DIY replacement lamp for projector

[Tuga]

I don’t know.
I myself would be interested on that info.
Nevertheless, I measured the voltage supplied to the half of the PSU on the pic, its approx 400vdc, soooooo….
I’ll build a 400v supply, just a simple one, with a bridge and then I’ll connect a 150w metal halide lamp to see what happens.
Its off the projector anyway so worst case I blow up a lamp worth £9…lol.

I’ll keep you posted.

[msx-2]

i searched and found that it was Mathias from Sweden who wrote about uhp replacement bulbs for $40. Maybe he can post the link here.

i myself wrote this a week ago , it may be dangerous but what do you think (noone replied to it ,so i post it here again):

Problem with retrofitting projectors is that there is not enough space. However i want to try to make a cdm-t or a similar lamp smaller.

1-i was thinking some projectors use 150w metal hallide lamps, My question is :will a different metal hallide work (electrical speaking , are all 150w mh lamps compatible or does a UHP (the lamps usually used in projectors) have a lower or a higher ignition voltage?)

2- if it would work then there is no problem using the original ballast and ignitor

3-you have to get a very small metal hallide lamp to fit in the original lamp house, would it be possible to remove the outer glass from for example a hqi 150 fc2 ?(its dangerous i know, you have to do it in controlled circumstances face protection , thick leather gloves )If you look at all these lamps
http://www.andrewjjstanley.btinterne...halidelamp.htm
you can clearly see the inner part which is seperate from the rest of the lamp, this is the part that lights up. The outer glass is probably uv protection. (and you can get that from the uv protecting glass of the original lamp house)
If you would remove the inner part (of course without breaking it) will it work? Has anyone ever tried this?

4-then there is the problem of fitting the lamp , if you have the original lamp house , you would have a reflector and all the things you need, just put your slaughtered hqi in there , and there you go 10000 hours for 30 bucks!

Am i completely stupid , or would it work?

BTW i am not responsible if you blow your eyes out or get a lot of nice glass tatoos in your face , or get a nice hairmodel after killing yourself with a electrical igniter with 50KV , in other words dont try this at home or without the right equipment

[Tuga]

I have plenty of space for a 80-90mm lamp on mine. The lamp compartment is 85x85 by 120mm long.

Since I have removed half of the PSU I even have room for a ballast and igniter for a 150W MH lamp, in its place; (200x75x50mm space).

I’ll try the experiment described on my previous post and if it doesn’t work what I’ll do is get a ballast, an igniter and a 150W lamp for about £50 and fit everything inside the projector.

I don’t think you want to remove any of the glass from the lamp!!! But I am only a noob. I know nothing about lamps…

[mathias]

My question is :will a different metal hallide work (electrical speaking , are all 150w mh lamps compatible or does a UHP (the lamps usually used in projectors) have a lower or a higher ignition voltage?)

UHP and MH (HQI) lamps are very different, most UHP-projector lamps run on DC-voltage some on AC. MH-lamps always run on AC-voltage. Acoustic Resonance is an other problem MH-lamps have, they get unstable on higher frequency > 4kHz, if a UHP-lamp have this problem I don´t know so the UHP-ballast maybe use more than 4kHz AC if the UHP lamp run on AC-voltage. Most 150w MH lamps are compatible with eath others, but not with UHP.

If we remove the PSU from the projector I think there is alot of space left so we can place a 150W HM lamp in the orginalcase. I think a 150W HQI is the best choice it´s smaller than a cdm-t and it has 6000-7000K colortemp like the orginal UHP-lamp.

Here is the link to my thread: Put a HQI-bulb in a commercialprojector

Keep up the good work and good luck !

[msx-2]

here the question to the answer will a lamp run without the outer glass casing. It does ,this is about a mercury high pressure lamp , but they are very similar.

http://www.savel.org/hardware/uv.html

mathias> UHP and MH lamps are not that different , they are both metal halide lamps, pressures and gap lenghts are different but they are essentially the same and so they will both work on direct current (DC) i think.

[msx-2]

some other guys were busy here a while ago. Its interesting reading for those who are interested
http://www.diyaudio.com/forums/showthread/t-4445.html

[Tuga]

Very interesting…..cant wait to get my hands on a 150W MH lamp and try it with the original parts!!!!


PS: Slickwillie, 'r you still alive man????

[slickwillie]

yup, i'm here. I'm just a little nervous and slightly overwhelmed. I'm way new to electronics like this, beisdes the very basics. I'm gonna get a drawing together probably by wednesday, since I've got no school then (yup, I'm just a kid!)

p.s. Thanks so much for all your help so far!

[msx-2]

Originally posted by Tuga
Very interesting…..cant wait to get my hands on a 150W MH lamp and try it with the original parts!!!!

be careful if you try it , at the moment i am trying to find out what the difference is between ignition voltage and running voltage between a normal MH and a UHP , i am not sure yet , but ignition is probably 5KV for both , i havent found out how fast the drop is after ignition.(for a UHP it is around 1 second) , running voltage are maybe different, but i am not sure. If someone has some knowledge here. please

[Tuga]

I'm just a little nervous and slightly overwhelmed

If you’re not sure, get someone to help you.
We are dealing with lethal voltages here.
“Shaky hands” have no place near electronics…lol.
Just be careful.

be careful if you try it

Don’t worry I’m a qualified Electronics Test Tech….I’ll take all the precautions necessary.

My biggest problem is to get a MH lamp before the weekend. I don’t know any shop where I could just go and buy it.
I’ll have to order online.


Anyway until then I’ll just have to run my 24v 250w Halogen bulb using a 24v@27Amps PSU (650W ) that I bought from ebay for £10. lol it costs £450 new.

And I still have to make a screen somehow…