Found in a PE Hobbyst Handbook, this circuit checks if there is voltage in a power outlet by emitting sound and lighting an LED.
We found this circuit in the March 1976 Radio Electronics magazine. The circuit is very...
This high impedance step suggested by an English publication can operate up to 1 MHz with 1 V rms...
This circuit found in an American documentation from 1964, alters the duration of a pulse and can...