DIY LEDs - The write-up

[ddwbeagles]

Since this seems to be the general LED thread, anyone having any luck finding a 10V power supply for the meanwells? I know I can step down a 12V, but would prefer just to buy a regulated 10V power supply if they are out there. Any leads would be great. Thanks in advance.

 

[SWINGRRRR]

Since this seems to be the general LED thread, anyone having any luck finding a 10V power supply for the meanwells? I know I can step down a 12V, but would prefer just to buy a regulated 10V power supply if they are out there. Any leads would be great. Thanks in advance.

Ive got a lead on some. They are 10V 700mA WW for Yamaha keyboards. But my local guitar center does not open till 11am, in 2 hours here.
Google "Yamaha PS03"


If you get your hands on one, just check it before you hook it up. Ive never had a WW output exactly what it says. I have a 12V at the house that puts out 16V!!!!!

 

[adova]

I am confused - I thought the Meanwells (I was planning to use teh ELN-60-48D) had an input of 100 - 240v. Is there a different meanwell that people are using that requires a power supply?

 

[TheFishMan65]

Thie 10 volts is for the dimming circuit of some meanwells. The AC is for powering the LEDs.

 

[SWINGRRRR]

I am confused - I thought the Meanwells (I was planning to use teh ELN-60-48D) had an input of 100 - 240v. Is there a different meanwell that people are using that requires a power supply?

It takes 110 from the wall, but it has a seperate dimming circuit that requires =<10V to turn it on.

 

[adova]

Crap - more homework to do

 

[SWINGRRRR]

Crap - more homework to do

Ehhh, its not hard. AC brown and blue to 110 from the wall. Use an extension cord. It doesnt matter how you hook these up since its non-polar specific. Then on DC side, red to + on first LED, then black to - on last LED. Blue to + on Dim circuit, - to white. Done. You can use a 9V battery hooked to blue/white to test. A 10V WW just provides the dim curcuit with power to turn on the LED's. I keep trying to think of a good anaology of the dim circuit, but I cant.

 

[der_wille_zur_macht]

For people "afraid" of soldering up a voltage regulator or other totally-diy solution for manual dimming, you can get adjustable DC-DC power supplies from most of the hobby electronics stores out there. This one is a little pricey and way more robust and feature-laden than what we "need" but it would do the trick. From Adafruit Industries:

http://www.adafruit.com/index.php?main_page=product_info&cPath=38&products_id=184

Plug in a wall wart outputting anything above 10.5v, set it to "adjustable", and you can dim your LEDs. Just be sure not to go over 10v. As with other adjustable supplies, you might want to set it to 10v, leave the internal adjustment alone, then use a pot on the output to do the actual dimming.

 

[adova]

Is there anything else that makes up the dim circuit other than a radioshack potentiometer?

 

[der_wille_zur_macht]

Is there anything else that makes up the dim circuit other than a radioshack potentiometer?

For which driver?

For a buckpuck, all you need is a pot.

For the Meanwell ELNs, you need to bring your own juice to the party (i.e. a 10v voltage source that you're then either cutting down with a pot or other analog circuit or PWM'ing with a microcontroller).

 

[adova]

Gotcha - yea, I was referring to a driver. So dimming circuit is just a power source (above 10v) and a pot, or a power source that has built in voltage adjustment. That should do it, thanks!

Shawn

 

[der_wille_zur_macht]

Gotcha - yea, I was referring to a driver. So dimming circuit is just a power source (above 10v) and a pot, or a power source that has built in voltage adjustment. That should do it, thanks!

Shawn

Yes, assuming you have the D-type meanwell ELNs. The P-type, should, in theory, be fed a PWM signal, not an analog signal.

Whatever you come up with, just be sure it can't "accidentally" go over 10v, and check it's output with a multimeter - don't trust the sticker on a wall wart to be 100% accurate.

 

[SWINGRRRR]

So dimming circuit is just a power source (above 10v)

10V is max power, so you want below 10V and below!!!

 

[adova]

Ideally, I would guess that I want it exactly at 10v, but I get it.

Is it reasonable to have one power source to power all of my dimming on the meanwells? i.e., I am going to have 6 MW for the royals and 6 for the whites - could I run one 10v for all 6 so I can dim together? Do amps come into play here?

 

[Jay1982]

Ok so I called them and they are pretty nice people. I'll probably be ordering from them. But now I've been looking at compaing XR-Es to XP-Gs. I know the XPGs are considered more efficient and brighter. If I switched my CW XREs to XPGs how many less CW LEDs would I need assuming I would want the same output from my original plan of 80 LEDs (45 Royal Blue and 35 CW)? Or does it not work like that and I still need the same amount but run them at a lower intensity?

 

[der_wille_zur_macht]

Is it reasonable to have one power source to power all of my dimming on the meanwells? i.e., I am going to have 6 MW for the royals and 6 for the whites - could I run one 10v for all 6 so I can dim together? Do amps come into play here?

Completely reasonable. The meanwells draw very very little current on the DIM circuit so you can probably run as many as you'd ever care to off the same signal source.

Ok so I called them and they are pretty nice people. I'll probably be ordering from them. But now I've been looking at compaing XR-Es to XP-Gs. I know the XPGs are considered more efficient and brighter. If I switched my CW XREs to XPGs how many less CW LEDs would I need assuming I would want the same output from my original plan of 80 LEDs (45 Royal Blue and 35 CW)? Or does it not work like that and I still need the same amount but run them at a lower intensity?

XP-G are about 30% more efficient than XR-E so you can use that as a rough guide. But, they also have a slightly wider viewing angle, so the light they produce is a little more spread out, which makes it seem like not as much of a jump in intensity as it really is (unless you're using optics, in which case it depends on the particular optic.)

Personally, for new DIY rigs, I wouldn't consider XR-E cool whites unless I got them dirt dirt cheap or was building a really small rig for a nano and the difference didn't matter.

 

[fstar25]

Looking for some people to weigh in on the following layout for my LEDs.

They are going over a 29g biocube. I will have dimming control of all the blues one channel and the whites together on another.

The whites will be higher bin (not exactly sure yet) Cree XPG. The blues are Cree XRE (D14D3 bins).

Let me know what you think.

I just noticed, I only colored one open space as dark gray. all of the spaces that have boxes are potential locations for the stars. The heatsink is basically a 9x6 grid. with 6 spaces from front to back of the tank and 9 spaces on each row going across the tank

 

[der_wille_zur_macht]

fstar, with no optics, spacing and patterns become a little less critical - what you have should be totally fine.

 

[Jay1982]

Personally, for new DIY rigs, I wouldn't consider XR-E cool whites unless I got them dirt dirt cheap or was building a really small rig for a nano and the difference didn't matter.

So would you say that I could easily do with 45 XRE RBs and 25 XPG CWs? Bringing my total LED count from 80 to 70. I plan on using 40 degree optics.

Thanks DWZM

 

[der_wille_zur_macht]

Yeah, depending on mounting height that would probably be OK. With optics in the 40 degree range you really don't want to be close to the water if you can help it - you'll have spotlighting unless you up your LED count to increase coverage.