Cool Running red diodes, mah-han

[pschlosser]

In my ReKe RGB Chi-jector, I am seeing what looks like two (2) 150mW 660nm red diodes combined through a PBS cube.

What gets me, is they are not heat sinked, nor fan cooled. In fact, they are wrapped in a rubber foam and pressed into clamps so they don't rotate.

Are there red diodes that run so cool, we need not worry about over-heating and/or duty cycles?

Where are the limits? Surely a 500mW red diode must be cooled. Does this Rastafarian coolness apply to all the reds? or just specific wavelengths or diode configurations?

 

[cheech226]

i would think some type of sinking would be proper. pics?

 

[pschlosser]

i would think some type of sinking would be proper. pics?

This is not my pic. I pulled it from another post:

See what I mean? The grey material the two reds (combining through the PBS cube) are surrounded by feels like latex. It's spongy and rubbery. And clearly, little heat-sinking is occurring to the optics table.

I suspect they need this to minimize rotation, which would impact efficiency through the cube (hence the P of PBS)

I've not removed them, but the specs claim they're 150mW each.

 

[ARG]

There's only half a watt of heat or so being dissipated by each diode, probably isn't a problem. In the user manual they recommend a 2h duty cycle, should be fine for that.

 

[Things]

How you describe it, sounds kind of like that insulating material you see commonly on heatsinked electronics, like MOSFETs and stuff. Forget what it's called, but it has pretty good thermal transfer if it's the same stuff.

 

[pschlosser]

How you describe it, sounds kind of like that insulating material you see commonly on heatsinked electronics, like MOSFETs and stuff. Forget what it's called, but it has pretty good thermal transfer if it's the same stuff.

oooooohhhhhhhh, really? So maybe heat IS being transferred.

Which in turn, means, I cannot build a red laser diode pointer and throw heat-sinking to the wind, if I choose the right diode and power.

Rats. Just when you think of something no one else is talking about, you find out you're dead wrong.

feeling small.

 

[Meatball]

I believe in they case they also need to electrically isolate the cases from the chassis. Lots of reds diodes are case negative my nature IIRC. Someone correct me on that if I'm wrong.

 

[BShanahan14rulz]

Berquist Silpad

 

[pschlosser]

Berquist Silpad

Ning, ning, ning. We have a winner.

Sil-Pad Products ~ Thermal Materials, Thermal Solutions ~ The Bergquist Company

 

[blasterman]

I have several Reke's and other clones running the bi-reds just like above. Mine however aren't even that nice. The reds are mounted in metal cubes about 3/4 on an inch square with no other heat sinking. Doesn't seem to have a problem after a ~hundred hours of running though. I suspect the two reds are closer to 100 mW though just on visual observation.

Oh yeah, I get a kick out of how the Chinese like to make sure you can't pull the diodes out of their sinks in stuff like this I've tried to remove a few dead diodes from these type of projectors and re-use the sinks and it's next to impossible.

You'd also think it would be easier/cheaper to use a single 200mW 650nm red given how common and cheap they are, but the Reke people like those ~100-150 mW combos, so I suspect they are really cheap.