Power Inverters

[Noddie]

Hia Guys,
I would like to get a power inverter for my car so that i can change my laptop 'on the go'.
Now, here is my question:
When i tried to get the Wattage needed i looked at the charger input which was 240V at 1.5 amps. and Volts X Amps = watts right? so i would need a 360 watt converter!? that a third of a kilowatt!
am i making a mistake here?

 

[frank]

i think a DC-DC converter would be a better option ed (maplin do one, £25 ? but they wont be the cheapest eh)

 

[superls]

Yes in rough terms thats right volts x amps = watts.

however i would have thought as most laptop psu's are dual voltage, ie 110v and 230, the 1.5A would be for the 110v, and it will be no where near the 1.5 on 230V

laptop psu.s are about 100watt output so would be a similar input, assming losses say 120watt input, @ 230v ~0.5A, at 110v ~1A.

you can get some real cheap inverters nowdays, check to see if maplin has anything on offer.

 

[Noddie]

so id be looking for one over about 150W, that sounds more like it
thanks for the help guys

 

[frank]

so id be looking for one over about 150W, that sounds more like it
thanks for the help guys

it seems daft to covert from 12v dc to ac mains, then back from ac to dc ed fwn , when you can just stepup via dc http://www.maplin.co.uk/Module.aspx?ModuleNo=36836

 

[Manny]

it seems daft to covert from 12v dc to ac mains, then back from ac to dc ed fwn , when you can just stepup via dc http://www.maplin.co.uk/Module.aspx?ModuleNo=36836

yeah just get what frank says, what the point of messing about.

 

[Noddie]

it seems daft to covert from 12v dc to ac mains, then back from ac to dc ed fwn , when you can just stepup via dc http://www.maplin.co.uk/Module.aspx?ModuleNo=36836

no doubt man, but then you cant use it to charge your phone and other stuff. Also, i have fried a phone and a sat-nav with those 'multi-voltage' things

 

[frank]

non true sinewave inverters are more risky than dc-dc gear ed (ac multivolt adapters are dodgy like you say tho)

 

[superls]

anything that increases voltage involves chopping the original 12v up and making it noisy etc, i have one of those 12 to ~19v things, used it loads never had any trouble, and at ~£15 its fine, but if i were going to fit someething semi-fixed in the car id have a small <300watt inverter, that way you can as noddie says charge a phone etc, keeps your options open.

the laptop psu you have converts the ac going in straight to dc anyway, so in theory you could supply them with dc if it were above 100v, so the input doesnt have to be highly accurate anyway.

 

[Noddie]

just got this http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=220357128672&ssPageName=STRK:MEWNX:IT think il put it under the seat and run a power cable to some where more convienient, plus its got a 5V usb connector which is useful. not bad for £15 (in theory).

 

[Ed]

I have loads of 12-240v mains inverters, and never have a prob, I use them for all sorts. Get a 300w one minimum to be on the safe side, Modified sine wave will be fine, then you can do with it what you wish. DO NOT use the 12v dash plug as it will not be able to cope with the current of a laptop continuously. Wire it directly to the battery with at least 30A cable.