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 obtained in a Radio Electronics of the 90s. The circuit uses an integrated circuit...
This is the traditional configuration of na Astable Multivibrator using two NPN ttransistor....
Found in the 1995 Encyclopedia of Electronic Circuits volume 5, this circuit has a constant...