This circuit was found in the September 1972 issue of Radio Electronics magazine. The circuit uses an operational amplifier of the time and a symmetrical 9 V source.
This circuit was obtained in a Radio Shack documentation from 1977. The circuit generates a...
This commercial circuit of 3 transistors was found in Japanese documentation from the 1960s. The...
This electronic car lock was found in a 1988 magazine. It uses a code key that must be activated to...