We found this circuit in the May 1989 Radio Electronics magazine. The circuit can have its values changed to operate at other frequencies and the power supply must be symmetrical.
This is a typical point scale or moving bar circuit with the LM3915. We found it in old American...
This circuit simulates the actual departure of a train as the speed increases slowly. The power...
This circuit was found in an Electronics World magazine from 1990. The circuit can be mounted...