Arduino Forum

Using Arduino => Project Guidance => Topic started by: superdave on May 23, 2013, 09:36 pm

Title: Power 5 meters of LED, instead of 1 meter in tutorial
Post by: superdave on May 23, 2013, 09:36 pm
I'm looking to recreate this exact project, but I would like to use 5 meters of RGB LED strip, instead of only 1 meter as found here:


http://learn.adafruit.com/rgb-led-strips/overview


According to my calculations, I need 3 amps to power all the LEDs. I plan on purchasing these:

http://www.ebay.com/itm/310396179218


Will this power supply work?

http://www.adafruit.com/products/352


Can I power the Adruino separately since it needs 5v? 

Are there any other components I need to change?

Will the N-channel MOSFETs (STP16NF06) work or do I need something else?

Any help would be appreciated!
Title: Re: Power 5 meters of LED, instead of 1 meter in tutorial
Post by: KirAsh4 on May 23, 2013, 09:42 pm
30 LEDS per meter - 5 meters = 150 LEDs.

If you only light up one channel at a time, that's 150 * 20mA = 3A
However, if you plan on lighting any combination of channels, you're going to need more.  150 LEDS x 3 channels (RGB) x 20mA (per channel) = up to 9A

You're going to run out of juice on that power supply if you turn the whole string on full white ... it will look more like a dark yellow to dark pink.
Title: Re: Power 5 meters of LED, instead of 1 meter in tutorial
Post by: superdave on May 23, 2013, 09:54 pm
Any ideas of where I can get a power supply that will work?

And are the STP16NF06 OK to use?
Title: Re: Power 5 meters of LED, instead of 1 meter in tutorial
Post by: KirAsh4 on May 23, 2013, 10:34 pm
You need something like this: http://r.ebay.com/9INoNM

I don't know the answer for the MOSFET.  Someone else with more knowledge can answer that.
Title: Re: Power 5 meters of LED, instead of 1 meter in tutorial
Post by: superdave on May 23, 2013, 10:51 pm
Are there any diagrams I can follow for which AC adapter to buy and how to wire it?
Title: Re: Power 5 meters of LED, instead of 1 meter in tutorial
Post by: alexval1323 on May 23, 2013, 10:58 pm
im trying to do something similar, but underwater...can u point me in the right direction
Title: Re: Power 5 meters of LED, instead of 1 meter in tutorial
Post by: superdave on May 23, 2013, 11:25 pm
If I wanted to power 20 meters, needing about 36 amps, could I use a computer power supply rated at 500w and wire it into the 12v wire?
Title: Re: Power 5 meters of LED, instead of 1 meter in tutorial
Post by: Grumpy_Mike on May 23, 2013, 11:30 pm

If I wanted to power 20 meters, needing about 36 amps, could I use a computer power supply rated at 500w and wire it into the 12v wire?



No because a computer supply is not 12V at 500W but many different power rails at different voltages. That amount of current is a seriously large amount and lots of other factors come into play that would normally be insignificant, like the resistance of the connecting wire and smoothing of the supply with larger capacitors.