on/off timer for diy led build?

[dread240]

I see that you had them drawn as 2 strings of 4... combining them puts you at 32fv and still within spec's of a 700l driver and lets you add more to other strings (which you will, believe me... with what you've chosen you're going to want more blue/violet to get color)

the current does not change... with 700l drivers they're each pulling 700ma of current... so you would need 2800ma for 4 channels, or 2.8a

With those drivers and power supply though... you could run up to...

8 4v whites
9 3.5v blues
13 2.4v reds
8 3.8 violets

Those numbers increase if you go with a 48v supply and the H series drivers... the L's can only take up to 36v input, the H's up to 54v input

I was actually able to bump my ebay 48v power supply up to about 52v... so I have 49v available to the drivers (need a 3v overhead)... which allows me to run upwards of 16 LED's per string

The biggest benefit of using constant current drivers is that you don't have to mess with the power for the LED's... the drivers will take care of it for you... just have a power supply capable of the demand and let them handle the voltage control depending on how many LED's you've stuck on the string

 

[dread240]

I guess I should explain a bit more on how the drivers work....

These are constant current drivers... meaning they supply a steady amperage depending on the model and dimming... at max intensity a 700l(h) provides 700ma... a 1000h provides 1000ma... 400l(h) 400ma and so on

They vary the voltage to meet the demands placed on the driver all while keeping current constant... These drivers actually vary the v- side of it...

If you hook it up to a 36v... then the vout+ is at 36v....

It can sense by current draw the load put on it... so if you put say 4 3v LED's on the driver... it keeps vout- at 24v... which gives you a potential difference of 12v to power your string (each LED uses up 3v)

If you add 4 more LED's to that string it sense the current and moves vout- to 12v... giving you a 24v potential difference, so that it can maintain the 700ma current on the string

There is an absolutely huge thread on the meanwell LDD drivers in the diy forums

http://reefcentral.com/forums/showthread.php?t=2222702

it's a great read and will clear up alot of your questions and misconceptions over how this all works