DIY LEDs - The write-up

[rpp]

GDominy thanks for information. I'll have 6 Meanwells so I prefer to use 2 dim ports instead of 3 especially that I'm planning 2 controlable Tunze pomps and right now I have only "standard" Profilux (4 available L ports).

And as I see I'll use EVG-AP-2F to be sure that power is totally cutted. As I understand I can connect to this board 2 sets of Meanwell (in each set 3 supplies). Through this board I set only dim signal or also power cords? (never saw this board).

 

[old_mr2]

more pics for those interested. Feel ree to leave a comment :frog:

 

[GDominy]

GDominy thanks for information. I'll have 6 Meanwells so I prefer to use 2 dim ports instead of 3 especially that I'm planning 2 controlable Tunze pomps and right now I have only "standard" Profilux (4 available L ports).

And as I see I'll use EVG-AP-2F to be sure that power is totally cutted. As I understand I can connect to this board 2 sets of Meanwell (in each set 3 supplies). Through this board I set only dim signal or also power cords? (never saw this board).

This board allows you to connect your dimming leads and your mains power to the ballasts/drivers. Here is a picture of the module:

Its very easy to wire!

I think you "should" be able to connect 3 Meanwells to each dimming channel, but as we mentioned ealier its best to measure the mA draw to be certain. I'll give this a whirl this weekend, my epoxy just arrived so I can start my own build!

 

[stugray]

old_mr2,

It looks like you have slots in the top of those heatsinks.

In fact, it looks like you have lengthwise slots AND slots that run perpendicular to those.

Finally, it looks like you centered a few of those LEDs directly over the intersection of the slots.

Sorry, but that is the worst thing to do as the hottest part of the star is not touching perfectly flat aluminum.

It might be fine, but you should measure the LED junction temperatures after running for a few hours.

I assume that you used thermal epoxy?

Stu

 

[kcress]

you should measure the LED junction temperatures after running for a few hours.

Make that 30 minutes.

 

[old_mr2]

Thanks for the feedback!

Yes they have all been epoxyed. I wasnt aware that the small grooves would be an issue as the epoxy would have filled in any gaps (the grooves arent even .5mm deep)

The horizontal lines are just black marker and they are not grooves.

I have noticed the heatsinks are quite hot after a couple of hours. I am thinking about running a small fan over the heatsinks. Your thoughts>?

 

[jusmee]

Thanks for the feedback!

Yes they have all been epoxyed. I wasnt aware that the small grooves would be an issue as the epoxy would have filled in any gaps (the grooves arent even .5mm deep)

The horizontal lines are just black marker and they are not grooves.

I have noticed the heatsinks are quite hot after a couple of hours. I am thinking about running a small fan over the heatsinks. Your thoughts>?

How hot? A quick calc on thermal resistance - XR-E LEDs for example have a chip to solder point resistance of 8 deg/Watt and allowing 1 more degree for the MCPCB and heatsink coupling - at 3 watts, that's 27 degrees. This means that the temperature of the heatsink just near the LEDs can rise to 150-27 = 123 degC before the chip is in danger (max temp allowed is 150).

That's above boiling, so the spit test applies. Wet your finger and touch it, it is doesn't go phzzt, then it is OK. Only OK however, and they may well last longer if run cooler, so, yes put a fan on there if you desire

 

[Mmckibben]

i use 21 cree xpgs and 60 degree optics.

 

[Mmckibben]

oh, i forgot to mention i use a multi voltage power supply that is compatible with profilux.

 

[rpp]

Did anyone anodized heatsink? I want to make it in black colour but don't know if this process will have any impact on cooling process (especially bad impact)

 

[kcress]

Black anodizing increases a heat sink's ability.

Normally you get the heat sink anodized you don't do it yourself as it gets expensive in low quantities.

Chances are good that your system won't notice any difference either way.

 

[stugray]

"Black anodizing increases a heat sink's ability."

Yes as far as radiative heat goes, but it reduces the ability to conduct heat.

Therefore, the best heatsink would be anodized then the anodization sanded off where the LEDS attach.

Stu

 

[Norahsdad]

what is the high bin number you guys keep talking, about the cree's being better with a high bin number?
thanks Glen

 

[laverda]

This board allows you to connect your dimming leads and your mains power to the ballasts/drivers. Here is a picture of the module:

Its very easy to wire!

I think you "should" be able to connect 3 Meanwells to each dimming channel, but as we mentioned ealier its best to measure the mA draw to be certain. I'll give this a whirl this weekend, my epoxy just arrived so I can start my own build!

GDominy
That board looks like a clean way to connect things up. Is that 2 resistors between everything? If so what are they there for? Where did you get them and how much where they?

 

[pheinzig]

Got a question about a splash guard.
Since acrylic warps, I was going to do a 1/2" thick Acrylic splash guard to make it a heavy duty splash guard/protector. How bad will the light diffusion be through that?

 

[kcress]

Is that 2 resistors between everything?

Negatory. Those are relays.

 

[jusmee]

what is the high bin number you guys keep talking, about the cree's being better with a high bin number?
thanks Glen

Bin numbers let you select LEDs that have more light output per watt. Even LEDs of the same type very in the amount they produce, so bin numbers let you pick one with the desired output. Mostly, we look for lot's of light so high bin numbers.

 

[laverda]

Negatory. Those are relays.

Ok Do you know how they are wired exactly? I assume they cut the power to the drivers 100 percent, but wondering how. I will be using aquacontrollers to control my lights, but they only have 2 wires 0-10V for each channel. I see their are 6 controller connections, so maybe this is not suitable for use with the Aquacontroller.

 

[pheinzig]

Check this control box I made:

Left room for the second box that will control the other half of my array when I finish it:

Looks cool so far. I can dim 4 banks: 2w+2b independently, and monitor the voltage for an accurate power reading. I can mix and match as I see fit to make some rad color schemes:

Now I just need help choosing the right thickness on my acrylic splash guard. is 1/2" too thick?

 

[kcress]

Ahhh nice build pheinzig!

Splash guard should not be more than 1/4". Any more is a waste. If it won't be trapped in a moist air location 1/8 would work.

Remember the fastest aging of LEDs is heat around their lenses. Make sure you don't stagnate the air flow around them with the splash guard.