LED wiring question

[mockery]

Final stages of my LED planning and have a question.

I am planning to run 11 3w LEDs on this driver.
http://www.rapidled.com/servlet/the-3/driver-700ma-48v-drivers/Detail">http://www.rapidled.com/servlet/the-3/driver-700ma-48v-drivers/Detail</a>

My question; can I wire this as 2 different series strands that are parallel to the driver? So one series would have 6 LEDs and one would have 5 LEDs? And would it be possible to put a switch on one of the strands to be able to turn it on and off by a simple switch?

Hope this makes sense.

Thanks,
Colin

Here is a quick drawing of what I'm thinking. Each box is a 3w LED.
[IMG]http://i212.photobucket.com/albums/cc246/mockery1982/008c651f.jpg alt="" />

 

[roundman]

Everything I have read the strings have to be equal. Also it is recommended that you put fuses in line with each LED string so if on light goes out the other won't have to much current and blow out the second string so I think the switch might be a problem. I posted a diagram of how to set up what you are looking at on my LED thread.

 

[morganatlanta]

This won't work well for a number of reasons. If you want to be able to run two strings independently, get two 18W drivers instead of the one 30W. See

 

[mockery]

MorganAtlanta;646076 wrote: This won't work well for a number of reasons. If you want to be able to run two strings independently, get two 18W drivers instead of the one 30W. See http://www.wattsupply.com">www.wattsupply.com</a> for more driver options.[/QUOTE]

What are the reasons?
That mean well runs between 3 and 12 LEDs and I'm under the maximum and above the minimum. Do the strings need to have equal numbers? If so that I can do. I really don't want to run more them three drivers.

 

[morganatlanta]

Having problems getting this to post right....

Edit: Reason 1:
You'll get full current through the 5 leds when you have the switch open, and half current through each string when you close it.

Reason 2:
You have a mismatch in voltage requirement between the two strings. Not sure how that would affect the LEDs, but at least one or both strings won't be at the "right" forward voltage. You could fix that with a resistor, but you probably don't want this setup due to reason 1 anyway.

Reason 3:
I would use dimmable drivers unless you are sure that you have the right color mix and overall intensity base just on the number of LEDs and the driver current, but that's just a preference thing, not a "won't work" thing.

You can put all 11 LEDs in series with the driver with no problem. That would have them always on. If you want to keep 5 on and be able to turn on/off the other six, put them in all in series, but put a switch between the 5th and 6th that runs to ground. When the switch is closed, the current will shunt through that and not go through the last six LEDs. Since the power supply is variable voltage, it should adjust the voltage out to the lower requirements of only 5 LEDs versus all 11.

I'd suggest posting a full diagram of the whole setup before your order too much stuff.

 

[mockery]

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That is how the LEDs are going to be placed. Here's the basic idea of what I want to do. I'll try and map out the how each driver tomorrow. But basically I'm wondering if it is possible to turn off the color LEDs but still run 4 or 5 blues. This seems like I lot of work for 6 LEDs I think I might just have to pass on the switch part.

Weird don't know why its not showing up.

 

[morganatlanta]

The switch would need to go on the wire that goes around the colored LEDs, not on the wire to the colored LEDs. Current goes down different paths in opposite proportion to the resistance on a path. So if there is a path with zero resistance around the colored LEDs (when the switch is closed) then all of the current will flow that way. If you break that path (when the switch is open) the current will have no choice but to flow through the LEDs.

How do you plan to open/close the switch? Just a manual thing?

Personally, I'd just put them on another driver.

Also, compare sum of the red/yellow/green LED's spectrums to the spectrum of a warm white, they might effectively be almost the same thing, and it might be easier to just throw a couple warm whites in on the whites string. That would give you fewer funny colored shadows.

 

[mockery]

Probally going to be a manual switch thing. But that watts supply place when it says 18 watts does that mean it will do 6 3 watt LEDs?

Planned LED layout.

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Current wiring plan looks like this.

Dimmable driver with 9 whites and 4 blues.

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Dimmable driver with 14 blues.

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Constant current with 2 reds, 2 yellows, 2 greens, and 4 blues.

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[coolsurf]

Colin....cool LED build.

I've been doing so much research that I am going google eyed.

Red's typically run at a different forward voltage versus white and royal blue. I am going to use an additional driver just for my reds. These will be controlled by PWM. I'll run an extra white and blue to maximize my drivers. My whites and blues run an average of 3.6 and my reds will run an average of 2.6 forward voltage.

As for what you can run...(quoted) "Say an *average* CREE XR-E has a forward voltage of 3.7v @ it's maximum drive current of 1000mA. Your mean-well 60-48 produces 48 volts max. 48 divided by 3.7 is 12.97 so 12 LEDs."

 

[tjyoung]

Does anyone in here have any moonlights for sale i would prefer purple but any color will work