Meanwell LDD driver: for those who want to dim to 0 using Arduino

[rrasco]

Originally Posted by chema

Do these drivers get very hot when in use? I mean, should they be in open air or may be placed in an enclosed area?

I'll let you know by tomorrow. I have some coming in today so I can retrofit a coralife t5 fixture. I plan on enclosing them. All drivers will get hot to some degree, so we'll see how manageable it is. You could always check the data sheet to see if it says anything about cooling.

[rrasco]

Looking at the data sheet, it says it is cooled by free air convection and has a max case operating temperature of 100*C, which is 212*F. If your enclosure gets that hot, you have other problems.

http://www.meanwell.com/search/LDD-L/default.htm

[bhazard451]

Originally Posted by rrasco

Looking at the data sheet, it says it is cooled by free air convection and has a max case operating temperature of 100*C, which is 212*F. If your enclosure gets that hot, you have other problems.

http://www.meanwell.com/search/LDD-L/default.htm

Mine are going into a project box on top of the heatsink/fixture.

I also got my jarduino from the video up and running last night. The new slider bars for the leds are sweet, and resemble Ecotech's bars. I cant wait to put it all together.

[rrasco]

Right. I was posting that for the guy who asked about how hot they get.

[chema]

[QUOTE=bhazard451;20888831]Mine are going into a project box on top of the heatsink/fixture.

Some pictures showing how you mount the drivers in that project box would be great. I also plan to put them on top of the heatsink

[chema]

[QUOTE=chema;20889728][QUOTE=bhazard451;20888831]Mine are going into a project box on top of the heatsink/fixture.

Some pictures showing how you mount the drivers in that project box would be great. I also plan to put them on top of the heatsink

[rrasco]

These things are so small I might not even mount them. If anything, I might use thermal adhesive to stick them to the enclosure. The ones without leads have pins on the bottom b/c they are meant to be mounted to a PCB, so still trying to figure out what I'm going to do. Guess I could get a proto board, but then I still have to mount that.

[megadeth72]

wish they had these in ~1400ma

[pwreef]

Originally Posted by megadeth72

wish they had these in ~1400ma

To drive what?

[megadeth72]

dreamchip, it peaks out around there

[pwreef]

Driving LEDs at their peak current is really not a great idea. As you approach the top, there is not really that much more light. Also do you realize that when LED emitter gets hotter it's light output is reduced? If you don't have ideal cooling, then you are just wasting both electricity and the life of your LEDs.

[megadeth72]

have cooling taken care of, 1200ma would probably be ok, I dont want to run at peak, I need 3 that can do that, and the other 2 can be 1000ma drivers

[rrasco]

Even with proper cooling, it is a bad idea to run LEDs at max intensity. Not only will you reduce output and emitter life, but you'll probably kill your corals too. I'm killing stuff at 350mA.

[megadeth72]

I'll take that under consideration, I ran a 400w halide over a 20g tank for years, did not kill corals

specs on the led I'm using

60cm air par
700ma = 332 par
1000ma = 486 par
1400ma = 563 par

[pwreef]

Yup its not possible to kill anything with MH because the light spreads out. Put some XM-L or XT-E with 60 degree lenses and you will be bleaching corals left and right. With LEDs its possible to create light that will be even stronger than natural sunlight and cook everything in your tank.

[megadeth72]

milliamps does not mean much unless you clarify what it's going into, personally I've not been impressed with 1 or 3w leds even with lenses, and with 60 the disco is pretty bad unless you mount it high, then the par drops quick. They spread the light out more like vho/pc's, I prefer point source like halide/pendants, with high/hot spots in the tank, just place corals accordingly

par numbers are with my uncalibrated DIY par meter, so subject to change, but for comparison of my own lights it works fine

3 lights I just tested
12x3w 10k bridgelux on my planted tank 60 degree lens, these are 3.7V @700mA chips
50x1 multichip 10-14k ebay special on reef 62 degree lens these are 32-34v @ 1500mA
marineland 18-24 doublebright piece of crap that came with tank

on air the 12x3w is putting out 85 par at 24" using 10k leds the heatsink is a big aluminum thing with a fan, it runs 80 degrees
on air the 50x1w multichip is putting out 220par at 24" it's a 12-14k array the emitter runs 92 degrees at max, and it's using a P4 cpu heatsink
on air the marineland put out 20 par at 24"

I run all of mine at 100 % capacity, I'm not worried about life, and the temps are so low compared to what these can withstand, it's just not a concern of mine

[dread240]

just had 11 ldd-700's show up today (since that's the max current for my bridgelux led's... besides not many people even run cree's past that)

The LED's are in the mail, waiting on some protoboards... got a null modem cable and some pcb mount connectors, some 10 pole screw terminals, and a 48v 350w power supply.

Hope at least the pcb's show up tomorrow, can get the control boards built and waiting for the led's

[rrasco]

Over my 105 I am running two arrays of 36 LEDs each with 60* optics. They are bridgelux 3w varying in color from 4500K, 6500K, 10000K, RB, and Pink. Running them off CAT4101 set with a resistor to limit current to 700mA, their max. I am running whites at 50% and blues (and pink, only 2 per array) at 55%. So 350mA and 385mA respectively. Whites to blues is 2:1. They are 10" AWL on a 21" deep tank.

When I had access to a par meter, I didn't have any optics. They were the 'built-in' optics. At the time, I was getting pretty bad numbers. Ranging from 50-80 at the sand and only about 150-200 at water level. I added 60* optics the next week but unfortunately have not been able to borrow another meter yet. The tank got about 3x brighter though, and it's supporting everything including SPS.

I had the lights running at 45% and 50%, tried bumping them up to 55% and 60%, and it starting bleaching corals. Dropped them back down 5% and am still recovering from that mishap. So basically what I am saying is, be careful with LEDs. What works for one might not work for another, based on tons of variables, especially in DIY systems.

[chema]

Originally Posted by pwreef

PWM- goes to Vin- , PWM+ goes to the DIM pin. This is common design practice not to create extra solder points.

I don't quite understand this. Vin- and Vi+ are not supposed to be hooked to the power supply? Do you connect the Vin- pin of the LDD both to the negative of the power supply and the negative of the controller PWM-?

[rrasco]

Originally Posted by chema

I don't quite understand this. Vin- and Vi+ are not supposed to be hooked to the power supply? Do you connect the Vin- pin of the LDD both to the negative of the power supply and the negative of the controller PWM-?

Sounds about right. They can share a common ground. My PWM signals are always 1 pin from the microcontroller though, so I've never seen this setup before. Ground is a ground though, normally, just not on the output side of the LDD.

[rrasco]

This is my frag tank retro fit with these drivers.

[chema]

Thank you for the picts. The wiring of the LDDs is very clean. Was it difficult to sold the wires to the small pins?

[rrasco]

I didn't find it difficult, but that will depend on your soldering experience.

FWIW, I put a lead on the PWM pin, but didn't connect anything to it so I am running them at max (of the driver) which is 600mA, so they are at 85% of the emitter's max. I am working on another project for a DIY arduino that is fairly cheap, so I might control them via that at a later date. For now, this works with a timer.

I am not running them with optics so I don't kill anything over this small tank.

[chema]

I'm glad to hear that. I had read that it was pretty tricky and that is why I'm very interested in how to mount them in a protoboard. If soldering the wires is not very difficult then they can be placed almost anywhere.

I'm curious about the dimming when you build the arduino.

Congratulations for the setup and the nice tank

[rrasco]

Thanks.

I will follow up with saying it's not technically 'easy', it can be tricky to do, but it's not an insurmountable task. Holding the wire still is the hardest part IMO. If you have not soldered before, it might not be so easy-peasy.