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Author Topic: Powering light strip from arduino?  (Read 1141 times)
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Aurora, ON, Canada
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Hey guys,

I recently accomplished at making led lights light up to music, was proud of that smiley

I now face a problem with powering a strip of 30 LEDs, looks a bit like this: http://www.acmelite.net/images/1/p/R30X_S/led-strip-light-R30X_S-2930.jpg

From what i see on different suppliers, this strip of lights require 12V, is there any way i can provide that much voltage from arduino, or anything close to it?

Unfortunately, i have no information on my strip of lights...

Sorry, if this is a poor question, i am only a beginner.

Cheers,

Phil.
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Massachusetts, USA
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Use and NPN transistor or an N-channel MOSFET to switch the voltage and current.  See this tutorial about high current 9and voltage) loads: http://itp.nyu.edu/physcomp/Tutorials/HighCurrentLoads
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Manchester (England England)
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You can't power the strip from the arduino but you can control the strip from the arduino.
There is an important distinction there.
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Aurora, ON, Canada
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Thanks Mike,

I found that the strip needs 12V.

Would i use a transistor to make this work?

I have a couple 2n2222 transistors and UA741CN Op Amps, would those work?

Thanks.
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Manchester (England England)
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Quote
I have a couple 2n2222 transistors and UA741CN Op Amps, would those work?
Probably not.
The 741 is a very old op amp and has no role in controlling an LED strip.
The 2n2222 can only handle 500mA of current or so. What current does you LED strip take?
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The packaging states 12V DC and 24W, so... 2A? (ohms law).
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Manchester (England England)
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Seems a reasonable assumption.

You are best using a logic level FET to switch this.
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Any specific one?

I have never used and know basically nothing about those transistors, whats the basic difference in the field effect type? i would have to do some research while i'm at it.
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From what i understand so far, you tell me to use a FET since it has a huge resistance, allowing for practically any current to go through and not damage the semiconductor?
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FET since it has a huge resistance,
No it has a very small resistance.
Try reading this:-
http://reibot.org/2011/09/06/a-beginners-guide-to-the-mosfet/
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Which FET should i buy, doesn't seem like anyone at the store was able to assist me... :\
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You want an n-channel logic level FET.
That is one where they specify the on resistance Ron at a gate voltage of 5V or so.
Most FETs need 10V on the gate to fully turn them on.
Do not mix this up with a gate threshold voltage of 5V as this is the point where the FET just starts to switch on.
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