Found in a 90s Electronic Design, this circuit is used with a 9 V adapter for powering small circuits. The maximum current is given by the 250-mW regulator.
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...