Nano DIY LED

[tomwheeler87]

Hi

 

Im looking at ordering my LEDs from you as i cant find anyone in the UK.

 

Its is for an Aqua one Aquanano 40 tank which is a 40cm Cube.

 

Id like to keep SPS in the future and also be able to control my LEDs either with a controller or an Arduino.

 

This is what i have come up with so far.

 

 

The part i am struggling with is the power requirements and the temperature calculations.

 

In series a string of blues requires 24v, whites 12v, OCW 25.8v, and true violets 12v adding the forward voltages.

 

I was looking at a 500mAh LDD for the OCW, 700mAh for the true violets and 1000mAh for the whites and blues.

 

Can i supply them all with say a 26v laptop charger and they take what they need or do i have to reduce the voltages for the separate strings?

 

The heat sinks i am looking at give there ratings in degrees C/W. can i assume that 60W's of LED's give of 60W of heat? What is the max temperature they can rise to to remain efficient?

 

Thanks in advance for your help

 

Tom

[BlueThumb]

There are a lot of people on this forum who do LED design who will hopefully comment here. I'll only comment generally about your design based on my own personal experience doing several builds.

 

Though many would disagree with me, I would not run true violets at 700mA unless they are dual core. Instead, consider running single core at 500mA .

 

Yes, you can use a 26-volt laptop power supply with the LDDs as they are voltage bucking down to 12V from what I recall.

 

As far as heat-sinks, plan to actively cool with a fan to, which helps get you away from having to use C/W to calculate how much metal you need.

[tomwheeler87]

Thanks for your fast reply.

 

I will bear that in mind with the Violets. This is my first marine tank and first DIY lighting rig so theres been a steep learning curve to get this far lol.

 

will the LDD still supply the 25.8v required for the OCW LEDs?

 

Thanks for the advice on the fan. Im looking at adding a 140mm PC case fan to the top of the heatsink and enclosing the Heatsink as looks are also important (there is no hood to hide it in). the reason the C/W is important is for the fin height, i want the light to be as thin as possible and hopefully use 25mm height profile.

 

Thanks again

 

Tom

[jedimasterben]

The LDD use around 3-4v of the input voltage, so that must be taken into account. It doesn't matter what the input voltage is, up to 56v, the LDD will convert the extra voltage into drive current so it won't use any more power on a 36v or 48v supply.

[tomwheeler87]

Thanks for that.

 

So i can use a 30v for example power supple to drive sll my strings even though they have different voltage requirements?

[tomwheeler87]

Hey

 

Can someone help me out with the above question please?

 

Thanks

 

Tom

[jedimasterben]

The LDD adjust the output to match their load, so you don't need different input voltages.

[tomwheeler87]

Thanks very much for that

 

Kind regards

Tom