This telephone circuit was found on a 90's EDN. It keeps a flashing LED to indicate that there was a call in your absence. The components admit equivalents.
The flashing LEDs in this circuit simulate a working alarm and can serve as a deterrent to a...
This oscillator or clock generator generates rectangular signals and frequencies up to 100 kHz....
The critical component of this project from a 1988 publication is the transformer. The final power...