This circuit activates a relay after a time given by C1 and R1. The circuit is from a Radio Electronics from December 1974. The relay voltage is the same as that used in the power supply.
This is the traditional sequence of 10 reverse LED sequences, that is, the LED goes out in...
This circuit is in the SGS manual of linear integrated circuits of 1982. The integrated circuit is of...
With the circuit shown, you can have a fast response with a Darlington configuration. The circuit is...