This circuit generates short pulses. The transistor can be a 2N2222 or BC548 and the frequency is given by the resistors and the capacitor that can be changed.
This set-rest relay uses two SCR and two switches to control a DC relay. The circuit can be used...
This circuit with only one tuned coil was found in a 1980s American documentation. The circuit uses...
This circuit was found in the February 1997 Electronics Now magazine. The circuit has a power...