This circuit is from a 1965 Motorola documentation. The transistors are of the time as is the uninformed magnetic sensor.
This circuit was found in a Radio Electronics magazine from May 1967. The circuit has the time...
This detector is from the 1990 Motorola Dataar Databook, but can be adapted to work with more...
This grounding test circuit was found in an American 80's documentation. The circuit is for the...