kind of OT: any suggestions for 12V to 110VAC inverter?

Mon Mar 08, 2010 3:59 pm   

Anyone have any suggestions or warnings on the purchase of a 12VDC
to 110VAC inverter in the US?

I have a 65W TV that I would like to run on one, but it wouldn't hurt
my feelings to pay a bit more for a 150-200W unit. And how necessary
is a "peak wattage" rating for devices with a surge at power up?

I have noticed that after some point in wattage, they come with large
battery clips rather than a cigarette light plug, which I prefer.

I have seen some reviews for inexpensive Black and Decker units, and
the reviews have been bad. Not much else.

--- news://freenews.netfront.net/ - complaints: news_at_netfront.net ---

Mon Mar 08, 2010 5:00 pm   

Gary Peek wrote:

Necessary, although you need "peak power" for long enough to supply the
surge -- if the "peak wattage" specification has become a victim of
specsmanship then someone will figure out a way to make it huge and
meaningless.


Because cigarette lighter sockets are limited in current delivering
ability. Get the inverter you need, then if necessary wire a connector
into your car that will carry the necessary current for the inverter.


Good luck. RV magazines would probably be the best place to look for
reviews.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Mon Mar 08, 2010 6:31 pm   

Gary Peek wrote:

Find a small UPS that someone has discarded because of a bad battery.


Cigarette lighter (I think the politically correct have managed
to rename this a "power port" for fear that calling it a
"cigarette lighter" will encourage people to start smoking
which, in turn, will lead to harder drugs, drunk driving, etc.)
is usually only rated 15A (maybe 20A). So, you have less than
200W available there. Note that any inverter will be less
than 100% efficient (Some are 90+ but I tend to figure on
about 85%) so your load will "look bigger" to the lighter
socket.

You have to deal with intial turn on surge as well as when
battery voltage sags. If you can't count on a still 12V
supply, the UPS will yell at you (and possibly shutdown).

Better bet is to add a dedicated wiring harness right to
the battery so you can cut down on I.R losses.

Thu Mar 11, 2010 3:21 am   

On Mon, 08 Mar 2010 08:59:00 -0600, Gary Peek
<mylastname_at_mycompanyname.com> wrote:


Is this a CRT TV ?

The starting current can be quite large due to the degauss coil.

Take a look what a new TV that operates directly from 12 V would cost,
since you would avoid the power losses on in both the inverter and the
TV power supply.