Power Supply Recommendation

EL Wire/Tape/Panels, LEDs, pixels and strips, LCDs and TFTs, etc products from Adafruit

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TurboBry77
 
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Power Supply Recommendation

Post by TurboBry77 »

Hello,

Have tons of adafruit products and have decided to use some of my neopixel strip to make a digital light wand. I am running the 144/meter strip, currently 1.5 meter so 216 LED. Im controlling it with the Arduino Mega. I purchased the 8AA battery pack and thought that would work. I think I was way wrong on that. I am using a 12V to 5V regulator and (2) 10uf capacitors.

I think I had enough juice to run one image on the wand and it seems there isn't enough power. What do you recommend, preferably something rechargeable if possible.

Thank you!

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adafruit_support_bill
 
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Re: Power Supply Recommendation

Post by adafruit_support_bill »

I purchased the 8AA battery pack and thought that would work. I think I was way wrong on that. I am using a 12V to 5V regulator and (2) 10uf capacitors.
What kind of regulator are you using? A linear regulator will need to burn off 7 of those 12 volts as heat to give you a 5v output. A switching type 'buck' regulator will be much more efficient. Especially if you start with a battery voltage much closer to the 5v that the pixels require.

Another approach is to use rechargeable NiMH cells. A 4x NiMH pack will be 4.8v. That is close enough to 5v for the Neopixels and there is no efficiency loss in voltage conversion.

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TurboBry77
 
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Re: Power Supply Recommendation

Post by TurboBry77 »

Ok thanks, yes its a linear regulator which I knew wasn't very efficient. I didn't realize that you had buck regulators.

I think the 8AA batteries will be eaten up too fast though? The NiMH pack may be a better fit? In that case I'd need no regulator correct, just direct power through/to the Mega and pixels?

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TurboBry77
 
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Re: Power Supply Recommendation

Post by TurboBry77 »

adafruit_support_bill wrote:
I purchased the 8AA battery pack and thought that would work. I think I was way wrong on that. I am using a 12V to 5V regulator and (2) 10uf capacitors.
What kind of regulator are you using? A linear regulator will need to burn off 7 of those 12 volts as heat to give you a 5v output. A switching type 'buck' regulator will be much more efficient. Especially if you start with a battery voltage much closer to the 5v that the pixels require.

Another approach is to use rechargeable NiMH cells. A 4x NiMH pack will be 4.8v. That is close enough to 5v for the Neopixels and there is no efficiency loss in voltage conversion.
Which buck regulator do you recommend, also do you think the 8AA is enough and it is my linear regulator that is giving me issues?

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adafruit_support_bill
 
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Re: Power Supply Recommendation

Post by adafruit_support_bill »

216 pixels requires a LOT of current. At full-white max-intensity, they will need nearly 13 Amps. When dealing with high currents like that, you want to get your primary power source as close to the load voltage as possible, because every type of power conversion has some efficiency loss.

In this case, I would look for a high-capacity 4.8v NiMH battery pack. This is close enough to 5v to run both your Mega and the Neopixel strip directly.
http://www.batteryspace.com/4-8v-batter ... -13ah.aspx

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TurboBry77
 
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Re: Power Supply Recommendation

Post by TurboBry77 »

Perfect thank you, that was one of the places I was looking at. I am also thinking about taking one of those USB portable power packs and hacking a USB cable. I have one that is 5V 1500 mah. It may get it done :-)

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