This variable oscillator with power step for alarms was found in an American documentation from the 90's. The power transistor must be equipped with a heat sink.
This circuit was found in a former Popular Electronics. The timing is set on the potentiometer and the...
This circuit transmits signals to an FM receiver at a distance of up to a few tens of meters. The...
This circuit was found in a 1969 US documentation. It provides a signal that can be externally...