Wind/Solar Electrics ???

The quality of the wave form is directly proportional to the money you put into it.

I've used a small generator to power just about everything in here. I've since upped that to 9,500 watts continuous which seems to work well. It does tend to mess with the clocks if we're on generator power for more than a few hours.

I've never had any problems with the computers of printers though.

Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair)

Purchase a cheap one. They must try.

When a scope is put on the waveform the shape is a "modified sine wave"

This is not a hard concept.

inverters (marketed as

inverters, which are

equipment can't tell the

trying to justify the

logic to it. Folks

"agree" with george

hey, he has a point

I guess you have no experience with creating digital waveforms with a D/A converter and computer algoryths then.

sound terrible.

They didn't

filter.

The application I'm familiar with (well I was 10 years ago) was electrically fired glass melting units. The resistive load didn't much care about cross phase interference. :-)

Matt

(100/10)+1 = 11 I used to farm.

There are only two steps. on the stairway. The others are landings

Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair)

The ones I'm referring to were large ovens with, I'd presume, resistive elements as well. I finally gave up and purchased a comercial unit.

Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair)

Why don't you ask this in the wind/solar electric NG you dumbass MoFo.

Actually it's not a modified sine wave, it's still a square wave with many fine steps. Again, it's a marketing term, not a technical one. You don't "modify" the sine wave, you modify the square wave to approximate a sine wave.

I like that one, but "approximated sine wave" just doesn't have the same marketing ring to it. :-)

Cheers! Rich

You might not call it 'aliasing' -- it's arguably more appropriate to call it 'imaging' -- but a DAC that only outputs unit impulses scaled by the desired output level creates infinitely many replicas of a band-limited sampled input signal. Adding a first order (sample-and-) hold thereby gets you infinitely many replicas scaled by a sinc function and -- as you mention -- typically needs to be corrected or 'smoothed.' It isn't uncommon to purposely make use of one the replicas, though, just as it isn't uncommon to sub-sample a band-limited signal at well below its center frequency.

It's all just linear system convolution with sample functions, hold functions, etc. 'Nyquist aliasing' is one of those kinda vauge terms where it's usually clear from the context what's meant, but it doesn't have any particularly formal meaning. (I can't tell you how many times I've seen people stating something like, 'The Nyquist theorem requires sampling at at least twice the highest frequency present in the signal," when of course it says no such thing.)

---Joel Kolstad

Except that if you actually had any understanding of the product you were expounding upon, you would know that the generator portion of this product, produces DC Current, that is then supplied to an internal inverter, which then converts the DC current into AC current. The only question being debated about the product is, if produces a true Sinewave output, or a modified Squarewave output, during the conversion process.

Apparently you seem to lack visulization capabilities altogether.....

Me

"MSW is a shysters sales pitch which misrepresents the product. "

Are there deterministic tests that tell when a device has a "good enough" sine wave? Or is there some sort of accepted "spec"?

I saw in another post where one of the EU2000 hondas had a beautiful "looking" wave form, but failed to run a furnace.

What can we use to "know for sure" that the wave form of a device is adequate BEFORE buying it?

Thanks Phil

Also, some old systems used self-saturating reactors (magnetic amplifiers, 'magamps') for instrumentation. Things could take some severe environments, but calibration tended to drift a lot. Required fairly frequent 'trip & cals' to keep them in spec.

daestrom

Aliasing happens on the analog to digital conversion, not the digital to analog conversion. That's why low-pass filters are put 'in front' of analog to digital converters.

When going from digital to analog, all you *really* need is a sample/hold circuit to maintain output until the next digital sample comes through for conversion. But the step change from one sample to the next, if done with a very fast slew rate can introduce some harmonics (rapid step changes are always rich in high harmonics). But this is *not* aliasing ala Nyquist. These can be 'smoothed' with a variety of filter circuits.

daestrom

Well, it ain't a perfect sinewave..it's a modified one.

a square wave with

You don't "modify"

approximate a sine wave.

doesn't have the

We still use saturable reactor based battery chargers with a solid state feedback system for voltage and current regulation. Still the latest and greatest, most reliable technology we have in chargers. Not completely mag amps but same idea.

Our mag amps use all went out years ago. I don't remember ever having to recal them.

Wow! takes me back a ways...LOL

in message

off part of a sine wave

rectifiers and not

off part of the wave

make the control of

but I never once

interact. Turn one

down and the other

Now there is a

(magnetic amplifiers,

some severe environments,

fairly frequent 'trip &

Three risers though.

"sunken living

---------------------------

others are landings