单结晶体管也称双基极二极管,简称UJT。由于它是一种电流控制型负阻器件,所以用途很广,可以组成自激多谐振荡器、单稳和双稳电路、锯齿波发生器、分频器、方波发生器、阶梯波发生器等电路。尤其是电力系统的可控硅触发电路,UJT更是常用的触发元件。但是有时手头上没有适当的单结晶体管,这时可用普通PNP和NPN型晶体三极管来组成和单结晶体管特性一样的电路(如下图所示)。从BG_1 Single junction transistor, also known as double base diode, referred to as UJT. Because it is a current-controlled negative resistance device, it is versatile and can be used as a self-excited multivibrator, monostable and bistable circuits, sawtooth generator, divider, square wave generator, staircase wave generation Other circuits. Especially the thyristor trigger circuit of power system, UJT is the most commonly used trigger element. However, sometimes there is no proper single-junction transistor on hand. In this case, an ordinary PNP and NPN transistor can be used to form the same circuit as the one-junction transistor (as shown in the figure below). From BG_1