This circuit was found in a 1968 documentation. It makes use of both NO and NC reed-switches and small magnets attached to a card in the form that results in the drive combination.
This circuit was found in the June 1978 issue of Radio Electronics magazine. The circuit is...
The slope of an object causes the sensor, a mercury switch to be triggered. The circuit activates...
This circuit for the logic control of the 555 in a power supply was found in the October 1989...