Friday, February 17, 2012

Projector HID arc light mounted into a desk lamp

I combined the High Intensity Discharge bulb and power supply from an old LCD with a desk lamp to create a 270W spotlight. I bypassed the power supply's interlocks and shorted an optocoupler to cause the power supply to always turn the lamp on when AC power is applied. I used an inline power switch to control the device. The desk lamp's existing wiring is able to withstand the high starting voltage of the HID lamp (probably a few KV). Once the arc strikes, the voltage is much lower and the current much higher.


  1. Yikes! That's an insane desk lamp!

    I hope you were wearing eye protection while the lamp was on. HID lamps give off enormous amounts of UV light, and you can damage your eyes without even realizing it.

    At one point I was working on building a DIY projector out of an old LCD monitor (it's on the wayside while I'm away at school). The HID lamp I got was 400w, and it used a large aquarium lamp ballast to power it.
    Here's a video of the first time I powered it up:

  2. Well it is a fun project, but I have to say it is proof of concept. Concept....unknown.... BUt still proof that it can work... I love it... When i heard the watts... lol... i about shiznit my self I didnt realize they were THAT bright Maybe 150-200, but 270? That is like friggin awsome! Love it!

  3. Nice work, but I think too that it is a prrof of concept.
    How about the very short lifetime of such lamps, and the huge replacement cost ?

  4. I've considered something similar to, oddly enough, save my eyes. The lcd welding goggles take a split second to turn dark and that time adds up badly. By supplying a very bright light to the subject, I can see the item being welded through regular goggles.