DIY LEDs - The write-up

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I am going to try it on a 30g. This way I can start my sw experience and not have major headaches when I fill my 240g and 2x112g. For me they will be setup for a total 14ft tank [which is actually 3 tanks] so a LED system will work great. Just trying to get complete understanding

72x24x30h and 2x 48x24x30h
 
<a href=showthread.php?s=&postid=14674020#post14674020 target=_blank>Originally posted</a> by ReefEnabler
Wondering if somebody can help me answer a wiring question.

I would like to power (2) 700ma BuckPucks from a single 32VDC 2.2a power source.

In the datasheet there is mention that "Where DC input units more than 18" from source, a 220µF, 50V capacitor should be placed across the input terminals..."

Now this would of course be a nobrainer if it was one source and one buckpuck, but does it change things if I want to run two Pucks in Parallel? Do I just need a capacitor for each buckpuck??? Could I just wire the two capacitors in parallel then two the two buckpucks?
Click to expand...

The cap is for noise just put the cap across the + and _ terminals of both the Buck Pucks as close as possible to the Buck Puck terminals.
 
I just ordered 30 each of these Blues
and 30 of these White LEDs for my 90gal reef.

Will I need 5 buck pucks to drive them? If so then I think that I know how to wire them. If there is another way then please let me know.

Also what do you think is the best controller for the dollar amount out there that would be capable of running these?. Luxdrive has a 4 channel that I think would work with the 7021's.....then I'd just run the other puck on a timer.

Thanks for any input,
Kevin
 
If my tank is going to be 30x24x18 do you think i could use half the equipment you use and maybe only have to raise the fixture up to get full coverage? would i need to use the lenses for the depth of my tank?
 
<a href=showthread.php?s=&postid=14668300#post14668300 target=_blank>Originally posted</a> by kcress
Sure The0wn4g3. Now if one fries you a while to replace it before damage will occur too your others.

james3370; You will be happy with the dimmable aspect. Without it you can do nothing in that regard. I have made LED fixtures wishing I had an easy way to dim them numerous times.

Also as you dim them they last longer. Or more importantly keep there output higher.
Click to expand...

Hi Just few questions since I myself got little bit confused on few issues you have highlighted.
If I have 30 x 3 watts LEDs, which means 90 watts in total power consumption. I would like to light all 30 LEDs from a single 12Volt 100 watt LED power driver. What would the best way to place my LEDs? Parallel or Series? I need to know if one LED blows then what method would be the best to keep the rest of the LEDS working.

Would you shed your expert advice on these questions? I would highly regard your kind help.
 
and here is some info on the LED driver to run my 30 x 3 watts LEDs individual section.

DC output voltage 12V
Output voltage error ±0.5%
Rated output current 8.3A
Output current rage 0-8.3A
Wave and noise 50mVp-p
DC output power 100W
Efficiency 80%
AC input voltage range 170~250VAC
Input current 0.85A/235V
AC impulse current Cold-start current 1.0A/235V
Leakage current <0.5mA/240VAC
Overload protection 125%Type Reset: auto recovery
Temperature coefficient ±0.02%(050)
Setup rise hold up time 100ms
Vibration 10500Hz,2G 10min./1cycle,Period for 60min,Each axes
Withstand voltage Input and output interval2.0KVAC,Input and enclosure2.0KVAC,Output and enclosure500VAC
Isolation sistance Input and output interval,Input and enclosure,Output and enclosure2000VAC/3S
Working temperature and humidity -10~+60,20%90%RH
Store temperature and humidity -20~+85,10%95RH
Overall dimension 230x71x45mm
Weight 1.5Kgs
Lead Wire 0.75 mm2 VDE power cord 30CM

By the way having lovely time in Sweden....... leaving for Germany tomorrow so if I don't reply, you would know why..lol... Got to hit the bed it's nearly 2AM.....
 
Last edited:
<a href=showthread.php?s=&postid=14674020#post14674020 target=_blank>Originally posted</a> by ReefEnabler
Wondering if somebody can help me answer a wiring question.

I would like to power (2) 700ma BuckPucks from a single 32VDC 2.2a power source.

In the datasheet there is mention that "Where DC input units more than 18" from source, a 220µF, 50V capacitor should be placed across the input terminals..."

Now this would of course be a nobrainer if it was one source and one buckpuck, but does it change things if I want to run two Pucks in Parallel? Do I just need a capacitor for each buckpuck??? Could I just wire the two capacitors in parallel then two the two buckpucks?
Click to expand...

Hi Reef,
Those caps are for stability of the switching controller inside the BuckPucks. Without them the switching controller can go into damaging oscillation.

They are for each controller so if you have leads that long running to each, then each should have a cap. If you ran say a 6 foot cord from the floor up to the hood where the two BPs were mounted 4~5 inches apart you would need just one to nullify the wires run up from the power supply. If you had several BPs you'd want more than just one though.
 
<a href=showthread.php?s=&postid=14676016#post14676016 target=_blank>Originally posted</a> by tahiriqbal
Hi Just few questions since I myself got little bit confused on few issues you have highlighted.
If I have 30 x 3 watts LEDs, which means 90 watts in total power consumption. I would like to light all 30 LEDs from a single 12Volt 100 watt LED power driver. What would the best way to place my LEDs? Parallel or Series? I need to know if one LED blows then what method would be the best to keep the rest of the LEDS working.

Would you shed your expert advice on these questions? I would highly regard your kind help.
Click to expand...


Hi tahiriqbal.

It depends heavily on the forward voltage Vf of the LEDs you are using.

You cannot drive more than a certain amount of forward voltage with any particular voltage supply.

Example: If you have 3.2V LEDs four in series would add up to 3.2V+3.2V+3.2V+3.2V = 12.8V

Since this forward voltage sum exceeds a 12V supply very likely the LEDs would not even glow. The supply voltage has to exceed the sum of all the LED's Vf in series by a finite amount. Typically a 1V or so. This 1V would be called "head room" and is the voltage your driver(possibly a BuckPuck) would work with to regulate the current to whatever it's data sheet specifies.

This means that if you stick with your 12V supply and if your LED's Vf is 3.2V you would only be able to use three in series to leave some head room for the driver.

This means with 30 LEDs you'd need 10 drivers to provide the ten - 3 LED strings.

This gets pretty pricey. This is why you want a higher supply voltage. A 24V supply would allow 24V/3.2V = 7 LEDs in a string.

30/7 = 4 drivers. (With 3 LEDs left over)


Alternatively you can use a 32V supply. Now 32V/3.2V = 10 per string. BUT(!) you have to keep in mind the "head room" I mentioned and since 10 LEDs leaves NO head room you must use only 9 LEDs per string.

So 30/9 = 3 (strings of 9 LEDs in series) [and three unused spares(?)] It also means only three drive controllers.

This goes on up in a continuing manner. But! You really start to need to know what you're doing, as 48V is starting to get to dangerous personal levels. Furthermore driver availabilities start topping out at these higher voltages and become harder to find.

Streetlights sometimes run 80 to 100V strings of LEDs. But they are an engineered device meeting special requirements.

So tahiriqbal, my recommendation for you to protect your investment in LEDs is to dump that 12V supply.

Get a 24V or 36V supply.

Look up the Vf for your LEDs and do the math I showed above.

Then get the number of BuckPucks you need to do the job for however many strings you arrive at.

This is the only way to properly protect and drive these more expensive high power LEDs.
 
Kcress
You seem to know more about LEDs and drivers then most.... what LED Driver would you recommend or have used that is dimmable by PWM and has a shutdown pin and requires few external components. Also do you know what they use in the Buck Puck?
 
Hi lynxvs.

I haven't used many off-the-shelf drivers because I normally design drivers from scratch for commercial use and don't use pre-made ones.

I can say that there are three main ones out there.

1) The BuckPucks we've been discussing.

2) LumiDrives: http://www.ledsupply.com/lumidrives.php

3) Xitaniums: http://www.ledsupply.com/xitanium.php

BuckPucks you need to feed with you own DC power supply. This kind of setup is always going to be less efficient than the second two listed above. These are called OFF-LINE drivers. You power them from the wall directly. There is no separate power supply. The reason they can be more efficient is because they actually convert the wall power down to exactly what's needed by your LED chain. This is in contrast to a supply creating a fixed voltage, like 24VDC and then another device having to limit or control that in turn.

As for dimming and an ON/OFF signal, I don't think any of these have that, though they may have models I haven't seen yet.
 
<a href=showthread.php?s=&postid=14668300#post14668300 target=_blank>Originally posted</a> by kcress
james3370; You will be happy with the dimmable aspect. Without it you can do nothing in that regard. I have made LED fixtures wishing I had an easy way to dim them numerous times.

Also as you dim them they last longer. Or more importantly keep there output higher.
Click to expand...

yeah, i think i'm gonna bite the bullet & go ahead & order the dimable w/ pot....heck it's only $25 w/ shipping
 
<a href=showthread.php?s=&postid=14676307#post14676307 target=_blank>Originally posted</a> by tahiriqbal
and here is some info on the LED driver to run my 30 x 3 watts LEDs individual section.

DC output voltage 12V
Output voltage error ±0.5%
Rated output current 8.3A
Output current rage 0-8.3A
Wave and noise 50mVp-p
DC output power 100W
Efficiency 80%
AC input voltage range 170~250VAC
Input current 0.85A/235V
AC impulse current Cold-start current 1.0A/235V
Leakage current <0.5mA/240VAC
Overload protection 125%Type Reset: auto recovery
Temperature coefficient ±0.02%(050)
Setup rise hold up time 100ms
Vibration 10500Hz,2G 10min./1cycle,Period for 60min,Each axes
Withstand voltage Input and output interval2.0KVAC,Input and enclosure2.0KVAC,Output and enclosure500VAC
Isolation sistance Input and output interval,Input and enclosure,Output and enclosure2000VAC/3S
Working temperature and humidity -10~+60,20%90%RH
Store temperature and humidity -20~+85,10%95RH
Overall dimension 230x71x45mm
Weight 1.5Kgs
Lead Wire 0.75 mm2 VDE power cord 30CM

By the way having lovely time in Sweden....... leaving for Germany tomorrow so if I don't reply, you would know why..lol... Got to hit the bed it's nearly 2AM.....
Click to expand...

So "Kcress", this LED driver would not do the job to run my 30 x 3 watts = 90 watts total useage section?

Are you sure this won't work?
 
<a href=showthread.php?s=&postid=14678455#post14678455 target=_blank>Originally posted</a> by kcress
Hi lynxvs.

I haven't used many off-the-shelf drivers because I normally design drivers from scratch for commercial use and don't use pre-made ones.

I can say that there are three main ones out there.

1) The BuckPucks we've been discussing.

2) LumiDrives: http://www.ledsupply.com/lumidrives.php

3) Xitaniums: http://www.ledsupply.com/xitanium.php

BuckPucks you need to feed with you own DC power supply. This kind of setup is always going to be less efficient than the second two listed above. These are called OFF-LINE drivers. You power them from the wall directly. There is no separate power supply. The reason they can be more efficient is because they actually convert the wall power down to exactly what's needed by your LED chain. This is in contrast to a supply creating a fixed voltage, like 24VDC and then another device having to limit or control that in turn.

As for dimming and an ON/OFF signal, I don't think any of these have that, though they may have models I haven't seen yet.
Click to expand...

Do you mean you design drivers from discrete components or from some IC?. If it's an IC which one do you use?
 
tahiriqbal; You keep calling that power supply a "driver"!! It is not a driver in any way. It is just a 12V source.

You need to look carefully at these things. I see these all the time that say, "LED supply", but you look closely and see it is just a power supply to be used with a driver and the power supply maker is fishing for new customers by using the latest buzz word, "LED".

If you want to run LEDs with it and no driver you would need some whopping power resistors to drop the excess voltage down so the LEDs are driven at their optimum current.

While wasteful of some energy and unable to compensate for voltage and temperature changes resistors can be used to good effect. This is because our tank hoods live in a pretty constant temperature. The down side is the values need to figured out by trial and error which can be very tedious and resistors alone don't provide any protection from a shorted LED to the rest of the string.
 
Those Xitanium drivers look nice, but it does look rather expensive since it would require so many.

The 700ma version only puts out 17w..... or is there a way to get the higher current versions to power more LEDs at lower current?

Seems like if you wanted to spend alot on power supplies, why not just get buckpucks and go all out with a controllable DC power supply, not really much more expensive :D

i-market_2045_45999705
 
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