I have been looking at driving LED’s in series with 240v Drivers from Mean Well.
HLG-320H-C2100 76~152V - 319.2W
ELG-75-C700A 53~107V - 75W
HLG-60H-C700 50~100V - 70W
When I look at DC options that could be powered from Batteries.
Mean Well have LDD-700H 9~56DC - Output 2~52 700mA, Approx 36W
What other Suppliers have efficient reliable DC Powered Drivers?
Thanks
Why do you need to power that many LED’s in series? Why not simply break them up into a few parallel sets of LED’s?
It gets hard to find power supplies over ~50v as it starts getting dangerous higher then that.
+1 Texas_Ace
50 leds in series is too much. If one led is burn, one wire is pressed and cutted, one bad solder joint, one broken pcb trace and all you 50 leds will be not able to work.
P.S. There is no visible difference in efficiency of ac-dc 2-cascade circuits of drivers made by different companies.
As far as actually finding such supplies, we don’t generally mess with things like that around here so I doubt people will be able to point you to much more then the offerings on ebay/aliexpress (which would do what you want BTW, although efficiency is unknown).
Got it.
You dont need mean well analog.
You just need dc powered led driver big Vf compatible.
It may be trucky to found, but they defenetly exist and may be based on lt3756-2 chip for example.
Hi Guy Fawkes,
This is just the problem I had when installed a long string for a garden party.
+2 for Texas_Ace: the higher voltage puts more danger to it. Take his advice seriously. Two kids were killed in a small wet garden next to an apartment pool in Jakarta about three months ago. They were electrocuted from touching/stepping exposed bare cable from rat’s bite.
If you really know what you’re doing then it’s fine. Most LED enthusiasts started dealing with low DC power supplies, sometimes they forget the risk of high voltage AC. I myself got electrocuted many times over the years, and got less and less with more safety measures 
.
I installed many outdoor AC powered LED lights running for almost two years now (mostly 12 hours/day). Almost all of them are waterproof AC-DC LED drivers (IP65-67). I only used few Meanwells due to it’s high price. The rest are MIC generic LED drivers with efficiency between 80-88% (some can go as low as 70% - test first), good enough, heard no complaints, and VERY cheap. Also don’t forget to limit your warranty to the clients to reasonable time if you’re using generic MIC products.
- Clemence
Sorry, I understood your post wrong, my bad. I thought you were looking for AC driver with high voltage DC output. :person_facepalming:
Have you consider to use boost DC-DC driver? There are plenty cheapos out there
I bought some of these: http://www.ebay.com/itm/DC-DC-boost-converter-Constant-Current-Mobile-Power-supply-10A-250W-LED-Driver-/191827311442?hash=item2ca9cc7b52:g:9KoAAOSwv9hW6Aft
And never really try it. Planned to build high power LED spotlights from a 12V car/bike battery. Never really have the time to start it.
Those power supplies you listed are step-down supplies. They can only step the voltage down, they can not go up. So then would need an input of 51V to output 51v. From a 12V battery they would only output 12v. You would need a boost converter in order to use a 12V battery.
For an AC to DC power supply, only computer servers have nice supplies that would do what you want, you just have to search around for one with the specs you need. I have a DELL 47v 480W supply I got for $19 myself that works great.
Or if you want to buy new then you have a lot of choices, just depends on how much you want to spend.
I don’t really care to be honest. For simple quick project I just buy bunch of cheap drivers and test the efficiency by simply calculate the input vs output of the config I use. Anything above 80% is good enough for me.
With Meanwell you can get 90+% efficiency at a cost….
Normally, bucking is more effcient than boosting, that’s the fact.
If you really need a HIGH QUALITY boost driver with high efficiency, high output, and high quality components this might be what you’re looking for: http://www.taskled.com/hboost.shtml
Vin: 8V - 50V
Vout: max 80 V
Iout: max 3200 mA
Price + shipping approx. USD 40 + USD 15. Not cheap
- Clemence
Maybe, hyperboost driver from Taskled meets your criteria
Using LT3756 AFAIK
It might be easier if you tell us what you are doing and how it will be used. Right now I don’t have a clue what the end goal is.
First off do not assume that the VF of the LED’s will be 2.91v. It generally varies a fair amount from batch to batch. Make sure to build in some wiggle room.
If you will be using batteries then it is best to have the battery voltage as close as possible to the LED voltage. So it you would want 12 LED’s in series that would be about 36V so I would run 4x 12V batteries in series and use a buck converter to drop the voltage down to 36v. Boost converters work but will always be less efficient then a buck. So unless you are forced to use low voltage you are better off raising the input voltage and using a buck converter.
To power them off the mains you would simply need a 48V power supply, and hook it up to the same converter, it would make everything simpler as well. The 48v power supply could even float charge the batteries (assuming you would be using lead acid batteries) with a cheap converter of it’s own.
So if it needs to run off batteries long term and they must be run in series of 12x then 4x 12V batteries with a buck converter is the best option I see. You could go with higher voltage but it gets dangerous, even 48V can kill you, this is why many things set ~24V as the max, it is safer.
Interesting topic, I’m listening……
48V will work fine if it is wired properly, just treat the wiring like mains wiring and you should be fine.
If it is only for testing you can find 47 to 48v power supplies from china for cheap with plenty of power for what you need. That would be the simpler option most likely. The sever power supplies are very nice but it can take a lot of research to find one with 47V. Most are 12V or 24V.
- Tex: I think to get better idea he could start the research by using that DPS5015 we discussed earlier. It’s a good investment for future updates too. For such many strings and combo possibilities, a bench power supply can give better preliminary results before the real PSU chosen.
When you design parallel connections in long separated strings you will get uneven current distribution problems. Unlike in many flashlight practice where the common MCPCB base lessen the tendency of uneven distribution. With long strings the load/resistance will be very different to each other. The current will take the least resistant path, makes a particular string to be brighter than the other. And as the strings heat up, thing will get worse. One simple solution is to install several PTC resistors in each string. But to give you better control over current distribution, you might want to look at these examples:
http://www.ledsmagazine.com/articles/print/volume-6/issue-2/features/led-design-forum-avoiding-thermal-runaway-when-driving-multiple-led-strings-magazine.html
- Clemence
No, actually many industries use CV driver before CC drivers to better suits each string’s requirement.
CV driver has broader range with loose control, while CC driver has tighter range and control. That’s the idea.
You can get more freedom by using CV driver first. For example:
And as a bonus, you’ll get more stable protected power supply too. Especially from inrush over voltage/current.
Constant voltage driver are usually cheaper and more efficient than fully constant current drivers.
In general:
- Constant current AC - DC drivers are less efficient with varying loads than constant current DC - DC drivers
You know what, I really interested in solar powered lighting too. There are many project candidates in my country for such application.
- Clemence