Use the potentiometer for setting the timing period within these intervals. For the 0.3 second to 10 minutes timer version the potentiometer is 100kΩ, R1 = 9.1kΩ, R2 = 910kΩ, R3 = 220kkΩ and C1 = ...
This circuit is designed to provide delayed relay switching action at power on. The delay is a function of the time constant produced by the combination of R1 and C1. At power on, C1 charges slowly ...