| fido13uk |
would it be possible to use another light source in a commercial lcd projector ? and if so would it be possible to use the projector without its original lamp by using an external bulb and ballast, by somehow making a bigger box outside the projector and directing the light into the projector, does anyone know if this is possible ?and does a commercial projector use a ballast seeing that it uses metal halide bulbs so that you can use another bulb and get the power from the projector or do projectors not have ballasts in them, does any one have any experience or ideas using an alternative light souce in these type of projectors ? as the lamp costs in these types are horrendous
any help appreciated
fido |
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| xblocker |
Fido13uk,
as far as i know, most projectors will only start if a lamp is plugged in. Using an external lamp would mean to circumvent completely the projectors power controller or emulate the presence of a lamp.
Doing that is only possible, if you can get the electronic schematics of the projector and this will cost you $$$.
If another lamp can produce the same light beam it could be possible by mirroring the light into the original light path.
xblocker |
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| fido13uk |
thanx 4 the reply, could it be possible to somehow trick the projector into thinking there is a lamp in there by linking the circuit where the bulb would have been or even using the same power supply to link to another outside lamp ? or even take the bulb from its holder and replace with another bulb of the same wattage voltage and lumen rating.
fido |
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| eebasist |
| my understanding is that it can be done......I am buying a projector with a dead bulb that the user put another duller bulb into.....i will see how he defeated the interlocks and then tell you.....it cant be to hard however, just takes time |
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| fido13uk |
Thanx 4 the reply but it seems to defeat the object by putting a duller bulb in there doesn,t it ?
i suppose if you could find another bulb of the same rating it should work in theory, however i dont understand why the makers charge so much for a metal halide bulb when you can buy much more powerful halide bulbs for only a fraction of the cost of these projector replacement bulbs, i am suprised that there isn,t much covered on this topic in this forum, it would be interesting to get feedback from those who maybe have tried different bulbs and what results they got, I look forward to hearing from how you get on with the dead projector bulb as mine still has a few more hours to go and i dont want to investigate until it has died.
I suppose osram sylvania would sell bulbs of either the same or simalar rating just a case of searching for a supplier really, I was wondering though the metal halide bulbs that are for sale are usually much higher in lumen and wattage rating.
ps: do you know what kind and where he got the alternative bulb from ?
it seems that all hid bulbs need ballasts to run so projectors must have these built into them somewhere so another matal halide bulb should run from its power supply without adding another ballast
cheers
fido:) |
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| woneill |
Hi All,
One of the big differences between the "projector-style" MH bulbs and the "lighting-style" bulbs is the spark gap.
The projection bulbs generally have a much narrower gap which acts more like an ideal point source than the lighting bulbs. A small point source of light is generally easier to focus into a uniform beam profile suited to the LCD panel being used - the larger emitting area of the lighting style bulbs is harder to focus into a uniform beam.
Another difference is the size of the bulbs - lighting bulbs generally have a double envelope which (I think) screens out much of the UV light coming from the spark gap, as well as providing a degree of protection from the inner core exploding. Many projection bulbs ommit this and are MUCH smaller.
Most projectors don't just use a bulb, they use a "light module". This is generally an assembly that contains the bulb, a suitable reflector - tuned to the characteristics of both the projector and the bulb - and a high voltage connector. This is all mounted in a metal package, designed to be physically, thermally and electrically safe if the bulb explodes... (Red hot fragments of quartz-glass flying around a room at high speeds can cause LOTS of damage...)
Electrically, most projection bulbs require a pulse-start ballast containing an additional ignitor that supplies a high voltage pulse needed to ignite the lamp. Most of the 400W lighting style bulbs do not need an ignitor - the ballast supplies a high enough open circuit voltage to ignite the lamp.
Many of the projectors contain an electronic ballast and ignitor that is specifically designed to be compatible with the electrical parameters of a specific bulb - such parameters include:
1) Open circuit voltage (bulb not ignited - often 120V - 240V);
2) Cold strike ignition voltage (often @ 4-5kV for projector bulbs);
3) Hot strike ignition voltage (often @ 20kV for projector bulbs);
4) Operating voltage (bulb ignited - generally 50V to 120V);
5) Operating current (bulb ignited - often 2A to 7A dependent on power rating).
The electronic ballast built into a projector is in many ways like the 12V to Mains AC inverters available to power electrical equipment from a car battery. It produces a high power AC signal with current limiting. Some manufacturers build the igniter directly into the ballast. Othes employ a separate ignitor between the ballast and the bulb. Often the electronic ballast units operate at much higher AC frequencies than the magnetic types - reducing any flicker.
ALL electronic ballasts generate high voltages at high power and are VERY dangerous to play with!!! Only experiment if you are a trained Electrical Engineer, AND you are experienced in dealing with Switch-Mode Power Supplies and High Power, High Voltage equipment. They can easily kill.
That said, if you know what you are doing, it is often fairly easy to determine how the main projection electronics can tell if the bulb is working properly. Many electronic ballast units send a signal to the main electronics to indicate if the bulb is working. Working/Non-working is often indicated by an open/closed circuit from a relay. Very few devices use a specific voltage level from the ballast unit as these devices are prone to failure and could inject a high power signal into the sensitive electronics on the main board.
Some projectors have no connection between the ballast and the main electronics at all - and instead use a light detector built into the optical path to determine success/failure.
You might find that some OHP bulbs are a quite effective alternative light source (often requiring that he ballast be replaced by a simple diode-and-resistor combination as a power source) - IF you can handle the short ~50h life span...
All in all, be VERY careful...
Bill. |
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| fido13uk |
i trust you know what you are talking about, so basically its probably unlikely that any of us are going to find a cheaper replacement bulb for commercial projectors as by your statement they sound like they are very specific bulbs and cannot be replaced by any regular metal halide bulb. one question i would like to ask is could the electronics inside my projecter i.e: lense lcd panels be used to make a diy projector that will last more than the regular 2000 hours if so i would rather salvage it for a project than pay the £400 for a measly lamp:mad: also are these diy projectors as good picture quality as the commercially sold type ? if so i would definately salvage my projector for to start a project, as the running cost of my projector is way out of my league really.
thanx for the reply
fido:) |
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| woneill |
Fido,
The general quality of the DIY projectors is actually quite good - not as good as the latest and greatest of the newest projectors, but equivalent to something produced in the mid 90's (say, a Proxima 2800 as seen regularly on Ebay).
Most people start with a 640x480 LCD Overhead Projector panel built in the mid 90's and going for less than $100 from Ebay or various other suppliers (check out the old DIY projector thread for suppliers). When used with a high brightness OHP, the results are not quite full DVD quality, but are much better than a normal TV (if watched with the lights off).
Many people have replced the normal short-life halogen OHP bulb with a 400W MH general lighting bulb which gives out MUCH more light, and will last for 20,000 hours +.
In this configuration, much of the light is lost by the normal OHP optics, and while the bulb is not an optimal point source, the larger case and loose tolerances of the design tend to make this less of a problem than if you were to try and use one of these bulbs in a commercial projector. Some people have gone the next step, and created a new cabinet and reflector arrangement - but are still essentially using the OHP configuration in a single enclosed box.
I tend to prefer using as much hardware from a dead projector as I can because I am not very good with power-tools, and the commercial units are generally much more compact than something built from scratch.
If you are at all competent with electronics, and are attempting to cannibalise an old projector, I would first suggest completely removing the ballast and ignitor and storing them away - you do not want them accidentally hitting you with a 20,000V belt while you are probing around. Then, see if, using a lamp or torch as a temporary light source, you can get the rest of the projector to fire-up - look for leads going from the ballast to the main circuit board.
Commercial projectors, especially if they use three panels for RGB, are generally much brighter than those that use one panel (the type used by the OHP Panels). This is why some projectors give very high lumen outputs with only a 200 Watt bulb.
If you can get the basic projector electronics working, then you can figure out a suitable light source for it afterwards... I have done this with a number of projectors for myself and friends.
I sometimes re-use the old ballast with a MH bulb of equivalent electrical characteristics (different mount/reflector), or cobble together something using the more standard 400 Watt parts, but sacrifice brightness for quality - only using a fraction of the total light...
If you have an old dead light module, you might want to check out what type the raw bulb was - you might be able to find its electrical equivalent at the Osram web site - they have basic data sheets for all their bulbs, and you might be able to re-use the ballast, and/or parts of the light module.
Be careful, though, if you intend to play with these things - the bulbs are VERY high pressure, and can explode in your face if stressed.
Definitely check out other opinions than mine though - there are some awesome people working on this stuff!!!
Bill. |
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| eebasist |
I consider myself qualified to go poking around on the insides. I've build HV power supplies for HeNe lasers years ago and still work with tube electronics so I think the ballast won't scare me.....i just need to find out the electrical characteristics of the bulb, or completely replace it with one from Osram......
By the way, Osram does make projector lamps that act as a point light source so that shouldnt be much of a problem after determining the appropriate electrical characteristics of the bulb
One last thing, if you are looking for a replacement bulb and yours currently works.....measure out the voltage at startup and when running.....so you dont get into the same situation that I'm in. |
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| fido13uk |
thanx for that very interesting info lads, I do build my own programmers and dabble in electronics to an extent, but with these high voltages I suppose i would be a little wary of measuring the voltage at start up as i only use standard uk 240 volt multimeter and i,m sure this is insufficient for the high voltage it takes to start these bulbs, although i could take a reading while running normally, one thing about the bulbs that osram sell would they be that much cheaper to buy than buying a full lamp unit from a commercial supplier ?
thanx
fido |
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| eebasist |
| I dont believe osram will sell direct to the public, you have to find a supplier. The bulb will be cheaper than buying a proxima, or ctx branded bulb assebly. |
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| fido13uk |
if i cant find a suitable replacement or if the bulbs are still quite expensive i may try the earlier post method and remove the ballast and ignitor from the projector and try a different less expensive light source.
fido |
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| eebasist |
| yep, thats probably what i'll be doing.....the whole assebly and ballast.......guess i have to find the relay that tells the projector that the bulb is lit. |
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| fido13uk |
i guess some external box will have to be put together to direct the light into correct path, i think in my projector the lamp depresses 2 spring loaded terminals bridged by a fuse to indicate that there is a lamp present so mine may not have a relay switch hopefully
fido |
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| fido13uk |
Well i guess i,m outa luck here as this is the reply i got from osram
Hi Edward,
I apologise at the delay in responding.
From the number and the pictures and sketch I suspect this to be a Philips lamp. Often projector manufacturers ask us to develop a lamp specially for them and since they pay for research and development, such lamps are only sold to projector manufacturer.
We have nothing in our range.
I think this is one such case.
Regards
-----Original |
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| fido13uk |
quote:
Fido13uk,
as far as i know, most projectors will only start if a lamp is plugged in. Using an external lamp would mean to circumvent completely the projectors power controller or emulate the presence of a lamp.
i think you may be wrong here as i took the lamp from my projector and it started up without the lamp module in place the fans also kicked in so this is good news for using alternative lighting without taking out the ballast and ignitor
fido |
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| woneill |
fido,
Did you see anything on the LCDs? Most projectors "power up", but will only switch into a usable state when the lamp is working.
Try shining a torch into the hole where the lamp module went, and see if anything comes out the other end...
If so, then success, and congratulations!!!
Bill. |
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| fido13uk |
yes i used a table lamp without the shade and a pear household bulb it shorn the infocus start page onto my hand but very dull, so i guess i can use another light source but the problem would be getting another light source into the recess on the bottom of the projector so as to guide the light into the glass panel, I think this going to be my problem and also cooling etc.
fido |
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| woneill |
Excellent!!! Well done!!!
Now you need a cool light source... ;)
For short-term experimentation, you might want to try OHP bulbs - the ones with a built-in reflector. They run hot, need cooling, and don't last very long, but are easy to set up and have a decent beam profile that can easily be optimised with a couple of lenses.
If you can handle lower power outputs, try one (or possibly more) of the higher-power projector-beam fog lamps (110 Watts or so). Much less bright than the OHP variety, but MUCH cooler, cheap, long-lasting, already collimated, and if your projector is high efficiency, then it might be usable.
Finally, you could try to achieve the holy grail (or one of them) of the DIY projector enthusiasts - a using a standard "lighting" MH combination with a suitable reflector to produce a highly collimated beam with a uniform intensity profile (no hotspots...)
If you have been following the other threads, you will know that Pressurised Sodium, Mercury Vapour and conventional Fluorescent bulbs have been tried and found wanting...
You may also wish to explore some of the more esoteric MH "Track Lighting" variants which seem to include bulb/ballast/reflector technologies somewhere between projection lamps and the conventional lighting variants... They usually have a lower maximum power than the 400W M59s, but if your original bulb was lower powered anyway, then that might be for the best. (Less things melting etc.)
Bill. |
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| eebasist |
| any links to MH track lighting....i dont recal seeing that anywhere |
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| fido13uk |
thanx for the info womeil but i still dont understand how i can get the light source into the projector it is awkward with the opening being underneath the projector and doesnt have a great deal of space in there for any larger bulbs.
If i was to use a higher lumen rated bulb for my light source would it not matter much about the melting of panels etc as this would be outside the projector.
also i cant understand some specs about projectors some folk say that you need at least 1000 lumens rated projectors to watch during the day:confused: but mine is only rated 150 watt 450 lumens and it is perfectly watchable even in bright daylight:confused:
mine is an infocus litepro 720 and i,ve seen some other more expensive models that dont look as good as mine:confused:
can you reall go on specs that much ?
fido |
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| woneill |
Here's the first web page that came up from entering into Yahoo!, the words: "metal halide track lighting"
http://eclecticlighting.homestead.c...TAL_HALIDE.html
There are a lot of other matches...
I have seen bulbs that go up to around 250 Watts, with magnetic/electronic ballast combinations.
Electronic would probably be better than magnetic for projection work - they operate at a higher frequency, and generate less possibility of flicker. The bulbs last longer too.
The bulbs don't generally last for millions of hours, but they are still much cheaper than the projection varieties...
Bill. |
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| woneill |
To get the light into the projector you might have to do some fancy wood/metal/plastic work with the case, and possibly use a couple of front-surface mirrors/prism assemblies to get the beam to go in the right direction.
This is the price you pay if you move away from the nicely matched modules that slot right in... This is why they are expensive...
When I have done this in the past, I have been working on the bigger older projectors and generally have to build a new case (or case-extension) for the thing. Luckily, up to now this has been quite simple.
If the light module is in an inaccessible position underneath, you might want to build a box for the larger lamp enclosure plus optics, and then sit the projector on top of this so that the light path can be channeled using a periscope arrangement into the guts of your old projetor. Don't know the details, though...
As for melting things - the beam that emerges from some of these higher power bulbs can contain much infra-red and be very hot. Check out the posts by Marklar in the original DIY thread and his ability to burn paper with the beam from his light assembly.
Bill. |
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| fido13uk |
are there any longer life halogen bulbs available that would fit into my parabolic reflector if it was modified i.e take out the metal halide bulb and replace with halogen type.?
fido |
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| woneill |
As for specs, output and power ratings, the reason the DIY requirements are SO high is because everybody is using a single RGB panel, and not three separate panels for R, G and B.
For each pixel, the red shutter absorbs green and blue light and only passes a proportion of the red. The Green absorbs the blue and red components, and only passes a proportion of the green. The blue...
As you can see, each shutter absorbs 66% of the light that falls on it that is not within its colour range, and only passes a proportion of the light that is.
Thus, when you factor in polarisation effects, apeture size, TFT transistors taking up space on the panel etc, you will understand why these panels only transmit about 10% of all the light that hits them - IF they are pretty good!!!
Most of the OHP and DIY projectors make pretty poor and inefficient use of the light that comes out of the bulb - lots of light is lost, even in the better designs. Marklar's excellent beast is a noted exception...
Thus, they need the power of the sun to get a decent picture.
In the three-panel projectors, a special set of dichroic half-mirrors is used to split the light into its components without using filters which would simply absorb any light of the wrong colour. Not much light is lost.
Each light beam is fed into an LCD panel where ALL the pixel realestate is devoted to that colour - not just 1/3 of it as is the case on the single panel devices.
Thus, each panel can easily be three times brighter with the same light level, and there are three panels feeding the output. That sounds like a potential 9x gain in light levels to me!
Hence, you could probably get away with a much smaller, lower power bulb... |
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| woneill |
There are probably lots of halogen bulbs that can be used - ranging from OHP bulbs without reflectors, to the car headlamp bulbs.
If you intend to remove the bulb from your lamp module, be VERY careful: wear heavy protective clothing (heavy biker jacket and gauntlets etc.), eye/face protection, and preferably work behind a large heavy fresnel lens so that if the bulb explodes, your new hobby for the next few years won't be picking pieces of glass from your skin... :(
If you have already negotiated this task with no injury (the probable case), then you should check out the heat produced by any bulb situated at the prime focus of the reflector - you don't want it to be too hot - if it is too hot for your hand, then your LCD panels will not be happy.
Look for bulbs with small filament areas - they give the best beam characteristics, and you will probably want to adjust the bulb positioning to avoid any hotspots due to misalignment etc.
Good luck!
Bill. |
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| fido13uk |
woneill you say that halogen type bulbs dont last long but if some of those car headlamps can be used then these have quite a long life rating, would these be suitable by fitting into my lamp module ? and i guess i would need a 12 volt power supply too if was to use these. also dont metal halide bulbs give off more heat than halogen any way ? so the existing fan cooling system would be sufficient.
fido |
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| woneill |
Hi Fido,
OHP halogen bulbs with high power outputs often have lives as short as 50 hours... This is why many people have been switching to the use of MH in their OHPs.
Car headlamps are generally (legally in the US) limited to around 55/65 Watts, and are built to last for much longer - in the range of thousands (though many are actually only rated for hundreds of hours...)
A 55/65 Watt halogen would probably not be bright enough for serious use even in a high efficiency projector, and you would need to go for the less standard higher power (110 Watt) "off-road" bulbs that may not have the same life as the standard variety. On the other hand, they might - I don't know.
Surprisingly, many of the HID bulbs used in Beemers etc. are only 35 Watts each!
Bill. |
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| woneill |
MH bulbs are MUCH more efficient than Halogen - it is the halogen bulbs that need the most cooling!
:eek: |
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| fido13uk |
oh it seems i have a lot to learn about optics etc, surely there must be somewhere that sells small tube like metal halide bulbs that would fit into a lamp module:(
so do you think the best way for me to go would be to build an external box and somehow using optics to redirect into the light path ?
fido |
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| fido13uk |
quote by woneill:
If you can handle lower power outputs, try one (or possibly more) of the higher-power projector-beam fog lamps (110 Watts or so). Much less bright than the OHP variety, but MUCH cooler, cheap, long-lasting, already collimated, and if your projector is high efficiency, then it might be usable.
would these fit into my lamp module ?
fido |
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| woneill |
Hi Fido,
You might try these people:
http://www.eurotekmarketing.com/index.html
There are others, but these give a pretty comprehensive list of the bulbs out there, and with pictures too. :D
If you see a bulb you like, do a google/yahoo search on its part number, and you might find other suppliers, or more info on that, or similar bulbs.
Alternatively, you might want to check out the osram/sylvania/philips/ushio sites for info. The bulbs I have been looking at seem to be mainly for film/photographic work in enclosed spotlights etc.
My personal favourite is the HMI575WGS as used in some of the higher power OHP/LCD projectors from the mid 90's. I THINK it will work with an M59 400W balast, but I managed to get my old ballast working before I had to spend any money...
You may find something more appropriate for your needs...
Beware of the ballast requirements though - many of these bulbs have weird characteristics...
Bill. |
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| eebasist |
i like the looks of this one so far
HTI 400WDE
integrated reflector....now to see more info |
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| woneill |
The Projector Fog Lamps are often a complete headlamp assembley containing bulb, reflector, condenser lens etc.
They MIGHT fit, and they might not - it depends on the size of your lamp module, and the size of the lamp. Don't buy anything without seeing it - both in terms of size, and beam profile. Not all projector fog lamps are equal.
If you can put a suitable bulb into your existing module then you have won big time.
Anything else is probably going to dramatically increase the size of your projector...
Bill. |
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| fido13uk |
quote:
i like the looks of this one so far
HTI 400WDE
integrated reflector....now to see more info
cant seem to see that one anywhere:confused:
oh i see it now still a little expensive though dont you think ?
fido |
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| woneill |
Nope... Just check out the lamp life...
:( |
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| fido13uk |
woneill,
if my projector is rated at 450 lumens and 150 watt metal halide lamp, what would you reckon would be the closest alternative lamp rating i would need /
I know 450 lumen sounds low but this projector is much brighter than its rated i can watch this clearly even in bright daylight, it also has very good colour quality too.
fido |
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| woneill |
Hi Fido,
Using anything other than a perfectly optimised optical arrangement (i.e. the original lamp module) will result in light loss.
If you are doing your own bulb and reflector system, you must expect to lose light in an attempt to get an even uniform beam with the right divergence/convergence properties (I would assume parallel).
If you use the same wattage bulb, you will almost certainly get a weaker output than you are used to.
If you try to fit a higher power bulb into the cavity of your original lamp module, you will probably fry something due to the original cooling systems not being designed to handle more than originally expected.
If you go with an external light unit then you might get away with a standard 400 Watt system, or you might be better served with a more esoteric, but smaller 250 watt unit. Generally, the more powerful the bulb, the more space it will take up, and the more cooling it will need. The standard 400 watt lighting bulbs are BIG - the light module you would need to build around it could easily be much bigger than your projector.
For starting from scratch, with a brighter projector, my first instinct would be to explore the track lighting units - you can get some MH bulbs < 250 Watts with a rough parabolic reflector built in. It isn't perfect, but it will save you much effort and wasted light in creating your own. Smaller bulbs also support smaller reflectors...
While the the track lighting modules have matched parts - ballast, ignitor, bulb, and possibly reflector, they are much more expensive than standard lighting units...
In the end, do as much research about what is out there as possible, and then pick an option that works for your desires and abilities - if you are a whizz with powertools, you might want to build your "new" projector into a fancy case anyway!!!
In my case, I am a hardware minimalist, and want to limit box building as much as possible. Unfortunately, I am also a perfectionist. Not compatible.
Bill.
P.S. 450 lumens for a projected image is VERY bright. Most OHP ratings at 2000/4000 are using a transparency. As mentioned earlier, with an LCD panel, you are lucky to be pushing 10% of that - 200/400 lumens. If you were using the projector in a big hall, your image would probably be spread much thinner than if you were projecting on your wall at home. Thus, the latest projectors quote 2000 lumens+. This is not generally necessary for home use. |
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| fido13uk |
thanx for all that info woneill,
I think i may go about building a custom made box for my projector, one thing about if i make myself a custom box would one of the regular 400 watt metal halide setups give me more light than my original if i get the light path correct ? i could build a very closed unit around the the light path thus reducing light escaping.
fido |
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| woneill |
Hi Fido,
Ordinarily, light escaping is not the problem, the problem is getting it to go in the right direction in an orderly manner...
Depending on the quality of your setup, you could end up needing sunglasses, or needing a photomultiplier.
It is all down to how well you get the light to enter the hole left by the original lamp module, and onto the actual LCD panels.
Read the original DIY thread for details of the different attempts tried. My guess is that unless you find a reflector similar to Marklar's, or do something really esoteric - like a sealed box with its inside surfaces completely coated with front-surface reflectors except for a very small exit apeture, (not guaranteed to work at all), you will end up with either less light, or lower contrast.
The standard 400 watt bulbs do not emit with a point source, which means that unless you have a really esoteric reflection system, if you want a perfectly collimated beam, you are going to have to loose a lot of light.
Bill. |
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| fido13uk |
so is it the lumen rating that generates more heat from the bulb or the wattage ?
fido |
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| fido13uk |
would using a parabolic reflector like those in original lamps make the light source go in uniform manner ?
fido |
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| woneill |
Fido,
Though the MH bulbs are more efficient, the higher power the bulb, the more heat it generates - both to touch, and in the form of IR light that transmits the heat to whatever absorbs it.
Lumen ratings are a guide to perceived brightness.
With a pure point source of light, a parabolic reflector will generate a parallel beam of light if the light source is placed at its focal point. The bigger MH lighting bulbs are not point sources of light, and are probably too bulky to get the brightest point of their emitting volume close to the focal point of any reasonably sized parabolic dishes. Even if you could, the output would contain a combination of parallel, diverging and converging rays. If your projector needed parallel rays, then you would need to focus this beam through a diaphragm that could be used to mask off the rays that do not follow the path - causing a loss in light output. This might not be the case, and you might get away with something simple...
Other than Marklar's awesome beast, most reflectors built by the DIY gurus for these bulbs are similar in configuration to the rectangular reflectors used in the external halogen/MV/MH/PS work-lights you can buy at DIY places.
Building the precision ortho-parabolic reflectors needed to make the most out of these bulbs is not the strongest skill of the DIYers here, and so far, a lot of light is being lost...
This is why I suggested the (physically) smaller bulbs designed for other things - they may be more expensive with shorter lives than the bigger MH bulbs, but they are much more usable, and still much cheaper to replace than the official projector bulbs. Also, dependant on the percentage of usable light from these things, you might be able to get a brighter, clearer image from these lower powered bulbs...
Bill. |
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| xblocker |
Fido,
making this external lightsource depends of the size of the lamp, which you should get in to a parabolic reflector. Remember, the lightsource has to be at the focal point of the reflector to get a parallel beam out of it. The aperture of the reflector should of course not extend the size of original lamp. This could be a mechanical problem, to get the lightpoint at the focal point of such a small reflector.
BTW, do you notice any life on LCDpanel without a lamp?
xblocker |
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| fido13uk |
i dont understand life on lcd panel without a lamp ?
I may just sell it as there is 1800 hours lamp life left and i cant really afford the upkeep of these things
fido |
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| xblocker |
fido,
sorry, it was the question, that woneill already asked, did you see the LCDs working without a lamp?
xblocker |
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| eebasist |
Now i have another dead projector to design stuff for.
http://cgi.ebay.com/ws/eBayISAPI.dl...item=1364794572
Its native svga so thats a plus.....now to get the focal length and right type of light......any thoughts
Before I go off the deep end witch project should i work on first
1) 3 panel Proxima DP5100 with canabalized lamp...uses evd bulbs...dimmer than the 250 watt MH that was there
Specs: 640*480 3 panel lcd with 200:1 contrast ratio 16.7m colors, power zoom lens
2)Infocus LightPro 220
http://cgi.ebay.com/ws/eBayISAPI.dl...item=1364794572
Missing bulb and lens assebmly
Specs: 800*600 native....interpolation to 1024*768, 200:1 contrast ratio.
I currently have a 3M 9550 OHP with an infocus TVT3000 LCD 640*480 res that I'm using.......
3) Upgrade LCD panel to a 1024*768 panel. (still have to purchase)
Whats the best option for me guys......wich PJ should i start working on first?
I dont plan on using the correct bulb in any situation...will be a custom job, and i will source a lens from somewhere for the infocus. Where should I spend my time/efforts/money on first |
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| woneill |
eebasist,
Wow, sounds like fun!
I would go after the latest one - just to see if a fix is feasible and to see if you can learn something new.
You might find something in the one you know least about that could change your approach on the other ones you have been working with. e.g. As a result of receiving a couple of projector beam fog lamps yeaterday, I am now currently experimenting with the use of prisms to merge two beams of collimated light into one.
If I can produce something useful, we might be able to get around some of the limitations and lost light resulting from the large size of the big MH bulbs. Then again, we might not...
All learning is good learning! Enjoy!!!
Bill. |
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| remp |
Work on the SVGA model.
I assume the bulb is dead and you are not going to locate a new one and you will no be able to locate a small enough bulb to fit in situ so pull the bulb, reflector and ballast taking great care with the bulb that it does not explode. Face mask and heavy duty leather clothing and gloves is a must. Its very unlikely a cold bulb will explode but dont touch the bulb and dont take any chances. They are under pressure even when cold. The bulb and reflector assembly is probably in a metal enclosure.
There should be a mechanism that tells the projector if the bulb is lit or not . You will need to work out a bypass. Often its just a light activated device like an LDR. Sometimes its a switch contact that only determines if a bulb is in place.
You either have an elliptical reflector or a parallel reflector. either one is based on a point source bulb which you will find expensive so you need an alternative. Most likely it will be a parallel reflector. You might be able to find a larger bulb that will fit inside the reflector. Careful with the original bare bulb.
Initially a car headlamp through a 2 inch hole should give you a rough parallel beam, aim it into the projector where the original light path was and in darkness with luck you can see the white light going to the 1st beam splitter and coming out red blue and green.
When you have finished experimenting cover the unit to keep out dust and dont be tempted to touch any of the adjustment screws.
Overall you will have some difficulty getting a parallel beam of sufficient strenght as original so you will have to use something like a 400 watt metal halide and waste some light to get it going.
Not a bad tradeoff and a lot of fun.
Good luck |
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| fido13uk |
you say put a larger bulb into the reflector:confused: how can you put a 400 watt metal halide bulb in there ?
what is an ldr ? and where would it be located ?
fido |
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| xblocker |
Fido,
in a german HT-forum i have read from a guy, who replaced the original 400w MH lamp with a 250w halogen from a slide projector.
He used the original parabolic reflector and fiddled the socket of the halogen lamp at the reflector. He couldn't bypass the power modul, so he used the complete power section of the slide projector.
The results seem to be good, image is little more reddish, but usable, as he said.
xblocker |
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| fido13uk |
sounds interesting xblocker, so is it possible for me to put in a metal halide bulb with same rating even if i have to fiddle the lamp terminals etc as long as it sits into the lamp module and doesnt petrude out it has a good chance of working ? i have found some metal halide bulbs with same wattage as mine and would be small enough to fit in my projector lamp unit if i modified them slightly would it be pssible to try these as i would assume the worst would be a blown lamp/fuse. also is it bulb wattage or lumen rating that makes them hotter ? and does it matter about the polarity of these bulbs ? i am wanting to find out what voltage my lamps starts at and runs at.... is there any safe way of achieving this without danger of electric shock i guess the start voltage would be way to high to test with a domestic multimeter.
these lamps are very cheap and are rated the same wattage as my original they are also igniter started
or maybe these could be modified also same rating
fido |
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| xblocker |
It may depend of the lamp design to get it into the reflector. If you get the lightpoint at the focus point it should work, but the lamps design should not conflict with the light path. perhaps you should use an additional safety glass between the lamp and the rest(including yourself). And, yes, lamps wattage corresponds with heat. So a 120 UHP lamp is brighter and generates much less heat than a 400w conventional MH lamp. It's the lumen/wattage ratio, which dramatically increase with new technologies, as $$$ increase.
MHs are driven by AC or DC, and as far as i know DC powered lamps should last longer. In every case starting voltage is very high (dangerous!) and should not checked out without basic knowledge and knowing of specifications.
xblocker |
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| fido13uk |
so although the above lamps are much higher in lumen than my original it shouldnt burn anything out considering they are the same wattage ? so how would the extra lumen in these bulbs affect my projector ?
fido |
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| xblocker |
I suppose, if wattage is the same it shouln't burn the projector.
xblocker |
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| fido13uk |
aren,t lumen and ansi the same ?
but what about the much higher lumen will this make my projector better or worse ? |
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| xblocker |
NO,NO,NO!!
Very short: Lumen is the overall brightness of a lamp, ANSI lumen is a measure, defined by SMPTE society to judge projector's brightness on a screen. A screen is diveded by 9 symmetrical parts and each part's brightness is measured. The medium value gives ANSI lumens! The lamps lumen value is of course much more than ANSI can be due to light loss and absorbation.
xblocker |
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| woneill |
Fido,
When you say you would modify the bulbs slightly, what exactly do you mean?
If you are thinking of physically altering them in any way, especially the glass bit, be VERY careful - they are highly pressurised and can explode.
As for running equivalent wattage bulbs with your original ballast, I would listen to Xblockers suggestion about the extra safety glass.
Even if the power ratings are the same, the bulb could be expecting a very different drive signal from the one produced by the ballast. If they are too mismatched, then one or other could smoke, or blow up. Fuses don't always work, especially when connected to the input to the ballast - it might draw the same power, but could still be operating way outside of its safe zone.
Keep a fire extinguisher handy, just in case.
Bill. :eek: |
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| eebasist |
| fido.....do you know the lumen rating or ballast required for those bulbs.....i might be interested in them |
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| fido13uk |
well i telephoned the guy selling these and he only knows the lumen, wattage and he said they run 120 volts which is ideal for my projector:) as thats what my bulb runs at
think i will go ahead and try one of these preferably the tube shaped one as its the closest to my bulb
fido |
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| eebasist |
| Fido, do you know the lumens for the bulb that is running 150 watts? Also did you ask about the bulb position.....not all are universal some must be horizontal or vertical...... |
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| fido13uk |
yes 4000 lumen and the bulbs are vertical he said that they can also be used as a point light source which is why i,m so excited about trying them, i,ve ordered mine online 2day, keeping my fingers crossed though as i would hate for something bad happening to my projector
i suppose some has to be a gunea pig so i,m volunteering
£12.14 uk
metal halide
150 watts
lumen 4000
hours 9000
120 volts running
igniter starting
fido |
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| fido13uk |
just contacted bulbs direct and they have despatched mine today...... what service:) :cool: :cool:
will let u know results if they turn up 2morrow as i will be starting it right away
fido |
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| woneill |
Hi Fido,
Is there a link to these bulbs? You have me VERY interested...
:)
Bill. |
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| woneill |
Re Fido's bulbs,
Ooohhh, nice!!! I've been looking for a decent HQI bulb that does not have a colour temperature of 10,000K, and this could be it!
Most of the ones I have seen are from aquarium suppliers, and they don't tend to do the daylight/warm-white variety.
Thanks!!!
Bill. |
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| NordicNINE |
What type of socket/fixture would you need to hook up that light?
PS- What's the perfect color temp for a projector? Around 4K-5K? |
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| eebasist |
| could go custom and solder onto it.....Dont know the socket offhand though.....email them and find out.....they should know |
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| woneill |
Eebasist,
Having never tried this, I am not sure: These bulbs can get very hot. Can they get hot enough to melt the solder?
Bill. |
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| Invictum |
| woneill, I'm not sure how hot the bulbs get, but I think that your normal solder needs to get to about 400F to melt. There's this other solder with silver added, but my father tells me that you would need a blowtorch to work with it. |
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| fido13uk |
yipee:cool: :) :cool: :) :cool:
good news folk got my bulbs today 3 of em (lightning fast service)..... and after a little modification to the module i,ve got it working and i must say the brightness of these bulbs is a big improvement over my original bulb, and no screen hot spots either with very crisp white light i used the neutral type, the good news is it isnt creating too much heat either i was worried about this at first but i have watched 2 movies continuous i then decided to take out the lamp module and check for scorched interior and it looks fine:)
I have now ordered another 3.
i hope you guys have success with these lamps too, oh i forgot to say i was given some ceramic type cement from a friend and i used this to hold the bulb in place after modifying the hole entrance to the module, damn thing took nearly 2 hours to take out the existing ceramic by tediously scraping at it. but well worth it in the end
someone could be on a fortune wagon here by mass producing these things and dramatically undercutting the big boys
fido ;) :cool: ;) |
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| xblocker |
Gratulation fido! Seems to be a good progress! Do you now use these new bulbs with original projectors powersupply? Have you thought of bringing a temperature sensor into the lighting house?
xblocker |
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| fido13uk |
yes xblocker i use it in my original projector with original power supply.... its awesome aint it :cool:
for those who intend using in there original reflector when placing the bulb make sure the dome part of the filament is at the point source location on the parabolic reflector
@xblocker: how do u mean about the sensor ?
fido |
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| woneill |
| Awesome!!! Well done!!! |
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| xblocker |
fido,
i meant, if you have thought about a temp. sensor for (panels)safety reasons. Or is there already one in the projector, which gives alarm, if temp is to high?
xblocker |
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| fido13uk |
oh i see dunno i,ll maybe look into this as its always good to be safe, i,m over the moon that these bulbs have a lifespan of 9000 hours, i will probs use this as a regular TV now that i know the bulbs wont break the bank. :) :)
and another good thing now is my projector is now 4000 lumen and not 450, and i can really tell in the daylight now the difference in the light its much brighter so i may put a sensor in just in case the lcd panels dont like the new brightness
fido |
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| eebasist |
| Fido, what wattage was your projector before the upgrade? Mine used to be 250 watt, I wouldnt mind loosing 100 watts if it could still be efficient. |
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| xblocker |
fido,
how long did you work to fiddle this new lamp together? What special parts did you need? I'm asking, 'cause some day i will have the same problem! My new projectors lamp (UHP 120W) has only 50 hours now and should last 4000h, but you never know...!
It could explode very unexpected, and a new one costs me 550$, so it may be worth to think about such a solution!
xblocker |
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| fido13uk |
@eebasist,
the wattage is the same as my original 150 which was perfect for me.
@xblocker
as i stated earlier the main problem was chipping out the old ceramic at the base of the reflector which was quite tedious but worth it, However i did have to use a glass drill bit to slightly widen the aperture of the reflector so the the bulb would fit. After that it was just a case of soldering the lamp terminals to the existing ones which at first i was worried about thinking that the heat would melt the solder, but fortunately solder must be able to withstand immense heat as it is still intact....... I keep checking this at intervals to make sure everything is running smoothly, and touch wood up to now it is. :)
fido |
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| fido13uk |
so basically projectors must use the same or very simalar devices to start the bulbs. I guess i must have struck lucky here as even the way the bulb starts is identical to the way it started with my original.
fido |
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| woneill |
Fido,
Yup, and yup!
Projectors often do use similar ignitors to start the bulbs, but not all necessarily the same as this.
If your current drain had been different for the two bulbs, you might have reached a condition where either the bulb, ballast or ignitor burnt out or exploded.
So, you were lucky too. But, who dares, wins!
Enjoy!!!
Bill. |
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| fido13uk |
I guess so woneill :) :)
fido |
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| eebasist |
| Great....too bad i cant find a cheap ballast to use for this project. I was hoping i could get a ballast for 50$, bulb for 30 and be happy, but a 100$ ballast for something that might not work, now that makes me think i should find something that works on 250 watts for the extra money. |
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| woneill |
Eebasist,
Search on the web for HQI ballast manufacturers, and try talking to these people:
http://www.icecapinc.com/methal.htm
They claim their ballast will drive ANY 250 Watt HQI bulb...
Tell them the parameters of the bulb you are looking at, and they might be able to help.
Bill. |
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| fido13uk |
i saw that they have ballasts to drive all 250 watt bulbs, this would be the safest way to go as you know you cant damage your projector this way, may cost a little more but in the long run you will save because you only need to buy the ballast once.
good luck eebasist
fido ;) |
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| eebasist |
| Sounds good to me....now to find a suitable bulb. |
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| fido13uk |
i,m sure osram do HQI type bulb at 250 watt go to and search there site for a suitable bulb. If i come across any i wil let you know eebasist
fido |
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| eebasist |
| Yeah, been to the site...cant open the catalogue from home though. I havent been impressed with the hours on the HQI 250 if i recall correctly. And the cost of the bulb is signifigantly higher than the 150 watt.....but i guess if thats the best i can do |
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| eebasist |
| Well I've searched and am not very impressed with the 250watt specs.....a life of 750 hours just isnt worth it. Anyone know of any other Single ended 250 watt MH bulbs that last a long time and are cheap.......or should I start looking at double ended bulbs and try and make a reflector. BTW how hot is too hot? |
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| NordicNINE |
Anyone know if Home Depot or Menard's carry ballasts or fixtures (like a flood light) for Metal Halide?
They both carry Metal Halide bulbs I know. |
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| eebasist |
| They do, but the selection is awful. |
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| fido13uk |
I would stay with the double ended eebasist they are a good source cheap and last very long
fido:) |
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| NordicNINE |
I was thinking of getting something like this
That way I have the ballast, socket, relector, casing, bulb all.
Uses pretty standard bulbs too. They run about $24 at Home Depot & Menard's and are 36000 lumens and run 10000hrs. |
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| eebasist |
| Yeah i just found out i have to use a double ended bulb. I just have to decide if i need 250 watts or 150. Thats almost a 2x difference in lumens. I've been looking everywhere online....now i need to look at the dimensions. of the box i have.....i need to make sure it will fit. Part of me wants to drill a hole in the projector to fit a mogul based bulb. Who knows |
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| woneill |
NordicNINE,
Floodzilla!!! It's expensive, though... You can get 400 Watt MH setups for half the price! See DIY thread 1.
Eebasist,
Drilling holes is fun, but the problem with the bigger bulbs is finding a suitable reflector.
Bill. |
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| NordicNINE |
Doesn't seem outrageous though.
You're looking at about what $65 for a ballast & socket. $25 for bulb, $10 for reflector. That's $100 total. I don't live near a Home Depot, but I'm going near one tomorrow when I have to go get some PC parts. Do they carry the reflectors, ballasts, etc...? |
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