This interesting circuit found in American documentation generates a busy signal, without you having to take the phone off the hook if you do not want to answer. The components used are common.
We found this circuit in a 1998 documentation. It tests common household appliances to see if they...
We found this electronic organ circuit in a 1987 documentation. The circuit should be powered by...
This circuit was found in an Electronic Design from the 80's. It shows how to use a MOSFET driver with...