Based on an integrated circuit of the time, this circuit appeared in the October 1979 issue of Radio Electronics magazine. The circuit monitors voltages in the range of 10.5 to 16.0 V.
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...