UJT - Unijunction Transistor
Transistors are normally used for switching . For example ,BJT acts as switch but it has low efficiency and many faults. Therefore UJT and SCR are more useful in electronic circuit for switching purpose. In this article we learn about UJT which has high impedance at off condition and low impedance at on condition. History It was developed by shockley in 1949 from the alloyed germanium bar structure and that time it called as filamentary transistor .The first UJT is in form of bar and then it form in cubr structure at 1994. UJT construction It consist of lightly doped silicon bar and heavily doped p-type material. P type material attached to n type firmly and produces a single P-N junction. In UJT emitter is nearest to base2 than base1. i.e emitter= b1>b2 Symbol UJT has 3 terminals emitter (E),base1 and base2. Emitter is formed by P-type material and base1 and base2 formed by N-type. Emitter arrow indicates emitter current (IE) which decides wheater UJT...