Basically, a VU Meter measures loudness (volume units) of an audio signal. But this blinking VU meter project catches the eye more than the ear. The construction of the VU meter using 12 flashing bulbs is relatively simple. At the heart is a 12 outlet controller box with each outlet connected to two layers of six solid state relays. An mp3 player is plugged into a VU meter controller which also outputs the audio to an attached speaker.
The VU Meter through the solid state devices relays the analog audio to the bulbs which flash to the song. Interesting variations can hacked out using LEDs instead of bulbs with the Lm3915 chip.
The costliest parts of the whole project are the solid state relays. They are quite expensive in the US ($50), so buy them on eBay for about $10.Â The complete plans for the giant flashing bulb VU meter are available at Inventgeek. Play it and take a â€˜lookâ€™ at sound volume. A lot of our projects have brought together sound and light for extraordinary effects: