This circuit with unijunction transistors was found in a documentation from the 80's. The trigger times of the SCRs depend on the capacitors and are adjusted in the 5M (4M7) potentiometers.
Found in a 90s nHands On Electronics, this circuit triggers a relay that shuts off the load when...
This project was found in a 1982 publication, using only two transistors. Signal injectors are...
Designed by Philips in 1968 to control the washer water level this circuit uses components from the era....