PSU hotwire Question?

**magnethead** · 08-12-2008, 01:48 AM

I'm converting an old 235W ATX PSU (chose it over the AT i have for 3.3 and -5V) into a cheapo lab bench supply, what i read says solder the green and black together, but i thought you just tap them? OR does it matter?

Which is proper- constant connection, or momentary?

**linderman** · 08-12-2008, 04:36 PM

I am rather sure its suppose to be constant

**magnethead** · 08-12-2008, 08:57 PM

you would be right my friend.

blue/black: -10.9 (0.8A)
white/black: -4.9 (0.5A)
orange/black: +3.3 (14A)
red/black: +5.1 (23A)
yellow/black: +11.5 (8A)

yellow/red: +6.4 (8A)
orange/red: -1.7 (14A)
white/red: -10.00 (0.5A)
blue/red: -16.00 (0.8A)

orange/yellow: -8.1 (8A)
blue/yellow: -22.4 (0.8A)
white/yellow: -16.4 (0.5A)
red/yellow: -6.3 (8A)

blue/orange: -14.2 (0.8A)
white/orange: -8.2 (0.5A)
red/orange: +1.8 (14A)
yellow/orange: +8.2 (8A)

white/blue: +5.9 (0.5A)
orange/blue: +14.3 (0.8A)
red/blue: +16 (0.8A)
yellow/blue: +22.5 (0.8A)

blue/white: -5.98 (0.5A)
orange/white: +8.31 (0.5A)
red/white: +10.1 (0.5A)
yellow/white: +16.52 (0.5A)

looks like both the positive and negative 12 volt rails are off by a full volt. amperages listed are the lesser rated of the 2 chosen wires. connected positive lead to first wire, negative to second.

**magnethead** · 08-12-2008, 09:15 PM

List, significant amps/pos volts only:

orange/black: +3.3 (14A)
red/black: +5.1 (23A)
yellow/black: +11.5 (8A)

yellow/red: +6.4 (8A)

red/orange: +1.8 (14A)
yellow/orange: +8.2 (8A)

so, loks like things that can be powered are (other than power brick devices):

1.5V (1 AA)
3V (2 AA)
5V (??? or comp)
6V (4 AA or lantern batt)
8V (????)
9V (6 AA or 9V batt) barely
12V (auto, comp) barely

oh, plus i left 2 molexes on it :D

**peterhuang913** · 08-12-2008, 09:30 PM

Yea, green and black. I've always just used a paperclip and left the connectors intact.

**magnethead** · 08-12-2008, 09:32 PM

my next task may be buying a 24 pin 12" extension cable (so it supports 24 and 20 pin plugs), and cutting off the motherboard side.So i can basically have a box I carry with me, just plug the 20/4 pin in and have an instant bench unit, without cutting wires permanently. and use speaker style spring loaded connectors for connections, plus a female car power socket on the 12V rails.

**linderman** · 08-13-2008, 01:20 PM

sounds very promising

**magnethead** · 08-13-2008, 10:53 PM

Well, here's what i got. Using the above idea would be nice and (mostly) organized, but costly.

Price as pictured: 2.75 for the barrier strip. And I kept the purple, green, and gray wires uncut inside, incase i want to use them at a later time.

08-12-2008, 01:48 AM	#1 (permalink)
magnethead Registered User Join Date: Mar 2006 Location: Texas, USA Posts: 3,570 OS: Vista ultimate 32bit My System Blog Entries: 3	PSU hotwire Question? I'm converting an old 235W ATX PSU (chose it over the AT i have for 3.3 and -5V) into a cheapo lab bench supply, what i read says solder the green and black together, but i thought you just tap them? OR does it matter? Which is proper- constant connection, or momentary? __________________ For proper support: what are you running? graphics, cpu, m/board, ram, PSU brand wattage PCI-E requires 26 amps at 12 volts. That's a 650W PSU. Power Supply Info and Selection . Info on thermal compounds & application . TEST PSU USING MULTI-METER . Bench Testing Your System

08-12-2008, 04:36 PM	#2 (permalink)
linderman Moderator, Hardware Team Join Date: May 2005 Posts: 20,437 OS: win 2000 pro / Win XP pro My System	Re: PSU hotwire Question? I am rather sure its suppose to be constant __________________ I still know nothing and I respect that fact, striving to improve and, along the way, help anyone that comes from the place that I used to be! Power Supply Selection LEARN TO BACK-UP YOUR DATA FREE & EASY YouTube - Runtime Software DriveImage XML tutorial

08-12-2008, 08:57 PM	#3 (permalink)
magnethead Registered User Join Date: Mar 2006 Location: Texas, USA Posts: 3,570 OS: Vista ultimate 32bit My System Blog Entries: 3	Re: PSU hotwire Question? you would be right my friend. blue/black: -10.9 (0.8A) white/black: -4.9 (0.5A) orange/black: +3.3 (14A) red/black: +5.1 (23A) yellow/black: +11.5 (8A) yellow/red: +6.4 (8A) orange/red: -1.7 (14A) white/red: -10.00 (0.5A) blue/red: -16.00 (0.8A) orange/yellow: -8.1 (8A) blue/yellow: -22.4 (0.8A) white/yellow: -16.4 (0.5A) red/yellow: -6.3 (8A) blue/orange: -14.2 (0.8A) white/orange: -8.2 (0.5A) red/orange: +1.8 (14A) yellow/orange: +8.2 (8A) white/blue: +5.9 (0.5A) orange/blue: +14.3 (0.8A) red/blue: +16 (0.8A) yellow/blue: +22.5 (0.8A) blue/white: -5.98 (0.5A) orange/white: +8.31 (0.5A) red/white: +10.1 (0.5A) yellow/white: +16.52 (0.5A) looks like both the positive and negative 12 volt rails are off by a full volt. amperages listed are the lesser rated of the 2 chosen wires. connected positive lead to first wire, negative to second. __________________ For proper support: what are you running? graphics, cpu, m/board, ram, PSU brand wattage PCI-E requires 26 amps at 12 volts. That's a 650W PSU. Power Supply Info and Selection . Info on thermal compounds & application . TEST PSU USING MULTI-METER . Bench Testing Your System Last edited by magnethead; 08-12-2008 at 09:12 PM.

08-12-2008, 09:15 PM	#4 (permalink)
magnethead Registered User Join Date: Mar 2006 Location: Texas, USA Posts: 3,570 OS: Vista ultimate 32bit My System Blog Entries: 3	Re: PSU hotwire Question? List, significant amps/pos volts only: orange/black: +3.3 (14A) red/black: +5.1 (23A) yellow/black: +11.5 (8A) yellow/red: +6.4 (8A) red/orange: +1.8 (14A) yellow/orange: +8.2 (8A) so, loks like things that can be powered are (other than power brick devices): 1.5V (1 AA) 3V (2 AA) 5V (??? or comp) 6V (4 AA or lantern batt) 8V (????) 9V (6 AA or 9V batt) barely 12V (auto, comp) barely oh, plus i left 2 molexes on it :D __________________ For proper support: what are you running? graphics, cpu, m/board, ram, PSU brand wattage PCI-E requires 26 amps at 12 volts. That's a 650W PSU. Power Supply Info and Selection . Info on thermal compounds & application . TEST PSU USING MULTI-METER . Bench Testing Your System Last edited by magnethead; 08-12-2008 at 09:25 PM.

08-12-2008, 09:30 PM	#5 (permalink)
peterhuang913 TSF Enthusiast Join Date: May 2008 Posts: 946 OS: XP Home SP2	Re: PSU hotwire Question? Yea, green and black. I've always just used a paperclip and left the connectors intact.

08-12-2008, 09:32 PM	#6 (permalink)
magnethead Registered User Join Date: Mar 2006 Location: Texas, USA Posts: 3,570 OS: Vista ultimate 32bit My System Blog Entries: 3	Re: PSU hotwire Question? my next task may be buying a 24 pin 12" extension cable (so it supports 24 and 20 pin plugs), and cutting off the motherboard side.So i can basically have a box I carry with me, just plug the 20/4 pin in and have an instant bench unit, without cutting wires permanently. and use speaker style spring loaded connectors for connections, plus a female car power socket on the 12V rails. __________________ For proper support: what are you running? graphics, cpu, m/board, ram, PSU brand wattage PCI-E requires 26 amps at 12 volts. That's a 650W PSU. Power Supply Info and Selection . Info on thermal compounds & application . TEST PSU USING MULTI-METER . Bench Testing Your System Last edited by magnethead; 08-12-2008 at 09:34 PM.

08-13-2008, 01:20 PM	#7 (permalink)
linderman Moderator, Hardware Team Join Date: May 2005 Posts: 20,437 OS: win 2000 pro / Win XP pro My System	Re: PSU hotwire Question? sounds very promising __________________ I still know nothing and I respect that fact, striving to improve and, along the way, help anyone that comes from the place that I used to be! Power Supply Selection LEARN TO BACK-UP YOUR DATA FREE & EASY YouTube - Runtime Software DriveImage XML tutorial

08-13-2008, 10:53 PM	#8 (permalink)
magnethead Registered User Join Date: Mar 2006 Location: Texas, USA Posts: 3,570 OS: Vista ultimate 32bit My System Blog Entries: 3	Re: PSU hotwire Question? Well, here's what i got. Using the above idea would be nice and (mostly) organized, but costly. Price as pictured: 2.75 for the barrier strip. And I kept the purple, green, and gray wires uncut inside, incase i want to use them at a later time. __________________ For proper support: what are you running? graphics, cpu, m/board, ram, PSU brand wattage PCI-E requires 26 amps at 12 volts. That's a 650W PSU. Power Supply Info and Selection . Info on thermal compounds & application . TEST PSU USING MULTI-METER . Bench Testing Your System