A rhythmic LED system that can be used with fixed sound equipment
We describe the assembly of a rhythmic LED system that can be used with fixed sound equipment and also in the car. The indicator is a movable bar type with 10 LEDs, in a simple assembly that uses low cost components. What this circuit does is trigger a LED bar, such as a volume indicator (VU) from the audio signal obtained from the output of any sound equipment. The drive is of the type shown in figure 1, in which we have a bar of LEDs whose quantity lights according to the music volume. Figure 1 - The mobile bar drive The circuit operates 8 LEDs in a system that uses common components and can be extended with more integrated circuits . For a stereo system two circuits must be mounted, one for each channel. How it works The circuit is based on the action of voltage comparators that trigger with signals of different levels. As we can see from figure 2, a voltage comparator has two inputs. Figure 2 - The voltage comparator By applying a reference voltage to...