This 3-digit digital gauge was found in the July 1900 issue of Radio Electronics magazine. The circuit is based on the CA3161 and CA3162 A/D converters of the time.
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...