Indicated for activation by microcontrollers, this circuit was found in the Radio Electronics magazine of December 1987. The MOSFET can be of any type according to the buzzer.
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...