Using the CA3140 integrated circuit, this switch was found in the June 1986 Radio Electronics magazine. Sensitivity adjustment is made at the trimpot in series with the sensor.
This circuit is from an article in Radio Electronics magazine from August 1972. The circuit is...
Found in 1969 RCA documentation, this circuit maintains constant current in the filament of a lamp...
The integrated circuit used in this application is uncommon today. The circuit is from American...