DIY driver question

2clown

New member
I currently have a reefready 90 gal tank. I have diy led lights with3 watt chips. I would like to try 10 watt multichips. How many can I run on each or my current drivers? I have three meanwell lpf 90D-48 drivers. Thank you for any assistance
 

mcgyvr

New member
IMO.. The real answer is "none" (properly) with that driver..
The 1.88A constant current is too much for 3W or 10W LEDs..
A 10W is what 9-12Vf @ 1A (max)
A 3W is what 2-3.5Vf @ 1A (max)

The only way to do it (unsafely/not as reliable IMO) is run parallel strings to split that current in half..

But.. Lets assume you got a driver with a 48V @1A output..
Then the max number of 10W you can run is 48/12 = 4
The min number of 10W you can run is 3 (because 3 x 12 > 28.8 (28.8 is the min voltage for proper current regulation)

aka.. The sum of the max forward voltage drops of each LED in the string must be less than the max dc voltage output range and greater than the min dc voltage output range..
 

2clown

New member
Ok. I thought 3or 4. I was trying not to start from completely scratch. But I will have to. What I wanted to do was to continue to light the 90 and expand for a future 210. Any recommendation on drivers for 10 watt multis?
 

mcgyvr

New member
Any recommendation on drivers for 10 watt multis?

How many 10W LEDs per series string (each channel) ?
How many strings?
Vf rating of LED?
Current rating of LED?

The LPF series are great drivers.. You just need the right one..
LPF-40D-48 is perfect for 4 x 10W (given the voltage/current I posted above)
 
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2clown

New member
I'm thinking of 4 each for a total of 12 white. 12 royal blue and 8 blue, 6 5watt uv, and 6 rgb 10 watts. But why the 40 instead of the 90? I figure #1 channel for the whites, #2 for blues, #3 for misc colors.
 

oreo57

Active member
The 1.88A constant current is too much for 3W or 10W LEDs.

40@ 48v is only .84A drive current.

but that requires one driver per 4 10W chips..
DC Forward Voltage (VF): DC 9V-11V
DC Forward Current (IF): 1A

I suppose you are considering 3 rows of 4 chips in a series/parallel arrangement..In which case your 1.88A current is divided by 3 so each 4 get 626mA.
 
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2smokes

In Memoriam
For 10 w led chips you would also need MR16 driver for each led chip.They are cheap.With these you can use any 12V source as long as the source can handle.I recommend to use an old PC source as thoose can have like 400W and high amperage(i have one that goes up to 18 amp).An old 12v computer source is in my opinion more performant and safer than most of the sources buyed directly as 12 v,it has a fan for cooling and you can buy it for 5 dollars.
sku_374572_2.jpg
And here is my source of 18 amp_i used it to run xenon HID bulbs and thoose take a lot of amperage to start.
lampa_0.jpg
 

mcgyvr

New member
I'm thinking of 4 each for a total of 12 white. 12 royal blue and 8 blue, 6 5watt uv, and 6 rgb 10 watts. But why the 40 instead of the 90? I figure #1 channel for the whites, #2 for blues, #3 for misc colors.

The 40 is just about perfect for 4 x 10W LEDs as its fixed output current is 840mA and the 10W chips can handle 1000mA MAX...
The 90 is 1880mA fixed output current and is almost 2 x what the 10W chips can handle.. It will not work with series only LED circuits..
So with 10W LEDs that means 1 LPF-40d-48 for each 4 LEDs..

I will only recommend/talk about series strings with newbies.. Parallel strings of LEDs without current limiting each string is a poor choice IMO and not something for the inexperienced. If you are ready for parallel you don't have to ask questions here about it..

Now if the cost of that many LPF's is too much for you then maybe you want to look into multiple LDD drivers and a single constant voltage power supply feeding them.. 1 x 1000mA (or 750mA) LDD for each 4 x 10W LEDs will be a bit cheaper than LPF series drivers (but more wiring is involved too)
 

2clown

New member
Lpf is dimmible. Which is what I am currently doing for my 3 watt chips. I would like to continue to dim so that I fine tune for my corals. I thought about the ldd's but would need some type of controller to dim them. I'm working with a "family", diy build as I go budget.
 

oreo57

Active member
Lpf is dimmible. Which is what I am currently doing for my 3 watt chips. I would like to continue to dim so that I fine tune for my corals. I thought about the ldd's but would need some type of controller to dim them. I'm working with a "family", diy build as I go budget.


Well presently your only cheap options are (and I will start by saying SERIES/PARALLELLING 10w chips is certainly problematic)

1)Your orig thought w/ 4/3 arrangement is add "at least" 1A fuses at the end of each series string
2)Adding a current balancing circuit to each group.
https://ledlight.osram-os.com/wp-co...rentDistributioninParallelLEDStrings.Web_.pdf
http://www.ledsmagazine.com/article...en-driving-multiple-led-strings-magazine.html
and fuses..

You have 3 drivers that can't exceed a total wattage of 90x3= 270W
so .. in a sense your hard limit is really 27 10w chips..

Part of the point I'm getting at is "if" you want expand-ability in the future.. these drivers are insufficient..

Best to "bite the bullet" and go LDD because it offers a cheap path to that.. Adding $7 drivers for every 4 10w chips..

So to that effect.. you would need a 5V PWM controller. Current options in retail ones go from $30 (modified TC-420, do a search for ldd and TC-420) to $50 (Typhons,storms) to $100 plus (bluefish, bluefish mini, storm X)

you can use your "drivers" as power supplies for now AFAICT BUT need confirmation on this..

So bottom line 10LDD's @ 7 and a TC-420 is $100 w/out a new power supply..
You can expand from there to almost any size tank w/ probably 1)change in power supplies to just a "plain old" switching unit @48V (45V effective due to "losses" w/ the LDD's) and $7 driver for every 135W approx)

How are you currently dimming them?
 
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2clown

New member
I am currently using a potentiometer. But the ldd and storm combo sounds like the way to go. That way the Reef Angel I dream of would work perfectly.
 

2clown

New member
Ok. I've checked online. With 7 drivers. That's more than the number of channels that the Typhon has. So would I be able to combine some strings? Or would it be better to get the Coralux storm with 16 channels? Also, would it possible to run the 1000H ldds and under drive the lights, meaning never run at 100%? Also, running multiple boards to get the desired number of channels?
 

oreo57

Active member
Ok. I've checked online. With 7 drivers. That's more than the number of channels that the Typhon has. So would I be able to combine some strings? Or would it be better to get the Coralux storm with 16 channels? Also, would it possible to run the 1000H ldds and under drive the lights, meaning never run at 100%?
You can put a lot of LDD's on one PWM channel (at least 10).
As to Corallux vs Typhon, your call..
One thing to mention though is 'IF" you go "up" from the Typhon, go w/ higher than 8bit dimming..Just nicer..HurricaneX is 4096 "steps"
More a personal than functional choice though..
I find 4 channels a bit restrictive, esp when one goes w/ "pucks" or multichips..More depends on if you want "fancy" things..
Storm X is a nice controller..
But for the price and running LDD-h's you may want to check out the Bluefish mini.. at least if you are not "cloud" adverse..The networking thing is a bit err..daunting for some.

Going 1000mA and dimming is fine, though I'd prefer to go w/ what I consider max always.. No "pulsing"..Though most pulse around 600mH (forgot the exact but under 1000 or 1kH) avoiding any flicker is arguably best. no real proof of harm though AFAICT. sorry I can't be any more concrete on this.. It is more of a feel..


Also, running multiple boards to get the desired number of channels?

?
 

perkint

New member
I would add - knocking together a pot' based dimmer for the LDDs is very cheap and easy :) just need a pot' for each channel you want to independently alter, an arduino, a small box to put it in, a few bits of wire and a 5 - 12V PSU (ie USB or phone charger or owt like that)...

So if you just use a pot' on the LPFs it would be cheap and easy to get the same functionality for LDDs and I would say that sort of design is more flexible :)

Tim
 

oreo57

Active member
I would add - knocking together a pot' based dimmer for the LDDs is very cheap and easy :) just need a pot' for each channel you want to independently alter, an arduino, a small box to put it in, a few bits of wire and a 5 - 12V PSU (ie USB or phone charger or owt like that)...

So if you just use a pot' on the LPFs it would be cheap and easy to get the same functionality for LDDs and I would say that sort of design is more flexible :)

Tim
Actually all you need is one of those cheap "strip" dimmers (under $5 from China).
Just solder a wire from the gate of the internal MOSFET (5V PWM) and attach to the LDD PWM.
Need to power it of course (listed as 12-24V but will take less, personally used 9v) and "common" the neutral line..

dim2.JPG


Can't guarantee this "always' works.. Never got a good check on both the PWM frequency (appears to be around 900mH) nor gate voltage (appears to be 5) or Chinese changes..
But both these and the modified TC-420 worked for me..
 
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2clown

New member
Very tempting. But after looking around. I'm actually leaning toward the Storm, with an eye towards a Reef Angel setup later. The Bluefish seems to be similar. The ready made system with boards an jumpers is great. The wireless capabilities of the Bluefish are very tempting. I'm actually at work crunching numbers for the build. I'm looking into the multichips after lunch.
 

spjames

New member
I have a Reef Angel Plus and pwm expansion - you won't be disappointed when you eventually get one. I use it with a 5-up LDD-700H board ($41 populated) and a 48v, 7A switching PSU...and I'm just getting ready to add another 5-up to drive 2 more led clusters.

You can also use a 555-based pwm signal generator, about $5 on eBay to dim.
 

oreo57

Active member
You can also use a 555-based pwm signal generator, about $5 on eBay to dim.

that is pretty much what is in the "box" I posted above..
As to the 555 boards.. there seem to be some limits:

This is a nano 555 signal generator module that is able to create square waves in different duty cycles patterns from 4%-96% with selectable frequency from 0.6 to 640kHZ.

AFAICT no dim to zero..

Besides... $1.90 and you get a box and a pot..;)

http://www.ebay.com/itm/PWM-Dimmer-...401271?hash=item280f00c7f7:g:s1EAAOSwX~dWigHm

There are multiple versions.. but basically a signal generator, MOSFET, potentiometer, and voltage regulator..

pwm1.jpg


TC-420 w/ PWM "hack" only configured 4 channels for it
tcmod1.jpg

Manual dimmer:
hack.JPG
 
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perkint

New member
Actually all you need is one of those cheap "strip" dimmers (under $5 from China).
Just solder a wire from the gate of the internal MOSFET (5V PWM) and attach to the LDD PWM.
Need to power it of course (listed as 12-24V but will take less, personally used 9v) and "common" the neutral line..

Can't guarantee this "always' works.. Never got a good check on both the PWM frequency (appears to be around 900mH) nor gate voltage (appears to be 5) or Chinese changes..
But both these and the modified TC-420 worked for me..
I prefer my way - not because I think it's better, just more my home territory, if you see what I mean. Arduino, line of code or two for the dimming and a pot' :) All stuff I have and stuff I (just about!) know what im doing with! :p

Tim
 
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