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 circuit from a Radio Electronics from February 1976 activates the relay in two different ways...
The integrated circuit used in this project is unusual and it includes internal transistors that...
This circuit is quite old, from 1964, but can still be mounted with BC558 transistors. The circuit is...