I've been having problems with a laptop of mine burning through power supplies. The laptop requires 19v @ 6.3 amps vdc, which works out to 120W. I've gone through 6 different AC power adapters with this laptop and refuse to buy another one.

Since portability isn't required of this laptop, I need it to just sit in the corner and crunch on numbers in matlab I was thinking about getting an ATX type power supply one that might be used for a desktop. Here is the catch, the typical voltages on an ATX power supply are +12, -12, +5, -5, and +3.3v. I'm not entirely sure how sensitive the laptop is to the specced voltage, but I would like to get as close as possible. Obviously a combination of those voltages needs to be used to make 19 volts, but what combination? And that is my question, what external circuitry do I need with the ATX voltages to achieve the 19v?

I've not done much work where the current requirements are more than a couple hundred mA, so I'm not quite sure how to proceed.

Any help will be appreciated.

 

ATX power supplies are not a good choice to power a laptop. Most of the power is available at 5V, and they don't like running with no load on that.

All the voltages share the same 0V so you can't connect them in series.

You need an enable signal to turn them on.

It sounds like you need a higher rating of power supply, or the ones that you are buying are not good quality.

I suggest you find a power supply at a higher current from a different manufacturer. A volt or two either way on the voltage won't matter.

http://uk.farnell.com/1289211/electr...WER-AML150PS20

 

I'm not interested in buying another laptop power supply. And all the downsides you mentioned are trivial matters. A switch will take care of the enable signal, or the more uncomplicated version is run a short from the +5 to the enable.

There should be a 20 dollar solution to this problem, and the solution you suggested is 120 dollars, unacceptable.

 

That isn't a price that I was asking for. I was just suggesting a possible supplier.

Quite a lot of people regard around $100 for a laptop power supply as normal.

http://store.apple.com/1-800-MY-APPL...nplm=MA938LL/A
and that is only 85W

http://accessories.euro.dell.com/sna...&sku=450-11261

I don't know what the 6 previous power supplies cost you, but I would guess that the total was a lot more than $120

If you find a $20 solution, and the laptop survives, please post details.

 

Hmm... that's weird. If you go thru 6 power adapters, do you think the issue is the laptop and not the power adapter?

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I'm sure there is an issue with the laptop, but its not like I can tell the laptop draw less current so the power supply doesn't burn up. I got 3 from the manufacturer and 3 from ebatts.com.

If I go with another power supply, I'd have to buy a 150W or greater, and I'd still have to change the tip on it as there is not 150W power supply designed for my specific laptop.

In the end there has to be a way to power a working laptop other than a 120W AC power adapter that ends up burning out in a couple months. A bigger power supply is the solution, the difficult part is making it work with the laptop.

 

It's hard for me to believe that the laptop is destroying power supplies. You should look carefully at the quality of the power that you're supplying.

 

Can you tell us the laptops model number?

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Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

I solved the problem with a voltage regulator, thank you all for the assistance.

 

It must've been a pretty big voltage regulator.

Was it a switching regulator?

Could you please post a schematic or the datasheet for the part you used?

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