12V to 19V converters?

[kaspaas]

Hi,

Laptops usually have 19V DC power supplies.

Why convert 12V DC to 220V AC and back again to 19V DC?

Can't one get a 12V DC to 19 V DC converter?

[BiteMe]

where does your 12v dc come from in your above question?
or is that what they are wiring the houses up with thesedays...?

[Gnome]

Hi,

Laptops usually have 19V DC power supplies.

Why convert 12V DC to 220V AC and back again to 19V DC?

Can't one get a 12V DC to 19 V DC converter?

I bought a DC->DC 150W switchmode power supply from Electronics 123 (input voltage: 11 - 16Vdc) about a week ago for my laptop, it's got a car lighter plug and voltage selector (selectable voltages: 15, 16, 18, 19, 20, 22 or 24Vdc), also includes many plugs (the type that plug into the laptops,etc) it works very well only problem is it costs R450

Might be possible to get one from communica for cheaper, if you're not in Pretoria then I'm not sure where you can get one tho, Electronics 123 does ship, I think...

http://www.electronics123.co.za/Main...CategoryID=874

[Defib]

i have a 12v to 220v inverter, powers my notebook perfectly

[kaspaas]

I bought a DC->DC 150W switchmode power supply from Electronics 123 (input voltage: 11 - 16Vdc) about a week ago for my laptop, it's got a car lighter plug and voltage selector (selectable voltages: 15, 16, 18, 19, 20, 22 or 24Vdc), also includes many plugs (the type that plug into the laptops,etc) it works very well only problem is it costs R450

Might be possible to get one from communica for cheaper, if you're not in Pretoria then I'm not sure where you can get one tho, Electronics 123 does ship, I think...

http://www.electronics123.co.za/Main...CategoryID=874

Thanks.

I'm thinking of rigging a deep cycle 12V battery with a suitably sized charger in my office and running my laptop from there when then power fails.

Obviously it is a question of effeciency: Which is more efficient: 12V to 19V or 12V to 220V(Inverter) to 19V (normal latop charger)?

[Zyzzyva]

i Asked this question in another thread but the thread seems to be kind of dead now.

If you were to hook up a laptop to a car battery using the best method, how long roughly could the laptop run for.

Any Ideas.

The car battery could obviously be replaced with a quality deep cycle battery.

[BiteMe]

buy this
http://www.carnetix.com/CNXP1900.htm
12dc/dc regulator, used to run laptops as carpcs, i.e. from a 12v source giving a 19v output.
this avoids the messy dc-->ac--->dc conversion you will get when using an invertor, as well as the power losses involved.

from a good car battery, you should get about 15 hours of runtime

240v invertors are about 60% efficient, so the time will drop to about 9 hours

[Zyzzyva]

buy this
http://www.carnetix.com/CNXP1900.htm
12dc/dc regulator, used to run laptops as carpcs, i.e. from a 12v source giving a 19v output.
this avoids the messy dc-->ac--->dc conversion you will get when using an invertor, as well as the power losses involved.

from a good car battery, you should get about 15 hours of runtime

240v invertors are about 60% efficient, so the time will drop to about 9 hours

Thanks