DIY moonlight from LED bulbs...have a question??

TIMMYE · 05/29/2007, 07:33 PM

So I am trying to do a DIY moonlight for my tank using 1 watt LED's bulbs with resitors. The problem I am having is I cant get more than one to light. How can I get these to run in a series and work? I am powering these off of a 12V dc converter that ranges from 1.3 to 12V for output. I am planning on using around 11 of these. TIA Tim

nynex · 06/05/2007, 02:52 PM

Im just learning all this stuff myself. But I bought a bulk of different types of LEDs
that im using to completely light one of my nano cubes and some other projects
I have going.

First I must ask..How do you know your LEDs are 1 watt? LEDs cant be measured
in watts. They are measured in mcd's ( millicandelas). Candelas are measured at
the point of origin. 1000mcds = 1 candela or 1 candle power.

LEDs take very low power to run them and they last much much longer.
Incandescents and Flouresents are measured from watts of power it takes to
run them. Basicly you really cant truly figure out how many watts an LED is.
Different light sources could have the same power requirements, but vastly
different light output. They are just not directly related enough.For example,
searching Amazon.com I found descriptions of two different 12,000 candlepower
flashlights. One was listed as 3 watt and another listed as 1 watt.

Most LEDs used for moonlights are between 5000 and 6000 mcds and 5mm in
size. To use these with a 12 volt power supply. You want to use a 12 volt resistor
either at the end of the series (say you want to power 5 leds for moonlights) or
you can put a resistor at the end of each positive lead of each LED. So that way if
one goes out, they dont all go out. Problem is that you are wasting power with 5
resistors instead of one. You also need to know what your forward or current
voltage draw is of each LED. I would say a 5000 mcd LED most likely would have a
forward draw of 20ma. (ma stands for milliamps, 1000ma = 1 amp).

To power an array of 11 LEDs. You would need a 12 volt 300ma power supply to
run your array. With a resistor at the begining of the series and at the end. You
can wire them several different ways. This is what im learning right now.

I also found this helpful tool. It will make schematic of your array.
http://led.linear1.org/led.wiz

Hope this helps...

05/29/2007, 07:33 PM	#1
TIMMYE Registered Member Join Date: Nov 2006 Location: South Central Wisconsin Posts: 857	DIY moonlight from LED bulbs...have a question?? So I am trying to do a DIY moonlight for my tank using 1 watt LED's bulbs with resitors. The problem I am having is I cant get more than one to light. How can I get these to run in a series and work? I am powering these off of a 12V dc converter that ranges from 1.3 to 12V for output. I am planning on using around 11 of these. TIA Tim __________________ Honey, can I have a bigger one please? This is the last time I will upsize, I promise!

06/05/2007, 02:52 PM	#2
nynex Registered Member Join Date: Oct 2006 Posts: 141	Im just learning all this stuff myself. But I bought a bulk of different types of LEDs that im using to completely light one of my nano cubes and some other projects I have going. First I must ask..How do you know your LEDs are 1 watt? LEDs cant be measured in watts. They are measured in mcd's ( millicandelas). Candelas are measured at the point of origin. 1000mcds = 1 candela or 1 candle power. LEDs take very low power to run them and they last much much longer. Incandescents and Flouresents are measured from watts of power it takes to run them. Basicly you really cant truly figure out how many watts an LED is. Different light sources could have the same power requirements, but vastly different light output. They are just not directly related enough.For example, searching Amazon.com I found descriptions of two different 12,000 candlepower flashlights. One was listed as 3 watt and another listed as 1 watt. Most LEDs used for moonlights are between 5000 and 6000 mcds and 5mm in size. To use these with a 12 volt power supply. You want to use a 12 volt resistor either at the end of the series (say you want to power 5 leds for moonlights) or you can put a resistor at the end of each positive lead of each LED. So that way if one goes out, they dont all go out. Problem is that you are wasting power with 5 resistors instead of one. You also need to know what your forward or current voltage draw is of each LED. I would say a 5000 mcd LED most likely would have a forward draw of 20ma. (ma stands for milliamps, 1000ma = 1 amp). To power an array of 11 LEDs. You would need a 12 volt 300ma power supply to run your array. With a resistor at the begining of the series and at the end. You can wire them several different ways. This is what im learning right now. I also found this helpful tool. It will make schematic of your array. http://led.linear1.org/led.wiz Hope this helps... Last edited by nynex; 06/05/2007 at 03:03 PM.