This simple optical alarm circuit was found in the 1991 Electronics Experimenter Handbook. The circuit uses a lamp as the emitter but can use LEDs.
April 2017 - Mouser Electronics already has the MAX4007 from Maxim Integrated in its inventory, an...
This experimental receiver works with alternative sources of energy or a single cell of any type....
This beacon causes an LED to flash with the mains voltage. The frequency depends on the capacitor. For...