This circuit was obtained from an 80's EDN. The components used are still common. The circuit can be used as a shield and the frequency is approximately 775 Hz.
Mouser Electronics is now shipping DA14585, a kit for the development of voice remote control...
The presented circuit causes an LED to flash with voltages of 85 to 200 V continuous and has a low...
This circuit for analog video signals was found in a March 1988 Radio Electronics. The Maxim...