This timer circuit was found in a 1980s American documentation. Transistors and SCR support modern equivalents. The circuit was originally designed to control a motor.
This circuit can be used in demonstrations or science fairs. The circuit uses headphones and can...
We found this wiretapping circuit in a publication from the 90s. The circuit allows the cable...
This circuit uses a resonant reed switch at the trigger frequency. The circuit is from General...