# Manual PWM dimmer and LDD-h



## jeffkrol (Jun 5, 2013)

https://youtu.be/NcEA1gLPgdY


Prrof of concept. Green light is a 3w diode running off the LDD. White light is a strip light..


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## Gamezawy (Apr 3, 2012)

i have tried it, it worked just fine i always wanted a manual dimmers for the LDDs, really thank you for the idea 

but it won't work until you attach the same power in for this dimmers with the same power in for the ldds, so this means the maximum in voltage you can use with your LDDs will be only 24 as this is the maximum in for those dimmers this means the maximum voltage you can get from your LDDs will be only 20V this means you can drive only 6 leds 

I hope we can find a way to separate the in power for both dimmer and LDD driver or some how we can manage to make those dimmer accept more than 24 volt 

Thanks again it is a great idea


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## jeffkrol (Jun 5, 2013)

Gamezawy said:


> i have tried it, it worked just fine i always wanted a manual dimmers for the LDDs, really thank you for the idea
> 
> but it won't work until you attach the same power in for this dimmers with the same power in for the ldds, so this means the maximum in voltage you can use with your LDDs will be only 24 as this


you can separate the power..
Use a 12V wall wart to run the dimmer..
Use any PS you want to run the lights..
I think I got a sketch somewhere.
Just don't hook the positive of the "big" ps to the dimmer.. But you do have to share grounds..but will check
Will get back to this..
Oh and by using the tap off the internal "gate" you don't need to power the dimmer w/ 12V either..
Internally there is a voltage regulator that feeds the op amp timer circuit that pulses the MOSFET base..The 12-24V is for the output of the mosfets, which you won't be using if just running ldd's

fixed..


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## jeffkrol (Jun 5, 2013)

Got it working.. not sure why the first attempt failed .. but here try this..
9v DC ps to plus minus in
Larger power supply to minus in
LDD "input" negative to minus in (so you have 3 wires ganged into the mius in on the dimmer..
LDD "input" pos to large power supply positive..

Jumper wire from base of internal mosfet to dim on LDD..

Easy peasy.. 
IF you use a 12V in power supply you can still use the mosfet "outs" on the dimmer..

crude but you get the picture:











BTW best guess on pwm voltage and frequency.. 
>3V, 780-ish Hz..


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## Gamezawy (Apr 3, 2012)

I tried it i powered the dimmer with 12v and powered the LDD with a laptop charger that gives 19v and i shared the ground as you told me it worked like a charm, thank you 

but tell me how i can use this dimmer without powering it as you said ( you don't need to power the dimmer w/ 12V either.. ) sorry i didn't understand this part

And thank you for taking this time to draw this pic


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## Hoppy (Dec 24, 2005)

Will this work with a Finnex Planted Plus? I haven't checked what voltage it runs at.

Oops! I see it only works with the LDD drivers, not a commercial LED light. Right?


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## Gamezawy (Apr 3, 2012)

we are using it as a Manual PWM dimmer i think it can work with anything that accepts PWM


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## jeffkrol (Jun 5, 2013)

Hoppy said:


> Will this work with a Finnex Planted Plus? I haven't checked what voltage it runs at.
> 
> Oops! I see it only works with the LDD drivers, not a commercial LED light. Right?


Out of the box it will work w/ the planted plus if you put it between the power supply and the light..
As long as you don't exceed the 6A rating.
90W at 15V..

It will work w/ any constant voltage array running 12-24V 6A.
Won't work w/ some of the larger Beamsworks.. ect..

The LDD is another "hack" to the controller..
I really should take a picture of it..

THIS is what you need to do for the LDD thing..









Hoppy you may be interested in the guy who split the 3 channels (W,R,B) and put a tc-420 and a couple of MOSFETS and now has a 3 channel progammable planted plus.. 

Here:
https://youtu.be/V3EdwQmYyk0

http://www.plantedtank.net/forums/20-diy/647434-diy-timer-dimmer-kind-4.html


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## jeffkrol (Jun 5, 2013)

Gamezawy said:


> but tell me how i can use this dimmer without powering it as you said ( you don't need to power the dimmer w/ 12V either.. ) sorry i didn't understand this part
> 
> And thank you for taking this time to draw this pic


I meant if you are not adding strips you can power the circuit w/ other than 12V... Sorry for the confusion.. 
You have to power the dimmer w/ something..
Haven't checked on the real specs of the gate circuitry (probably won't either. ) but more than likely any ps 5v or above should work and only really a few mA,
Technically a 1 power supply system could be built using a voltage regulator.. 
Say 36V for the LED's and add a 12v voltage regulator to feed the dimmer..
Not exactly sure how you do the grounding for that one though..


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## trodrigues (May 29, 2017)

can you guys please post an ebay link or vendor name for this pwm controller, I ordered one but the internals were completely different 

Thanks Antonio


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## ajmckay (Apr 19, 2012)

Old thread but I have to ask the question - why isn't this solution more common? I just put it together this evening and it's working fantastically! Easy too.

I have a Fluval Spec III that I've been delaying the lighting on. I have a nice 3-up LED but no real good solution for operating it. I'm not looking for multi-channel control but only simple dimming. I have some extra LDD drivers from another project but I wasn't about to buy a full PWM controller for this small light. The objective here is a cheap light that works well.

I found this based on some research I was doing on using a 555 circuit as a PWM source but this looked easier and it came with a housing too. Also the housing was big enough that I ended up just mounting the LDD driver inside it and then adding a plug that would go directly to the LED.

Total cost for a nice powerful light for my 3g Spec? Conservatively $25. That's $5 for a 12v power supply, $5 for a Meanwell LDD, $5 for this PWM dimmer, and $10 for 3-4 LEDs. I suppose the only additional piece of hardware I might want is a wall timer which is another few $. Could likely get everything cheaper as well if you're willing to wait for shipping from China. 

Thanks a ton Jeffkrol for the information and the pictures it really made the project simple.


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## Lingwendil (Nov 16, 2012)

I would wager it's not more popular because it just simply isn't as well known, and lots of people want an off-the-shelf plug-in solution. A bunch of people don't really care for having to modify products, or want a super-whiz-bang feature rich solution like an arduino type of controller.


You can also do a similar setup with a simple potentiometer, a MeanWell LDD1000-L, and a few diodes with a series resistor as a simple shunt regulator (or for this particular application, a TL431 shunt reference) to supply ~2.5v for the pot. Same setup would also work with the LDB-L series drivers, just with a 10v supply for the pot, such as the LM7810 which can also provide DC for your fan supply if needed, and the LDB driver has the added benefit of being able to supply higher voltage than your input voltage, which is handy for running smaller CoB type arrays (such as the Bridgelux Vero) on smaller tanks and setups. You could easily run everything off of a 12v supply this way.


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## jeffkrol (Jun 5, 2013)

As peoples eyes glaze over....


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## Lingwendil (Nov 16, 2012)

jeffkrol said:


> As peoples eyes glaze over....



:crying:


This electronics knowledge of mine is a curse lol


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## Lboe (Jan 12, 2018)

Lingwendil said:


> I would wager it's not more popular because it just simply isn't as well known, and lots of people want an off-the-shelf plug-in solution. A bunch of people don't really care for having to modify products, or want a super-whiz-bang feature rich solution like an arduino type of controller.
> 
> 
> You can also do a similar setup with a simple potentiometer, a MeanWell LDD1000-L, and a few diodes with a series resistor as a simple shunt regulator (or for this particular application, a TL431 shunt reference) to supply ~2.5v for the pot. Same setup would also work with the LDB-L series drivers, just with a 10v supply for the pot, such as the LM7810 which can also provide DC for your fan supply if needed, and the LDB driver has the added benefit of being able to supply higher voltage than your input voltage, which is handy for running smaller CoB type arrays (such as the Bridgelux Vero) on smaller tanks and setups. You could easily run everything off of a 12v supply this way.


Can you expand upon the LDD-1000L and a potentiometer? I've tried a simple 1Mg pot on the LDD-1500L as per Meanwell's diagram in the spec sheet but all of the dimming occurs in the 0-10% range and the rest of the range is just full on. I've tried lower value pots but they have even less effect.


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## jeffkrol (Jun 5, 2013)

Lboe said:


> Can you expand upon the LDD-1000L and a potentiometer? I've tried a simple 1Mg pot on the LDD-1500L as per Meanwell's diagram in the spec sheet but all of the dimming occurs in the 0-10% range and the rest of the range is just full on. I've tried lower value pots but they have even less effect.


http://www.plantedtank.net/forums/20-diy/1187625-analog-dimming-w-meanwell-ldd-l-prototype.html


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## Lboe (Jan 12, 2018)

ajmckay said:


> Old thread but I have to ask the question - why isn't this solution more common? I just put it together this evening and it's working fantastically! Easy too.
> 
> I have a Fluval Spec III that I've been delaying the lighting on. I have a nice 3-up LED but no real good solution for operating it. I'm not looking for multi-channel control but only simple dimming. I have some extra LDD drivers from another project but I wasn't about to buy a full PWM controller for this small light. The objective here is a cheap light that works well.
> 
> ...


Well I tried the hack with an LDD-L1500 but it doesn't dim all the way down to 0. It stays at about 10% on and goes up from there. Does that only work (0-100%) with the LDD-H series drivers? What's the difference between the LDD-H & LDD-L drivers?


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## jeffkrol (Jun 5, 2013)

The Ldd-H's and high current LDD-l's are more similar than the low current Ldd-l's and h's

As to PWM differences in frequency Ldd-l's >900mA only go to 500Hz not 1KHz..
Low current Ldd-ls PWM voltage doesn't go below 5..

Only low current Ldd-L's do analog voltage dimming..

ALL will smoothly dim to zero w/ 0-100% PWM duty cycles per spec sheets..
https://www.mouser.com/ds/2/260/LDD-H-spec-766227.pdf
http://www.mouser.com/ds/2/260/LDD-L-spec-47593.pdf

There is nothing obvious that would cause a difference.
Only "suspects" would be a faulty dimmer or possibly effects of too high of frequency (>500Hz) but that is unlikely..but not impossible.
I've personally never used LDD-L's


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## ranjib (Jan 19, 2018)

Curious, the frequency in LDD drivers are not adjustable?


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## jeffkrol (Jun 5, 2013)

ranjib said:


> Curious, the frequency in LDD drivers are not adjustable?


They "accept" a PWM signal from a controller within a range..


It's the sender that would need to be ajusted to match the range of acceptance within the LDD's potted circuitry.

Senders like Aduino or other controllers are frequency "fixed" by code and just need to be set to a frequency within the LDD's range for proper dimming.


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## ChrisX (May 28, 2017)

jeffkrol said:


> I meant if you are not adding strips you can power the circuit w/ other than 12V... Sorry for the confusion..
> You have to power the dimmer w/ something..
> Haven't checked on the real specs of the gate circuitry (probably won't either. ) but more than likely any ps 5v or above should work and only really a few mA,
> Technically a 1 power supply system could be built using a voltage regulator..
> ...


Just want to verify that with separate power supplies, this can dim a strip powered by a ldd 700h @ 48v(44)? Or is it still limited to 24v?


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## jeffkrol (Jun 5, 2013)

Hmm, If I understand your question correctly dimmer never "sees" 48V..
Only sees either a separate power supply of between 9-24V (confirmed).. or the voltage provided by a tap off the 48V and voltage regulator..

The dim wire to the LDD is off the logic circuit (555 timing chip) and about 5V.
The dimmer has a built in voltage regulator converting what ever you feed it (in range of course) to 5V to "open" the gate on the MOFET (which you aren't using..)










Just substitute Manual PWM dimmer for the TC-420.. Basically identical principles.
AS a side note and reminder.. IF you use, say a 12V separate power supply (w/ correct amps for the strips) you CAN run both strips and LDD's off the same channel.. 
I've only briefly tested it though..
LDD and 12V LED strip off the same channel..
https://youtu.be/NcEA1gLPgdY


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## ChrisX (May 28, 2017)

jeffkrol said:


> Hmm, If I understand your question correctly dimmer never "sees" 48V..
> Only sees either a separate power supply of between 9-24V (confirmed).. or the voltage provided by a tap off the 48V and voltage regulator..
> 
> The dim wire to the LDD is off the logic circuit (555 timing chip) and about 5V.
> ...


Thanks. For my upcoming build, I need some LDD-700H. Unfortunately they don't support analog dimming. I did find a cheap source of those PWM controllers which is not much more than the cost of a pot. 

In the initial development and testing phases, I need manual PWM controls to find correct color balance. Maybe eventually I will move to an arduino with ramping. Fish don't really like the "big bang" lights on.

Did you decide to get another parrot for your 55?


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## jeffkrol (Jun 5, 2013)

ChrisX said:


> Did you decide to get another parrot for your 55?


Not ATM.. Need to move some fish round first...55 has room..


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## ChrisX (May 28, 2017)

jeffkrol said:


> Not ATM.. Need to move some fish round first...55 has room..


While I have your attention, how do I determine the wattage requirements of the resistors in this current mirror circuit?










From article:
http://www.ledsmagazine.com/article...en-driving-multiple-led-strings-magazine.html

The reason I'm still pursuing this is that I have a handful of LDD-1200Ls and you can run considerably more leds in parallel than you could with an HDD-700H. (Also the 1200 is more versatile).

The HDD-H has higher voltage output, but using a standard 48V power supply, final Vout is around 42-44. Compared to the HDD-L which provides 30V from a std 36V supply. For my project size, the LDD-1200Ls, provide better groupings, but need a current mirror.

Am I in the stone ages using 3W leds? I checked the Fresh Fish COBs and they require too much voltage to run with LLD-Ls. Would need LDD-1200Hs w/ 48V supply, but alot of power would be lost in that organization.

Any other high CRI COBs in the 20W range? Can get EPI COBs from alibaba dirt cheap. SunPlus not in the cards unless I see a datasheet with spectrum. Stevesleds description makes it sound like it needs the other colors for any CRI.


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## jeffkrol (Jun 5, 2013)

Those are the values... 
680 Ohms and 1.5 Ohms (though technically that would be 1R50)

Less complicated version..








https://www.edn.com/design/led/4368158/Protect-power-LED-strings-from-overcurrent

ahh mystery solved as to the "complication".. 


> If an LED of String 2 fails, however, no base current flows to transistors Q1 and Q2, and they turn off. All LEDs in String 1 have automatic overcurrent protection. The circuit doesn’t perform the same function if an LED in String 1 fails because all of the 700-mA driver current flows into String 2, which needs some form of protection. You can solve this problem by adding only three components (Figure 2).


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## ChrisX (May 28, 2017)

Thanks. I just found the SunPlus datasheet on mouser and depending on the bin, they could have less than half the output of better bins. Huge range of voltage and current.


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## jeffkrol (Jun 5, 2013)

Luxeon never got back to me regarding the question of any differences between Sunplus and Rebel C at 6500k. Assuming at this point they are identical except for lensing.
Def. different than the fresh fish though.. 
https://www.luxeonstar.com/cool-white-6500k-20mm-star-rebel-220lm
c rebel whatever.. 70 CRI



JUST an FYI and more than is necessary.. 
https://www.google.com/url?sa=t&rct...00145612.pdf&usg=AOvVaw2xlak7Tx97jsDcIVSL-UEe


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## ChrisX (May 28, 2017)

jeffkrol said:


> Those are the values...
> 680 Ohms and 1.5 Ohms (though technically that would be 1R50)
> 
> Less complicated version..
> ...


From what I gather, this version of the circuit will only work at 400mA maximum as that is the specification of the diode. So this is more of a specific circuit; 2x350mA driven by 700mA.

That said, do you know if using the circuit I posted with a 1200mA driver divided into two 600mA strings will require different resistor values?


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## ChrisX (May 28, 2017)

jeffkrol said:


> Those are the values...
> 680 Ohms and 1.5 Ohms (though technically that would be 1R50)


Also need to know how much power it can handle.


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## napaeozapus (Feb 22, 2014)

ChrisX said:


> From what I gather, this version of the circuit will only work at 400mA maximum as that is the specification of the diode. So this is more of a specific circuit; 2x350mA driven by 700mA.
> 
> That said, do you know if using the circuit I posted with a 1200mA driver divided into two 600mA strings will require different resistor values?




If you lose one of the 600 mA strings is it going to pump the full 1200 mA through the remaining one? I decided to go with the AcroIQ drivers. Two channels, pot adjustable between 400-1000 mA with PWM dimming in tandem.


Sent from my iPhone using Tapatalk


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## ChrisX (May 28, 2017)

napaeozapus said:


> If you lose one of the 600 mA strings is it going to pump the full 1200 mA through the remaining one? I decided to go with the AcroIQ drivers. Two channels, pot adjustable between 400-1000 mA with PWM dimming in tandem.
> 
> 
> Sent from my iPhone using Tapatalk


The reason to use a 1200mA driver and a current mirror is to run two strings of LEDs in parallel at 600mA @ 36V. This gives the least possible wastage for my project.

For instance, if you have a 48V power supply, with that AcroIQ driver or Meanwell LDD-700H, the most you can run is 42 / 3.4 = 12-13 x 3W (per channel).

Using two 600mA strings and an LDD-1200L w/ 36V power, you can run 30 / 3.2 * 2 = 18 x 3W. Granted at slightly lower lumens. 

Additionally, because the power supply is running at 36V as opposed to 48V, it will supply more current for the same Wattage. In my case, a 36V/350Watt (9.7 A) supply can run eight channels(drivers) of 1200mA drivers. A 48V/350Watt (7.2 A) supply will only be able to manage six channels.


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## jeffkrol (Jun 5, 2013)

Just use fuses that blow at over current.. Say 1A..
Saves a bunch of work and cyphering..
3/4A or 1A should work..

Blown fuse is the good string..
Less than $1 each.. 
https://www.walmart.com/ip/FAST-ACT...6495&wl11=online&wl12=147055804&wl13=&veh=sem


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## Marko_Sp (Jun 5, 2010)

ChrisX said:


> Any other high CRI COBs in the 20W range? Can get EPI COBs from alibaba dirt cheap. SunPlus not in the cards unless I see a datasheet with spectrum. Stevesleds description makes it sound like it needs the other colors for any CRI.


Have You look at Nichia? Nichia NFCWL072B-V2, 2800lm, 5000K, CRI 90, at 9eu VAT included (in Europe)...hard to bet


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## ChrisX (May 28, 2017)

Marko_Sp said:


> Have You look at Nichia? Nichia NFCWL072B-V2, 2800lm, 5000K, CRI 90, at 9eu VAT included (in Europe)...hard to bet


Cant find in the US. Might be worth ordering.


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## Maryland Guppy (Dec 6, 2014)

ChrisX said:


> For instance, if you have a 48V power supply, or Meanwell LDD-700H, the most you can run is 42 / 3.4 = 12-13 x 3W (per channel).


Running 14 x 3watt with 700 driver, adjust power supplies up to 52VDC.


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