"PeeCee" wrote in message
...

"Jumpster Jiver" wrote in message
news:nYgKh.16531$2%3.15177@trndny06...
JWBH wrote:

My young son's friend came around to our house the other evening with
his notebook pc. The friend's battery started running low, so my son
took the transformer from my wife's laptop and plugged it into his
friends computer.

I was horrified that he hadn't checked the voltage the amperage or the
polarity. He knows more than me about computers, but was he right to
not check these things or does a few volts, the polarity or the likely
difference in amperage between notebook computers not matter much.
grateful for other opinions on this. thanks.
It matters a lot.
The wrong voltage or polarity could potentially destroy the laptop, the
power supply or both. The wrong size plug could damage the plug or the
jack.
Using an adapter with the correct voltage, plug and polarity but not
enough current probably would not work well or has a chance of
overheating the power supply as it tries to provide more current than it
is designed to.
In all or most modern laptops, the power supply is integrated on the
motherboard so the cost of repairing the damage could be very high.

Jumpster

With respect I have not seen a Laptop/Notebook with the 'Power Supply'
integrated on the motherboard since the days of 486's (Toshiba for
example)
'Power Supply' being the components that convert the AC mains from the
wall socket to the DC voltage required to run the Laptop / Charge it's
battery. These days universally an 'external' power brick or
'transformer' as described by the OP.

Quite agree with your first two points though.


I believe the point he was trying to make isn't the power transformer and
ac/dc conversion being on the motherboard of the laptop, but with the
charging circuits, and the voltage converters/regulators, etc., being
integrated internally in the laptop. I've seen a number of adapters with
multiple voltage outputs, but more and more I see these single voltage
barrel plug connectors with 19V or whatever. Knowing that the components in
the PC actually run primarily on 5 and 12 volts, the conversion is being
done in the laptop. Mess that up, and you've got an expensive repair.