230W HID spotlight from video projector parts

[kimmik]

Hi all, i recently got a few old projectors and had the whirlwind idea of building a spotlight from the HID and ballast inside.

I couldn't actually find any other instance of anyone doing something similar... so i figured i'd post it here both for your interest, and to hear from anyone else who did this mod!

http://img812.imageshack.us/i/mg5319large.jpg/

i modified a 12v-240v inverter to output 320V DC, supplying the ballast, which drives the UHP bulb. the light came with original lensing so the beam is nicely focused.

i haven't had time to take it for a drive yet or else would've shared a few better photos lol

 

[ma_sha1]

Nice!

There was one guy on CPF who did this, but he ended up poofing the lamp.
http://www.candlepowerforums.com/vb/showthread.php?t=254557

Which Projector did you start with?

How did you get pass the ballast ? He has to mod the ballast a bit.

 

[BVH]

I picked up some GE Marc 300/16 - 300 Watt, 5,000K projector lamp/reflector assemblies of Ebay thinking I might build something. By coincidence, my Locator searchlight ballast system provides the 36-38 Volt DC to the bulb that the lamp requires so I fired a few of them up for fun. They'd make a very bright floody light if fitted into something handheld.

 

[ma_sha1]

I picked up some GE Marc 300/16 - 300 Watt, 5,000K projector lamp/reflector assemblies of Ebay thinking I might build something. By coincidence, my Locator searchlight ballast system provides the 36-38 Volt DC to the bulb that the lamp requires so I fired a few of them up for fun. They'd make a very bright floody light if fitted into something handheld.

From what I read, The Marc family is Short Arc Metal Halide, it should really throw. I wonder if the reflector that came with your lamp is elliptical? If so, it'll give only flood.

Majority of the lamps used in projector come with a built in elliptical reflector. I wonder if the OP had to purchase a separate UHP lamp with parabola reflector.
.
.

 

[Walterk]

Nice shot already. What's the diameter ?
Edit: of the reflector I meant

 

[kimmik]

Nice!

There was one guy on CPF who did this, but he ended up poofing the lamp.
http://www.candlepowerforums.com/vb/showthread.php?t=254557

Which Projector did you start with?

How did you get pass the ballast ? He has to mod the ballast a bit.

I had a quick look at his mod and its no wonder he blew the lamp.

The thing is designed with high flow cooling both of the reflector and of the bulb. most of the work i did was basically cooling the ballast, reflector, and bulb using an 80mm fan and a mini blower.

I started with a Hitachi x445 but just about any is fine. i also have a few other old pjs with 275W HID but i figured i'd rather some more battery life lol.

The tricks and mods to successfully making a spotlight from projector parts:

1. cool the light assembly with high flow, particularly take note of the air channel that they all have for the inside of the reflector. thats why i had to use 2 fans.
2. find a source for 300V or whatever your ballast uses. in my case i tapped the DC stage of a 12-240v inverter.
3. The ballast will only turn on if you find the trigger signal path. which is actually quite easy. All projector ballasts have three connectors 1 for the lamp, 1 for input power, 1 for signal in/out. the signal in is isolated from the ballast driver using optocouplers. There are either two or three of them. Just short each optocoupler and see which one turns the lamp on, and either wire that connection to a switch or hard short it with solder.
4. maybe i'm just paranoid but i've heard of projector bulbs exploding, so i've built everything into a 100mm pvc pipe to act as both a chassis and a shield from hot bits of quartz lol

http://yfrog.com/ekimg5311mj

here's a messy image of the light. the white pvc tube is attached to the square 300W inverter. the inverter's on/off switch turns the inverter+ballast+lamp on and off. 80mm fan is inside the tube blowing towards the light, the blower i haven't added yet in this picture, but it sticks out of the tube like a snail lol. The 80mm fan sits between the light and the ballast, cooling both.

i've tested it running for about 1hr no problems. i thought it was overheating when puffs of smoke came out but upon closer inspection, they were just little moths that flew into the light beam.

 

[kimmik]

And regarding the lamp, its all original from the projector i took apart. i dont know much about reflectors and lenses, though the beam is already nicely collimated. (still nothing compared to the thread with the tank 1kw xenon arc lamp.... hectic!)

I'm not sure what's meant by diameter, the beam diameter or the reflector? the second photo shows the reflector size, about 50mm i think.