From what I gather a microwave oven operates much more efficiently (less
power, faster cooking) running on pure sine wave. I understand there are
also some other types devices that either require or benefit from pure sine
wave power. In view of the premium price of pure sine wave inverters, I was
wondering if it's worth it or even necessary. For instance, if it used say
25% less battery capacity that would be important. Can anyone comment on
this and other considerations for selecting a pure vs. modified since wave
inverter for onboard use?
Thanks,
Len Krauss


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Eliminate "ns" for email address.

Hello Len,

I don't think the advantages of pure sine wave inverters
really fall into the category of efficiency as you've
suggested. Some appliances will not work at all, or will
work poorly, with less than pure sine waves. Whether to pay
a price premium for a pure sine wave inverter usually
depends on that consideration, rather than on anticipated
savings in cost or energy, which are not likely to be
noticeable.

There are also modified sine wave inverters that provide
"purity" between a pure sine wave and a square wave. These
may be a better buy, but your choice should be dictated by
the appliances you intend to operate.

Here's a web site you can start with. Do a Google search on
"pure sine wave inverter advantages" to learn more.

http://www.q3wholesale.com/Resources-sinewave-guide.htm
Sine Wave Guide

Good luck.

Chuck







Len Krauss wrote:
From what I gather a microwave oven operates much more efficiently (less
power, faster cooking) running on pure sine wave. I understand there are
also some other types devices that either require or benefit from pure sine
wave power. In view of the premium price of pure sine wave inverters, I was
wondering if it's worth it or even necessary. For instance, if it used say
25% less battery capacity that would be important. Can anyone comment on
this and other considerations for selecting a pure vs. modified since wave
inverter for onboard use?
Thanks,
Len Krauss

"Len Krauss" wrote in message
...
From what I gather a microwave oven operates much more efficiently (less
power, faster cooking) running on pure sine wave.

Probably, but a microwave runs so little that efficiency is not likely much
of an issue.

I understand there are
also some other types devices that either require or benefit from pure
sine
wave power.

True. Some TVs, VCRs, DVDs, etc run better off of pure sinewave. In my case
none of these devices seem to care so my modified sinewave inverter is fine.

In view of the premium price of pure sine wave inverters, I was
wondering if it's worth it or even necessary.

Try a modified sinewave inverter and see how it works. Only switch to
a true sinewave unit if you have problems.

For instance, if it used say
25% less battery capacity that would be important.

I'm not sure that effeciency is the question. Some devices do not run as
well
on modified sinewave. For example, my microwave does run cooler so has
to run a bit longer. Other than that, I don;t notice any larger draw for any
given device.

Can anyone comment on
this and other considerations for selecting a pure vs. modified since wave
inverter for onboard use?

Use a pure sinewave unit if any of the devices you are trying to drive have
problems with a modified sinewave unit. I wouldn;t be too concerned about
efficency.

Thanks,
Len Krauss


--
Eliminate "ns" for email address.

I have a 1500 W modified sine wave inverter. I use it for my microwave
( 600W, dial timer). I only use it for rehating stuff. For cooking I
use my 2 burner propane stove or oven. The amount of time I use the the
microwave is so small that efficiency really does not matter. Actually
I installed the microwave be3casue there was a space, and it was so
cheap ( $50), that there was no real reason not to have it. The other
110V applienaces I use: drill, power tools, coffemaker, toaster, TV (17
inch CRT) VCR, vaccuum cleaner, all run just fine. I think the extra
cost of a true sine wave inverter is a waste of money. My inverter is
hard wired to the 110 V system on my boat with a seletor switch, so I
can ahve 110V power in all of the outlets from either the inverter or
the shore power.
Rolf

"Rolf" wrote in message
oups.com...
I have a 1500 W modified sine wave inverter. I use it for my microwave
( 600W, dial timer). I only use it for rehating stuff. For cooking I
use my 2 burner propane stove or oven. The amount of time I use the the
microwave is so small that efficiency really does not matter. Actually
I installed the microwave be3casue there was a space, and it was so
cheap ( $50), that there was no real reason not to have it. The other
110V applienaces I use: drill, power tools, coffemaker, toaster, TV (17
inch CRT) VCR, vaccuum cleaner, all run just fine. I think the extra
cost of a true sine wave inverter is a waste of money. My inverter is
hard wired to the 110 V system on my boat with a seletor switch, so I
can ahve 110V power in all of the outlets from either the inverter or
the shore power.
Rolf

I have had to remove non-pure sine wave units from new boats a few times due
to one or more of the following:
1) microwave would not work whatsoever
2) PC would not work, as in running Nobeltech, etc.
3) HF SSB noise
4) TV receiver would not work at all
Some of these problems may have been ground loop related, rather than the
purity of the sine wave, such as the TV and satellite converter box using
wall wart power units, the same with some laptop PCs running off wall wart
unit. However, in all cases, replaced it with a sine wave unit fixed the
problem, or substituting a different brand of microwave, etc.
I suggest that for small boats or RVs, use a very basic microwave, such as
no membrane keypad or digital display. A push button, rotary mechanical
timer unit works fine off basic inverters.

73
Doug K7ABX