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.
This circuit uses an operational amplifier to simulate an inductor. The circuit is from old...
This voltage level-triggered circuit was found in a 1969 Ferranti English documentation. Modern...
Found in a 90s General Electric documentation, this circuit has a drain current of just 1.5 uA....