This circuit, to control air conditioning systems, was found in July 1984 Radio Electronics magazine. The circuit is for old types of the time that did not have microcontroller control.
This Nixie pipe circuit was found in 1965 documentation. Note the high supply voltage. Appropriate...
This circuit is from a 1976 publication, but it can be assembled with modern components. For the...
Found in Popular Electronics from the 90's, this circuit consists of an audio oscillator for Morse...