I need a creative electrician

Brad Grimmett · May 5, 2009

I'd like to build a light around a particular bulb. You can see it here.

I don't know enough to do it myself, so I need a bit of help. I need a directional source and am looking for someone who knows how to do this type of thing. Please reply or PM me if you think you can help.

Thanks.

Hal Smith · May 5, 2009

I'd like to build a light around a particular bulb. You can see it here.
I don't know enough to do it myself, so I need a bit of help. I need a directional source and am looking for someone who knows how to do this type of thing. Please reply or PM me if you think you can help.

Thanks.

Hi Brad,

The bulb is from a Sperti Psoriaisis Lamp. This link has a floor and a table version of the lamp.

http://www.moviestartanning.com/2007/Sperti/psoriasis.htm

UV lamps are discharge types, one could cannibalize one of these lamps to get everything they need to build a custom UV lamp. Given the price of the Sperti fixtures I suspect they have a very basic ballast and starter circuit inside, I don't think there's enough money in their cost to implement an electronic ballast...of course if Chinese they could have a complete HMI style flickerfree electronic ballast inside for $270! If the lamp does indeed have a magnetic ballast, all filming would have to be done at the same frame rates and shutter angles as required by magnetic ballast HMI lamps.

Depending on exactly what sort of beam shape you have in mind, I'd build the new UV fixture around an existing open face movie/theatrical fixture. A lensed fixture won't work for UV, all the conventional glasses absorb UV. The fixture would be best with an aluminum or chrome reflector (they reflect UV) , a Source Four type reflector with an aluminized glass reflector would be iffy.

Sincerely,

Hal

Brad Grimmett · May 6, 2009

Thanks for the tips Hal. I'm not gonna shoot with it though, I just have psoriasis and want to build a very spotty light for treatment. I managed to get rid of the psoriasis in an affected area on my back last year while working in the Bahamas. I accidentally burned the crap out of it and it went away and never came back. All of the other areas went away thanks to all the sunlight, but since they didn't burn, they all came back. So, my plan is to burn every spot I have, which is why I want such a spotty light. These lights aren't great for the rest of your skin, so I'd prefer to confine it to the affected area as much as possible. I figured we might have some good electricians here on the forum that would enjoy building a light for the fun of it and some pocket change. These lights are available with a prescription, but I don't think any of them really fit the bill for exactly what I'm looking for...oh, and they're all very expensive.

Thanks again Hal.

Paul Bruening · May 6, 2009

Is it a specific frequency of light? Is it gas filled? If not, would an unfiltered HMI with a fresnel and gobo-spot do the trick?

Hal Smith · May 7, 2009

Thanks for the tips Hal. I'm not gonna shoot with it though, I just have psoriasis and want to build a very spotty light for treatment.......

Is the $270 for a Sperti too much? If I needed to cobble up a spotty UV lamp I'd make a theatrical lighting style snoot for a Sperti. The important thing about a psoriasis light would be the UV intensity and snooting a Sperti wouldn't change the flux, just limit the coverage.

I judge the UV has to be pretty stout since the Sperti using that bulb is a 800 watt model. The only concern I'd have about snooting the Sperti is to make certain that there's still plenty of cooling air getting to the bulb. It wouldn't work to just screw a piece of sheet metal with a tube (and a matching hole) attached perpendicular (geometrically normal) to the sheet since that would block the cooling air to the front of the lamp.

(PS: When I was a young tad I was a biomedical research engineer at the University of Chicago Psychology Department and also did EEG research at the Illinois Institute for Juvenile Research. I've actually got some chops (albeit very rusty) in biomedical techie things.)

Doug Brantner · May 7, 2009

If Hal is correct about the ballast, etc., which he probably is, it might be worth it to just buy the fixture and use as-is. Maybe make yourself a tin foil t-shirt that you can cut up and only expose the parts you want to hit...

Also, have you considered a tanning salon? Not sure if it's the same UVA/UVB wavelengths but it might do the trick...

Brad Grimmett · May 7, 2009

Is the $270 for a Sperti too much?

Well, for that price I may as well just avoid the hassle and just pay a bit more for an existing lamp.

The important thing about a psoriasis light would be the UV intensity and snooting a Sperti wouldn't change the flux, just limit the coverage.

Of course it would be nice to increase intensity, but the main thing is to try not to treat the unaffected areas too much, since it's not great for your skin.

(PS: When I was a young tad I was a biomedical research engineer at the University of Chicago Psychology Department and also did EEG research at the Illinois Institute for Juvenile Research. I've actually got some chops (albeit very rusty) in biomedical techie things.)

I can tell you know what you're talking about. I'm sure if we continued the discussion you'd quickly fly right over my head!

Brad Grimmett · May 7, 2009

If Hal is correct about the ballast, etc., which he probably is, it might be worth it to just buy the fixture and use as-is.

Yeah, I think you're right. I was hoping someone would pop up and say, "Oh, yeah, I could build something for you easily!"

Maybe make yourself a tin foil t-shirt that you can cut up and only expose the parts you want to hit...

Now that would be a sight to see!

Also, have you considered a tanning salon? Not sure if it's the same UVA/UVB wavelengths but it might do the trick...

I have, but the UV levels in those lights is often quite a bit lower than in psoriasis specific bulbs. Also, I would prefer to avoid exposing the rest of my body to that light. I've spent much more time in the sun than the average person, growing up in FL and the Cayman Islands, so if I can avoid any unnecessary exposure, that would be good. I've seen way too many cases of skin cancer among old friends.