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.
In the figure we have the way to obtain 500 gain from a FET. FETs can be BF245 or MPF102. The...
With the circuit shown in the figure, we have a logic signal to activate a calling device when...
Found in 1980s Electronics Design, this circuit covers 4 decades of frequencies with a unique...