How to jump together two power supplies to run one motherboard?

[marvinmartian]

I've seen the cable on cablesaurus.  But I don't want to pay $25, especially since it just appears to be tapping two wires from the main mobo connector.

Which wires?  I can't tell from their picture.  I'd much rather spend $2 at Radio Shack on two wire lead taps and just roll my own.  I'd love to put all my 300w power supplies into service.

[cicada]

There are a couple of ways to do this.

You can simply short the GREEN PS_ON to any one of the black 'COM' pins (ground), this will render the power supply 'always on'.

If you want it to turn on with the mobo connected supply, wire the same green PS_ON pin from the mobo supply to your second supply's PS_ON pin, along with one of the adjacent COM (ground) pins.  This is how the cablesaurus adapter works.

Their adapter is handy if you're not comfortable soldering on new wires (recommended), but you can try it out just securing it with electrical tape (not recommended, definitely not permanent)

[marvinmartian]

Cool, thanks.  I don't think we need to solder wires.  These wire taps should work fine, no?

http://www.radioshack.com/product/index.jsp?productId=2104093

[BkkCoins]

You may want to use such taps on the older 300W supplies but I suspect people wouldn't want to on high end new units.

Keep in mind with older low-efficiency units you will pay a significant ongoing cost premium in electricity due to lower efficiency. Most of the older units are sub-80%, often 70% or even less in some cases. I was going to do this myself until I calculated a new 80+ supply would be paid for in 3-4 months by daily savings. Unlike an average system, where this has less effect, miner systems are usually consuming much higher loads where efficiency impacts more.

Another way to tap into supply pins for free (on some types of connectors) is to insert a thin point into the pin socket and depress the lock tab so you can remove the pin. Then you can usually carefully pry the compression joint and insert a second thin wire, and re-squeeze with pliers. As long as you get a solid joint (and maybe add tape as well) it should be good. This way is less destructive to the wiring. You can buy new pins if one becomes munged (though that is a hassle).

[jwzguy]

Safest way to do this is to buy an adapter. They're not expensive.
http://www.performance-pcs.com/catalog/index.php?main_page=product_info&products_id=21193

[Xephan]

Another way to tap into supply pins for free (on some types of connectors) is to insert a thin point into the pin socket and depress the lock tab so you can remove the pin. Then you can usually carefully pry the compression joint and insert a second thin wire, and re-squeeze with pliers. As long as you get a solid joint (and maybe add tape as well) it should be good. This way is less destructive to the wiring. You can buy new pins if one becomes munged (though that is a hassle).

What I do, and I believe it is the cheapest, easiest and reversible way, is to insert the bridging wire into through the back of the ATX connector and secure firmly it with cable tie or velcro strips. This can be done for up to control four (likely more if you use thinner wires) additional PSU.

[max in montreal]

What I do, and I believe it is the cheapest, easiest and reversible way, is to insert the bridging wire into through the back of the ATX connector and secure firmly it with cable tie or velcro strips. This can be done for up to control four (likely more if you use thinner wires) additional PSU.

you meant to say thinner or thicker...

[Xephan]

What I do, and I believe it is the cheapest, easiest and reversible way, is to insert the bridging wire into through the back of the ATX connector and secure firmly it with cable tie or velcro strips. This can be done for up to control four (likely more if you use thinner wires) additional PSU.

you meant to say thinner or thicker...

Thinner. There is only that much room around the actual green wire that you can use to insert more wires. But too thin and you risk the tip not actually making proper contact with the pin. But I don't see anybody realistically needing more than 5 PSU per board, even if they ran 6x6990, splitting 5x 800W would be more than enough even with some overclocking.

[macbook-air]

http://item.taobao.com/item.htm?id=8924249776

Less than $3. I ordered five of them. I can help you order some if you are interested. The length of the cable is customized.

[BkkCoins]

Somebody is selling those same ones on eBay for $28.95 (inc. shpg).

http://cgi.ebay.com/Dual-PSU-Power-Supply-24-Pin-Motherboard-Adapter-Cable-/150626589467?pt=PCC_Video_TV_Cards&hash=item23120b5b1b

[Reckman]

I've done this before, I simply cut the ATX off the cheaper psu, spliced the green power in wire into the host PSUs green power on wire, and spliced a ground wire into a ground on the host.

[Meatball]

You know, a heavy duty paper clip, bent and cut, works just as well for the 'always on' setup. 

[Xephan]

http://img03.taobaocdn.com/imgextra/i3/479193704/T2wDtLXa8bXXXXXXXX_!!479193704.jpg

This picture should help to make it clear to those who prefer to do it themselves for the cost of the two wires.

If you note, the secondary connector is basically connected to the primary by two wires going into the same holes as the original Pin 14 and any ground pin. This is what I mean by inserting a wire through the back of the connector.

To save money, instead of using a nice secondary connector, just repeat the insertion into the actual connector of the second PSU.

Since such a connection is not physically secured and easily loosen, use a cable tie, velcro strap or "twisty" wire to secure firmly.