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Author Topic: Good power supply for arduino projects (7.5A @ 5V)  (Read 1782 times)
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North Yorkshire, UK
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I thought I would throw this one in as a good(?) power supply for arduino projects.

https://www.voltageconversion.co.uk/store/product.php?productid=16276
If you're anything like me then you have had times when you've been running a servo motor and an LCD and the brightness dims every time the servo motor moves (becuase you're using a shitty 600mAh power supply).

That power supply should solve all that. It will pump out 7.5A at 5v and still good at other voltages. Because it is designed with laptops in mind, it should be pretty smooth and precise.

Yes I know you can get an ATX power supply and pump out about 30A at 5v but you normally have a fan, it is much bigger and it is not as neat and easy to transport.

If anyone has any alternatives then please say before I go and buy one of these smiley-grin

Mowcius
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If anyone has any alternatives then please say before I go and buy one of these

Looks good to me. Are you going to use this just for external +5vdc devices, or are you also wishing to power your Arduino board at the same time? Wiring +5vdc directly to an Arduino's 5vdc pin can be tricky when you then plug in the USB link as you are then tying in two different +5vdc sources together and that can lead to problems as they are usually not at exactly the same voltage.

Lefty

Lefty
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Looks good to me. Are you going to use this just for external +5vdc devices, or are you also wishing to power your Arduino board at the same time? Wiring +5vdc directly to an Arduino's 5vdc pin can be tricky when you then plug in the USB link as you are then tying in two different +5vdc sources together and that can lead to problems as they are usually not at exactly the same voltage.

Lefty

Lefty

I would be using it on 7-8v when prototyping and 5v with a 'finished' project when I don't need to plug in my arduino again.

Have you gained a second name somewhere?

Mowcius

Mowcius smiley-grin
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Have you gained a second name somewhere?

Must have been typing from both sides of my brain.  smiley-wink

Lefty (one and only)
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Must have been typing from both sides of my brain.

Ahh, I see. I do that sometimes smiley-grin
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Laptop brick may or may not be overkill, I guess it depends on what your doing, but these generic bricks are so cheap, if your looking for a beefy supply then how can you go wrong.

Well heres how, Most laptop bricks are on the high side of voltage, 14-24 volts, most lappys run on 18.x, I was surprised that this one goes as low as 5 volts... yea the 7805's can handle it but at a very high heat price.

Also do you know how to select what its going to run at, I dont see any switches on it

[edit]my bad theres a "slot" on the side, didnt see that in the description the first time[/edit]
« Last Edit: December 16, 2009, 05:25:53 pm by Osgeld » Logged


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I was pleasantly pleased to find a module that looks just like that, rated at +12vdc at 4 amps, at a thrift store for $2 last week. Regulated switching supplies sure are small and light for their ratings. 8-)

Lefty
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oh yea, Ive got a couple 12v 3 amp supplies one is old iron the other switching

the old iron one is about the size of a man's shoe (well maybe not that long) and the switching one is so small its questionable
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Just a word of caution. The problem with a supply that can provide a lot of current is that it is very unforgiving of short circuits. Things tend to melt rather than just trip the over current protection. This includes tracks on PCBs vaporising. This is much more difficult to repair.
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Just a word of caution. The problem with a supply that can provide a lot of current is that it is very unforgiving of short circuits. Things tend to melt rather than just trip the over current protection. This includes tracks on PCBs vaporising. This is much more difficult to repair.

Yeah hadn't thought of that. Maybe not good for everything then but if you need to power a high power circuit then it's probably a good one to get...

I suppose you can fit in a auto-resettable fuse in the loop?

Mowcius
« Last Edit: December 17, 2009, 09:41:59 am by mowcius » Logged

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In the US, these folks sell pretty decent stuff.  I've bought some chargers from them.
http://powerstream.com/power2-3-6.html

And here's a little reminder - this offer still stands since I have a big pile of various models in my garage right now: I'll send you one free plus the cost of shipping.
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1254460064

If you short one of these babies out, you'll make heater elements out of your wires, if for only a moment.  So be sure to put a light-weight fuse on there or at least be very careful.  I accidentally shorted mine out on the 12V line and effectively arc-welded a paper clip to the pin of a 50W halogen bulb.  It was rather startling.   :o
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And here's a little reminder - this offer still stands since I have a big pile of various models in my garage right now: I'll send you one free plus the cost of shipping.
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1254460064
I know nothing about what all of these look like. I may be interested. Can you stick up a few photos? You got any small ones? Fanless ones? Ones that don't weigh a tonne? (postage could get expensive - that's a metric tonne  smiley-wink).

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If you short one of these babies out, you'll make heater elements out of your wires, if for only a moment.  So be sure to put a light-weight fuse on there or at least be very careful.  I accidentally shorted mine out on the 12V line and effectively arc-welded a paper clip to the pin of a 50W halogen bulb.  It was rather startling.
Yeah it sounds interesting. I have soldered to a 9v battery before (by accident of course) and that was bad enough. I may get one just for some fun high current experiments ;D

Mowcius
« Last Edit: December 18, 2009, 02:08:50 pm by mowcius » Logged

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if you link dance to 3 deep you can see it

http://www.rcgroups.com/forums/attachment.php?s=d33aa0d3a1029ba5f8ab54318140ee44&attachmentid=2781176&d=1253952079
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Can you stick up a few photos?
http://www.chesterfamily.org/gallery/ProjectsAndStuff/ServerPowerSupplies/

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You got any small ones? Fanless ones? Ones that don't weigh a tonne?
Sort of, no and maybe.  The smallest ones may not work.  I haven't tried them yet and they all were rejected by their servers as "bad".  It may only mean they were out of spec or could be that they smoked.  The noise isn't so bad that you wouldn't want it on the workbench.  But more than you want running in the house for long periods.  The heaviest one is about 7lbs (3kg) and twice the size of a red brick.  

I've gotten two of the five shown to work.  One became my new bench supply.  The other is the 106A/12V unit.  I haven't tried the others yet.   But so far the concept is the same - you have to ground two control pins to get the units to turn on.  It's usually the shortest pin ("Pwr OK") and one other ("PS On").  You have to probe around with a 1k resistor to ground to find them.  However, in some cases there is an emergency shut-off pin that will kill the supply until power is removed and restored.  That always makes the search for the right pins just a little more interesting.  smiley-wink  I've documented the two I got to work.

If you want one, PM me your address and I'll figure out the shipping costs.
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What about elevensies? Luncheon? Afternoon tea? Dinner? Supper?

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