Hello, I know this has been discussed before but I have a few questions.
I picked up a Sharp Notevision DLP projector with a dead ballast and no lamp for $10 (1024x768 Native) and a 100W LED array and driver for $7.
I have the ballast control bypassed and the projector works (I put a small 9LED flashlight in the bulb compartment and was able to project a visible 10" Image in a dark room, so I know that part works. My question is of heat, The spec sheet for the LED gave an operating temp of -20~+120C, I attached the LED with some arctic silver to a CPU heat sink and fan and placed a thermometer at the center of the LED itself and it stabilizes at around 146C, (an infrared thermometer reads over 160C but maybe the light is fooling it?) I know this will shorten the life of the LED but will it really be an operation issue? (the LED wont catch fire will it?) The other issue I had was with the color wheel, currently I do not have a reflector or lens on the LED but if I did will I risk damaging the color wheel? And last If I did want to reduce the power of the array could I put a PWM SSR between the LED and the Driver or will this damage the Driver (I think it is a CC Driver)? I dont think PWM on the Driver would work as it has works down to 80V AC or so. Thanks
-Brad
I picked up a Sharp Notevision DLP projector with a dead ballast and no lamp for $10 (1024x768 Native) and a 100W LED array and driver for $7.
I have the ballast control bypassed and the projector works (I put a small 9LED flashlight in the bulb compartment and was able to project a visible 10" Image in a dark room, so I know that part works. My question is of heat, The spec sheet for the LED gave an operating temp of -20~+120C, I attached the LED with some arctic silver to a CPU heat sink and fan and placed a thermometer at the center of the LED itself and it stabilizes at around 146C, (an infrared thermometer reads over 160C but maybe the light is fooling it?) I know this will shorten the life of the LED but will it really be an operation issue? (the LED wont catch fire will it?) The other issue I had was with the color wheel, currently I do not have a reflector or lens on the LED but if I did will I risk damaging the color wheel? And last If I did want to reduce the power of the array could I put a PWM SSR between the LED and the Driver or will this damage the Driver (I think it is a CC Driver)? I dont think PWM on the Driver would work as it has works down to 80V AC or so. Thanks
-Brad
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Hi wyteNoyes, 160C is way to much heat, try to use a quality CPU Cooler, a simple Intel CPU Cooler was not enough even for a CREE 10W LED in my case, or go with water cooling, it won't catch fire but the solder could melt and short the LED, the color wheel will be ok, it's made of glass and the coating is heat resistant, the heat from the LED is not even 10% of what the projector is used to. At 100W of power I would not recommend any type of resistor, even if you try to take 10% off the load on the LED you have 10W to dissipate and that is allot of heat. So let the LED as is, try to get better cooling, use a lens and a reflector to get more light and you should be fine.
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