Different AC Adapter

[JigPu]

Has anybody here ran their laptop (or heard of somebody running) with an adapter that wasn't designed for their laptop? I've ran tons of other devices off of adapters that they wern't designed for, and was wondering if a laptop would be any different. I'm fairly sure the charging mechanism or the battery probably wouldn't be too hapy about an over/undervolt, though to what extent? How much off would the voltage have to be to do immediate/eventual/no damage? Somebody here's got to have a good story or something

This post brought to you by me forgetting my adapter at my parent's house, and desperatly running around to find a way to recharge my laptop. No, I'm NOT going to do this, though I couldn't help from wondering after spying an adapter for another laptop I don't use =D. Guess I'm just a Tim (The Tool Man) Taylor kinda guy ;-)

JigPu

 

[seadave77]

Well me and my wife have the same model laptop but her power adapter has a lower max wattage than mine (75 vs 90 watts) and we use them interchangably. When I was fixing hers though, I got the polarity wrong but it didn't blow it (I was happy) so mine at least is tougher than I would have thought.

 

[skab]

I had a Toshiba 7200CTE that I bought without the adapter, went to Radio Shack and bought an adjustable power supply with adapters and ran it tha way for a year. I did make sure that I had the correct voltage but did'nt worry to much about the amperage figuring the charging time might be a little longer or shorter but since I did'nt know what it should be it did'nt matter.

 

[BUBBLE]

You have to use correct voltage in order to run the machine smoothly, but inthe amperage you can have it low than the mention rate and then the battery won't get charge properly. If the amperage is little bit high then it's ok no bigger problem. So far I've used and tested laptops with higher amperage ones and the lappies works fine.

 

[ozzlo]

my laptop can take a 56watt adapter and a 90watt adapter... somehow the bios is able to detect which adapter is plugged into it and can also display issues about it but it only has DC which leads me to beleive the bios has other ways of determining adapter problems...


adapters vary wildly and two different adapters rated with the same wattage can operate on different voltage and current levels... that's why you should go by current and voltage instead of wattage in determining the right adapter...


also some things to look out for in adapters are a thing called stiff voltage source...

the load resistance must be 100 times the internal source resistance or you will get a voltage drop... to calculate the laptop's load resistance... just take the rated voltage and divide that by the rated current. then all you need to do is make sure that the adapter's internal resistance is 100 times less than the laptop's load resistance or else the adapter won't be able to supply enougf power.

edit use the power supply's voltage and current to calculate the internal resistance...

edit 2 actually you could probbably get away with about 95 times and you would still have 95% of the voltage actually get to your laptop...

anything over 100 times means less than a 1% voltage drop and if the internal source resistance and the laptops load resistance are equal then the adapter will only supply 50% voltage and only 25% wattage which is a bad thing.

I think I did that right but let me know If i screwed up somewhere...