This circuit was found in American documentation from the 1980s. The integrated circuit used is a voltage comparator of the time. Modern equivalents can be tested.
This audio-driven relay was published in the July 1977 issue of Radio Electronics magazine. The...
This circuit can be used for signaling a panel with a common incandescent lamp. The lamp will...
This crystal oscillator is indicated for the calibration of IF steps of common radio receivers. The...