This SCR timer was found in an old English documentation. The SCR can be the TUIC106 and modern equivalent transistors like the BC557 for TR1 and BC547 for the others.
This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit...
This circuit generates signals from 0.01 Hz to 10 kHz, but uses unusual components today. The...
This dimmer or light control for incandescent light bulbs or even small heaters, is one of many...