This 80's Exar circuit has a carrier detector for frequencies up to 500 kHz. The circuit uses a company 567 which is still a common component.
This circuit was found in a 1964 Electronic Design. The components are of the time, and modern...
This circuit was found in a 1999 publication. Its purpose is to flash two LEDs according to the...
This circuit is from a Popular Electronics from the 90's. The circuit directly drives high power...