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.
March 2017 - Texas Instruments' new TPS2H160-Q1 smart switches can now be obtained from Mouser...
This circuit was found in a Electronics Handbook (1989). The shown amplifier provides a few...
The gain of this amplifier is 10 times and the excursion to the output voltage is 6.0 V (peak to...