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.
We found this circuit in an English documentation from 1995. With it it is possible to measure a...
This circuit is from an ancient American documentation. The coil is frequency dependent and the...
We have here a simple signaling circuit for two common incandescent lamps, which is used for...