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 implement a monostable with a comparator 139, 239 or 339. The...
This circuit can be used in a digital measuring or shield interface. The circuit is from old...
We find this TTL configuration in a 1978s documentation. The circuit generates variable pulses...