Using the 723 integrated circuit, this circuit was found in an article on power supplies in the August 1971 Radio Electronics magazine. The transistor may be the BD136 on a heatsink.
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...