LED Lights - anybody taken them apart?

[MikeO]

Shocked there's no thermal paste between the LEDs and heatsink, or mechanical fixing for that matter (relying on the reflector assembly it seems).


- Outsider
Via Tapatalk on iPhone.

The small screws fix the reflector to the inner metal plate. The reflector is plastic, so the heat presumably transfers through the metal plates to the body and then to the main heat sink which screws to the back of the lamp (the fluted part in this picture)...

 

[stever1]

DUH, whats all this talk about heat ?. I thought LED's didn't produce heat due to being magic.

 

[MikeO]

Heat is produced at the rear of the LED, rather than the light-source...

 

[Outsider]

Yep, the heat is generated at the die and is conducted away through the metal backed carrier (stars in this case). There should be thermal paste between all mating surfaces else the thermal path has too much thermal resistance and the LEDs overheat, shortening their life.
Perhaps that's what happened. How long did they run for before packing up?


- Outsider
Via Tapatalk on iPhone.

 

[MikeO]

Yep, the heat is generated at the die and is conducted away through the metal backed carrier (stars in this case). There should be thermal paste between all mating surfaces else the thermal path has too much thermal resistance and the LEDs overheat, shortening their life.
Perhaps that's what happened. How long did they run for before packing up?

I'm not sure on this one. One only lasted an hour or so - others were OK for a few weeks.

There is a white paste on the front of the backing plate...

...which has been spread about by my rotating the plate from the back when I was trying to work out how to disassemble it all.

When I come to rebuild, any idea what I need to use and where I can get it?

 

[Outsider]

Cool, didn't spot that there.
Any PC supply place should have a small syringe of white or silver paste. Sometimes called heatsink compound. The same stuff you put between your PC processor and it's heatsink. Arctic something-or-other is a brand name.


- Outsider
Via Tapatalk on iPhone.

 

[Fanum]

Cool, didn't spot that there.
Any PC supply place should have a small syringe of white or silver paste. Sometimes called heatsink compound. The same stuff you put between your PC processor and it's heatsink. Arctic something-or-other is a brand name.


- Outsider
Via Tapatalk on iPhone.

Yup......what he said.

If you or anyone you know has ever upgraded a CPU on a computer, there's a good chance they will have a tiny foil envelope (2cm-ish square) with a smidgeon of the stuff in it

You can use silicone or molybdenum grease if you have any kicking around.....the almost dry stuff on the lid will do it