power supply

[Jim March]

There's one more thing about laptop bricks.

The wattage.

You want a replacement with as much or more wattage as what you have.
Never less.  Common sizes run from 45watt on the low end to the 60 to
75 range as the most common, 90 to 120 for the big guys.

It's OK to use a brick with "too much" wattage on a smaller machine,
so long as the voltage and plug size/pins are correct.  The lappy will
only draw what it needs.

On the aforementioned Dell brick I used as an example, it doesn't list
watts directly.  It says 19.5 volts at 3.34 amps.  So take a nice
little conversion website like:

http://www.supercircuits.com/resources/tools/Volts-Watts-Amps-Converter

Punch in whatever two items you know and it will calculate the third -
in this case, 65.13 amps, right in the "midsize" range.

So if I was shopping for a replacement brick, I would know a 60 would
be trouble and a 75 would be fine.

Cool, huh?

Your existing brick will ALWAYS tell you what's going on - both on the
input (AC) side and output (DC) side.  Unless you peeled the sticker
off listing all that...

Jim