Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [atx]

ATX is the standard for PC power supplies. It has +3.3 V, +5 V, and +12 V. They share a common ground. It has a PS_ON# signal which needs to be grounded to turn it on. Don't open power supplies that run on line voltage (AC). They have dangerous voltages and currents inside

It stands for "Advanced Technology eXtended". There are low-current -12 V and +5 V (called 5 Vsb) that are always on, even when the main supplies are off.

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What is this transformer-like component, and why is it not really connected?

Recently, a power surge took out a few components in my PC's ATX power supply. While repairing (I hope), one component in the power drew my attention. I'm an electronics engineer, but I'm confused about it's purpose: At first sight, it looks like a…
jcoppens
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24V 3A from ATX power supply?

I am looking for a cheap way to get +24V DC max 3A from computer power supply. I prefer easy soldering solution like DIP, and standard components that do not need to be purchased over internet. Any ideas, please?
avra
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Can an ATX PSU power a USB port directly?

I'm going to build a benchtop PSU from an ATX PSU, and I would like to add a USB charging port on it. It should be able to power an Arduino or charge my (non-Apple) phone. (I know Apple devices require additional circuits, but I don't own any so I…
Daniel A.A. Pelsmaeker
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Why is there a -12V rail for ATX

The ATX specification includes a -12V (and an optional -5V) rail on the main power connector. What are these negative voltage rail used for on the connected circuits?
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How can I use an ATX power supply for my own experiments?

I've been trying to turn on an ATX power supply I had lying around, and I plan to use it for some electronic experiments. Note: I don't want to have to open up the PSU for any reason. I've tried connecting the green wire (PS-ON) and a black wire…
Earlz
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Using PWR_OK to Activate an ATX Power Supply Automatically

Okay so, I have an ATX PSU that isn't connected to a motherboard, and I'm currently using the simple paper-clip trick to ground PS_On in order to trick the PSU into providing power when I need. However, doing this cleanly means wiring in a switch to…
Haravikk
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Why are DC-DC ATX converters so big?

I watched an interesting video in which the caster reverse engineers a modern 850W computer PSU. From this teardown one can see that 90% of the bulk of the PSU is devoted to synchronous conversion of the 120V input to the ultimate output which is a…
Tyler Durden
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What's all this "rails" nonsense on a computer power supply?

This is in danger of becoming a computer question, but I've always wondered why do computer power supplies have so many 12V "rails". I have a 800W dead supply with four 12V 16A "rails", but internally, they are all connected to the same transformer,…
Thomas O
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Fixing an ATX PSU

I have an 800W ATX power supply given to me by a friend because it doesn't work any more. It's quite a beast and would set me back a considerable amount new, so I'd like to see if I can fix it. Well, here's the story. It has standby power at 5.15V.…
Thomas O
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ATX PSU 5VSB + 5V

Is it possible to connect both the 5VSB and 5V pins of an ATX PSU to provide +5V? I would like to be able to initially boot using the 5VSB, which is always enabled. Once I've completed setup I would like to enable the ATX PSU. This would help with…
Hair_of_the_Dog
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LED specs for atx power on status

Most ATX motherboards have those same pins for 'interfacing' with the computer case... depending on the manufacturer they vary on position (hence loose wires at the case end) but never function. So i guess there is a standard somewhere. they usually…
gcb
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What is the capacity of capacitors in this power supply circuit?

Imagine the following circuit with two capacitors and diodes acting as passive PFC. My question is what is the capacity of these two capacitors? I mean compared to a circuit with just a single capacitor. Some people say they are in series so their…
Al Kepp
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ATX power supply minimum load

I know this is a commonly asked question but most of the answers I got are more than 5 years ago. So basically, my friend found a ATX power supply and was going to give it to me. Since I already have a power supply for my computer, I planned on…
Khyles Gibrian Ramos
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Combine multiple ATX power supplies?

For several different projects, I need high current DC power (25-50 Amps). The first project needs roughly 50 Amps at 12 volts, which isn't something one ATX can provide on its own (at least I don't think it is.) So is it possible to wire 3 ATX…
Spooky
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Is it safe? 9v from 12 to 3.3 on ATX PSU

I've an ATX PSU that I've modified to run without a motherboard, to power the many (6 or so) low amperage 12v and 5v devices at my workspace, to reduce # of power adapters plugged in and to provide dedicated toggle switches for some devices. I've…
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