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.
This test consists of a simple Hartley oscillator using a transformer of the type found on older...
n be assembled with BC558 transistors for low power transistors and a BD136 for the output. The...
This oscillator takes advantage of the 2000 ohms headphone inductance as the oscillator circuit coil....