Steve Lusardi wrote:
The sine wave inverters that I am refering to cost in the area of $100 for a
150 watt model. I just went through this experience for a radar screen and I
had exactly your questions. I was specificically concerned about it's RF
noise emissions, native resolution, correct aspect ratio and the efficiency
of the inverter with a 40 watt draw. I made the plunge picked up a screen
for 140 Euros and the inverter from Conrad. I then tested the setup with a
lab power supply and a AM radio tuned off station, where I could monitor the
power draw precisely for all conditions and I was pleasantly surprised. The
screen was rated at 34 watts and I saw 36 watts off the lab supply when on
and displaying an image and when the screen was off, the inverter was
drawing just a few milliwatts. Also, when the inverter was powered up, the
radio emitted no white noise. In conclusion, the sine wave inverter works a
treat and the setup cost much less than a certified marine screen.
Steve



Thanks shipmate!
That's the way to go then.



"cavelamb" wrote in message
m...
Steve Lusardi wrote:

You will find that finding a 12 V or 24 V DC LCD screen is very difficult
at best. You will also find that when found for marine use, they are very
expensive. There are reasons for this beyond those very valid caveats
made bt Larry. One of which is black is not black. Most screens glow
somewhat when displaying black. Marine screens do not, as protection of
night vision is pretty importsnt on a bridge. But your requirement is not
a ship's bridge and can be met with an inexpensive computer display that
runs off AC with the use of the low wattage sine wave inverters. The good
ones do not radiate and are amazingly efficient. If you want to keep this
screen inexpensive, you may find that you will have to drop your contrast
ratio spec of 1000 to 1 to 800 to 1.
Steve

I didn't know that about marine screens. The non-glow thing.
Interesting point and maybe the extra bucks are not just fools gold.

Plain old flat panel computer monitors are certainly cheap enough these
days.

The 1000:1 ratio is pretty old fashioned stuff these days at least among
computer monitors. Some of them are amazingly high.
I didn't see anything in the 1280 x ? resolution at less than 1000:1.

A good 18" matte finished display (Dell?) was about $125 or so.

The inverter is going to be the trick that makes the rabbit pop out of the
hat.
If it can run the CPU and the display, I think I'd quit there.

The one I had before was not a true sine wave output - but a stair step
sorta sine wave. Some things did not so well with that (actually died
at first sight!) I'm sure things have improved since then (10 years?).
But how would one know before hand???

Lastly, I need a simple way to switch from inverter to shore power.
Probably easiest would be to have a 110 connection - one socket marked
shore power, the other marked inverter and a single plug to the system.
Plug it into one or the other?


Surely ought to do a good job discharging the house batteries!