Found in a 1968 US publication, this circuit can operate on any power grid. The thickness of the wire depends on the load current.
This circuit can handle 25 A unde a 32 V voltage using a hight power old transistor. This...
Found in a PE Hobbyst Handbook, this circuit checks if there is voltage in a power outlet by...
This circuit was found in a 90s Hands-On Electronics. When a signal appears at the headphone...