda vermella està connectada al_càtode K, i la quedant és el ànode A. Per provar la qualitat de tiristors, pot utilitzar la placa d'ensenyament circuit demostrat abans. Connectar la alimentació SB, si la bombeta emet llum, és és bona; si it no emet llum, és és dolent.
The most basic use of ordinary thyristors is controllable rectification. The well-known diode rectifier circuit belongs to uncontrolled rectifier circuit. If diodes are replaced with thyristors, it can form controllable rectification circuits, inverters, speed regulation, motor excitation, contactless switches, and automatic control. Now I will draw the simplest single-phase half wave controllable rectification circuit. During the positive half cycle of the sinusoidal AC voltage U2, if the control pole of VS does not receive a trigger pulse Ug, VS still cannot conduct. Only when U2 is in the positive half cycle and a trigger pulse Ug is applied to the control pole, the thyristor is triggered to conduct. Now, drawing its waveform diagram, it can be seen that only when the trigger pulse Ug arrives, there is a voltage UL output on the load RL (shaded area on the waveform diagram). If Ug arrives early, the thyristor will conduct earlier; If Ug arrives late, the time for the thyristor to conduct will be late. By changing the timing of the trigger pulse Ug on the control pole, the average output voltage UL (the size of the shaded area) on the load can be adjusted. In electrical technology, the half cycle of alternating current is often set at 180 degree , which is called the electrical angle. In each positive half cycle of U2, the electrical angle experienced from zero to the moment of the trigger pulse arrival is called the control angle ; The electrical angle at which the thyristor conducts during each positive half cycle is called the conduction angle θ. Obviously, both and θ are used to represent the conduction or blocking range of a thyristor during half a cycle of forward voltage. By changing the control angle or conduction angle θ, the average value UL of the pulsed DC voltage on the load is altered, achieving controllable rectification.
