This windshield wiper timer was obtained in an 80's Hands On. The transistor can be the BC548 and the relay is 12 V sensitive. The time is set to R3.
We can implement this filter with more modern equivalent operational amplifiers, since the LM110 is...
This common transistor-based circuit provides power for 20 mA common white LEDs from a single 1.5...
This filter was obtained from Radio Electronics from the 80's. The configuration applies to any...