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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
Posted to sci.electronics.design,sci.electronics.repair
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Converting video projectors to LED lamp ?
Like the ink-jet printer nonsense. Loads of nominally working video
projectors around where the lamp has worn out after its 1000 to 2000 hours and a complete new projector is a little more than the cost of a replacement discharge lamp . Anyone done a conversion to high power LED emitter lamp? tips/pitfalls ? Obviously a number of opto-coupler functions need fudging as well as disconnecting the original lamp supply and HV ignitor sub-circuit lamp supply input side optos , ignitor-on , lamp on, half/full brightness output side optos , ignitor cct ok, lamp on (drawing correct current) confirmation Perhaps should only consider projectors that allow colour temperature setting within the menu structures any other considerations? I just saw reference to this LED lamp cluster , anyone sen the spec of the beam angle for it http://www.ledengin.com/news-events/2012-08 |
#2
Posted to sci.electronics.design,sci.electronics.repair
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Converting video projectors to LED lamp ?
"N_Cook" wrote in message ... Like the ink-jet printer nonsense. Loads of nominally working video projectors around where the lamp has worn out after its 1000 to 2000 hours and a complete new projector is a little more than the cost of a replacement discharge lamp . Anyone done a conversion to high power LED emitter lamp? tips/pitfalls ? Obviously a number of opto-coupler functions need fudging as well as disconnecting the original lamp supply and HV ignitor sub-circuit lamp supply input side optos , ignitor-on , lamp on, half/full brightness output side optos , ignitor cct ok, lamp on (drawing correct current) confirmation Perhaps should only consider projectors that allow colour temperature setting within the menu structures any other considerations? I just saw reference to this LED lamp cluster , anyone sen the spec of the beam angle for it http://www.ledengin.com/news-events/2012-08 Don't even bother. It is totally impossible to retrofit an off the shelf LED 'light engine' into the existing projector optics. You *will* be wasting your time. The original short-arc, ultra-high pressure mercury or metal halide lamps will have lumen outputs typically 20-30x the best you could achieve with an LED 'cluster'. Even if you got the lumens from the LEDs, the optical source 'dimensions' would be far too massive for the existing lens system to focus on. The thermal issues would be 'interesting' too as you would be looking at at least 200W of LED to achieve anything like the original screen brightness, even with an optical system matched to the larger LED source. JB |
#3
Posted to sci.electronics.design,sci.electronics.repair
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Converting video projectors to LED lamp ?
JB wrote in message ...
"N_Cook" wrote in message ... Like the ink-jet printer nonsense. Loads of nominally working video projectors around where the lamp has worn out after its 1000 to 2000 hours and a complete new projector is a little more than the cost of a replacement discharge lamp . Anyone done a conversion to high power LED emitter lamp? tips/pitfalls ? Obviously a number of opto-coupler functions need fudging as well as disconnecting the original lamp supply and HV ignitor sub-circuit lamp supply input side optos , ignitor-on , lamp on, half/full brightness output side optos , ignitor cct ok, lamp on (drawing correct current) confirmation Perhaps should only consider projectors that allow colour temperature setting within the menu structures any other considerations? I just saw reference to this LED lamp cluster , anyone sen the spec of the beam angle for it http://www.ledengin.com/news-events/2012-08 Don't even bother. It is totally impossible to retrofit an off the shelf LED 'light engine' into the existing projector optics. You *will* be wasting your time. The original short-arc, ultra-high pressure mercury or metal halide lamps will have lumen outputs typically 20-30x the best you could achieve with an LED 'cluster'. Even if you got the lumens from the LEDs, the optical source 'dimensions' would be far too massive for the existing lens system to focus on. The thermal issues would be 'interesting' too as you would be looking at at least 200W of LED to achieve anything like the original screen brightness, even with an optical system matched to the larger LED source. JB The active window for the colour wheel / light tunnel is usually of the order 10 mm diameter. At least with a single LED cluster you can direct the majority of its light into that 10mm aperture. Compared to discharge lamp , not point source, reflected off non ideal dicroic reflector with an open-end diameter of the lamp reflector 60mm or larger, how much of the discharge lamp light gets to the 10mm active window and how much is wasted. ? Off-the shelf current generation of manufacured projectors with LED lamp sources rated 200 lumens are sufficiennt for 6 foot diagonal screens in dim not dark rooms,(room-light level where you can just read a book) |
#4
Posted to sci.electronics.design,sci.electronics.repair
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Converting video projectors to LED lamp ?
"N_Cook" wrote in message ... JB wrote in message ... "N_Cook" wrote in message ... Like the ink-jet printer nonsense. Loads of nominally working snip The active window for the colour wheel / light tunnel is usually of the order 10 mm diameter. At least with a single LED cluster you can direct the majority of its light into that 10mm aperture. Not of homogenous white light you can't. Compared to discharge lamp , not point source, reflected off non ideal dicroic reflector with an open-end diameter of the lamp reflector 60mm or larger, how much of the discharge lamp light gets to the 10mm active window and how much is wasted. ? These short arc HID lamps with integral ellipsoidal dochroic reflectors are about as efficient as it is possible to get for this type of application. when you have a bare arc-tube producing 25-35kLm, who cares that your optical efficiency is typically 40%. You simply can't get a better source which can provide this level of lumen output. Off-the shelf current generation of manufacured projectors with LED lamp sources rated 200 lumens are sufficiennt for 6 foot diagonal screens in dim not dark rooms,(room-light level where you can just read a book) Comparing apples with oranges. A 200Lm (source lumens) LED projector is in no way comparable to the output of an HID projector. I'm not on a rant here! I'm trying to save you time and money and considerable frustration. I have been working in the lighting industry designing luminaires, lamps, and optics for over 30yrs and beleive it or not, have gained some valuable experience in this time. JB |
#5
Posted to sci.electronics.design,sci.electronics.repair
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Converting video projectors to LED lamp ?
On 25/9/2012 5:53 PM, N_Cook wrote: Like the ink-jet printer nonsense. Loads of nominally working video projectors around where the lamp has worn out after its 1000 to 2000 hours and a complete new projector is a little more than the cost of a replacement discharge lamp . Anyone done a conversion to high power LED emitter lamp? tips/pitfalls ? Obviously a number of opto-coupler functions need fudging as well as disconnecting the original lamp supply and HV ignitor sub-circuit lamp supply input side optos , ignitor-on , lamp on, half/full brightness output side optos , ignitor cct ok, lamp on (drawing correct current) confirmation Perhaps should only consider projectors that allow colour temperature setting within the menu structures any other considerations? I just saw reference to this LED lamp cluster , anyone sen the spec of the beam angle for it http://www.ledengin.com/news-events/2012-08 More specs at http://www.ledengin.com/products/emitters/#LZ9 But 1300 lumens is still a long way from a typical video projector. eg the NEC NP64 is supposed to put 3000 lumens on the screen, that includes all the optical losses along the way. -- Regards, Adrian Jansen adrianjansen at internode dot on dot net Note reply address is invalid, convert address above to machine form. |
#6
Posted to sci.electronics.design,sci.electronics.repair
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Converting video projectors to LED lamp ?
Adrian Jansen wrote in message
eb.com... On 25/9/2012 5:53 PM, N_Cook wrote: Like the ink-jet printer nonsense. Loads of nominally working video projectors around where the lamp has worn out after its 1000 to 2000 hours and a complete new projector is a little more than the cost of a replacement discharge lamp . Anyone done a conversion to high power LED emitter lamp? tips/pitfalls ? Obviously a number of opto-coupler functions need fudging as well as disconnecting the original lamp supply and HV ignitor sub-circuit lamp supply input side optos , ignitor-on , lamp on, half/full brightness output side optos , ignitor cct ok, lamp on (drawing correct current) confirmation Perhaps should only consider projectors that allow colour temperature setting within the menu structures any other considerations? I just saw reference to this LED lamp cluster , anyone sen the spec of the beam angle for it http://www.ledengin.com/news-events/2012-08 More specs at http://www.ledengin.com/products/emitters/#LZ9 But 1300 lumens is still a long way from a typical video projector. eg the NEC NP64 is supposed to put 3000 lumens on the screen, that includes all the optical losses along the way. -- Regards, Adrian Jansen adrianjansen at internode dot on dot net Note reply address is invalid, convert address above to machine form. I still cannot find the half-power beam angle. It 15 degrees fine but if 120 degrees then back to all the optics losses business |
#7
Posted to sci.electronics.design,sci.electronics.repair
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Converting video projectors to LED lamp ?
On Tue, 25 Sep 2012 13:29:47 +0100, "JB" wrote:
"N_Cook" wrote in message ... JB wrote in message ... "N_Cook" wrote in message ... Like the ink-jet printer nonsense. Loads of nominally working snip The active window for the colour wheel / light tunnel is usually of the order 10 mm diameter. At least with a single LED cluster you can direct the majority of its light into that 10mm aperture. Not of homogenous white light you can't. Compared to discharge lamp , not point source, reflected off non ideal dicroic reflector with an open-end diameter of the lamp reflector 60mm or larger, how much of the discharge lamp light gets to the 10mm active window and how much is wasted. ? These short arc HID lamps with integral ellipsoidal dochroic reflectors are about as efficient as it is possible to get for this type of application. when you have a bare arc-tube producing 25-35kLm, who cares that your optical efficiency is typically 40%. You simply can't get a better source which can provide this level of lumen output. Wow, a 400 W arc lamp. That is the rating and power input for that many lumens for HID lamps. That lamp must power large screen movie theater projectors. YCLIU Off-the shelf current generation of manufacured projectors with LED lamp sources rated 200 lumens are sufficiennt for 6 foot diagonal screens in dim not dark rooms,(room-light level where you can just read a book) Comparing apples with oranges. A 200Lm (source lumens) LED projector is in no way comparable to the output of an HID projector. I'm not on a rant here! I'm trying to save you time and money and considerable frustration. I have been working in the lighting industry designing luminaires, lamps, and optics for over 30yrs and beleive it or not, have gained some valuable experience in this time. JB I am not believing it. ?-) |
#8
Posted to sci.electronics.design,sci.electronics.repair
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Converting video projectors to LED lamp ?
On Wed, 26 Sep 2012 09:16:24 +0100, "N_Cook" wrote:
Adrian Jansen wrote in message web.com... On 25/9/2012 5:53 PM, N_Cook wrote: Like the ink-jet printer nonsense. Loads of nominally working video projectors around where the lamp has worn out after its 1000 to 2000 hours and a complete new projector is a little more than the cost of a replacement discharge lamp . Anyone done a conversion to high power LED emitter lamp? tips/pitfalls ? Obviously a number of opto-coupler functions need fudging as well as disconnecting the original lamp supply and HV ignitor sub-circuit lamp supply input side optos , ignitor-on , lamp on, half/full brightness output side optos , ignitor cct ok, lamp on (drawing correct current) confirmation Perhaps should only consider projectors that allow colour temperature setting within the menu structures any other considerations? I just saw reference to this LED lamp cluster , anyone sen the spec of the beam angle for it http://www.ledengin.com/news-events/2012-08 More specs at http://www.ledengin.com/products/emitters/#LZ9 But 1300 lumens is still a long way from a typical video projector. eg the NEC NP64 is supposed to put 3000 lumens on the screen, that includes all the optical losses along the way. -- Regards, Adrian Jansen adrianjansen at internode dot on dot net Note reply address is invalid, convert address above to machine form. I still cannot find the half-power beam angle. It 15 degrees fine but if 120 degrees then back to all the optics losses business Due to the physics of the bare LED, about 45 to 60 degrees. With the fancy lens maybe 20 to 30 degrees, but that is a WAG. ?-) |
#9
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Converting video projectors to LED lamp ?
josephkk wrote in message
news On Wed, 26 Sep 2012 09:16:24 +0100, "N_Cook" wrote: Adrian Jansen wrote in message web.com... On 25/9/2012 5:53 PM, N_Cook wrote: Like the ink-jet printer nonsense. Loads of nominally working video projectors around where the lamp has worn out after its 1000 to 2000 hours and a complete new projector is a little more than the cost of a replacement discharge lamp . Anyone done a conversion to high power LED emitter lamp? tips/pitfalls ? Obviously a number of opto-coupler functions need fudging as well as disconnecting the original lamp supply and HV ignitor sub-circuit lamp supply input side optos , ignitor-on , lamp on, half/full brightness output side optos , ignitor cct ok, lamp on (drawing correct current) confirmation Perhaps should only consider projectors that allow colour temperature setting within the menu structures any other considerations? I just saw reference to this LED lamp cluster , anyone sen the spec of the beam angle for it http://www.ledengin.com/news-events/2012-08 More specs at http://www.ledengin.com/products/emitters/#LZ9 But 1300 lumens is still a long way from a typical video projector. eg the NEC NP64 is supposed to put 3000 lumens on the screen, that includes all the optical losses along the way. -- Regards, Adrian Jansen adrianjansen at internode dot on dot net Note reply address is invalid, convert address above to machine form. I still cannot find the half-power beam angle. It 15 degrees fine but if 120 degrees then back to all the optics losses business Due to the physics of the bare LED, about 45 to 60 degrees. With the fancy lens maybe 20 to 30 degrees, but that is a WAG. ?-) ++++ As that light source can be placed within 2 or 3 mm of the apertured mask over the rotating colour wheel then sounds promising. If like a short arc lamp , has to be set back 50 to 80mm then that 20 to 40 degrees would be a no-no I've seen a powerpoint presentation via one of these http://www.acerdirect.co.uk/Acer_K11...I_lumens_EY.K2 801.001/version.asp in a dim but not dark room and was perfectly acceptable, allowing for the poorish resolution. Certainly not a jokey gimmick gadget |
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