Free Circuit Diagram

Testing whether a transistor is shorted or open usually done by ohm meter. You test if the base to emitter  or collector permit a current flow in one direction. Here is the circuit’s schematic diagram:

The 555 timer ( IC1 ) operate as a 12hz  oscillator. The output of this oscillator (pin 3) drives the 4027 [...]

This transistor tester is very helpful if you need to sort bulk transistors. In  some market, if you know where to find it, sometimes you can get transistors sold in kg unit, not in single peaces unit. You can buy 1 kg of transistors with really cheap prices. Don’t be too happy right now because [...]