We found this circuit in the Philips integrated circuits manual of 1990. The circuit must be powered by a symmetrical high current source. The integrated circuit must have a good heat radiator.
The simple low voltage source that can be used as a battery eliminator, shown in the figure was...
Placed inside the refrigerator, this circuit triggers an oscillator when the part is opened...
This circuit was obtained in a 1972 Corriente Alterna magazine (Uruguay), using the traditional pair of...