This circuit was found in a Hands On Electronics from the 90s. It is intended to supply old tape players to batteries with a voltage of 7.5 V from the 12 V of a car battery or source.
This circuit is from a July 1970 Radio Electronics magazine. The sensors are metal probes. The 18 V...
This commercial medium and short-wave radio was manufactured in Japan in the 60s. The circuit has...
General Electric suggests this circuit in an 80's documentation. The circuit makes use of PUTs...