Woneill, with the light projecting itself back on the bulb is a sure-fire way to risk bulb rupture......it is very common in projectors that a mirror image reflected on itself (bulb) will very quickly destroy the bulb
Yup definitely with a bulb that has a high IR output (halogen etc.).
For the MH bulbs, I don't know.
What I was wondering about was whether you could run a halogen bulb at maybe 0.10 to 0.25 of its rated power, and still get the light output without things going up in a puff of smoke...
Bill.
For the MH bulbs, I don't know.
What I was wondering about was whether you could run a halogen bulb at maybe 0.10 to 0.25 of its rated power, and still get the light output without things going up in a puff of smoke...
Bill.
woneill said:
OK. That's what I was originally thinking. I have a fresnel from an old 3M projector for that purpose.
To prevent filaments (halogen etc.) from burning by reflected light from spherical reflectors, the bulb has to be slightly shifted from the middle of sphere's center! So the reflected filament image lays not ON, but BESIDE the real filament. Most manuals of halogen OHP and slide projectors give advice incl. pics to do that.
xblocker
xblocker
Remp, Xblocker,
Unlike the stuff in the other thread, this IS one of my whacked out theories: I was thinking along the lines of recycling the unused energy by actually reflecting it back directly onto the filament.
If the bulb were powered only at, say, 20%, and only 20% of the light energy was used - with 80% being reflected back onto the filament - then would it be feasible to suppose that the filament would glow to its full brightness & colour temp?
😕
Bill.
Unlike the stuff in the other thread, this IS one of my whacked out theories: I was thinking along the lines of recycling the unused energy by actually reflecting it back directly onto the filament.
If the bulb were powered only at, say, 20%, and only 20% of the light energy was used - with 80% being reflected back onto the filament - then would it be feasible to suppose that the filament would glow to its full brightness & colour temp?
😕
Bill.
Woneill
You are considering the case where you reflect the filament directly on top of the real filament with the idea that running the bulb under powered the reflection will add to the original, and you will save on your power account.
An ingenious idea. Halogens can be underpowered but MH I do not know if the ballast can do that. I think in your situation I would use an ordinary household lamp for a quick test. Probably even a flat mirror will give you some idea. Maybe running at 20% power will not be sufficient. More likely 50% but see what you think.
Have you access to a slide projector. They often use the reflected filament (side by side) but it would be a simple matter to reduce power to the bulb and overlay the reflection by adjustment in reflector support. Note before and after colour temperature and lumens output. Not out of the projector because their optics will be set for side by side operation, but out of the bulb in an area coresponding to forward going light beams. But you could get a rough idea straight out of the projector.
I used one time an ordinary magifying glass to see the imaged filament on a nearby screen but that was coming out of the projector optics.
You are considering the case where you reflect the filament directly on top of the real filament with the idea that running the bulb under powered the reflection will add to the original, and you will save on your power account.
An ingenious idea. Halogens can be underpowered but MH I do not know if the ballast can do that. I think in your situation I would use an ordinary household lamp for a quick test. Probably even a flat mirror will give you some idea. Maybe running at 20% power will not be sufficient. More likely 50% but see what you think.
Have you access to a slide projector. They often use the reflected filament (side by side) but it would be a simple matter to reduce power to the bulb and overlay the reflection by adjustment in reflector support. Note before and after colour temperature and lumens output. Not out of the projector because their optics will be set for side by side operation, but out of the bulb in an area coresponding to forward going light beams. But you could get a rough idea straight out of the projector.
I used one time an ordinary magifying glass to see the imaged filament on a nearby screen but that was coming out of the projector optics.
Hi remp,
Hmmm. I HAD bought a slide projector for $10 on ebay (+$20 shiping...), but UPS stitched me up, and it got sent back without me ever getting a chance to pick it up.
I think I should re-explore what happened... Time to order that Variac too...
My idea is less about being "green", though than about reducing heat and associated cooling efforts... I'm lazy... 🙄
Bill.
Hmmm. I HAD bought a slide projector for $10 on ebay (+$20 shiping...), but UPS stitched me up, and it got sent back without me ever getting a chance to pick it up.
I think I should re-explore what happened... Time to order that Variac too...
My idea is less about being "green", though than about reducing heat and associated cooling efforts... I'm lazy... 🙄
Bill.
Woneill,
Projectors and side by side filaments was discussed in part 1 video projector thread.
Searchword
slide
slide and projector
"slide projector"
One of them should work.
Projectors and side by side filaments was discussed in part 1 video projector thread.
Searchword
slide
slide and projector
"slide projector"
One of them should work.
Remp,
Yup, I remember reading the section during my month long odyssey through the first thread.
That's actually one of the things that triggered me to wonder about the power recycling concept. The other was the polarization issue, which at some point, I will feel compelled to explore (my knowledge of the finer points of polarization, polarizing filters, and polarizing reflectors, is still rather sketchy...)
I've just got past the fun of playing with prisms - wow, they are both fun and weird... But, one of the implications of Xblocker's find of the Xenon lamp array was that it nullified any obvious reason to merge multiple beams into one...
Bill.
Yup, I remember reading the section during my month long odyssey through the first thread.
That's actually one of the things that triggered me to wonder about the power recycling concept. The other was the polarization issue, which at some point, I will feel compelled to explore (my knowledge of the finer points of polarization, polarizing filters, and polarizing reflectors, is still rather sketchy...)
I've just got past the fun of playing with prisms - wow, they are both fun and weird... But, one of the implications of Xblocker's find of the Xenon lamp array was that it nullified any obvious reason to merge multiple beams into one...
Bill.
dukane image pro 7010
i just got a dukane image pro 7010 supposedly the same as some othere projectors, max screen size around 230in and 300 ansi lumens.... no bulb, i was wondering if its possible to use other types of bulbs in this... i dont care if i cant use the original power suupply and ballast im comfortable with electronics, soldering, etc.... i have an ancient overhead projector with some type of light that is VERY bright, now this overhead is broken, and i doubt this is the type of light they use today this ohp is probabally from the 70s, and the original bulb is still good. so this sounds like a good choice to me, it seems as bright as some mh ive seen and im wondering if it is a mh.... its about 2 inches long with kind of a ball and a pointed glass thing at the end, the filament is a twirled spring so it appears, it is sitting above a dish type reflector, really about the size of a spoon, if i removed all electronics would this be a good bulb type for my new projector, also ive been told my new lcd powers up without bulb, but if not does anyone know how to circumvent that? one more t hing the OHP is a 3m and its brown. i wouldnt mind using a large MH light and ballast if this would be better too, but im sure i would have to devise some way to get a beam from a separate box that i would have to build into the projector as the size of 250s and 400s are pretty large compared to projector bulbs, thats my ultimate goal but at first the ohp bulb would be great for tv 🙂 any tips comments and people bitching about my confused post are welcome
thanks
one more thing i have about 8-10 feet throw distance should i be able to get a 100in picture (size of my screen) if not how big will i be able to go
i just got a dukane image pro 7010 supposedly the same as some othere projectors, max screen size around 230in and 300 ansi lumens.... no bulb, i was wondering if its possible to use other types of bulbs in this... i dont care if i cant use the original power suupply and ballast im comfortable with electronics, soldering, etc.... i have an ancient overhead projector with some type of light that is VERY bright, now this overhead is broken, and i doubt this is the type of light they use today this ohp is probabally from the 70s, and the original bulb is still good. so this sounds like a good choice to me, it seems as bright as some mh ive seen and im wondering if it is a mh.... its about 2 inches long with kind of a ball and a pointed glass thing at the end, the filament is a twirled spring so it appears, it is sitting above a dish type reflector, really about the size of a spoon, if i removed all electronics would this be a good bulb type for my new projector, also ive been told my new lcd powers up without bulb, but if not does anyone know how to circumvent that? one more t hing the OHP is a 3m and its brown. i wouldnt mind using a large MH light and ballast if this would be better too, but im sure i would have to devise some way to get a beam from a separate box that i would have to build into the projector as the size of 250s and 400s are pretty large compared to projector bulbs, thats my ultimate goal but at first the ohp bulb would be great for tv 🙂 any tips comments and people bitching about my confused post are welcome
thanks
one more thing i have about 8-10 feet throw distance should i be able to get a 100in picture (size of my screen) if not how big will i be able to go
shr00m,
If your bulb has a filament and is as bright as a MH, then it is probably a quartz halogen.
The ones in OHP units generally have a life measured in 10s of hours - so don't be TOO surprised if it doesn't survive the transplant... (They are often cheap, though 🙂 )
The reflector you describe is probably designed to operate in the way described by Xblocker a couple of posts back in this thread. As such, it will produce a fairly even diverging beam, intended to be collimated by a couple of fresnels.
In your case, if you are intending to use this bulb to drive one of the 3-panel projectors that would normally have a light module, you will probably need to produce a smaller cross-section parallel beam, instead. This may be achievable by using your reflector and a lens of suitable diameter & focal length, or by using a parabolic reflector (car headlamp size). (If you go the car headlamp variety, you should look for one with "pencil beam" characteristics to get as close as possible to a parallel beam.)
Beware - halogen bulbs generate more heat per watt than MH, and emit a much higher IR content. You may need to do something to protect the LCD panels from this heat/IR. This could be something as simple as using an IR blocker, a cold mirror, or some other such filter. It does need to be included in the design, though...
Bypassing the projector light detectors can be an art in itself. Some will not power up the main electronics unless there is a signal from the bulb drive unit to say all is ok. Others have (possibly many) switch interlocks that also need to be fooled into thinking that all is as was intended.
The ones that use a LDR or photocel should not pose problems if your replacement light is suitable, because it will drive them the same way the original bulb would...
As for zoom, that is down to the focal length of your objective lens...
Bill.
If your bulb has a filament and is as bright as a MH, then it is probably a quartz halogen.
The ones in OHP units generally have a life measured in 10s of hours - so don't be TOO surprised if it doesn't survive the transplant... (They are often cheap, though 🙂 )
The reflector you describe is probably designed to operate in the way described by Xblocker a couple of posts back in this thread. As such, it will produce a fairly even diverging beam, intended to be collimated by a couple of fresnels.
In your case, if you are intending to use this bulb to drive one of the 3-panel projectors that would normally have a light module, you will probably need to produce a smaller cross-section parallel beam, instead. This may be achievable by using your reflector and a lens of suitable diameter & focal length, or by using a parabolic reflector (car headlamp size). (If you go the car headlamp variety, you should look for one with "pencil beam" characteristics to get as close as possible to a parallel beam.)
Beware - halogen bulbs generate more heat per watt than MH, and emit a much higher IR content. You may need to do something to protect the LCD panels from this heat/IR. This could be something as simple as using an IR blocker, a cold mirror, or some other such filter. It does need to be included in the design, though...
Bypassing the projector light detectors can be an art in itself. Some will not power up the main electronics unless there is a signal from the bulb drive unit to say all is ok. Others have (possibly many) switch interlocks that also need to be fooled into thinking that all is as was intended.
The ones that use a LDR or photocel should not pose problems if your replacement light is suitable, because it will drive them the same way the original bulb would...
As for zoom, that is down to the focal length of your objective lens...
Bill.
people arent going to do your work for you shroom!
http://www.projectorcentral.com/projection_calc.cfm
familiarize yourself with the threads. Dont just come here and expect to have everyone tell you the answers that you could find by reading.
I don't mean to rant, but you need to read and go the the usual websites to learn and not just expect information to be handed out to you.
If you see a fillament in the bulb it is most likely not a MH bulb. One other thing is if you design around a bulb you can't buy cheaply, you put yourself into the same situation a year from now or less
http://www.projectorcentral.com/projection_calc.cfm
familiarize yourself with the threads. Dont just come here and expect to have everyone tell you the answers that you could find by reading.
I don't mean to rant, but you need to read and go the the usual websites to learn and not just expect information to be handed out to you.
If you see a fillament in the bulb it is most likely not a MH bulb. One other thing is if you design around a bulb you can't buy cheaply, you put yourself into the same situation a year from now or less
i dont expect it to be handed to me, i mean i wouldnt have really posted if there was ANY type of organization here... not to rant but you cant deny it.... the search feature doesnt work to well any there are THOUSANDS of posts to read through that arent sorted... i apoligize though, thanks for the info
I think the only reasonable way to search the bigger thread was to format it for printing as a single page, and search that...
Woneill
Thats one way, but due to the length of the part 1 projector thread it takes 4 years to arrive if using a modem and you have to do that each session for searching but you can save the source code and strip web coding so is available on your own compter as text, but the search facilities provided here are effective if you get the search word(s) right and has the advantage of high speed. Presume there are other ways to save and search but I find the on line searching very useful.
Xblocker provided much information re slide projectors so search
slide and xblocker
gave many posts
Look at diy video projector part one date 05-19-2002 and before for text and pictures.
Thats one way, but due to the length of the part 1 projector thread it takes 4 years to arrive if using a modem and you have to do that each session for searching but you can save the source code and strip web coding so is available on your own compter as text, but the search facilities provided here are effective if you get the search word(s) right and has the advantage of high speed. Presume there are other ways to save and search but I find the on line searching very useful.
Xblocker provided much information re slide projectors so search
slide and xblocker
gave many posts
Look at diy video projector part one date 05-19-2002 and before for text and pictures.
I've taken the plunge and bought an ellipsoidal stage light. I'll let you guys know how it works out. If its as good as I hope it will give me a superbright image.
dukane imagepro 7010
hello, i have just received my dukane imagepro 7010 i was wondering if anyone could give some info on how to circumvent the lamp check, im sure this model doesnt use just a light sensor, there is a door check relay to make sure the lamp door is closed, but ive closed this and shined a light inside the projector and the lamp light still comes on, can anyone provide any info on how to get around this... easiest way possible, if its a relay i can do that, bt is there anyway to fake something being hooked up to the power, IE something like a electric motor that would allow power to pass through... anything just someone please help and get me going in the right direction
hello, i have just received my dukane imagepro 7010 i was wondering if anyone could give some info on how to circumvent the lamp check, im sure this model doesnt use just a light sensor, there is a door check relay to make sure the lamp door is closed, but ive closed this and shined a light inside the projector and the lamp light still comes on, can anyone provide any info on how to get around this... easiest way possible, if its a relay i can do that, bt is there anyway to fake something being hooked up to the power, IE something like a electric motor that would allow power to pass through... anything just someone please help and get me going in the right direction
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