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Charging w/ inverters - bad for laptops ? - RF Cafe Forums
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kbarb
Post subject: Charging w/ inverters - bad for laptops ? Posted:
Tue Dec 30, 2008 2:03 pm
Lieutenant
Joined: Tue Dec 30,
2008 1:53 pm
Posts: 4
hope this isn't too dumb a question for
this forum . . .
I'm thinking of getting an inexpensive inverter
for the car, to charge my Lenovo Thinkpad T61 laptop from the 12v source.
After doing a bit of research I found a few posts out there
that implied that using an inexpensive inverter with a modified sine-wave
(as most of them are) might damage a laptop.
But many of the
brand names in laptop devices sell these things, and laptops are listed
as devices that can be charged.
For example :
Xantrex XPower
Inverter 175 Plus
http://www.xantrex.com/web/id/26/p/1/pt/10/product.asp
Kensington Ultra Portable Power Inverter 150
http://us.kensington.com/html/10359.html
I can't seem to get the definitive answer on this.
I know
a pure sine-wave inverter would be the best (and more expensive), but
is it ok to use the modified sine-wave types?
.
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Mike_From_Plano
Post subject: Re: Charging w/ inverters
- bad for laptops ?Posted: Tue Apr 21, 2009 4:08 pm
Captain
Joined: Mon Apr 20, 2009 2:04 pm
Posts: 14
Hello,
I've done quite a bit with power supplies, and I don't think you have
anything to worry about.
Almost every computer power supply built
for the US market doesn't have power factor correction, or anything
elese that would worry about input waveshape. They simply rectify what
comes in, filter it with high voltage electrolytics, and then run it
through a switching supply.
As for the "modified AC" wave form,
it's simply flips polarity on the output with a little dead time (open
output) between. That helps loads which have induction motors by eliminating
the third harmonic from the output. The upper harmonics are as strong
as ever, but the leakage inductance of the motor deals with them...
Mike
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kbarb
Post subject: Re: Charging
w/ inverters - bad for laptops ?Posted: Sat Apr 25, 2009 12:04 am
Lieutenant
Joined: Tue Dec 30, 2008 1:53 pm
Posts:
4
Thanks very much for your reply.
I had posted on a few forums
but this is the first reply from someone who seems to know what they're
talking about.
I bought one in the meantime - haven't used it but
a few times - but I won't worry now.
Thanks !
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Mike_From_Plano
Post subject: Re: Charging w/ inverters
- bad for laptops ?Posted: Sat Apr 25, 2009 5:29 pm
Captain
Joined: Mon Apr 20, 2009 2:04 pm
Posts: 14
You're certainly
welcome.
Back in the day, I powered my PC while on the road using
150 volts DC, which I got from a supply I built. Using DC is generally
not a good idea (It requires special fuses at higher voltages.), but
a lot of the old power supplies didn't even care whether it was DC or
AC.
Posted
11/12/2012
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