Transistor is a solid semiconductor device, which can be used for detection, rectification, amplification, switching, voltage stabilization, signal modulation and other functions. As a variable switch, the transistor controls the outflow current according to the input voltage, so it can be used as a current switch. Different from general mechanical switches (such as relays and switches), the transistor is controlled by electrical signals, and the switching speed can be very fast, and the switching speed in the laboratory can reach 100GHz or above.
2. Thyristor is the abbreviation of thyratron, which can also be called SCR, formerly referred to as SCR; Thyristor is a PNPN four-layer semiconductor structure with three poles: anode, cathode and grid; The working conditions of thyristor are: DC voltage is applied, and the gate has trigger current; Its derivative devices are: fast thyristor, bidirectional thyristor, reverse thyristor, light-controlled thyristor and so on. It is a high-power switching semiconductor device, which is represented by "V" and "vt" in the circuit (represented by the letter "scr" in the old standard).