We found this circuit in the March 1980 Radio Electronics magazine. The circuit used is the HA2400 released at the time. The power supply must be symmetrical.
This simple Bargraph photometer with 4 LEDs was found in a 1997 documentation. The scale is...
This 7400 TTL circuit has a memory, keeping the LED on when a pulse is detected. The circuit must be...
This constant current source was found in the Linear Applications Handbook of the National...