This circuit is from an 80's Electronic Engineering. The base is a common operating and 4 single integrated voltage comparators. The circuit directly drives 4 indicator LEDs.
This circuit was found in an American 1980s documentation. It makes use of an unusual MOSFET today...
We find this circuit in American documentation from the 1980s. The accuracy of the circuit depends on the...
This circuit is from 1964 documentation but can be easily implemented based on current components....