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.
This audio-driven relay was published in the July 1977 issue of Radio Electronics magazine. The...
This circuit can be used for signaling a panel with a common incandescent lamp. The lamp will...
This crystal oscillator is indicated for the calibration of IF steps of common radio receivers. The...