computer PS and ohm law

I am trying to use an atx pc power supply without wasting your time going to details

There are two type of connectors:

1- One is 10pins x2 raw female connector 2- 3or4 with one raw of four pins (these you hook them to HD, floppy D, etc.

I think all I need is the first one

Green should be connected to ground, now the question Some suggest using small resistor, where do I hook it

If I need 12V which do I use? Yellow and ?? If I need 5V which do I use? Red and ?? If I need 3.3V which do I use? Orange and ??

can i use ohm law if using the 12V, would it be ok to use 10wat 2Ohm resistor so i get 6Amp and so on.

thanks in advance

Jed That should be fine but make sure to use the power equation P=IE so you pick the correct wattage! It seems to me that 6amps at 12 volts is going to need at least a 72 watt, or the next size up, resistor....Why don't you just fuse it if you are worried about overdrawing the supply. That resistor would be quite large......Probably a 2 ohm 100 watt!! For the wire colors...I would just do a Google search... good luck on your project....Ross

I am trying to use an atx pc power supply without wasting your time going to details

There are two type of connectors:

1- One is 10pins x2 raw female connector 2- 3or4 with one raw of four pins (these you hook them to HD, floppy D, etc.

I think all I need is the first one

Green should be connected to ground, now the question Some suggest using small resistor, where do I hook it

If I need 12V which do I use? Yellow and ?? If I need 5V which do I use? Red and ?? If I need 3.3V which do I use? Orange and ??

can i use ohm law if using the 12V, would it be ok to use 10wat 2Ohm resistor so i get 6Amp and so on.

thanks in advance

Jed One other thing here...if you are attempting to use this resistor as a current limiting device the calculation would be much different. Since the drop accross the resistor would depend on the internal resistance of the load. If you are just putting the resistor accross the supply, than 72 watts is it. If the resistor has .1 volts accross it then you would only need a 10 watt resistor....I wasn't very clear on what you were trying to do here!

to

etc.

Hi Jed.

What are people suggesting you use a resistor for? You *may* need to put a minimum load onto the +5V output so that it will regulate properly (or maybe even turn on at all). However you do not need a resistor to draw a particular current - if your load will draw 6 Amps, it will draw 6 Amps (as long as the power supply can cope).

One or more of the wires on the connector(s) will go to ground, which you will find will connect with the blacks on the FDD/HDD cables - use a multimeter to find out which one(s) this is. The outputs are between the various outputs and this earth.

Cheers.

Ken

Who suggested it? For what?

When I searched for "atx pinout color", I found many web pages that have exactly the info you are asking for. This question would have been answered quicker by learning to use web search engines than by posting it here,.

This page

says that you directly ground pin 14 (the green wire) to start the power supply.

No mention of any resistor (unless it is to provide the MINIMUM 5V load.)

Note that color codes are not necessarily standard. Pin connections ARE standard and you should work back from those.

Black is usually the common ground for ALL voltages.

Huh? What are you trying to do?

On Fri, 19 Dec 2003 13:32:34 +1300, "Ken Taylor" Gave us:

Absolutely true.

Usually on the +5V. This is because cheap ATX PSU will not work properly without a minimum load on the +5V. More expensive ones, I don't have any problem starting them and using them without a +5V load.

However, most ATX PSU cross regulate on the +5V and +12V so if you are going to draw quite a bit of power on the +12V, you will need a load on the +5V to keep the +12V voltage up.

All with the black ground wires.

6 Amps x 12 = 72 Watts, that 10W resistor will burn out pretty quickly :P Or parallel connect 10x 20 Ohmz 10W.

You might wanna look at some of these things I've been looking at for that kind of purposes.

I'm not recommending them as good or bad, I don't know. But these things appear to be only ones suitable for high loads on the +12V.

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I am trying to use an atx pc power supply without wasting your time going to details

There are two type of connectors:

1- One is 10pins x2 raw female connector 2- 3or4 with one raw of four pins (these you hook them to HD, floppy D, etc.

I think all I need is the first one

Green should be connected to ground, now the question Some suggest using small resistor, where do I hook it

If I need 12V which do I use? Yellow and ?? If I need 5V which do I use? Red and ?? If I need 3.3V which do I use? Orange and ??

can i use ohm law if using the 12V, would it be ok to use 10wat 2Ohm resistor so i get 6Amp and so on.

thanks in advance

Jed

All the power and volts stuff aside, you have to ground the "Power good" pin on the long connecting plug. Its pin #14, most likely green. go here, it's a good source !

--
Regards ............... Rheilly Phoull

I was going to post a question on this.

1- If I need 12V do i use Yellow and black from the 20pins Connectors dir= ect or should i use the 4 pins (ie hard disk Connectors) ?

2- As i am going to use it to charge 12v battery, does the proposed idea= of using resistor would post up the volt to 13.8V? you needed two resistors in s= eries 1 ohm+ 0.15 ohm).

thanx

Ian

g to details

or 2- 3or4 with

small resistor,

Red and ?? If I

istor so i get

using

You cannot charge a 12 volt battery from a 12 volt power supply - the charging voltage must be a little higher than the battery voltage.

For a lead-acid "12 volt" battery, a fully charged battery will be about 13.6 volts, and a battery charger will normally produce about

14.4 volts

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idea of using

series

Furthermore, using a resistor will not "post up" (whatever that means?) the voltage. Unless you are modifying the PS internally somehow (and your questions indicate that you likely shouldn't be messing around inside the PS for your own safety!)

Back? The childish 43YO is not back. The prick is still here! ...and hasn't learned a single thing.

It's amazing that one can survive into the forties with such a chip on the shoulder and nasty attitude. ...not to mention paying the rent with no knowledge. Though there is only one button on the fry-o-lator.

--
  Keith

On Sat, 20 Dec 2003 16:47:01 GMT, "Ross Mac" Gave us:

I never said I developed it, you goddamned lying retard.

When will you ever learn to proper comprehend what you read, without morphing it into another pone of your bullshit claims?

On Sat, 20 Dec 2003 19:55:22 GMT, "Ross Mac" Gave us:

You're an idiot.

Now comming from DopeMatter that really has some meaning! Bong on doper boy!

On Sat, 20 Dec 2003 20:27:47 GMT, "Ross Mac" Gave us:

I'll bet my health plan is better than yours is.

On Sat, 20 Dec 2003 20:27:47 GMT, "Ross Mac" Gave us:

What part of "show me the number" do you not comprehend?

By afford I meant that you cannot afford to lose any more cells! Considering you have about 2 or 3 left! As far as health plans go...I have a great one! I don't have to answer YES to the question "Do you use drugs or alcohol"....We know your answer to that question. That's why you need that guarantee issue insurance your employer provides....retire and see what they do to you! Oh, I forgot...you are the rubber helmeted, knicker wearing toothles tard with pre-existing conditions....maybe you should continue to work....errrrr....show up at work in your stroller with your great one liners like....dipshit, net twit, retard etc..... Rant on DopeMatter!

How about this link DopeMatter!.... I comprehend just fine bong 'n' snippet boy...perhaps you have those bicycle pants on a bit tight??

On Sun, 21 Dec 2003 01:47:34 GMT, "Ross Mac" Gave us:

Actually, dipshit... were I a prescribed user, I would not have to answer yes to the question. You are one retarded fukhead.

You're an idiot.

You could probably dig a bit deeper, and be a little more retarded, but you are nearing rock bottom.