Upon pressing the switch, the circuit generates a pulse whose duration depends on C. The transistors can be BC548 and the power can be between 1 and 6 V. The circuit is from a 1975 publication.
This shield uses a double optical coupler to control an alternating current motor. It is a version of...
In this interesting circuit, a common relay is used as a vibrator to obtain high voltage with a...
This circuit was found in a Popular Electronics of June 1978. The circuit is interleaved between the...