12v=19v?

[Howard Barlow]

Can I run my 19v Toshiba laptop on the 12v plug in my truck? The answer would seem obvious, but stranger things have worked.

[groovyone]

You should be able to with the right car adapter.

[kenw]

you will need an adapter, and one with the correct plug to fit the notebook. Fry's has 'em, Best Buy may have them.

[Howard Barlow]

I have adapters, I was worried about a 12v power supply, when the unit is 19v. So, that is good to go?

[kenw]

the adapter can convert the 12v from the cig lighter to 19v for the computer.

Another way to go is to get an INVERTER, it plugs into the cig lighter but converts it to 120v AC, so you will need to use your AC adapter from the house. This is what I do, and that way it can power all sorts of things, like battery chargers, ANY computer, curling irons (not mine...), etc....

[Howard Barlow]

Got it. Thanks. I will plug in my wife's laptop first. You know, just to be sure. I'm careful that way.

[Atfulldraw]

Originally Posted by kenw

Another way to go is to get an INVERTER, it plugs into the cig lighter but converts it to 120v AC, so you will need to use your AC adapter from the house. This is what I do, and that way it can power all sorts of things, like battery chargers, ANY computer, curling irons (not mine...), etc....

This is the way to go. I paid like $30 for mine at WMart -- it's still going strong three years later.

[Imagebuffet]

The inverter trades current for voltage, as specified by Ohm's Law, V = IR. Current and voltage multiplied together generally produce wattage. So, the potential capacity of your battery generally is limited by the wattage it can produce (other factors improve that approximation, by reducing the capacity available). For example, a 12 V battery that can sustain an output of 5 Amps can sustain a 60 Watt load.

[Jeff_Green]

Originally Posted by Imagebuffet

The inverter trades current for voltage, as specified by Ohm's Law, V = IR. Current and voltage multiplied together generally produce wattage. So, the potential capacity of your battery generally is limited by the wattage it can produce (other factors improve that approximation, by reducing the capacity available). For example, a 12 V battery that can sustain an output of 5 Amps can sustain a 60 Watt load.

I'm curious how that answers his question! lol Go buy an inverter that is rated for laptop use and don't worry about Ohm's Law.

[Imagebuffet]

Originally Posted by Jeff_Green

I'm curious how that answers his question! lol Go buy an inverter that is rated for laptop use and don't worry about Ohm's Law.

His question was answered before I posted my reply, but the answer was not explained. So, I offered a brief explanation.

[Jeff_Green]

Originally Posted by Imagebuffet

His question was answered before I posted my reply, but the answer was not explained. So, I offered a brief explanation.

Fair enough!

[Howard Barlow]

Thanks for all the replies, laws and all.

I used a little inverter my wife bought for that purpose. Indeed it works fine, powering the power supply, getting my 19v. Only problem is it is too small, apparently. The light on the unit, and on the computer, stay lit as long as the computer is not turned on. When I turn it on, the unit starts flashing in and out. My power icon flashes between ac power and battery power, losing battery all the while.

So, I guess I need a beefier inverter.

[KD5NRH]

Originally Posted by Howard Barlow

So, I guess I need a beefier inverter.

You should be able to get a 150-300W fairly cheaply. Look around the automotive section at WalMart, near the batteries and such.

The main concern is getting enough power to the inverter. They aren't particularly efficient, so you'll probably need about 6A in to keep everything happy. Lighter plugs are generally considered a 10A source, (that's generally what the socket itself is rated for) but I've had cars where the manufacturer got cheap with the wiring to the point where voltage started dropping off badly with more than 3-4A. I tend to run 8-10ga wire directly from the battery to another socket, or to a different connector to run any high-drain stuff. 12V @ 10A is 120W, so a 150W inverter is already going to have trouble getting the power it needs to run at capacity from a lighter socket safely. (And due to inefficiency of the conversion process, you always want a healthy margin in there - the more margin, the better.)

300W and larger inverters tend to have binding posts on the unit itself for 12V input, so you're not stuck trying to run them from a lighter plug. The preferred connector for something like that would be Anderson PowerPoles, but you can make do with something from Radio Shack if you're not going to be unplugging it very often. The PowerPoles tend to be much easier to disconnect and reconnect solidly, but it's worth noting that the 15A ones don't do well with 10ga and larger wire, so you'll want the 45A size. (Or larger, as the inverter capacity determines, but 45A @ 12V will give 540W, so unless you're wanting to run the refrigerator and a couple desk lamps, you should be fine with 10ga wire and 45A plugs.)

EDIT TO ADD: The ham radio world has pretty much standardized on PowerPoles, so rather than trying to find a dealer online that will sell small lots, and rather than having to buy the expensive crimper, check with your local ham club and see if they have someone who will sell you a couple sets and crimp them on for you. Hams are probably also the cheapest and best resource for automotive wiring and aftermarket electronics in general, since most have wired their own cars for high-draw radios.

[Imagebuffet]

Originally Posted by KD5NRH

EDIT TO ADD: The ham radio world has pretty much standardized on PowerPoles, so rather than trying to find a dealer online that will sell small lots, and rather than having to buy the expensive crimper, check with your local ham club and see if they have someone who will sell you a couple sets and crimp them on for you. Hams are probably also the cheapest and best resource for automotive wiring and aftermarket electronics in general, since most have wired their own cars for high-draw radios.

This is good to know and interesting to me. I would like to do some electrical customization work on my vehicle (or, more likely, pay someone to do it). I want to install video and still cameras around my car to feed into a file server that is also installed in the car. I would also like to install other sensors around my car. I would like to install GPS to record position and altitude, maybe a small weather station to record temperature, humidity and barometric pressure and maybe wind speed. I would like to install a wireless hotspot, so that, at least, I would be able to download and upload files wirelessly to a handheld device (perhaps a Palm or Archos device). It would be nice to have Internet access, at least by WiFi, and maybe by satellite telephone.

I would like to be able to drive across country while streaming live video of my trip across the Internet. I would like to record the video, so that a user could re-drive the route. It would also be nice if the cameras could be controlled remotely, either from the handheld device or by monitoring what I am looking at.

[KD5NRH]

Originally Posted by Imagebuffet

I would like to install GPS to record position and altitude, maybe a small weather station to record temperature, humidity and barometric pressure and maybe wind speed.

This part, at least, is fairly common with hams running APRS weather stations for storm spotting. If you can't find a truck with an obvious weather station at a GARC meeting, ask around. I know Plano and Dallas used to have a few guys who had done very nice jobs of it.