Found in documentation from the 90s, this circuit triggers a relay with inductive signals applied to a link. The sensitivity depends on the frequency and the power supply depends on the relay used.
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...