This circuit was found in a Popular Electronics from the 90s. The effect circuit uses components that are still common today. In fact, the circuit has only 3 channels of 12 LEDs.
August 2016 - It can be obtained from Mouser Electronics the new operational amplifiers series...
Found in the February 1990 Radio Electronics issue, this sophisticated 100 MHz probe uses a period...
This ultra-simple meter uses an output transformer and a small speaker as a microphone. The...