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bone_z
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Computer Power Source

07/03/2012 4:55 AM

Good day to all! If one would like to use a desktop power source for other uses rather than to power a PC, how do we have to connect the end terminals?
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Lo_Volt
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#1

Re: Computer Power Source

07/03/2012 7:35 AM

I worked with an old technician that found usage for an old AT style PC power supply on his test bench. He even added an indicator to show that it was powered up. He used it for powering boards or devices that required 5 or 12 volts.

PC power supplies are very low cost per watt, even when they are new and there are plenty of 'dead' PC's with perfectly good supplies being tossed into the landfills.

The ATX style supplies have a 'Power on' signal that must be grounded to turn the supply on.

See more info here:

Wikipedia: Power_supply_unit_(computer)
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NotUrOrdinaryJoe
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#2
In reply to #1

Re: Computer Power Source

07/03/2012 7:46 AM

How about this?

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Deefburger
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#7
In reply to #2

Re: Computer Power Source

07/04/2012 11:47 AM

That is a USB. Yes, there is +5V. No, there is not much current available. Next slide please!

Most modern PC power supplies have a low voltage solid state "switch" wire and it is usually Purple. It is in the 20 or 24 Pin connector that usually goes to the motherboard. When that line is connected (i think it is already +5V) to ground, the power supply turns on.

There are many usable voltages and they are output from the supply on several wires. All of the wires of the same color can generallly be ganged together for a large current source. Very handy.

Here is a pin-out diagram of a typical supply:

http://www.smpspowersupply.com/connectors-pinouts.html

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bone_z
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#6
In reply to #1

Re: Computer Power Source

07/04/2012 9:54 AM

So, you ground it to all zero volt´s terminals?
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rakesh_semwal
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#3

Re: Computer Power Source

07/03/2012 10:45 AM

A printed sticker at the side of PC SMPS tell's all wires volts and Amps rating with ref to common.
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SolarEagle
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#4

Re: Computer Power Source

07/03/2012 4:56 PM

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Deefburger
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#8
In reply to #4

Re: Computer Power Source

07/04/2012 11:47 AM

Hey! That's cool!

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leveles
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#5

Re: Computer Power Source

07/03/2012 11:52 PM

Well, yes, The switch, terminal lugs and fan are add-ons of this home modified power block. Some need some load to start up at all. They regulate decently, but electrically noisy.

Power supplies feeding a printer or such have one 110V cable and one, usually 12V or 24VDC connector. Easy to use. Do not overload.
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pantaz
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#9

Re: Computer Power Source

07/04/2012 5:26 PM

I've seen many tips and plans for doing this...

http://www.google.com/search?q=atx+power+supply+hack
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cwarner7_11
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#10

Re: Computer Power Source

07/04/2012 5:53 PM

Using an ATX computer power supply to power my Prusa Mendel 3D printer:

The actual connections (note- all I needed was various 12 V supplies and grounds- yellow is 12 V and ground is black):

The switch is used to short the "power on" signal to ground:

This gives me an "emergency" shut-off in case the extruder runs away and starts shooting hot polymer all over the place (so far, I haven't had a call to use the emergency shutoff...)
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Users who posted comments:

bone_z (1); cwarner7_11 (1); Deefburger (2); leveles (1); Lo_Volt (1); NotUrOrdinaryJoe (1); pantaz (1); rakesh_semwal (1); SolarEagle (1)

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