We found this circuit in an American publication from 1977. The circuit drives two LEDs according to the control of the inputs. The technology is TTL requiring 5 V to power supply.
The integrated circuit used in this stereo preamp is uncommon today, but the circuit can be...
This circuit was found in a 1967 General Electric manual. It is intended for the control of high...
Carbon microphones are no longer used in most projects. However, finding one in the scrap metal, it...