Question on LED build

[bblumberg]

Hi everyone,

I have a question regarding lighting for my new 150g (60 x 24 x 24) build. Based on my good experience with LEDs in my 24g nanocube (RapidLED retrofit) and my 75g corner tank (custom array of 52 LEDs in the RapidLED 6 x 20" enclosure), I am planning another LED build.

My current plan is to use 3 x 120w COB units from AC-RC hobby like this one
http://ac-rc.net/catalog/product_info.php?products_id=240&osCsid=s1j31vlnlj9a07edb93dij2p17
which has 5 channels running at 700 ma each and 31-36v. I plan to use 90 degree optics. These will be controlled from an Apex and I am planning on connecting them such that I have 5 channels total with each Apex channel controlling one channel of the 3 lights.

My question concerns what is the best way to drive/power these. In my limited experience, there are at least two straightforward options.

option 1 = use 3 boards each with 5 LDD-H drivers and either 3 corresponding power supplies (48v 5a) or one larger capacity power supply (48v 15a). In this scenario, each light would be powered separately, but controlled together by the Apex using a PWM converter. This will cost ~$275 for the driver/power supply/converter grouping, plus a pretty good size box to house it all and quite a few wires to manage.

option 2 = use 5 Meanwell dimmable drivers (maybe ELN-60-48D?), one for each channel of 3 lamps wired together in parallel. In this case, the lamps would run lower than their rated maximum amperage since these drivers max out at 1.3A. This will cost ~$160 for the drivers and also be a much tidier package all in all. It seems to me that wiring the lamps in parallel would be the best way to go here, running the lamps at less than their maximum amount of amps. Probably less light overall, but since it is unlikely that I will run any of these channels at 100%, probably not a huge problem.

Am I missing something important here? That is, are there other, better ways to accomplish what I am trying to do? Perhaps different drivers for option 2 that allow more drive current? I am no electronics expert, but I can handle simple wiring, soldering etc.

Alan at AC-RC Hobby has been very helpful. They sell JRTronic power supplies and drivers. I have used Meanwell in the past. Is one brand preferable to the other?

Depending on the performance of these lights in growing my corals (mixed reef, SPS dominant), I may fill in front and back of them with T5 retrofit kits, but thought I'd start with these and see how it goes.

Thanks for your advice,

 

[theatrus]

Link just asks me to sign in, but I think I see which one you're talking about.

My suggestion is pretty consistent: never run LED channels in parallel. You'll never truly balance them out, and burn a bunch of power in power resistors trying.

Meanwell has a series of high voltage drivers in the HLG-XXH-C700 range (the B variant accepts PWM/analog dimming), such as http://www.mouser.com/ProductDetail/Mean-Well/HLG-80H-C700B/ or http://www.mouser.com/ProductDetail/Mean-Well/HLG-120H-C700B/

These will output a ton of volts at 700mA which will let you string multiple channels in series.

Warning: there is very high voltage from driver anode to driver cathode. If you are not comfortable working with mains level voltages, do not use this driver. Do not work on the LED system in an energized state. Lockout the power before attempting repairs or adjustments. Use proper rated wiring.


As for power supplies, are they UL / CSA / TUV / ETL listed? CE is not a sufficient rating for basically anything. All Meanwell AC/DC supplies are, and its an important consideration when dealing with AC circuits.

(The HLG supplies mentioned above are not end-consumer friendly so they carry the RU rating from UL and not the main UL logo. This is likely because their output voltage is too high to certify and they don't have a standard AC cord or IEC plug. The mains power safety rating is however the same.)

 

[bblumberg]

Thanks! you saved me a lot of headaches. Sorry about the link - sometimes it goes to the right place and other times not. It is the "5 channels 50 version dream chip". Good violet, lots of royal blue and perhaps too much white for my taste, but at least it is 10K and 15K white.

If I am understanding correctly, the right power supply for me to purchase is the HLG-80H-C700B. If I get 5 of these, and wire one to each channel of the 3 lights, connected in series, then I should get the right voltage (94.5-108v) and maximum drive current. Correct? Do I need to set the output of each driver to match the voltage draw of the LED channel, or will the LEDs only draw what they need?

Thanks for the warning. Yes, I have the sense to unplug the mains power before messing around with the business end of the drivers. I was planning to use AWG 18G heatproof silicone wire for this application. Probably overkill, but the cost is moderate.

Very good info about the power supply. I was hesitant to change from Meanwell to a name I could not find out much about already. The JRtronic power supplies are only CE and; therefore, I will definitely avoid them for any future application as well.

Thanks again for pointing me to this driver. I can see lots of advantages for other future builds.

 

[theatrus]

No worries - those HLG series are pretty handy for series connected, and are one of the newer Meanwell lineups. Also a very good IP6x rating for aquarium use.

 

[oreo57]

First the spec sheet on those diodes uses 350mA as their base current. I recommend staying close to that.. not 700mA.
The "A" version of the hlg is current adjustable..but you lose dimming capability AFAICT

Voltage is about 31V (3.1 to 3.5 per chip) for ch 1,2, 4, 5 X 3 would be 93-105 V

Ch3 is a bit confusing (larger V(f) spread). at 350mA rated voltage is between 2.8 and 3.8....
84 to 114V
to be honest..not crazy about the HLG series..and you would need 5..
There are other options..
ELG-75-c500B
http://www.vozop.com/index.php/mean...ant-current-mode-led-driver-power-supply.html
http://www.meanwell.com/webapp/product/search.aspx?prod=ELG-75-c
I have concerns running out of the constant current region of the spec sheet.Maybe a pointless concern but the ELG's constant current region is 75-150V out, unlike the hlg.
And at 500mA "out of the box" seems a fair compromise..

Would stick w/ the 15 LDD's and a 360W 48V power supply personally. Easy and cheap to switch mA output..

Note: May have pulled the wrong spec sheet on the HLG series. One I looked at earlier seems to have been the HLG120 (107-215CC region).. my bad..
Still voting for LDD's..

 

[bblumberg]

Thank you. It is good to hear from two experts in this area. My sense is that the LDD option will cost much more with the Meanwell LDDs and Coralux boards, plus the adapters to convert 0-10v to PWM. I am strongly leaning toward the HLG option which will cost just about $230 for the 5 drivers (and less complicated for me) compared with north of $325 for LDD+boards+power supply + case. Not a big deal compared with the rest of the tank build, but not insignificant either.

 

[oreo57]

theatrus is a much better source than I..as you can see from screwing up the spec sheet..
That said, yes the added expense of the conversion is probably 1/2 the cost differential.

Waiting slow boat from China Ldd's run only $5 each inc. shipping..$75

even for me, w/ my aversion to putting all my eggs in one basket at high voltages () it would be a tough call...

BUT still consider that 700mA unless thermal needs are met is a bit on the riskier side for those chips..
It is listed as MAX current... and roughly 112W/chip

with all that siad, if those drivers were dimmable and current adj. we wouldn't be having this conversation..

 

[bblumberg]

Thanks for the information. I will be addressing the thermal needs of the chip with a heatpipe CPU cooler also sold by AC-RC so I am not very concerned about that. I am also buying thermal switches for the LED pucks that will shut them down if the temps exceed 65C. Unless I am mistaken, the power supply output can be adjusted from 420-700 mA so I can back this off a bit to be on the safe side.

 

[oreo57]

Unless I am mistaken, the power supply output can be adjusted from 420-700 mA so I can back this off a bit to be on the safe side.

Best to double check.. The series I looked at earlier was either current adjustable OR dimmable.. Not both in the same type.

"A" type current adj. no dim,
"B" type dim no adjust..
"D" is just some special w/ neither
http://www.meanwell.com/mw_search/HLG-80H-C/HLG-80H-C-spec.pdf
Same w/ the ELG series..
http://www.meanwell.com/mw_search/ELG-75-C/ELG-75-C-spec.pdf

Devil is always in the details..

 

[theatrus]

Yeah, the B series omits the pot.

However, the current output on the B may actually be current limited and not just PWMed (like an LDD would) - its likely Meanwell just has a current source/sink arrangement with a low pass filter in there to do the 3-in-1. I'll check for confirmation.

 

[bblumberg]

Yeah, the B series omits the pot.

However, the current output on the B may actually be current limited and not just PWMed (like an LDD would) - its likely Meanwell just has a current source/sink arrangement with a low pass filter in there to do the 3-in-1. I'll check for confirmation.

Thanks guys. All orders are placed and I am looking forward to getting started on this build. It is too bad that the B drivers are not current adjustable but I am not particularly worried about the 700 mA drivers and the maximum of 700 mA for the LED pucks since they will have good cooling and an overtemp shutoff.

 

[bblumberg]

Yeah, the B series omits the pot.

However, the current output on the B may actually be current limited and not just PWMed (like an LDD would) - its likely Meanwell just has a current source/sink arrangement with a low pass filter in there to do the 3-in-1. I'll check for confirmation.

OK, parts have all arrived and I want to test out the individual channels on the "dream chips" before assembling everything in the hood (in case I need to send any back). As noted above, my plan is to connect the individual channels of the 3 chips in series with the corresponding channel on the next one and power each channel with a single HLG-80H-C700B driver. Do I need to wire all 3 up or can I test a single chip on the driver. I guess what I am asking is whether one channel of a single chip (31.5-36v) will be overdriven by the driver or not since the indicated voltage range of the drivers is 84-129v? Alan from AC-RC hobby also told me that the dream chips require a minimum of 24v to light each channel so will I also be restricted in how low I can dim them by the output of the driver?

Thanks,

 

[oreo57]

Current stays constant regardless of the number of chips.
That said some drivers have a high minimum voltage and freak out..
Strobbing or not lighting in general.

So GENERALLY speaking you can test ind. chips but I'd wait till someone other than I chime in here..

If the driver range is indicative of the above then you most likely need to connect all 3 to get above the 84v...

 

[theatrus]

Yeah, the drivers will need all three in series to meet their minimum voltage. I imagine the driver would just cut out. You'll also want to mount them to something heat-conductive when testing

 

[bblumberg]

Yeah, the drivers will need all three in series to meet their minimum voltage. I imagine the driver would just cut out. You'll also want to mount them to something heat-conductive when testing

Great, thanks to both you and oreo57. I am definitely going to mount them on the coolers before powering up.

 

[bblumberg]

some questions

some questions

Hi Guys,

Well, I finally found the time to wire up my COB LEDS and everything worked as expected with the Meanwell HLG-80H-B drivers - thanks for the suggestion, Theatrus! These chips are BRIGHT, that's for sure. Now I need to get this whole mess assembled into my canopy.

As I am a relative electronics newb, the next questions may be too obvious, but I want to make a good looking and safe assembly. I purchased an amplifier chassis to house the 5 HLG-80H drivers and plan to screw these to an internal support, probably an empty PCB board that will also accept other stuff as needed.

My first question is what is the appropriate method to combine all of the power inputs to the drivers from the mains? There is a socket in the case as well as a power switch which I am going to keep. It seems to me that I need to combine the 5 power cables from the drivers to the 3 mains wires and that some sort of terminal block would be best for this. I didn't see any at Fry's that fit the bill, though. What I'd like is to have one side accept the mains input and then distribute this to the 5 drivers on the other side. Of course I could simply splice the wires with a wire nut, or make a waterproof splice as I did for the LED wires, but this doesn't seem very elegant. What would best practices be for such a connection?

Next, I am thinking to use 7-conductor cables of appropriate specs (probably 18AWG with suitable insulation) to carry power from the drivers to the LEDs and back. I need at least 7: 5 for the drivers to LEDS (up to around 110v DC @700 mA each), one for the DC fans in the hood (12v DC, 100 mA, each fan) and one for the heat sensitive switch circuit (could be mains AC, or perhaps a DC circuit to a relay?). I am thinking to use one cable from a socket in the driver box to the +side of the LEDs/fan/sensor and another from the -side of he LEDs/fan/sensor back to the driver box. Of course it would be easier to use one cable, but I am not certain that I can find suitable 14-conductor wire, whereas I am pretty confident that 7-conductor wire with the appropriate specs an be found fairly easily. I found with my other builds that it is a PITA not to be able to disconnect the canopy from the driver box. Does this sound like a reasonble approach? I ordered waterproof connectors to connect these cables to the driver box.

What to do with the thermal cutoff switch circuit? The most simple approach would be to wire the 3 switches in series to the mains power such that when one of the sensors overheats, power is shut off. Since the power cable to the LEDs will already be carrying 110v DC on each of 5 conductors, it should not be an issue to have another one of the conductors carry 115v AC, right? Or should I make this a lower voltage line and connect to a relay that shuts power off when the circuit is broken? How to power it? As below?

Lastly, it also seems to me that I should be generating 12v DC in the driver box to power the fans so some sort of transformer would be required. Any advice on how to go about selecting one would be helpful. Ideally, I'd like to be able to control the fan speed from my Apex. I have purchased Noctua IP-67 fans that have 4 wires, one of which is RPM sensor and another that will accept a PWM input to control the speed. Is it worth putting a PWM-10v converter in the box so that I can control direclty with Apex, or good enough to simply turn fans on and off with Apex via a separate wall-wart plugged into one of the EB-8 outlets? I have tons of Fanmate speed controllers laying around from computer builds so I could, inelegantly, control fan speed directly by running DC power to the fans through the Fanmate. More elegant would be to sense temperature in the hood via an Apex temperature sensor and adjust fan speed to keep the temp below some maximum allowable level. I suppose that if I go with the most elegant route, more conductors in the wire will be needed to carry the speed "dimming" circuit.

Thanks for reading. Any and all advice very much appreciated!

 

[bblumberg]

Anyone?

 

[oreo57]

Too many questions w/ dozens of answers.
In my "boxes hide many sins".. I'd just do al the AC via wire nut..and if really "fancy" solder and wire nut.
Drivers use .85A each at 110V.. Nothing taxing here..

As to fans.. Apex control is nice IF you also link it to a thermal sensor.. Time programmed fans are a waste of.....time.. in my mind.
Is it worth it is a your time, your money question and depends a lot on the current thermal transfer capabilities. Again a dozen ways to approach this. Personally doing a "stand alone" fan control based on non-cpu required controllers is a personal favorite unless you always feel the need to over-ride the system.
For one who thinks fans are a product of poor design, well that says it all. Fans are cheaper good construction. Sorry, personal rant

Easier to just wire a thermal switch into the fan 12v circuit..

As to the 12V supply, depends on fan max current draw and how many fans you have..Plenty of 1A plus 12V wall warts out there

 

[bblumberg]

Too many questions w/ dozens of answers.
In my "boxes hide many sins".. I'd just do al the AC via wire nut..and if really "fancy" solder and wire nut.
Drivers use .85A each at 110V.. Nothing taxing here..

As to fans.. Apex control is nice IF you also link it to a thermal sensor.. Time programmed fans are a waste of.....time.. in my mind.
Is it worth it is a your time, your money question and depends a lot on the current thermal transfer capabilities. Again a dozen ways to approach this. Personally doing a "stand alone" fan control based on non-cpu required controllers is a personal favorite unless you always feel the need to over-ride the system.
For one who thinks fans are a product of poor design, well that says it all. Fans are cheaper good construction. Sorry, personal rant

Easier to just wire a thermal switch into the fan 12v circuit..

As to the 12V supply, depends on fan max current draw and how many fans you have..Plenty of 1A plus 12V wall warts out there

Thanks for answering. I spent a few days looking for proper terminal blocks online and did not find any. My local electronics shop recommended either doing 3 strip terminal blocks and tying one side together, or just using wire nuts. I decided wire nuts are inelegant, but will save lots of time and effort.

I have been researching an analog to PWM control module but this also seems like too much effort for too little benefit. I have an extra temperature control line on the Apex and thought to have the fans turn on when the temp exceeded some setpoint. The canopy is almost entirely enclosed so the T5s need some cooling air. I have 5 nice Noctua industrial fans and wanted to use their tachometer and PWM lines for a finer control. Perhaps it would be better just to set them at a speed that gives sufficient cooling when all lights are on, but doesn't make too much noise.

The thermal switches are 65 C and to be mounted onto the LED so that if the chip gets too hot, the power is shut off. In practice, these are so bright that I don't imagine that they will ever run near 100% or come close to overheating, but I suppose this will be good in case a fan goes out.

Fans draw 100 mA each. There are 5 canopy fans and 3 CPU cooler fans on the LEDs. I can certainly get a separate wall wart and wire that in, but wanted this to be inside the driver box. I suppose that I can disassemble one and wire it directly.

 

[oreo57]

There are cheap "board only" AC/DC converters on eek bay.. Avoids using a wall wart..1/2 "elegent".
At least use one w/ wire on both ends and just tap into the ac line.

There are plenty of DIY photos here w/ and not exaggerating Masterful wiring jobs.. Maybe do a search.
Me I'm just a get er done kind of guy.......