Isolution IMove 50s LED

[Chris_k]

Evening all.

 

 

Im in the process of fixing some imove 50s moving heads. I need a replacement main LED for the fixture.

Its branded as a Phlatlight, made by Luminus and is allegedly 50w. I've been on to Prolyte, they can get the leds but dont know when.."Maybe in 12 weeks"!!

Does anybody know a replacement that's available?

After much searching on the internet ive found this My link that I think would work. Its available from mouser My link for less than half of what Prolyte want for one (assuming its the right one)

Has anybody worked on these fixtures before? Any help muchly appreciated.

http://i118.photobucket.com/albums/o116/chris_k_album/PhlatlightLED_zps2e13dc3b.jpg

[KevinE]

are you aware that there is a firmware upgrade for some of these imove LED lights to stop them burning the LEDs out?

[Chris_k]

mmmm no I didnt. Is it available from Prolyte?

On previous burntout leds ive seen theres usually a darkend part of the led. None on here though.

Are these the same lights as the IMG Stageline twist? They look similar. What do you recon about the replacement?

[KevinE]

I havent seen one of those LEDs like that but fitting something else in its place will necessitate checking how it's driven and at what level. Usually they are constant-current pwm driven from a small switching regulator, and will soon die if not driven or cooled properly.

All I can tell you about the mod is that one of our clients had a large number of these and they kept burning the led's out until, according to the client, a 'modified prom' was fitted. The downside was that it made the fixtures dimmer.

[timsabre]

I've designed several products with this LED. It is an unusual LED in that it requires a very high current, at a low voltage (most LEDs have a big stack of emitters grouped together, all in series, and take a high voltage, 36V or so, at a lowish current say 700mA or 1A).

 

You will not find an equivalent to this LED, and Luminus Devices have really really long lead times - The Mouser part is the same LED so if they have them in stock, go for it, but if they don't have stock, be prepared to wait an indefinite number of weeks for it.

[gyro_gearloose]

I don't think the LED on Mouser is quite the right one. Either that or the imove manufacturer has seriously over-stated the Wattage of the LED! :) The Mouser LED needs 3.15A at 3.25V, making its power consumption just over 10 Watts. That's a long way off the 50 Watts that the imove claims to have.

[timsabre]

It is the right one. You can drive them up to 13.5A, but they are just about impossible to keep cool at that current, presumably the reason for failure. And a constant current supply providing 13.5A at about 3.5V is not a fun thing to design either.

[gyro_gearloose]

You can drive them up to 13.5A, but they are just about impossible to keep cool at that current, presumably the reason for failure.

Then whoever designed the imove deserves a slap upside the head! Especially when you consider that there are brighter Phlatleds available which might have stood up better to being over driven.

[timsabre]

You can drive them up to 13.5A, but they are just about impossible to keep cool at that current, presumably the reason for failure.

Then whoever designed the imove deserves a slap upside the head! Especially when you consider that there are brighter Phlatleds available which might have stood up better to being over driven.

 

They aren't overdriving them, I think they just aren't cooling them properly. If you look at the extremes Varilite have gone to in their fixtures that use this LED, with copper heat pipes everywhere, I think you can see where the problem might be... The brighter LEDs are really really expensive. I think some value engineering has gone on here.

 

Interesting side issue, I thought the imove lights were all chinese made, but the Luminus parts are only available from Luminus in the USA. So is this LED a Luminus Devices copy made in China?

[gyro_gearloose]

They aren't overdriving them, I think they just aren't cooling them properly.

In that case the OP should get the LED from mouser, and then start reading up on the techniques that PC overclocking modders use to improve the efficiency of their heatsinks. Lapping the surface of the heatsink to get a perfectly flat surface, and using a very thin layer of good quality heatsink compound will help keep the LED cool. Thats about all you can do without getting into complex modifications to the cooling system, such as a better heatsink, possibly with heatpipes, or by adding water cooling somehow. Good luck with the last one :)

 

Interesting side issue, I thought the imove lights were all chinese made, but the Luminus parts are only available from Luminus in the USA. So is this LED a Luminus Devices copy made in China?

I'm surprised they didn't go with a Bridgelux emitter. They are cheaper and brighter than the Phlatlight LEDs, and they use a higher voltage/lower current power supply. The only issue would be whether the imove has condensing optics, or not. While both LEDs would benefit from condensing optics, the Bridgelux needs it more than the Phlatlight as its emitter is much bigger.

[KevinE]

I see many chinese LED fixtures at the 'value for money' end of the market fail just outside warranty, usually. Overdriving an LED looks impressive for a short period of time.

A small heatsink and a high speed fan is great until the cheap fan fails and the heatsink overheats. But it's cheaper than packing the light with aluminium or copper isn't it.

I wouldn't like to say if the OP's fixtures fall into that category though. :D

[Chris_k]

Evening.

 

Ive just taken another of the imoves in and bust her open to give a bit of detail about the cooling arrangements.

The led itself is made on a fairly chunky piece of copper. This is mounted onto the heat sink (ali) with transfer paste and is covered by this lens.

http://i118.photobucket.com/albums/o116/chris_k_album/20140219_221921_zpsb301facb.jpg

To the left of the lens is the temperature sensor.

This is the rear of the heat sink where the fan bolts on.

http://i118.photobucket.com/albums/o116/chris_k_album/20140219_222408_zps84133e64.jpg

 

To be fair to the lights they have soldiered on. They are from a bar/club which is open 5 nights a week and haven't been touched for 2 years.

Between the fan and the heat sink on all the lights had what can be best described as a small dogs worth of fluff. The lights were working for around 15 mins and then overheating. The temp sensor has been doing its job and turning the led off. When it does it ramps up the fan speed to aid cooling.

 

Im gonna take a gamble with the led from mouser. Ill post back with the results.

[KevinE]

tried to insert image

[paulears]

A lot of the Chinese factory seem to be using American LED assemblies, and making it a selling feature. Interesting that it's better to import them than produce them themselves? Strange isn't it.

[timsabre]

A lot of the Chinese factory seem to be using American LED assemblies, and making it a selling feature. Interesting that it's better to import them than produce them themselves? Strange isn't it.

 

It is quite challenging to make those very high power LEDs. The Chinese are very good at copying but not very good at actual design/engineering and I think they probably do not know how to make them, yet.