retsain Posted March 26, 2012 Share Posted March 26, 2012 I what to ask somebody" about the theory of lamp sensor" it looks like a LED ,besides in a lamp of coemar I spot 575 moving heads. I though it is defective but I am concern of what its meaning'' from cebu philippines. Link to comment Share on other sites More sharing options...
gyro_gearloose Posted March 26, 2012 Share Posted March 26, 2012 The reason it looks like and LED is because it is an LED :) As well as emitting light LEDs can also be used to detect light, which is its being used inside your moving head. It is used to check whether the lamp has struck or not. Link to comment Share on other sites More sharing options...
timsabre Posted March 26, 2012 Share Posted March 26, 2012 The reason it looks like and LED is because it is an LED :) As well as emitting light LEDs can also be used to detect light, which is its being used inside your moving head. It is used to check whether the lamp has struck or not. Sorry, this is complely not true (well the first bit anyway). You cannot detect light with an LED.It will be a phototransistor or photodiode, which just happens to be in the same package as an LED. If you get a lamp sensor error, it normally means the fixture is detecting the lamp being lit when it isn't supposed to be. This either means the sensor is faulty, or the lamp relay/triac is stuck on. Link to comment Share on other sites More sharing options...
gyro_gearloose Posted March 26, 2012 Share Posted March 26, 2012 Sorry, this is complely not true (well the first bit anyway). You cannot detect light with an LED.Sorry, this is completely not true. :) Here's some free knowledge. Enjoy Link to comment Share on other sites More sharing options...
timsabre Posted March 26, 2012 Share Posted March 26, 2012 Sorry, this is complely not true (well the first bit anyway). You cannot detect light with an LED.Sorry, this is completely not true. :) Here's some free knowledge. Enjoy{link from Wikipedia saying researchers have used LEDs as light detectors) Errr... ok ... well that's a new one on me. I guess it's one of those things that only works in the research lab, or everyone would be doing it. But let's not confuse our poster from the Philippines, in the real world, nobody uses LEDs for detecting light, his light sensor will be a blue/black coloured photodiode or phototransistor. Link to comment Share on other sites More sharing options...
gyro_gearloose Posted March 27, 2012 Share Posted March 27, 2012 in the real world, nobody uses LEDs for detecting lightPlease tell me exactly how you know this. his light sensor will be a blue/black coloured photodiode or phototransistor.You clearly don't know what you are talking about. It will be a clear LED. I know this because I've worked on Coemar iSpot fixtures. Take a look inside a moving head some time and you'll see LEDs used as light detectors. Lots of manufacturers do it. The idea that LEDs can be used as light detectors has been around since the seventies, though people tend to forget that LEDs are fundamentally photodiodes and can be used in place of one. Getting back to the OPs question, I can confirm that it will be an LED as I've serviced many Coemar iSpot fixtures. The LED is on a small board with a thermistor, and this board is mounted near to the lamp. The most common problem with the LED is that the plastic will degrade under the intense heat/UV given off by the discharge lamp. A new one will be clear, and if yours isn't it may be damaged. Link to comment Share on other sites More sharing options...
timsabre Posted March 27, 2012 Share Posted March 27, 2012 Ok, clearly I do not know what I am talking about. I bow to your experience of the product in question. Link to comment Share on other sites More sharing options...
retsain Posted July 26, 2012 Author Share Posted July 26, 2012 in the real world, nobody uses LEDs for detecting lightPlease tell me exactly how you know this. his light sensor will be a blue/black coloured photodiode or phototransistor.You clearly don't know what you are talking about. It will be a clear LED. I know this because I've worked on Coemar iSpot fixtures. Take a look inside a moving head some time and you'll see LEDs used as light detectors. Lots of manufacturers do it. The idea that LEDs can be used as light detectors has been around since the seventies, though people tend to forget that LEDs are fundamentally photodiodes and can be used in place of one. Getting back to the OPs question, I can confirm that it will be an LED as I've serviced many Coemar iSpot fixtures. The LED is on a small board with a thermistor, and this board is mounted near to the lamp. The most common problem with the LED is that the plastic will degrade under the intense heat/UV given off by the discharge lamp. A new one will be clear, and if yours isn't it may be damaged. thank you very much sir'''' ''god bless you" Link to comment Share on other sites More sharing options...
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