Originally, this circuit was created to monitor the liquid level in the reservoir of a car's windshield wiper. The circuit is from documentation from the 90s.
This circuit for VCR recording heads was found in the February 1990 issue of Radio Electronics magazine....
This very simple continuity tester uses a small 1.5 V lamp (type used in flashlights). Can be...
This commercial radio with 3 earphone listening transistors was manufactured in Japan in the...