Steves Digital drivers

[Steven Garland]

Does anyone have a diagram for wiring these ? I see diagrams and talk but its all pretty janky. I have the pot wired up,and all that but once I got it all wired up nothing lights up lol.

I'm probably just retarded,I don't need side tracking and flamming just help making sure all is good.

 

[oreo54]

Need more info..
Sometimes it's as simple as having a led diode wired backwards in a string..

 

[Steven Garland]

I got it figured out.

 

[oreo54]

Sooo what was it?

 

[Steven Garland]

Sooo what was it?

Well after connecting everything numerous times to the driver,something must have not been in there good enough. So I got some 20g solid core wire to replace the multi-strand that I originally got.

 

[oreo54]

Thanks for the follow up..
Yea sometimes little things are weird..

 

[User1]

What do you mean by driver? His 4 or 8LDD driver boards or the actual digital single or double dimming driver? I found back when I was using his 8LLD boards the site wasn't very clear on the documentation location so I just sent an email and he sent me the info.

Sounds like you got it all worked out though which is great. If it is the digital modules remember to use a heat sink. Those get hot.

 

[Steven Garland]

Yeah I sent Jeff and email and he got back to me,now we are trying to figure out what is wrong with the "double" driver. I may just get another single for what I want to do. No biggie. The "double" isn't getting power but the previous owner said he couldn't get it to work either,no blue led with power and the psu power light dimmly flashes.

I am waiting to get some thermal adhesive and I have 2 6" pieces of their square sink glued together to mount the drivers on as well.

What do you mean by driver? His 4 or 8LDD driver boards or the actual digital single or double dimming driver? I found back when I was using his 8LLD boards the site wasn't very clear on the documentation location so I just sent an email and he sent me the info.

Sounds like you got it all worked out though which is great. If it is the digital modules remember to use a heat sink. Those get hot.

 

[oreo54]

Trick w/ those is to get the output to closely match the input..
Adj power supplies and close to equal V(f) strings.. or good heat sinking.

They are linear drivers and need to dissipate excess voltage.. i.e like 24V ps and 12V v(f) string needs to shed 12V through the chip..

If input is like 24V and output like 23V not much of a heating problem..

Meanwell or Bluacro drivers are really preferred..
Steves driver chip has been a pretty standard workhorse chip though..

 

[Steven Garland]

Trick w/ those is to get the output to closely match the input..
Adj power supplies and close to equal V(f) strings.. or good heat sinking.

They are linear drivers and need to dissipate excess voltage.. i.e like 24V ps and 12V v(f) string needs to shed 12V through the chip..

If input is like 24V and output like 23V not much of a heating problem..

Meanwell or Bluacro drivers are really preferred..
Steves driver chip has been a pretty standard workhorse chip though..

If I was driving/powering a huge array I would definitely use LDD's or something of that nature but I am building a light for my pico,so I'm not too worried about it.

I just wanted 2 means of control and at this point it was the cheapest route and magically got this set up dropped in my lap.

 

[oreo54]

Well.. was more to show why they may get hot... ;)
And how to avoid it..

size of the array doesn't matter...

If you have a 48V power supply and run a string of diodes that uses 22.2V (6 "3W" Royal blues) you have a potential heat problem on the driver chip..

Linear drivers are a simple and cost effective solution for driving LEDs; if their heat generation is properly managed.

Basically there are only two LED driver types to select from; either linear or switching. Some of the key parameters to consider when selecting the proper LED driver are: EMI noise acceptability, supply voltage to total LED forward voltage, design/BOM complexity, driver efficiency, etc.

Switching drivers are efficient but complex since they require an MOSFET, inductor, and diode combination which will generate EMI noise.

Linear drivers are your no nonsense basic current controllers requiring minimum components and don’t generate EMI. Perhaps the only problem is they tend to get hot which limits their operation to tens of milliamps.Fortunately, ISSI has a variety of linear drivers with built in thermal management capability to cover a wide current range; from milliamps to amps.

http://www.issi.com/WW/pdf/whitepapers/IS31LT3117-Newsletter.pdf

 

[Steven Garland]

Ohhhhh lol I get what you are saying now lol. My fault I completely read thru that !!!

The psu is the lrs 75-24v I believe off of Steves site.

 

[oreo54]

So "ideally" an LED string should be slightly less than 24V total V(f) like 6 royal blue 3w diodes..

Running like 3 "moonlights" (11V) will generate a lot of heat on the driver chip.

of course all of this is diode dependent..

Point is to design the strings around the ps and driver...;)

21.6-28.8.. Adj range listed for the LRS..
Sooo one can tailor the ps a bit..w/ a VOM getting the real voltage across the diode string and dialing down or up on the ps.
Efficiency increases..

Trick is to make sure you supply more than enough voltage at that current .. dial up till string is err "stable" in voltage..
Measure..
dial down ps voltage to match.

Steve has a sheet on "tuning" drivers somewhere..

 

[Steven Garland]

Right now 1 string will be 4 royals at 3.4v at 700 and 2 violets (I can't remember the voltage) and the other will be slightly the same 1 semi nw,1 luxeon cb,1 mint and 1 390 violet.

 

[oreo54]

Hmmm.. Looks like you can turn the ps to lowest it can go..
String one should be about 21V..
Putting a VOM in series set to amps (need scale that can take 700mA to check that amp output is at "regulated" at that voltage..

Second string looks pretty low..Can't see it over 14V..IF you prefer.. might add like 2 diodes to it to balance..

I know kind of "anal"... ;)

ONE more itty bitty thing.. Driver drops .5V natively..
So input needs to be .5V larger than equal output.. IF you balance exactly..
24V power supply has a potential output of 23.5V..

Meanwells and the like usually drop 3-4V... 24v = 21V out

A word of caution regarding Steve's LEDs LED Drivers

I apologize if this information has been posted before. I couldn't find mention of it... PLEASE NOTE: I am not trying to bash Steve's LEDs LED driver circuit with this post. It is a perfectly capable LED driver and will work great so long as you realize some of the caveats of using a linear topol...

www.nano-reef.com

 

[Steven Garland]

Hmmm.. Looks like you can turn the ps to lowest it can go..
String one should be about 21V..
Putting a VOM in series set to amps (need scale that can take 700mA to check that amp output is at "regulated" at that voltage..

Second string looks pretty low..Can't see it over 14V..IF you prefer.. might add like 2 diodes to it to balance..

I know kind of "anal"... ;)

ONE more itty bitty thing.. Driver drops .5V natively..
So input needs to be .5V larger than equal output.. IF you balance exactly..
24V power supply has a potential output of 23.5V..

Meanwells and the like usually drop 3-4V... 24v = 21V out

A word of caution regarding Steve's LEDs LED Drivers

I apologize if this information has been posted before. I couldn't find mention of it... PLEASE NOTE: I am not trying to bash Steve's LEDs LED driver circuit with this post. It is a perfectly capable LED driver and will work great so long as you realize some of the caveats of using a linear topol...

www.nano-reef.com

Incredibly interesting honestly,and I really appreciate that info. I hadn't really taken any of that info into consideration. I would if possibly some different drivers would be better ?!

I have always used LDD's in the past with either a Coralux board or MakersLed basic 2up controller, so these types of drivers are a hair different to me. I guess in the meantime if they work,they work. The tank is to cure my itch for a tank until I can get stuff for my bigger setup I want lol.

 

[oreo54]

Devil is in the details... ;)