This simple 6 V source stabilized by zener diode was found in a European technical publication from 1972, but it is current for its simplicity and the components it uses.
This amplifier was published in the July 1961 Radio Electronics magazine. It announced the release of...
This circuit was found in a 1967 Electronics World. SCRs are according the controller load,...
This sophisticated circuit using a liquid crystal display was found in Radio Electronics from the...