N° of component 

Timer Using a UJT (CB478)

This circuit can be adjusted to time timer intervals up to1 hour using a 2,200 µF capacitor and a 2M2 potentiometer for R1. Power supply voltage depends on the relay and can range from 6 V to 12 V. R4 must be changed if problems to trigger the relay are observed.


Timer Using a UJT
Timer Using a UJT




Circuit Bench