Greetings everyone.
I have 2xHLG185-1400b (COBS) and 1xHLG240-1050b(QBs) each with it's own dimmer, working perfectly.
I am having trouble dimming all 3 drivers simultaneously.
I only had a 100K pot (90K, 100K, 116K tried them all) so I put a 3x33k resistor to the ground terminal of the pot, each going it's own wago where each of the negative dimming leads go.
The positive leads go into the middle terminal of the pot though a 5xWago.
The result was it dimmed all the way up using a third of turn of the pot.
I also tried connecting the resistors to the positive side dimming leads. No change.
I tried hooking up only 2 drivers using 51k resistors. Full dimming taking a half of a turn this time.
Ordered a 33K pot thinking my cheap Chinese ones are to blame. They sent a 100K (101K measured). Tried with the new pot. Not change in the results.
Now waiting on another 33K pot.
There isn't a lot of info on this specific issue online, any advice will be much appreciated..
Dimming multiple drivers simultaneously - Help needed
Unfortunately you NEED to have a 33K ohm pot for this to work properly. Adding resistors only increases the resistance of that 100K ohm pot, making your final resistance that much further from your target.
A 33K ohm pot hooked up to all 3 drivers with no resistors will solve the issue. However, if you find that your new pot measures considerably lower than 33K ohms, you may actually want to add a small resistor in series with each driver to get that total resistance for each driver up to at least 33K ohms.
A 33K ohm pot hooked up to all 3 drivers with no resistors will solve the issue. However, if you find that your new pot measures considerably lower than 33K ohms, you may actually want to add a small resistor in series with each driver to get that total resistance for each driver up to at least 33K ohms.
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Thanks admin for confirming I'm on the right path..
If the new pot does measure lower, lets say 30k. Is this just a matter of using 3x1k resistors? or are there calculation and measurements to take?
I have 2x1400mA drivers and 1x1050mA and I do see lower Lux values under the 1050mA - Quantom boards. Would I want to use a higher value resistor for that driver than the other two (maybe 2x900ohm and 1x1.1k)?
If the new pot does measure lower, lets say 30k. Is this just a matter of using 3x1k resistors? or are there calculation and measurements to take?
I have 2x1400mA drivers and 1x1050mA and I do see lower Lux values under the 1050mA - Quantom boards. Would I want to use a higher value resistor for that driver than the other two (maybe 2x900ohm and 1x1.1k)?
OK, so I received the 33K resistor (measured 31.1) and it is working relatively well.
I got a total of 616W off the 3 drivers where before I got 662w with individual pots. Maximum brightness is reached at about 90% rotation of the pot.
I placed what resistors I have inline with the negative dimming leads of the 3 drivers until getting the 662w I knew I can get. I settled on 9K (2.2K+6.8K - that's what I had) on each of the 185-C1400B and 4.7K on the 240-C1050B, measuring 10.1V and 9.7v respectively on the dimming leads when pot is cranked up all the way.
Still, it bugged me that the pot was only at 90% revolution when maximum wattage reached so I got creative. I put another resistor on the positive side of the pot.
Alarmingly pleased, I got 669 watts at the wall. 7 watts higher than I ever got. Incidentally, it a 1% increase, and I used 1K resistor. I forgot to measure the voltage on the dimming leads.
So what actually happened here? did I cause more than 10v on the dimming leads causing the drivers to go above the dimmable range towards the driver's absolute limit (same as the A type? - I guess it's the same hardware underneath)?
If I'm on the right path here, can someone advise if I can remedy the 90% revolution thing or should I remedy my brain for being such a stickler?
Also, It would be nice to know how to calculate the resistor values I needed without trial and error..
I got a total of 616W off the 3 drivers where before I got 662w with individual pots. Maximum brightness is reached at about 90% rotation of the pot.
I placed what resistors I have inline with the negative dimming leads of the 3 drivers until getting the 662w I knew I can get. I settled on 9K (2.2K+6.8K - that's what I had) on each of the 185-C1400B and 4.7K on the 240-C1050B, measuring 10.1V and 9.7v respectively on the dimming leads when pot is cranked up all the way.
Still, it bugged me that the pot was only at 90% revolution when maximum wattage reached so I got creative. I put another resistor on the positive side of the pot.
Alarmingly pleased, I got 669 watts at the wall. 7 watts higher than I ever got. Incidentally, it a 1% increase, and I used 1K resistor. I forgot to measure the voltage on the dimming leads.
So what actually happened here? did I cause more than 10v on the dimming leads causing the drivers to go above the dimmable range towards the driver's absolute limit (same as the A type? - I guess it's the same hardware underneath)?
If I'm on the right path here, can someone advise if I can remedy the 90% revolution thing or should I remedy my brain for being such a stickler?
Also, It would be nice to know how to calculate the resistor values I needed without trial and error..
A weird thing.. each day the total voltage drops by ~0.5v. Its down to 655 now from 662. I'm not touching the pot.
What's going on here? Cheap pot?
This was meant to make dimming easier but it's not going as expected. I might just flip back to individual pots.
Any ideas as to why the voltage jumped higher than I can go normally when I added a resistor to the positive dimming lead?
What's going on here? Cheap pot?
This was meant to make dimming easier but it's not going as expected. I might just flip back to individual pots.
Any ideas as to why the voltage jumped higher than I can go normally when I added a resistor to the positive dimming lead?
OK it reached 652 and I gave up and disconnected the pot.
Watts at the wall jumped to 686, higher than I ever saw it. I got my AC monitor after I had the pots wired. Never knew how much total with open dimming leads.
Started playing with the pots and resistors I have came on to something I can't explain myself.
All pots were above 100k to begin with. One needed no resistor. The other two came a few watts short with pots at 100% than with no pots at all. I discovered that when using a resistor value that got the watts up to the maximum possible (open dimming leads) I would also reach maximum brightness short of the pot's full rotation. I already knew that, I tried a 10k resistor when I first got the driver and noticed that, that's why I settled on no resistors and loss of a few watts.
What I did was wire 2 resistors half that value to both positive and negative dimming leads. That got me almost all of the potential watts and aligned the end of the pot's rotation with the driver's maximum brightness.
Of course my journey was more a trial and error one until I came to theses findings.
I understand why placing the resistor on either positive or negative leads would offset the watts but it would be great if someone can explain to me that balancing between pos and neg leads that sorted the pot's rotation out.
Thanks
Watts at the wall jumped to 686, higher than I ever saw it. I got my AC monitor after I had the pots wired. Never knew how much total with open dimming leads.
Started playing with the pots and resistors I have came on to something I can't explain myself.
All pots were above 100k to begin with. One needed no resistor. The other two came a few watts short with pots at 100% than with no pots at all. I discovered that when using a resistor value that got the watts up to the maximum possible (open dimming leads) I would also reach maximum brightness short of the pot's full rotation. I already knew that, I tried a 10k resistor when I first got the driver and noticed that, that's why I settled on no resistors and loss of a few watts.
What I did was wire 2 resistors half that value to both positive and negative dimming leads. That got me almost all of the potential watts and aligned the end of the pot's rotation with the driver's maximum brightness.
Of course my journey was more a trial and error one until I came to theses findings.
I understand why placing the resistor on either positive or negative leads would offset the watts but it would be great if someone can explain to me that balancing between pos and neg leads that sorted the pot's rotation out.
Thanks
My guess is that the true value of the sum of these resistors is lower than the 10K you had.
If you have 10K inline with a pot that actually measures 100K, when you turn that pot all the way up, obviously you have 110K and you may have hit 100K further back in the rotation, which should max the driver out. If this were the case, the extra 10K ohms you’re getting at the last 10% of turning the pot wouldn’t be increasing current at all.
My hunch is that maybe your 10K is actually very close to 10K ohms and that your 2x 5K are not quite 5K. If they were, say, 4.5K each then you’d only be adding 9K and it might affect the useful range of the pot - especially if the POT is not truly 100K ohms. I’m sure that if you wired both of the 5K resistors in series on the same side of the dimming leads, it’d have the same effect. I don’t think having one on either dimming lead is making a difference.
Your power draw from the wall is also bound to drop as your lights stay on and heat up, so make sure you are measuring at the same time every day to get consistent results. Hotter lights = lower voltage = less power. If you turn your light off, change your pots, then turn them back on, the power will spike because the diodes cooled off.
If you have 10K inline with a pot that actually measures 100K, when you turn that pot all the way up, obviously you have 110K and you may have hit 100K further back in the rotation, which should max the driver out. If this were the case, the extra 10K ohms you’re getting at the last 10% of turning the pot wouldn’t be increasing current at all.
My hunch is that maybe your 10K is actually very close to 10K ohms and that your 2x 5K are not quite 5K. If they were, say, 4.5K each then you’d only be adding 9K and it might affect the useful range of the pot - especially if the POT is not truly 100K ohms. I’m sure that if you wired both of the 5K resistors in series on the same side of the dimming leads, it’d have the same effect. I don’t think having one on either dimming lead is making a difference.
Your power draw from the wall is also bound to drop as your lights stay on and heat up, so make sure you are measuring at the same time every day to get consistent results. Hotter lights = lower voltage = less power. If you turn your light off, change your pots, then turn them back on, the power will spike because the diodes cooled off.
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Here some of the observations I have:
I added 2x 10k resistors to a 111k pot and 2x20k resistors to a 104k pot (measured with multimeter). So it's more like I need to get to 120K in order to get the maximum possible watts out of the drivers. That's 2xHLG185. A third HLG240 was paired with a 101K pot that required no resistor to be short a couple of watts off the maximum.
When I put 2x10k resistors in series (on the 104k pot) I do get max watts but sure enough I reach it at about 90% ratation of the pot. When I place them on the different leads, there is some kind of balancing going on the range of the pot which I don't know enough to explain.
Maybe it's a quality issue with the pots. The first two are cheap Chinese ones and the third is a less cheap Chinese one..
I added 2x 10k resistors to a 111k pot and 2x20k resistors to a 104k pot (measured with multimeter). So it's more like I need to get to 120K in order to get the maximum possible watts out of the drivers. That's 2xHLG185. A third HLG240 was paired with a 101K pot that required no resistor to be short a couple of watts off the maximum.
When I put 2x10k resistors in series (on the 104k pot) I do get max watts but sure enough I reach it at about 90% ratation of the pot. When I place them on the different leads, there is some kind of balancing going on the range of the pot which I don't know enough to explain.
Maybe it's a quality issue with the pots. The first two are cheap Chinese ones and the third is a less cheap Chinese one..
Weeeeeeeeird. Man, that just doesn’t make any sense to me. I can’t see the circuit caring what side of the pot the resistors are on, nor how it’d make any difference. Gonna experiment with this and see if I can replicate it this weekend.oozing wrote: ↑Fri Nov 17, 2017 9:24 pmHere some of the observations I have:
I added 2x 10k resistors to a 111k pot and 2x20k resistors to a 104k pot (measured with multimeter). So it's more like I need to get to 120K in order to get the maximum possible watts out of the drivers. That's 2xHLG185. A third HLG240 was paired with a 101K pot that required no resistor to be short a couple of watts off the maximum.
When I put 2x10k resistors in series (on the 104k pot) I do get max watts but sure enough I reach it at about 90% ratation of the pot. When I place them on the different leads, there is some kind of balancing going on the range of the pot which I don't know enough to explain.
Maybe it's a quality issue with the pots. The first two are cheap Chinese ones and the third is a less cheap Chinese one..
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I googled and found this, may explain some of it.
https://www.power-supplies-australia.co ... ed-drivers
https://www.power-supplies-australia.co ... ed-drivers