This simple transistor tester was found in a Japanese magazine in 1967. It tests general purpose transistors of both the NPN and PNP type and is powered by 4 batteries (6 V).
This circuit for controlling high power in the AC network was found in a Motorola documentation from 1968....
Found in American documentation from the 90's, this circuit consists of a solid state relay with...
This oscillator uses a small transistor amplifier or radio output transformer. We found it in a...