# power inverter



## queen8855 (Sep 29, 2007)

I know what I want to accomplish - just not sure what to buy or where. Here goes --- I want to use a cigerette plug with a power inverter so that I can connect both my laptop and a radar detector. I am very confused concerning amps and watts. Novice housewife here. Clarification and advice will be greatly appreciated.


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## ferrija1 (Apr 11, 2006)

You need a 12-volt DC power inverter. It sounds confusing but it's really not, it's a box that converts the 12 volt DC power from your cigarette lighter into standard 120 volts AC. A laptop typically takes less than 200 watts, but I'm not sure about a radar detector, although it shouldn't be much. If you look in the manual for the detector or along the power cord, it may say how many watts it requires. Here's an example of what you need.

http://www.dcacpowerinverters.com/itemdesc.asp?CartId={CC3D1759-2217-4EFE-9392-93318C43A989EVEREST}&ic=PW400-12


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## queen8855 (Sep 29, 2007)

Thank you so very much for the guidence. I shall check out the link you sent me. If I keep hanging out at this site I might even get smarter. Ha Ha


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## ferrija1 (Apr 11, 2006)

Ok, 400 watts should be good for what you're trying to do.


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## Knotbored (Jun 5, 2004)

It is likely the radar detector has a cord compatible with the 12V DC lighter socket, but the laptop needs 120V AC, so also get a Y shaped connector that allows the different types to be plugged in.
Also-most lighter sockets remain active when the key is turned off, so remember to unplug it (if necessary) so you don't run down the battery.
REMINDER-don't drive with the radar detector even exposed on the dashboard in Canada. They will remove and destroy them on the highway-no exceptions-so into the glove box if you go north.


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## ferrija1 (Apr 11, 2006)

Knotbored said:


> but the laptop needs 120V AC, so also get a Y shaped connector that allows the different types to be plugged in.


Why would you need that? I have a box just like the one I posted a link to and I can just plug my laptop right into it.


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## JohnWill (Oct 19, 2002)

You want to also remember that most dashboard receptacles will only supply 10A or so of 12V power. Given the conversion efficiency of the 12V/110V converter, you'll be lucky to get more than 100W out of it before you take out the fuse.


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## Knotbored (Jun 5, 2004)

ferrija1 said:


> Why would you need that? I have a box just like the one I posted a link to and I can just plug my laptop right into it.


I can't get that site to load, but I assume it provides 120AC for your laptop.
How do you plug in the 12VDC radar detector second connection asked for in the original message? My suggestion of a Y connector provides that second 12V connection.


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## ferrija1 (Apr 11, 2006)

I didn't know it was a cigarette-lighter radar detector. If it is you could use another lighter (if your car has one) or a box as you suggested.

Here's another of what I posted.
http://www.stacksandstacks.com/html/119962_12-volt-power-inverter-400-watt-maxxsst.htm


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## queen8855 (Sep 29, 2007)

JOHN -- I didn't even think about the fuse. THANK YOU -- I think I will settle for just hooking up my laptop. You saved me from the dreaded - "I didn't know"! Thaks to all who guided me!! I think I will go shopping now.


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## JohnWill (Oct 19, 2002)

A potentially better solution is a straight laptop automotive supply.

http://www.amazon.com/Targus-PAPWR200U-Universal-Airplane-Notebook/dp/B0000AKA8T

The reasoning here is, if you use a 12V/110V converter to power the laptop, the second supply (the laptop brick), does another conversion back to 18-22V. This is two conversions, and assuming 75% efficiency, for each of the switching P/S units, you're actually drawing 124 watts from the lighter. However, if you use a direct supply as noted above, you only draw 93 watts. That could be the difference between success and a blown fuse.

Just food for thought... 

BTW, there are cheaper ones, that one is just a really good universal supply.


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## queen8855 (Sep 29, 2007)

John, checked out the link you sent. $199.00 - I'm good lookin', not rich. lol


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## JohnWill (Oct 19, 2002)

I did mention there are cheaper options. 

The radar detector is probably a 12V device, so all it needs is a 2:1 split of the lighter jack. It also consumes very little power, so it's not a significant player in this discussion.

What is the exact make/model of the laptop in question? I can probably point you to a much cheaper model. For instance:

http://www.geeks.com/details.asp?InvtId=MWS2466W-1

http://www.meritline.com/car-power-adapter-laptop-notebook-computer.html

http://www.thelittlelaptopshop.com/uncarlapoadk.html

etc...


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## queen8855 (Sep 29, 2007)

John -- I got real happy at the "Computergeeks" web site. A universal, using only one cord would be super. Didn't know such a think existed. However, it won't work on my laptop -- which is a Gateway model#LM6427. The 6000 series is not listed. Dang it, double dang it. Sure appreciate your guidence! You are a jewel to novices like myself.


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## queen8855 (Sep 29, 2007)

You are so helpful -- May I change subjects on you? I bought "Microsoft Streets & Trips" with GPS. Here is my problem -- this is embarrassing! I cannot figure how to assemble the GPS parts. Part 1 - I have a cable with a standard usb plug one one end and then what looks like an oversized usb plug on the other end. Part 2 - is a clear plastic square over silver color. It is about 1 inch square. Part 3 - is a black oblong plastic -- 2 inches long, 3/4 of an inch wide and a little over 1/4 inch in depth. I cannot see how these parts work together. I know it cannot be that technical (that's why I am embarrased0 but I just can't figure it out. Sure hope you know what I am talking about. Wish I could find a picture, I could manage that, I think. Ha Ha


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## queen8855 (Sep 29, 2007)

John -- yes I am embarassed beyond words. I finally found a picture of the Microsoft GPS - The black oblong, thing a me bob, dah, removed the end caps and I am in business. I keep trying to become more competent, only to be foiled again and again. Yes, you may laugh at me! I am laughing at myself.


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## JohnWill (Oct 19, 2002)

We laugh with you, not at you. 

BTW, you need to look closely at those adapters. Many times, you can buy a new tip to connect it to non-listed machines. I have a 90W model that didn't list my laptop either. However, I was able to find a tip that matched my laptop, and the voltages all work out, and it works fine.

One thing I'd check before you go too far is how much power your laptop requires, and the size of the fuse on the lighter socket in the car in question.


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