This General Electric circuit was found in a 1964 documentation. The circuit triggers a relay when the sensor is activated. Trigger adjustment is done in a trimpot.
With 3 transistors, we found this receiver in a documentation from 1966. The circuit has an output...
This circuit was found in a publication for radio amateurs in 1978. The circuit is an automatic gain...
In this circuit R1 is 56 ohm and R2 is 220 ohm for the 110 V network. SCRs are according to the...