Meanwell LDD driver: for those who want to dim to 0 using Arduino
- Thread starter pwreef
- Start date
sfsuphysics
Active member
Where did you order them from? And how long ago?
Ronic
New member
I ordered 5 of the LDD 700H from Powergate today, they called to tell me that they where out of the 1000H till April. So I'm going to build my lights with the 700's and then swap them out for the 1000's.
sfsuphysics
Active member
Ah I see, I'm kind of in that same boat too, got a friend who's going to loan me a couple 1000s hopefully and I'll simply pay him back when they get back in stock. I should probably just get some of the 700s, I mean hell they're just over 5 bucks a piece.
Also does Powergate sell to individuals? Everything about their ordering page seems to point towards them only selling to businesses including needing a company name & webaddress.
Also does Powergate sell to individuals? Everything about their ordering page seems to point towards them only selling to businesses including needing a company name & webaddress.
Wait- What? You only received 6 of the boards you ordered, and got another 10 "typhon" boards as part of the open source option? Sounds like somebody at ITead's shipping dept been hitting the sauce a bit too hard during the new years celebration!
iced98lx
New member
No doubt.
I got confirmation that they shipped the rest of my 700's and 350's today.
No, what I ordered was 5 each of my board and your typhon controller , basically the minimum qty of each.. What I got was 6 of one and 10 of the other! And my "open source" option includes an arduino uno PCB.. too bad the surface mount stuff looks too small to hand solder. Maybe with flux/paste and a heat gun.
megadeth72
New member
google how to soldier the nano chip, it's easy, far easier than you think, you tac it, glob on soldier and then use a copper wick to remove the excess, it leaves it nice and neat
Yep that what it was, took me a while to figure it outthis driver works amazingly. I got the 4095 steps 16 channel pwm from adafruit.
Hi: please, ¿how many LDDs have you connected to each dimming channel? Also, ¿how many channels in total?
I guess you are using Arduino mega 2560
Regards
I hoping somebody else can chime in on this. I did some more current tests last night and found some very unexpected results. I thought the some of the numbers in the manufacturer's spec sheet looked a bit weird, so I decided to take some measurements to find out for sure.
First off all testing was done using an adjustable 48 volt supply, (4) LDD-1000H and 4 LED arrays. Each array was connected to one of the LDD's. The LDD's were then all connected back to the 48 V supply.
3 of the LED arrays were BridgeLux (BXRA-C4500) with an average Vf of 24.4 Volts.
The last array was a Chinese 100 watt model with a average Vf of 32 Volts.
I powered up all LDD's to 100% duty cycle and then took some current measurements. Here's what I found interesting-
Using a 48Vdc input Voltage-
Each of the 4 LDD's produced a consistent 980ma under full load. (As expected)
So total current out to the LED's = 3920ma.
Input current to the LDD's = 1980ma
I found that current number odd, as current out exceeded current in? So I then lowered the input voltage to 42V just to see what would happen, if anything.
@ 42V the current into the LDD's rose to 2500ma.
I then lowered the voltage again. This time to 36V. @ 36V current rose again to just shy of 3,000ma.
During all of these measurements and input voltage adjustments, the output current remained steady at 980ma for each of the four LDD's.
I guess my initial understanding of how these LDD's operate was completely incorrect. There has to be some Voltage to Current transformation going on inside these things?
Anybody got any ideas?
First off all testing was done using an adjustable 48 volt supply, (4) LDD-1000H and 4 LED arrays. Each array was connected to one of the LDD's. The LDD's were then all connected back to the 48 V supply.
3 of the LED arrays were BridgeLux (BXRA-C4500) with an average Vf of 24.4 Volts.
The last array was a Chinese 100 watt model with a average Vf of 32 Volts.
I powered up all LDD's to 100% duty cycle and then took some current measurements. Here's what I found interesting-
Using a 48Vdc input Voltage-
Each of the 4 LDD's produced a consistent 980ma under full load. (As expected)
So total current out to the LED's = 3920ma.
Input current to the LDD's = 1980ma
I found that current number odd, as current out exceeded current in? So I then lowered the input voltage to 42V just to see what would happen, if anything.
@ 42V the current into the LDD's rose to 2500ma.
I then lowered the voltage again. This time to 36V. @ 36V current rose again to just shy of 3,000ma.
During all of these measurements and input voltage adjustments, the output current remained steady at 980ma for each of the four LDD's.
I guess my initial understanding of how these LDD's operate was completely incorrect. There has to be some Voltage to Current transformation going on inside these things?
Anybody got any ideas?
AMDphenomx4
New member
As I responded may posts ago, Meanwell responded saying more or less, that as voltage difference increases, current requirements decrease. The extra voltage becomes higher current. Most likely it would be linear.
For my example it was an LDD-1000H with a 3V LED and a 12V 500mA PSU.
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Seems like it would have to work this way. Otherwise you'd end up needing to burn off the difference between your power supply voltage and the voltage drop in the LEDs times the rated current. That would be a lot of heat.
In your examples: 1.980A * 48V = 95 Watts power in
2.500A * 42V = 105 Watts power in
3.000A * 36V = 108 Watts power in
and (3*24.4V*.980A) + (32V*.980A) = 71.74 W + 31.36 W = 103.1 Watts power out
Probably an averaging error in there, but the deal is that the power in = power out neglecting power lost in the driver due to inefficiency.
Edit: By the way, my 3-Way O2Surplus boards left Hong Kong today!!
In your examples: 1.980A * 48V = 95 Watts power in
2.500A * 42V = 105 Watts power in
3.000A * 36V = 108 Watts power in
and (3*24.4V*.980A) + (32V*.980A) = 71.74 W + 31.36 W = 103.1 Watts power out
Probably an averaging error in there, but the deal is that the power in = power out neglecting power lost in the driver due to inefficiency.
Edit: By the way, my 3-Way O2Surplus boards left Hong Kong today!!
Yeah- I guess when you put it that way ( Power in = Power out- losses ) it should work that way. I'm not used to approaching it from that angle. The CAT4101 & LM3409 based drivers don't behave the same way as the LDD, so I'm used to only considering Voltage and current requirements and never thought to consider total power produced, i.e Wattage .
doh I just did the same math as Eud posted before I got to the bottom of the thread.....
103 watts out to LEDs all cases.
95 watts in to LDD @48volts
105 watts in to LDD @42volts
108 watts in to LDD @36volts
as Eud pointed out that doesnt seem right they can't be over 100% efficient@48volts, must be some small error in the calcs or the measurements by O2 are slightly off due to using 4 leds on 4 LDDs or some minor thing.
other than the slight discrepancy in the calcs this seems pretty awesome to me! the more over voltage the more efficient they seem to run. Fantastic! linear power conversion (watts in = ~ watts out, more or less) without having to mess with adjusting the power supply to match the output voltage!!!!!!!!!!!
I wonder if you'd get more efficiency gain running them closer to thier 56 volt input limit?
I now totaly scrap all plans of ever building or using a CAT based, or similar driver for future builds
I guess this changes how we look at power supplies. now it is just a question of total output watts, not voltage and amps. smaller less expensive power supplies, Yay!
Now to locate a near 100% efficient AC to DC power supply. Any suggestions??
103 watts out to LEDs all cases.
95 watts in to LDD @48volts
105 watts in to LDD @42volts
108 watts in to LDD @36volts
as Eud pointed out that doesnt seem right they can't be over 100% efficient@48volts, must be some small error in the calcs or the measurements by O2 are slightly off due to using 4 leds on 4 LDDs or some minor thing.
other than the slight discrepancy in the calcs this seems pretty awesome to me! the more over voltage the more efficient they seem to run. Fantastic! linear power conversion (watts in = ~ watts out, more or less) without having to mess with adjusting the power supply to match the output voltage!!!!!!!!!!!
I wonder if you'd get more efficiency gain running them closer to thier 56 volt input limit?
I now totaly scrap all plans of ever building or using a CAT based, or similar driver for future builds
I guess this changes how we look at power supplies. now it is just a question of total output watts, not voltage and amps. smaller less expensive power supplies, Yay!
Now to locate a near 100% efficient AC to DC power supply. Any suggestions??
doh I just did the same math as Eud posted before I got to the bottom of the thread.....
103 watts out to LEDs all cases.
95 watts in to LDD @48volts
105 watts in to LDD @42volts
108 watts in to LDD @36volts
as Eud pointed out that doesnt seem right they can't be over 100% efficient@48volts, must be some small error in the calcs or the measurements by O2 are slightly off due to using 4 leds on 4 LDDs or some minor thing.
other than the slight discrepancy in the calcs this seems pretty awesome to me! the more over voltage the more efficient they seem to run. Fantastic! linear power conversion (watts in = ~ watts out, more or less) without having to mess with adjusting the power supply to match the output voltage!!!!!!!!!!!
I wonder if you'd get more efficiency gain running them closer to thier 56 volt input limit?
I now totaly scrap all plans of ever building or using a CAT based, or similar driver for future builds
I guess this changes how we look at power supplies. now it is just a question of total output watts, not voltage and amps. smaller less expensive power supplies, Yay!
Now to locate a near 100% efficient AC to DC power supply. Any suggestions??
It's not like you're getting free current, you're just not wasting current on strings that are lower than the power supply voltage. So you're right, you can size your Power supply on wattage rather than current.
I wonder if the max current of the 48v power supply goes down if you turn the volts up to 56v. Seems like it would do that if it works similar to these LDDs where the power stays constant while the voltage varies...
Right, there's likely a small error somewhere in measurements or quick calcs we did at the 48volt reference from O2. generally from what I know of them that would be a fair asumption as they should still crank out the same total watts (volts times ampes) as they are rated at. I'm currious what effect even more extra voltage has on the LDD efficiency as the tests done by O2 seem to suggest greater efficiency with higher input voltage disregarding output voltage. according to the curve in the data sheet the opposite should have been true in O2's example. efficiency should have been greater at lower input voltage..............
oh well more testing for another day, sorry O2 if your like me now you'll just have to play around some more. only thing keeping me from wasting hours playing is that I haven't been able to get my hands on any LDDs when I 've been ordering other parts.
Now I really, really want to get some just to play around with!
oh well more testing for another day, sorry O2 if your like me now you'll just have to play around some more. only thing keeping me from wasting hours playing is that I haven't been able to get my hands on any LDDs when I 've been ordering other parts.
Now I really, really want to get some just to play around with!
Hey Guys, it's all good! I really like the fact that we don't need to be terribly concerned about spec'ing our power supplies based on their rated output current anymore. As long as we maintain enough voltage "headroom" and total Watt capacity, the LDD will take care of the rest.:thumbsup:
shark boy
New member
LDD's
LDD's
Anyone have any LDD-700ls or 700Hs they want to sell. I'm gonna need 3 or 6
either way. I'll use my cat4101 for 3 if I have to. I would of ordered from powergate but I was told shipping would be more than the drivers.
I could order 3 from mouser cheaper than from powergate.
What did powergate charge anyone who bought from them shipping?
LDD's
Anyone have any LDD-700ls or 700Hs they want to sell. I'm gonna need 3 or 6
either way. I'll use my cat4101 for 3 if I have to. I would of ordered from powergate but I was told shipping would be more than the drivers.
I could order 3 from mouser cheaper than from powergate.
What did powergate charge anyone who bought from them shipping?
