Help picking a power supply.

[JayPagi]

So I've kinda settled on a new lighting setup for my tank but I don't understand the voltage requirements for ldd drivers and power supplies. Here is what I plan on doing.

 

1 x Storm LED Controller

1 x LDD-5 Board

3 x 700ma LDD drivers for RB, NW and HV)

1 x 500ma LDD driver for OCW channel)

1 x 300ma LDD driver for moonlights

 

The layout is 2 clusters of this figure.

 

 

I know I need a power supply with at least 2.9A but what about the voltage?

 

I'm also open to any suggestions regarding my setup.

[evilc66]

Your power supply voltage should always be greater than the total forward voltage of the longest string. In this case, you have your royals as the longest. 8 royal blues at 700mA should run around 24v-25v. Seeing as the LDDs need a few volts, I would start with around 28v or higher. 36v is pretty common, and allows you some room for expansion if you feel the need.

 

Don't worry about going higher than necessary on voltage. The LDD-Hs can handle up to 52v, and will regulate the voltage for the LEDs that are connected to them. You lose some efficiency, but it's nothing to worry about.

[JayPagi]

Your power supply voltage should always be greater than the total forward voltage of the longest string. In this case, you have your royals as the longest. 8 royal blues at 700mA should run around 24v-25v. Seeing as the LDDs need a few volts, I would start with around 28v or higher. 36v is pretty common, and allows you some room for expansion if you feel the need.

 

Don't worry about going higher than necessary on voltage. The LDD-Hs can handle up to 52v, and will regulate the voltage for the LEDs that are connected to them. You lose some efficiency, but it's nothing to worry about.

 

Thanks Evil... so basically I don't want to pick a power supply that supplies less voltage than my longest string and won't exceed the max capacity of the LDD-H driver.

 

Just for my knowledge, how does the LDD-H deal with all that extra voltage?

[evilc66]

LDD drivers are what are known as buck drivers. What that means is that they internally step down the voltage automatically based on the needs of the load. There are also boost drivers, which take a low voltage and make it higher, but those aren't all that common in our part of the LED world.