This sophisticated circuit was found in the November 1978 issue of Radio Electronics magazine. Based on CMOS logic, it has several types of timing, controlling the wiper relay.
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...