Laptop power supply amp/volts question

[Crackle]

The power supply has gone on a laptop we have and while I'm waiting for a new one I'd like a considered opinion on whether I could use one from another laptop.

The broken one is a 19v 3.42amp unit and I have a 19v 3.97 amp one and an 18.5v 4.92amp one. Do you think either is safe to use instead?

 

[Rancid]

As long as the voltage is the same and the AMP is equal or greater than the original then you will be fine.
So the 19v 3.97 Amp will do just fine.

Its only when the device (the laptop) wants to draw more current (Apms) than the Powersupply can supply that you are going to run into issues.

 

[Crackle]

As long as the voltage is the same and the AMP is equal or greater than the original then you will be fine.
So the 19v 3.97 Amp will do just fine.

Its only when the device (the laptop) wants to draw more current (Apms) than the Powersupply can supply that you are going to run into issues.

Ok, thanks. So I wouldn't get away with the 18.5v one, shame, as I have a spare one of them.

 

[ColinJ]

I don't think that 0.5V is going to make much difference!

You need to have the same connector on each power supply lead, and make sure that the polarity of the two connectors is the same. 18.5V vs 19V shouldn't be an issue, but -18.5V vs 19V could be quite a showstopper!

 

[Rancid]

Ok, thanks. So I wouldn't get away with the 18.5v one, shame, as I have a spare one of them.

0.5v really isn't a big difference and should be well within the tolerance of the voltage regulators.
Its highly unlikely that you would suffer any negative effects from using the 18.5v

Keep an eye on the PSU to make sure it inst getting too hot.

ColinJ beat me to it....

 

[Crackle]

Thanks chaps. Yes polarity is the same Colin and the end seems to be standardised across the four we have in the house. So all good then.

 

[subaqua]

0.5v really isn't a big difference and should be well within the tolerance of the voltage regulators.
Its highly unlikely that you would suffer any negative effects from using the 18.5v

Keep an eye on the PSU to make sure it inst getting too hot.

ColinJ beat me to it....

they can run quite warm anyway. have often caught mrs subaqua with her slippers off and her tootsies sat on the PSU keeping them warm. recycling she calls it.
do laptops have an "idiot " diode in them . a lot of kit in work does to prevent the reverse polarity issue

 

[ColinJ]

do laptops have an "idiot " diode in them . a lot of kit in work does to prevent the reverse polarity issue

I thought of that after I posted, so I changed "would be quite a showstopper" to "could be quite a showstopper"!