Using a 74123 TTL this circuit was found in the Radio Elecronics magazine of June 1975. The power supply must be 5 V. The capacitor determines the activation time.
In the figure we have three voltage doubler configurations that can be used in high and low...
In this application, from English documentation, we have the way to activate an AC load up to 10 W...
This 1-transistor reflex receiver was found in a 1963 publication. The coil is for the mid wave...