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Should this halogen bulb work off a 24 volt socket?
Looking to power a mini halogen bulb to do film capture. It would be great
if I could power it off the movie projector itself without having to get an additional power supply. The socket for the projector reads slightly over 24v. However, the lamps it uses are 21v. Someone has stated that load is a factor. Does that mean that the voltage needs to be higher than the bulb rating or not necessarily? What I wonder is if this 24v bulb should work off the 24v socket on the projector? http://www.1000bulbs.com/product.php?product=685 Thanks |
Should this halogen bulb work off a 24 volt socket?
HiC wrote: Looking to power a mini halogen bulb to do film capture. It would be great if I could power it off the movie projector itself without having to get an additional power supply. The socket for the projector reads slightly over 24v. However, the lamps it uses are 21v. Someone has stated that load is a factor. Does that mean that the voltage needs to be higher than the bulb rating or not necessarily? What I wonder is if this 24v bulb should work off the 24v socket on the projector? I'd be more concerned about overloading the transformer in the projector myself. Graham |
Should this halogen bulb work off a 24 volt socket?
On Sun, 15 Oct 2006 08:37:01 GMT, "HiC" wrote:
Looking to power a mini halogen bulb to do film capture. It would be great if I could power it off the movie projector itself without having to get an additional power supply. The socket for the projector reads slightly over 24v. However, the lamps it uses are 21v. Someone has stated that load is a factor. Does that mean that the voltage needs to be higher than the bulb rating or not necessarily? The actual no load voltage will almost always be higher than the under-load voltage - unless the power supply is regulated (most movie projectors aren't regulated unless you have a theater projector) Voltage ratings on incandescent bulbs have to be taken with some skepticism. They are usually intended to be "nominal" ratings. For instance, a 12 Volt bulb intended for auto use will spend most of its life working at 13.8 or higher and the people that make the bulbs know that and take it into account. Likewise projectors. The 21 volt bulb may be intended to run at 21 volts or 24 volts - unless you see the manufacturers curves regarding ambient temperature, color temperature of the light, voltage and life expectancy you're just "whistling in the dark." Sometimes a lower voltage bulb is used at a higher voltage - it shortens the life, but puts out more light and puts out higher color temperature light - so color renditioning may be better. Likewise, under load, your 24 volts will almost certainly be lower than 24V. What I wonder is if this 24v bulb should work off the 24v socket on the projector? http://www.1000bulbs.com/product.php?product=685 Thanks Get a 24 V lamp and try it. If you can't live with the color (should be "warmer" -less blue) be happy and expect the lamp to last longer than a 21 V lamp in the same application . ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Should this halogen bulb work off a 24 volt socket?
On Sun, 15 Oct 2006 12:22:14 +0100, Eeyore
wrote: HiC wrote: Looking to power a mini halogen bulb to do film capture. It would be great if I could power it off the movie projector itself without having to get an additional power supply. The socket for the projector reads slightly over 24v. However, the lamps it uses are 21v. Someone has stated that load is a factor. Does that mean that the voltage needs to be higher than the bulb rating or not necessarily? What I wonder is if this 24v bulb should work off the 24v socket on the projector? I'd be more concerned about overloading the transformer in the projector myself. Graham He seems to be implying that the 24 volts is measured output and 21 volts is the proper bulb for the projector - so the voltage under load is expected to be lower. In that case using a 24 volt lamp to replace a 21 volt one will be less strain on the transformer. ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Should this halogen bulb work off a 24 volt socket?
default wrote:
On Sun, 15 Oct 2006 08:37:01 GMT, "HiC" wrote: Looking to power a mini halogen bulb to do film capture. It would be great if I could power it off the movie projector itself without having to get an additional power supply. The socket for the projector reads slightly over 24v. However, the lamps it uses are 21v. Someone has stated that load is a factor. Does that mean that the voltage needs to be higher than the bulb rating or not necessarily? The actual no load voltage will almost always be higher than the under-load voltage - unless the power supply is regulated (most movie projectors aren't regulated unless you have a theater projector) Voltage ratings on incandescent bulbs have to be taken with some skepticism. They are usually intended to be "nominal" ratings. For instance, a 12 Volt bulb intended for auto use will spend most of its life working at 13.8 or higher and the people that make the bulbs know that and take it into account. Likewise projectors. The 21 volt bulb may be intended to run at 21 volts or 24 volts - unless you see the manufacturers curves regarding ambient temperature, color temperature of the light, voltage and life expectancy you're just "whistling in the dark." Sometimes a lower voltage bulb is used at a higher voltage - it shortens the life, but puts out more light and puts out higher color temperature light - so color renditioning may be better. Likewise, under load, your 24 volts will almost certainly be lower than 24V. What I wonder is if this 24v bulb should work off the 24v socket on the projector? http://www.1000bulbs.com/product.php?product=685 Thanks Get a 24 V lamp and try it. If you can't live with the color (should be "warmer" -less blue) be happy and expect the lamp to last longer than a 21 V lamp in the same application . A 24v bulb is likely to be a 28-29v bulb in reality, running this on 21v will give a very poor result. OP needs to tell us if the 24v reading is under load or not. If its with no load, OP needs a 21v bulb, anything else will just be crap. Depending on the type of psu, it may be possible to change the output voltage to suit other bulbs voltage-wise. Whether they will have the right optical situatoin is another matter. NT |
Should this halogen bulb work off a 24 volt socket?
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Should this halogen bulb work off a 24 volt socket?
On Sun, 15 Oct 2006 16:27:06 +0100, in sci.electronics.design Eeyore
wrote: wrote: A 24v bulb is likely to be a 28-29v bulb in reality So how come you can buy 28V bulbs too ? Graham Thats for when you have a 35V supply :-) martin |
Should this halogen bulb work off a 24 volt socket?
You are supposed to underpower the light bulb. Why do you think normal
house light bulbs are 120v when you only have 110v at the outlet. It increases the life of the light bulb. On Oct 15, 9:35 am, martin griffith wrote: On Sun, 15 Oct 2006 16:27:06 +0100, in sci.electronics.design Eeyore wrote: wrote: A 24v bulb is likely to be a 28-29v bulb in reality So how come you can buy 28V bulbs too ? GrahamThats for when you have a 35V supply :-) martin |
Should this halogen bulb work off a 24 volt socket?
default wrote:
On 15 Oct 2006 07:43:59 -0700, wrote: A 24v bulb is likely to be a 28-29v bulb in reality, running this on 21v will give a very poor result. OP needs to tell us if the 24v reading is under load or not. If its with no load, OP needs a 21v bulb, anything else will just be crap. Depending on the type of psu, it may be possible to change the output voltage to suit other bulbs voltage-wise. Whether they will have the right optical situatoin is another matter. NT Then one is "second guessing" the lamp specifications, the manufacturer specifications, and the ops application. Not really. The vast majority of 24v bulbs are for road use, where nominally 24v systems are IRL approx 28-29v. The lamps are designed to run on those systems. I suppose the OP could underpower the bulb as you say, but its not the best option. It should work, but 21v on a 28v bulb will give lousy results. NT |
Should this halogen bulb work off a 24 volt socket?
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Should this halogen bulb work off a 24 volt socket?
"default" wrote in message ... Anyhow the op may be transferring film to video or digital. He states: "Looking to power a mini halogen bulb to do film capture." That could easily mean transferring film to digital (or tape). If it is done via computer he could just as easily adjust the white level / color temp, as fiddle with the hardware. Actually there's a specific reason to use a lower wattage mini-bulb. I need a less powerful lamp to project a useable image through a diffuser and condenser lens and bounce it into the camera with a front surface mirror. Normal projector lamps are too bright. |
Should this halogen bulb work off a 24 volt socket?
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Should this halogen bulb work off a 24 volt socket?
"Meat Plow" wrote in message ... What's the projector capable of delivering in full load watts ? Don't know, I just turned it to "lamp" and put the multi tester leads on it, came up with about 24.2 V. I know the bulbs it uses are rated at 150 w. Actually, that's another thing, how do I know if I can use a much lower wattage lamp without doing damage? Is there some way to tell? Any markings on the electronics of the projector I should look for? |
Should this halogen bulb work off a 24 volt socket?
"HiC" wrote in message ink.net... Actually, that's another thing, how do I know if I can use a much lower wattage lamp without doing damage? Is there some way to tell? Any markings on the electronics of the projector I should look for? Pretty much OK as long as the wattage is say 10% or more of original. |
Should this halogen bulb work off a 24 volt socket?
On Mon, 16 Oct 2006 00:23:52 GMT, "HiC" wrote:
"Meat Plow" wrote in message ... What's the projector capable of delivering in full load watts ? Don't know, I just turned it to "lamp" and put the multi tester leads on it, came up with about 24.2 V. I know the bulbs it uses are rated at 150 w. Actually, that's another thing, how do I know if I can use a much lower wattage lamp without doing damage? Is there some way to tell? Any markings on the electronics of the projector I should look for? If you are going from 150 watts to 10 watts . . . that is much less strain on the transformer and you'd want a 24 volt lamp as opposed to a 21 volt one - the voltage drop due to loading will be less As a general rule, you can always use less current/power safely - It is when you go higher that things tend to smoke. ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Should this halogen bulb work off a 24 volt socket?
On 15 Oct 2006 15:45:18 -0700, wrote:
default wrote: On 15 Oct 2006 07:43:59 -0700, wrote: A 24v bulb is likely to be a 28-29v bulb in reality, running this on 21v will give a very poor result. OP needs to tell us if the 24v reading is under load or not. If its with no load, OP needs a 21v bulb, anything else will just be crap. Depending on the type of psu, it may be possible to change the output voltage to suit other bulbs voltage-wise. Whether they will have the right optical situatoin is another matter. NT Then one is "second guessing" the lamp specifications, the manufacturer specifications, and the ops application. Not really. The vast majority of 24v bulbs are for road use, where nominally 24v systems are IRL approx 28-29v. The lamps are designed to run on those systems. I suppose the OP could underpower the bulb as you say, but its not the best option. It should work, but 21v on a 28v bulb will give lousy results. Here in the states, most cars use 12 volts. I've seen some indication that 42 volts may be in the offing in future cars. There are still a few 6 volt systems around in vehicles. We do have some 24 VAC equipment; it is a popular "control" voltage for relays, valves, HVAC control circuits, etc.. and some lighting . . .. like "landscape","accent" and pathway lights. He's talking about reducing the power used dramatically - so he will have close to 24 volts under load - assuming I'm following all this correctly. ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Should this halogen bulb work off a 24 volt socket?
default wrote:
On Mon, 16 Oct 2006 00:23:52 GMT, "HiC" wrote: "Meat Plow" wrote in message ... What's the projector capable of delivering in full load watts ? Don't know, I just turned it to "lamp" and put the multi tester leads on it, came up with about 24.2 V. I know the bulbs it uses are rated at 150 w. Actually, that's another thing, how do I know if I can use a much lower wattage lamp without doing damage? Is there some way to tell? Any markings on the electronics of the projector I should look for? If you are going from 150 watts to 10 watts . . . that is much less strain on the transformer and you'd want a 24 volt lamp as opposed to a 21 volt one - the voltage drop due to loading will be less As a general rule, you can always use less current/power safely - It is when you go higher that things tend to smoke. ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- A 10 watt lamp is not going to like the much higher transfomer output, any transformer, not loaded with 150 watts will output quite some more than 24 volts. (if the loaded voltage at 150W is 24.2) |
Should this halogen bulb work off a 24 volt socket?
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Should this halogen bulb work off a 24 volt socket?
"Sjouke Burry" wrote in message . .. A 10 watt lamp is not going to like the much higher transfomer output, any transformer, not loaded with 150 watts will output quite some more than 24 volts. (if the loaded voltage at 150W is 24.2) It's a a 20 watt bulb I'm looking to power. Might go higher if I don't find the light bright enough. Don't know if that makes a difference. |
Should this halogen bulb work off a 24 volt socket?
HiC wrote:
"Sjouke Burry" wrote in message . .. A 10 watt lamp is not going to like the much higher transfomer output, any transformer, not loaded with 150 watts will output quite some more than 24 volts. (if the loaded voltage at 150W is 24.2) It's a a 20 watt bulb I'm looking to power. Might go higher if I don't find the light bright enough. Don't know if that makes a difference. 20w 24v bulb should be fine. Ditto 35 or 50w 24v. NT |
Should this halogen bulb work off a 24 volt socket?
default wrote:
Here in the states, most cars use 12 volts. I've seen some indication that 42 volts may be in the offing in future cars. There are still a few 6 volt systems around in vehicles. We do have some 24 VAC equipment; it is a popular "control" voltage for relays, valves, HVAC control circuits, etc.. and some lighting . . . like "landscape","accent" and pathway lights. He's talking about reducing the power used dramatically - so he will have close to 24 volts under load - assuming I'm following all this correctly. No cars run on 12v, theyre 13-15v systems called 12v for historical reasons. 24v nominal or 28-29v real is standard voltage for truck electrical systems, which is what nearly all 24v bulbs are for, hence theyre really 28v bulbs. I thought 24v was the off load supply voltage... but I accept its not 100% clear. NT |
Should this halogen bulb work off a 24 volt socket?
HiC wrote: Actually there's a specific reason to use a lower wattage mini-bulb. I need a less powerful lamp to project a useable image through a diffuser and condenser lens and bounce it into the camera with a front surface mirror. Normal projector lamps are too bright. How about a neutral grey filter? I was origianlly going to write a warning about testing the new bulb arrangement before using it on unreplaceable film, to check for melting or scorching of the film. However, if you are going to a lower power bulb, and it survives, you shouldn't have that problem. Another worry: Are you planning to stop the film at each frame to capture the image? If so, beware of overheating the film. In normal use, each frame of the film spends a short time stopped for projection(1/24 second, is that right?) and is only illuminated for a portion of that time. |
Should this halogen bulb work off a 24 volt socket?
"Richard Henry" wrote in message ups.com... How about a neutral grey filter? I was origianlly going to write a warning about testing the new bulb arrangement before using it on unreplaceable film, to check for melting or scorching of the film. However, if you are going to a lower power bulb, and it survives, you shouldn't have that problem. Another worry: Are you planning to stop the film at each frame to capture the image? If so, beware of overheating the film. In normal use, each frame of the film spends a short time stopped for projection(1/24 second, is that right?) and is only illuminated for a portion of that time. Some projectors dropped in a metal shield with small holes punched in it for still frame projection. |
Should this halogen bulb work off a 24 volt socket?
Homer J Simpson spake thus:
"Richard Henry" wrote in message ups.com... Another worry: Are you planning to stop the film at each frame to capture the image? If so, beware of overheating the film. In normal use, each frame of the film spends a short time stopped for projection(1/24 second, is that right?) and is only illuminated for a portion of that time. Some projectors dropped in a metal shield with small holes punched in it for still frame projection. My old Hell & Bowel Filmosound has a neat little fail-safe "trap door" shield like that; a little perforated aluminum screen that's blown aloft by the fan so it's normally out of the way. If the fan ever fails for some reason, the screen drops into the light path. -- "In 1964 Barry Goldwater declared: 'Elect me president, and I will bomb the cities of Vietnam, defoliate the jungles, herd the population into concentration camps and turn the country into a wasteland.' But Lyndon Johnson said: 'No! No! No! Don't you dare do that. Let ME do it.'" - Characterization (paraphrased) of the 1964 Goldwater/Johnson presidential race by Professor Irwin Corey, "The World's Foremost Authority." |
Should this halogen bulb work off a 24 volt socket?
default wrote:
On 15 Oct 2006 15:45:18 -0700, wrote: default wrote: On 15 Oct 2006 07:43:59 -0700, wrote: A 24v bulb is likely to be a 28-29v bulb in reality, running this on 21v will give a very poor result. OP needs to tell us if the 24v reading is under load or not. If its with no load, OP needs a 21v bulb, anything else will just be crap. Depending on the type of psu, it may be possible to change the output voltage to suit other bulbs voltage-wise. Whether they will have the right optical situatoin is another matter. NT Then one is "second guessing" the lamp specifications, the manufacturer specifications, and the ops application. Not really. The vast majority of 24v bulbs are for road use, where nominally 24v systems are IRL approx 28-29v. The lamps are designed to run on those systems. Aircraft use 28V but I've never seen a 24V car, they're all 12V aside from very old 6V cars. |
Should this halogen bulb work off a 24 volt socket?
"James Sweet" wrote in message news:f0YYg.4599$5v5.2097@trndny08... Aircraft use 28V but I've never seen a 24V car, they're all 12V aside from very old 6V cars. IIRC many trucks use 24 volts. http://www.cb-shack.com/shop/index.php?cPath=81 |
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