This circuit controls 6 LEDs in two sets with the phase change cycles controlled by a 555 oscillator. The circuit can be powered by voltages between 6 and 12 V.
This control for bass, midrange, and treble was found in the March 1995 issue of Electronics Now...
This high-power shield is isolated from the control. The circuit was found in the June 1995...
This circuit was found in a Popular Electronics of the 1990s. The sensor is a rotating mechanical...