Unijunction metronome (CB21701E)

This traditional metronome circuit is powered by voltages from 9 to 12 V and output drives a common speaker.

Power Control (CB24109E)
This circuit is from a Radio Electronics from February 1971. The SCR is load controlled and the...
Inverter for Geiger Tube (CB24102E)
This circuit generates a high voltage of the order of 250 to 300 V from a 12 V battery to power a...
TRIAC Shot By Reed Relay 2 (CIR3265E)
We find this simple circuit in an English publication called Electronic Circuit Design no. 3 of...