20mA power source for LED strips tutorial?

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Kokodoko
 
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20mA power source for LED strips tutorial?

Post by Kokodoko »

Hi,
I am building a Neopixel installation with 330 pixels. It would be great if I could use this power supply (see link), which supplies 20mA, which should be exactly enough.
The store page mentions that this device can be used for LED strips, can anybody point me to a tutorial that shows how to use this kind of power supply? Will this work for Neopixels?

And perhaps most importantly, being a beginner, am I in any danger of electrocuting myself, should I accidentally plug a wire into the wrong breadboard hole?
Screen Shot 2014-09-11 at 17.00.35 .png
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Re: 20mA power source for LED strips tutorial?

Post by adafruit_support_bill »

It would be great if I could use this power supply (see link), which supplies 20mA,
Actually it supplies 20A. An Amp (A) is 1000 milliamps (mA).
20A is just about right for a 330 Neopixel installation. But it is a lot of power, and potentially dangerous if not wired properly. We do have a guide for powering Neopixels here:
https://learn.adafruit.com/adafruit-neo ... uide/power
But for large, high powered installations, we recommend that you consult with an engineer or electrician familiar with safety and local wiring codes.

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Kokodoko
 
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Re: 20mA power source for LED strips tutorial?

Post by Kokodoko »

Thanks for the warning. 20Amps will require a much more careful approach, I will keep that in mind.
The alternative would be splitting up the pixels into groups - requiring several Arduinos. But this makes it harder to create a sequential animation.

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Re: 20mA power source for LED strips tutorial?

Post by adafruit_support_bill »

You can control several groups from a single Arduino. Just connect each group to a different pin.
You can also spread the power for a single strip among several smaller power supplies.

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Kokodoko
 
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Re: 20mA power source for LED strips tutorial?

Post by Kokodoko »

So I can connect several power sources to one strip, as in this sketch? That would simplify matters a lot!
(note: I know the trinket doesn't have enough RAM, I'll need a PRO trinket or an UNO)
dual_power_330pixels.png
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Re: 20mA power source for LED strips tutorial?

Post by adafruit_support_bill »

If you are using multiple supplies, you do need to isolate the 5v side. With 2 supplies as shown, simply cut the 5v trace in the middle of the strip so that you have two separate power zones. Leave all the grounds connected.

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