Author Topic: Power supply for 12V analog LED strips  (Read 6721 times)

dougal

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Power supply for 12V analog LED strips
« on: July 24, 2013, 08:43:42 am »
A few months ago, before I had done any research, I ordered some LED strips off of eBay without paying enough attention to what I was getting. So I wound up with two 5M 12V analog LED strips.


The Adafruit tutorial for these gives a current requirement of about 1.2A/meter. So each strip would potentially need 6A, to be safe. And since I have two of them, we're talking 12A @ 12V = 144W.


So I guess to power these things, my best bet is going to be an old PC power supply? I certainly haven't seen a cheap wall wart with that kind of output recently.


Realistically, my most likely use for these will probably be to make some Christmas lighting, and I'd probably be blinking/fading them, so average current draw should be much less. But still...
 

CBcracker

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Re: Power supply for 12V analog LED strips
« Reply #1 on: July 24, 2013, 11:37:20 am »
A few months ago, before I had done any research, I ordered some LED strips off of eBay without paying enough attention to what I was getting. So I wound up with two 5M 12V analog LED strips.

The Adafruit tutorial for these gives a current requirement of about 1.2A/meter. So each strip would potentially need 6A, to be safe. And since I have two of them, we're talking 12A @ 12V = 144W.

That seems high.  3A each should be enough if they're anything like these:
http://www.taydaelectronics.com/5m-1-reel-5050-300-led-rgb-felxible-waterproof-light-strip.html
Using an old PC power supply sounds like a good idea.

Mark

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Re: Power supply for 12V analog LED strips
« Reply #2 on: July 25, 2013, 03:11:35 am »
Dougal
Sparkfun have a similar product and its 6A for the 5m length
(60mA/3 leds, 50mm spacing per 3 leds)

Some of the Laptop supplies are getting close, and I note that Sparkfun have 12v 100W (along with 150 and 300w) units available (at a price).

Most of the computer supplies have lots of 5v, but the 12v current is much lower.
A lot of the LCD monitors with external power are getting up to 100w, so you might get lucky.

Generally the LCD Monitors with a mains plug have a separate supply inside.
Be aware that you may want to replace the capacitors.
They generally have either poor quality or low hour rating capacitors for cost, but are easily replaced.

There is a good forum under http://www.badcaps.net/ which cover a wide range of products/types.


Mark

dougal

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Re: Power supply for 12V analog LED strips
« Reply #3 on: July 25, 2013, 07:17:58 am »
Another thought I had was to use them for interior lighting in my car (the ones I got aren't weatherproof). I know I can get plenty of 12V juice in there, but I'm not sure I'd know where to start. And I hesitate to start trying to take apart my 1-year-old Kia Soul.


Mark

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Re: Power supply for 12V analog LED strips
« Reply #4 on: July 25, 2013, 08:39:53 pm »
So Dougal .... what colour were you planning for the interior lighting ...???
Hopefully not a mobile red light district.

You'll probably need a manual, and do some digging around.
An optocoupler across the exiting light might be enough to trigger your other controller.


Mark