This circuit is from a Radio Electronics from October 1963. The transistor is a power transistor of the time, and two transformers are used. The input has 10k impedance and is powered by 12 V.
In this circuit, obtained from a 1979 publication, IC1 is a 555 and IC2 is a 4020. The transistor is the...
This is a circuit with the first commercial Darlington transistor, the 2N626. The circuit is from...
This simple SCR trigger was found in a 1965 General Electric SCR manual. The circuit makes use of a...