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Amps and Volts? Answered

So i have a atx pc power supply and i am going to use a pci cable to draw power from it for a led lighting system and the led light system can only take up to 12 v at 2 a, will that destroy the led light system or will it be fine? (also i cant open up the box that controls the light system to fix the blown fuse)

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Wired_Mist

Best Answer 4 years ago

By "PCI" do you mean Molex? like say the 12V connector to a PCI Video card?

Most 12V light strips can be run at up to 14.5V (at a reduced life Expectancy mind you) and don't worry about the amps; the strip will only take the amps it needs :)

Just connect your strip to the 12V leads and the green wire from the motherboard connector to a ground; Most ATX power supplies will turn on. If not, connect say a light to the 5V OR 3V Rail. ( Switching power supplies need a draw on most if not all rails to work properly, if at all. If your ATX supply doesn't have "dummy load" resistors it won't turn on.)

BTW, with 12V @2Amps, I'd suggest you save the ATX power supply for something else and use a simple wall-wart.

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AustinthemightyWired_Mist

Answer 4 years ago

no i mean like 4 by 2 pin connector like on a graphics card, also i am building a computer so i wanted to add a rbg lighing system

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Wired_MistAustinthemighty

Answer 4 years ago

Yeah, it's a special type of molex connector ( can't remember it's specific name atm)

If you are using a controller and lights like the ones in your picture, Simply hook up the 12V leads to it No Resistor or Regulator required :)

The light strips themselves have built in resistors so they won't need any additional components to funtion propporly. The controller will also do just fine connected directly to you power supply

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-max-

4 years ago

You can find pinnouts of the connectors on common ATX power supplies online, and easly determine which voltage you can use for your LEDs.

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-max-

4 years ago

Here is a 14 minute video I put together going over all you need to know about these types of things! (Watch in 1080p60 for best quality!)

ATX power supplies have many voltage outputs, ranging from -12V, 3.3V, 5V, and 12V. (I might be forgetting 1 or 2)

LEDs should ideally be powered with constant current sources. However, since ATX power supplies are basically not current limiting supplies, (the are constant voltage sources) You should use a resistor in between the LEDs and the supply. Go to 7:37 to see how to figure out what resistor to use.

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Vyger

4 years ago

What is a PCI cable?

An ATX power supply has a top voltage of 12 volts, usually both + and -

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iceng

4 years ago

How do you know the fuse is open if you can not reach it ? !