This is the traditional voltage follower configuration with the 741 operational amplifier. The circuit is from 1976 documentation and the power supply must be symmetrical from 6 to 15 V.
This circuit allows the coding of several relays from coded keys that must be activated, according to...
This circuit is from 1988 documentation. It uses a range of 30 LEDs driven by 4017 integrated...
Found in a 1970 publication by General Electric, this circuit makes use of a mobile...