You getting a watchable picture with a 90 watt lamp.
Thats pretty good.
Regarding the heat issue I take it the glass is not good enough even with a fan blowing cold air between two pieces. I am surprised at that but have a search on this forum for low e glass. Apparently that works but someone said it dropped the light a bit.
Thats pretty good.
Regarding the heat issue I take it the glass is not good enough even with a fan blowing cold air between two pieces. I am surprised at that but have a search on this forum for low e glass. Apparently that works but someone said it dropped the light a bit.
I'll check out that low e glass. Maybe that and a 250 watt halogen 10o spot light to compensate the drop in light. I myself am surprised at how it worked only being 90watts. But it is pretty hot. I used a thermometer to check and it only goes to 60c. It was at that temp in a few min. where the LCD would be sitting. Now the back of the therm. is black so maybe it is absorbing too much heat for a acurate reading I dunno. It'll make the colors go funny if it is too hot right. Wont just burn up without any signs or warning? The colors look ok but I was worried after I got a new temp reading of this bulb. I wouldnt have thought it to be hotter than the flood light at 125watts. The light is about 1 1/2' from the lcd and thats after the glass to cool and the fresnel. My thought also was maybe it was the concentrated light at the very center of the bulb that was the prob. and if I put a thick piece of glass in front of it that I have it will disrupt it some? This heavy glass is from outside halogen light 125watt unit and has the frosted type glass on one side and other side smooth. This may act like a difuser somewhat. That low e glass matbe the best solution though depending on the cost of the stuff. Thanks for the recomendation!😉
well, since i'm back in school i havent had much time to play. I have my proxima 2700 running. Its VGA only, but i'm mananging....i've only used it once in the past 3 weeks. Sorry but i doubt i'll have the time to try fashoning a bulb holder
I was just wondering.
Is your projector bright enough to get a good image onto the wall? How far are you projecting and how large an image are you getting?
Im projecting from about 9 1/2'away and im getting a 7' diagonal picture. I just need to decide what color to paint my walls and do the flooring. I made a screen from blackout cloth and got a new bulb for my projector just incase the one i have now goes.
ap0the0sis
Is your projector bright enough to get a good image onto the wall? How far are you projecting and how large an image are you getting?
Im projecting from about 9 1/2'away and im getting a 7' diagonal picture. I just need to decide what color to paint my walls and do the flooring. I made a screen from blackout cloth and got a new bulb for my projector just incase the one i have now goes.
ap0the0sis
hi guys, new to this forum and to projectors in general.
sorry i'm posting this here, but i keep getting a message saying 'please search the forum before you post' even though i have been searching on it for hours!
the reason for my new interest is that i have got my grubby paws on an lcd projector for very little money, but obviously not much lamp life left.
i admire everyone's efforts in making an ohp type diy projector, but i live in a small apartment and my girlfriend would kill me if i made a hulking great box to sit in our living room!
it was, therefore, with great interest that i read that some of you guys had attempted to put a cheap lamp into a commercial projector- it seems the logical thing to do, as these units are perfect other than the fact that the lamps cost so much.
i promise i have searched the forums from top to bottom, and i have come up with a few useful posts on the subject, but i can't seem to find anything that will tell me if this will work or not- success stories if you will.
now let's get a few things straight-
i would happily pay for a new bulb if they didn't have such a short life span, so that's not an option.
although i would love to use this projector as my main tv, i'm not expecting this to be plausable- movies only for now.
i don't mind if the light output is not as good as the original- watching movies in the dark is fine.
i don't care if the colours aren't perfect as long as it's watchable.
i don't care if the edges are slightly darker than the middle or whatever- my current tv has a green cast in one corner and i forget it's there most of the time.
what i want is a cheap and cheerful way to get some light into this thing to make it reasonably functional. i want bulbs that are cheap and widely available and last a reasonable amount of time (1500h is reasonable if they are cheap enough)
i'm not expecting miracles, but a way to watch the odd movie on a big screen for little outlay.
i have noticed that most of the posts on this subject are quite old, maybe there has been a bit more progress in this field since?
to start off, i have been thinking of this setup:
my projector uses a 260w mh bulb- how about if i (carefully) removed the bulb from the reflector, and popped a 240v 300w or even 500w halogen inside? (i'm in the uk, this is a plain mains voltage bulb- no ballast required)
from reading all the posts, i think the disadvantages would be:
1. heat (need a lot more cooling= noise)
2. colour temp- it would be on the yellow side (who cares? they are £1.19 each!!!)
3. have to bypass the bulb- sensing circuitry (i think i can do this though)
4. not a point light source (i thought maybe the wattage overkill might compensate enough to get a useable picture though)
5. overcompensation by a powerful bulb may not work, or may produce too much heat to manage
6. fitting the bulb may be problematic- i think it would fit in the reflector but the bulbs i have in mind are a strip with connectors at opposite ends- do they get too hot for solder?
advantages:
1. cheap, cheap, cheap! (maybe cheap enough to use as a regular tv if performance was adequate)
2. i think that overcompensation by a powerful bulb may work well enough- maybe not as well as the original, but well enough.
3. bulbs can be bought pretty much anywhere
4. no ballast- wiring would be really easy and the ballast could be removed and an extra cooling fan installed in the space
5. should fit into original casing no problem
i can't help thinking that somebody would have done this already if it would work, but at the same time i don't think our goal should be to emulate the original performance of the projector, rather provide a way for diy folks to use this technology that's very cheaply available and get a functional projector out of it.
it would probably be a lot easier and cheaper, not to mention smaller than an ohp based pj, and would probably perform as well as most of them.
come on guys, let's get our heads together on this- this could be the best thing to happen to diy projectors since lcd monitors!
james
sorry i'm posting this here, but i keep getting a message saying 'please search the forum before you post' even though i have been searching on it for hours!
the reason for my new interest is that i have got my grubby paws on an lcd projector for very little money, but obviously not much lamp life left.
i admire everyone's efforts in making an ohp type diy projector, but i live in a small apartment and my girlfriend would kill me if i made a hulking great box to sit in our living room!
it was, therefore, with great interest that i read that some of you guys had attempted to put a cheap lamp into a commercial projector- it seems the logical thing to do, as these units are perfect other than the fact that the lamps cost so much.
i promise i have searched the forums from top to bottom, and i have come up with a few useful posts on the subject, but i can't seem to find anything that will tell me if this will work or not- success stories if you will.
now let's get a few things straight-
i would happily pay for a new bulb if they didn't have such a short life span, so that's not an option.
although i would love to use this projector as my main tv, i'm not expecting this to be plausable- movies only for now.
i don't mind if the light output is not as good as the original- watching movies in the dark is fine.
i don't care if the colours aren't perfect as long as it's watchable.
i don't care if the edges are slightly darker than the middle or whatever- my current tv has a green cast in one corner and i forget it's there most of the time.
what i want is a cheap and cheerful way to get some light into this thing to make it reasonably functional. i want bulbs that are cheap and widely available and last a reasonable amount of time (1500h is reasonable if they are cheap enough)
i'm not expecting miracles, but a way to watch the odd movie on a big screen for little outlay.
i have noticed that most of the posts on this subject are quite old, maybe there has been a bit more progress in this field since?
to start off, i have been thinking of this setup:
my projector uses a 260w mh bulb- how about if i (carefully) removed the bulb from the reflector, and popped a 240v 300w or even 500w halogen inside? (i'm in the uk, this is a plain mains voltage bulb- no ballast required)
from reading all the posts, i think the disadvantages would be:
1. heat (need a lot more cooling= noise)
2. colour temp- it would be on the yellow side (who cares? they are £1.19 each!!!)
3. have to bypass the bulb- sensing circuitry (i think i can do this though)
4. not a point light source (i thought maybe the wattage overkill might compensate enough to get a useable picture though)
5. overcompensation by a powerful bulb may not work, or may produce too much heat to manage
6. fitting the bulb may be problematic- i think it would fit in the reflector but the bulbs i have in mind are a strip with connectors at opposite ends- do they get too hot for solder?
advantages:
1. cheap, cheap, cheap! (maybe cheap enough to use as a regular tv if performance was adequate)
2. i think that overcompensation by a powerful bulb may work well enough- maybe not as well as the original, but well enough.
3. bulbs can be bought pretty much anywhere
4. no ballast- wiring would be really easy and the ballast could be removed and an extra cooling fan installed in the space
5. should fit into original casing no problem
i can't help thinking that somebody would have done this already if it would work, but at the same time i don't think our goal should be to emulate the original performance of the projector, rather provide a way for diy folks to use this technology that's very cheaply available and get a functional projector out of it.
it would probably be a lot easier and cheaper, not to mention smaller than an ohp based pj, and would probably perform as well as most of them.
come on guys, let's get our heads together on this- this could be the best thing to happen to diy projectors since lcd monitors!
james
Halogen bulbs are far more expensive than metal halide. They consume more power for less light, obviously resulting in more heat. They also last nowhere near as long. Halogen projector bulbs get somewhere around 50 hours lifetime. Even if you manage to get a bulb for $10 (probably a low estimate) you'll spend $600 to match the 3000 hour life of a short-arc metal halide that cost $40 as posted in a recent an active thread.
Some have had luck retrofitting a different metal halide bulb into an LCD projector. I don't have any experience with that, just the hulking box method! If you are too whipped to say "this is the way things WILL BE" then I guess you have to stick with that broken TV! 😉
Some have had luck retrofitting a different metal halide bulb into an LCD projector. I don't have any experience with that, just the hulking box method! If you are too whipped to say "this is the way things WILL BE" then I guess you have to stick with that broken TV! 😉
useless cheap halogen lamps
Those very long skinny halogen lamps are useless for retrofitting: You need a lamp that generates all of its light from an area no larger than the original lamp. Look at the original lamp filament. I bet it is just a centimeter or so long. That means the projector's optics would only see the light generated in 1 cm of the 10 cm filament of the longer lamp. So instead of 300 Watts, it would effectively be a 30 Watt lamp with a 270 Watt heater!
Those very long skinny halogen lamps are useless for retrofitting: You need a lamp that generates all of its light from an area no larger than the original lamp. Look at the original lamp filament. I bet it is just a centimeter or so long. That means the projector's optics would only see the light generated in 1 cm of the 10 cm filament of the longer lamp. So instead of 300 Watts, it would effectively be a 30 Watt lamp with a 270 Watt heater!
yep, good points.
i have been reading about mh lamps, and it seems there may be hope!
all the information seems to indicate that any mh ballast should in theory be able to power any mh lamp so long as the wattage is correct and the striking method is the same. (sometimes even a different strike technique will work)
it would appear that although the voltages of the lamps can vary, the ballast is regulated for current- the lamp draws the voltage it needs.
providing the wattage of the lamp is within 10% of the rated wattage of the ballast, and the bulb is suitable for the striking method of the ballast, everything should work (in theory)
the lamp on my projector is 260w, so a 250w lamp is well within the 10% tolerance level.
now although i have some electronics experience, i know very little about these lamps- would somone like to offer a professional opinion on my findings, and let me know if they are correct?
my plan is to carefully remove the old lamp from it's housing, and replace it with a double ended mh lamp. i'm not sure if it will fit, but if it doesn't i'll remove the outer glass envelope first.
i'm going to try it thus: i'll extend the leads a bit so i can operate the new lamp outside the casing, and i will confine it to a metal cash box i have. the lock is missing, so there is a hole i can pass the wires through and to see if the lamp has lit ok.
i will position the hole away from me pointed at a piece of paper so i can see if the lamp is working without running the risk of getting glass in my eyes!
if the lamp works but does not fit, i'm going to wrap tape around it and gently squeeze it in a small vice until the outer glass cracks. this will give me the control i need so i don't crack the actual bulb as well. obviously i will be wearing protective gear for this!
i have read about people theorising about removing the glass envelope before, but never about anyone actually doing it!
the envelope is there to help with uv filtering and to help contain an explosion should the bulb fail, but the original reflector housing of the projector is also designed for this and so would perform the same task.
i can't try this yet as i have to use the original reflector and my lamp still has some life. i'll be sure to post my results when i do try it though.
wish me luck!!!
also, if any of my info is wrong, please let me know so i don't waste an expensive lamp!
i have been reading about mh lamps, and it seems there may be hope!
all the information seems to indicate that any mh ballast should in theory be able to power any mh lamp so long as the wattage is correct and the striking method is the same. (sometimes even a different strike technique will work)
it would appear that although the voltages of the lamps can vary, the ballast is regulated for current- the lamp draws the voltage it needs.
providing the wattage of the lamp is within 10% of the rated wattage of the ballast, and the bulb is suitable for the striking method of the ballast, everything should work (in theory)
the lamp on my projector is 260w, so a 250w lamp is well within the 10% tolerance level.
now although i have some electronics experience, i know very little about these lamps- would somone like to offer a professional opinion on my findings, and let me know if they are correct?
my plan is to carefully remove the old lamp from it's housing, and replace it with a double ended mh lamp. i'm not sure if it will fit, but if it doesn't i'll remove the outer glass envelope first.
i'm going to try it thus: i'll extend the leads a bit so i can operate the new lamp outside the casing, and i will confine it to a metal cash box i have. the lock is missing, so there is a hole i can pass the wires through and to see if the lamp has lit ok.
i will position the hole away from me pointed at a piece of paper so i can see if the lamp is working without running the risk of getting glass in my eyes!
if the lamp works but does not fit, i'm going to wrap tape around it and gently squeeze it in a small vice until the outer glass cracks. this will give me the control i need so i don't crack the actual bulb as well. obviously i will be wearing protective gear for this!
i have read about people theorising about removing the glass envelope before, but never about anyone actually doing it!
the envelope is there to help with uv filtering and to help contain an explosion should the bulb fail, but the original reflector housing of the projector is also designed for this and so would perform the same task.
i can't try this yet as i have to use the original reflector and my lamp still has some life. i'll be sure to post my results when i do try it though.
wish me luck!!!
also, if any of my info is wrong, please let me know so i don't waste an expensive lamp!
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