With this circuit from the September 1989 issue of Radio Electronics magazine, it is possible to receive VLF band signals on a common radio, just like the signals emitted by the previous receiver.
This flasher was found in an 80's Electronic Engineering but can be easily implemented with modern...
This circuit was obtained in an English publication of 1975. It is a regulator circuit for...
The basis of this circuit is a National Semiconductor operational amplifier that functions as a...