Can a computer be run from DC supply instead of connecting it to the usual AC?

Question

Yeah I know laptops rn on batteries, butI don't know the voltages that those batteries supply.

Also for desktops.
Of courseI know that your Processor and chips run on DC, so powersupply is there to convert convert AC to the required DC levels.

But what is the required DC voltage? And how can it be done? Like hhow to bypass all the circuitry?

A guy I know was asked that inan interview. Just curious.

Answer 1

Since your desktop computer has a multi-voltage power supply that converts 120VAC to 5VDC, 12VDC and -5VDC, you can't just plug it into DC current. So if you have a BATTERY and Voltage inverter that can generate clean 12-VAC, you can use the battery.

But the power inverter should be able to handle about 500 watts of peak power, since your old fashioned CRT monitor does wonders.

Many power inverters do not create a true sine wave output. I wonder about the long term damage to CRT monitors and other circuits with this sort of power input.

If you are thinking about creating your own DC power supply, you should simply measure the voltage from each of the wires that come from the 20 pin connector that attaches to the Motherboard. Keep in mind that the POWER is not turned on from the front panel circuitry directly, as this is just a POWER COMMAND sort of button. That means that you will need to have a shutoff circuit that mimics the regular AC power supply. This sounds pretty complicated to me.

Answer 2

I think you're confused on some points.

All computers require DC. The job of the power supply in a computer is to convert the AC from the wall to DC that the computer components require. A typical power supply supplies the following DC voltages.

CPU voltage - Varies depending on the processor (typically around 1.0 to 2.0 V range)

+3.3 V
+5 V
+12 V

There is no standard DC voltage for a laptop batteries. They vary depending on the model. Just by opening up the battery bay and looking at the battery will tell you the DC voltage of the battery along with other information.

Answer 3

If you want to run a laptop run off of external batteries then find a DC to DC converter which its output matches the output of the laptops AC adapter. Then you can use the laptops DC input jack. This way you only have to deal with one voltage.

A desktop can be run off an UPS system with banks of external batteries since the internal batteries would only give you 30 minutes of run time at the most. You would need a model designed for continuous operation. Again you only have one voltage to deal with.

Answer 4

Unfortunately, you will have a VERY challenging time trying to bypass the circuitry. Unless you are very skilled, you will be best to use a battery supply (uninteruptable power supply/UPS) to connect to your PC and continue to run on AC but from a battery.

The reason I say this is that the different colours of wires that come from the PC's internal power supply represent different voltages which are fed to the motherboard and drives. You would need to account for those different voltages when modifying any circuitry. That's why laptop accessories are so expensive - they're specialized. They are manufactured to consume as little electricity as possible because they're designed to work on (finite/limited) battery power.

A good resource is available at http://computer.howstuffworks.com/power-supply.htm .

Answer 5

Simple Answer... Balding is right. You can get an inexpensive converter from Radio Shack, Fred Meyers, WalMart.. lots of places that carry a few electronic gagets.
They come in one AC plug in up to 6 or more.
Work as a plug in to lighter found in your car. The other end is an A/C plug and you just use your A/C power cord to your computer.
If you don't have a car. You can buy rechargeable power batteries at camara stores... use to use them for longer batteries on camcorders. The lighter plug in was on a cord that went from the camcorder to the lighter OR to a portable battery called a Power Pack.
Some converters (I got one at Costco. around $100 give or take) and it had the ability to run from the car lighter or the terminals from a battery such as a car battery, lawnmower battery, etc.

Answer 6

Yes. It is possible. But there is a hitch, hard disk requires different voltages than motherboard and so do the CD/DVD drives. I am not sure what the voltage requirement for the present day systems. But you should be able to find them on internet and manuals.

Look for the "current" requirements for each of these device and the proper connectors.

There is some manual work needed, but it is absolutely possible.

Answer 7

It's called a UPS it has a battery that will keep the computer powered up till shut. So to answer the question yea you can use other resources other Thant he AC. But for the love of GOD do not hook it in to a cigarette lighter of your car.

Answer 8

They sell power converters for this purpose. Though they're generally used for other equipment, I see no reason a pc couldn't be ran off of them either. They look like power strips, but they plug into cigarette lighters.

Answer 9

Computers use +5VDC & +12VDC. If you can supply that, you would not need the internal supply.