This circuit was found in a March 1988 Radio Electronics. The voltage scale is set at R3. 19 LEDs are used in this indicator circuit.
In the figure we have the way to simulate the function S = AB + CD + E (CB + AD) using 5 switches or...
This circuit was obtained in a 1991 Electronics Handbook. The publication no longer exists, but...
We found this configuration in a documentation for radio amateurs from 1974. The circuit can be...