LAPTOP FORUM

I use an IBM Thinkpad T20 that needs 16V DC and 3.36 amps. Regret the
only power adapter for the car cig lighter that I have is 16 volts and
6 amps. Am I courting disaster to try this, does the ampage have to be
exact?
If so would be grateful if someone could point me to a 16V DC and 3.36
amps unit for my van and T20 Ta

Powered Up

On 2006-11-28, googlenospam@hotmail.co.uk wrote:

Your laptop will draw as many amps as it needs; the time to worry is if
you have an adaptor that is rated at fewer amps than the gadget you want
to run off it.

--
-- ^^^^^^^^^^
-- Whiskers
-- ~~~~~~~~~~

Whiskers wrote:


Thanks Whis

This implies that the laptop has its own way of regulating the ampage -
its not going to blow up if it sees a PSU that is putting out too many
amps?

On 29/11/2006 in message

googlenospam@hotmail.co.uk wrote:


This comes up quite lot in the homebuilt groups :-)

Im not sure that Im very good at explaining but Ill try and perhaps
somebody else can improve?

Any power supply provides power at a certain voltage - and you need to get
that right or youll see lots of smoke and perhaps flames from the
connected device.

The current drawn from the supply (measured in Amps) depends on the
resistance presented to it by the connected device. As long as the power
supply can provide the current needed then theres no problem. If the
device tries to draw more current than the power supply can provide then
its the power supply that will blow up. If the device draws less current
than the power supply can provide then the power supply will run a bit
cooler.

So the answer is get the voltage right and make sure the power supply can
provide at least the current the device needs and youll be fine.

--
Jeff Gaines
Damerham Hampshire UK

wrote in message
news:1164749249.865202.142340@l12g2000cwl.googlegroups.com...

Try Maplin

http://www.maplin.co.uk/Home.aspx

Item cat N59AC (Car laptop adaptor)

On 2006-11-29, googlenospam@hotmail.co.uk wrote:

The amps rating of a power supply, is the maximum rate at which the power
can be supplied; it will only ever supply what it is asked for, up to that
maximum (at which point it will either throttle the demand to what it can
safely cope with, or start getting over-heated).

Your laptop will probably draw power at a varying ampage depending on
what it is doing; as long as the power supply can cope with the maximum
power the laptop will want, then there wont be a problem. The laptop
doesnt exactly regulate the amps available, it just asks for what it
wants. The power supply is perfectly happy supplying nothing at all, if
thats what its being asked for - otherwise there would be amps squirting
out of all the power sockets everywhere, all the time

Volts are a different matter; mis-match those and nasty things can happen.
Likewise, polarity - make sure that a pin that wants + gets + not -;
otherwise, at worst, things will break - although there should be built-in
protection to make sure the laptop just does nothing if the polarity is
wrong, its better not to rely on that.

--
-- ^^^^^^^^^^
-- Whiskers
-- ~~~~~~~~~~