This 80's circuit has been winning. It is a 1 000 gain sample and hold circuit and an offset current setting. The configuration can be adapted to operate with modern equivalent components.
This 1960s Signalite circuit uses two SCRs to achieve full wave control. The trigger elements are...
This circuit is from a Popular Electronics from the 90's. The circuit activates a buzzer with...
Pressing and releasing S, the capacitor C1 charges and discharge slowly through the oscillator...