This tester is primarily meant to test bipolar transistors. It can indicate the type of the transistor as well as identify its base, collector and emitter pins. The circuit is very simple. The ...

Alternatively, you may want to connect its inputs and output in parallel with IC1.C to increase its drive power to the transistor test circuit. IC1.A and IC1.B together with R2, R3 and C1 form an ...