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.
This input stage has unit gain but a high input impedance and low output impedance. The circuit is...
This circuit is basically the same configuration as the previous one with a power stage with...
This audibility or loudness control for sound equipment is from 1992 documentation. The circuit uses...