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Topic: Constant current power supplies (Read 6 times) previous topic - next topic

draythomp

Has anyone else noticed that there are a ton of constant current power supplies out there for extremely low prices that are very small and quite powerful?  I've got a couple I'm experimenting with that supply 6-11 volts at 350ma.  I take it that that means they go as low as 6V and as high as 11V trying to supply 350ma to a fancy led or string of leds.

Well, why can't we hook one of those up to an arduino and have it run just fine.  There's already a regulator on the arduino that will take the incoming voltage and hold it at 5V for the board, so it shouldn't matter that the CCPS (constant current power supply, I just made that up) is varying its voltage as the current load changes.

Right???  Thoughts.
Trying to keep my house under control http://www.desert-home.com/

Grumpy_Mike

I have no idea what you want to acheave by connecting an arduino to a constant current supply. You will just end up supplying the maximum voltage into the arduino's vin pin.

draythomp

The supplies are amazingly cheap, on the order of a couple of bucks a piece and small, on the order of 1/2 x 3/4 x 1/2.  They hook directly to wall power, 85 - 265 VAC is not uncommon.  And, they're available all over the place.

One could put an entire arduino, power supply and all in a wall wart size package to do some project or other.

Such an item (cheap, small, common) doesn't exist for constant voltage supplies unless you gut one of those tiny wall warts, and that's a pain sometimes.
Trying to keep my house under control http://www.desert-home.com/

draythomp

go to ebay and take a look at LED power supplies.  There should be about a thousand or so.  Here's the link for the first one I found:

http://www.ebay.com/itm/Led-Driver-6-12x2W-Inside-Driver-Power-Supply-for-E27-GU10-Led-Light-Lamp-2pcs-/110982585621?pt=Lamps_US&hash=item19d713dd15

And, that was just a basic search.  Alibaba, sourcingmap, etc have many, many of these at prices that made my jaw drop.  I have two that I bought (quantity 1) for 3.95 free shipping.  If I bought ten of them and redeemed the coupon I got I would have gotten them for about .80 cents each (still free shipping).
Trying to keep my house under control http://www.desert-home.com/

retrolefty

#4
Dec 01, 2012, 02:32 am Last Edit: Dec 01, 2012, 02:36 am by retrolefty Reason: 1

go to ebay and take a look at LED power supplies.  There should be about a thousand or so.  Here's the link for the first one I found:

http://www.ebay.com/itm/Led-Driver-6-12x2W-Inside-Driver-Power-Supply-for-E27-GU10-Led-Light-Lamp-2pcs-/110982585621?pt=Lamps_US&hash=item19d713dd15

And, that was just a basic search.  Alibaba, sourcingmap, etc have many, many of these at prices that made my jaw drop.  I have two that I bought (quantity 1) for 3.95 free shipping.  If I bought ten of them and redeemed the coupon I got I would have gotten them for about .80 cents each (still free shipping).


Well check out what I bought a few days ago in the power supply regulator section of E-bay. Five buck switching regulators for $1.53 each. At that price I bought 5. Plus free shipping  ;)

http://www.ebay.com/itm/251066005460?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Lefty

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