Modified Sine Wave VS True Sine Wave Inverters

[boogiethecat]

A simple fix for MSW inverters is to run the output into a 1:1 transformer.  The output will clean up and become a true sine wave.  Normaly the items, particularly battery chargers that do not contain a transformer do not like the rapid rise of a square wave.  The magnetic propertys of a transformer will smooth out the rapid voltage rise of the MSW.  Yes you will have some loss in the transformer, but not as much as You might think.  Try it You will like it!  John

Not!
Yes a transformer's inductance will clean up a modified sine a little bit, and may filter out a few of the higher harmonics, but no-way will it convert a modified sine to a true sine, it just won't.
Please be accurate

G

[JimC]

I have a 2500 Freedom Marine unit and it runs everything I ask it to, including lap top and flat screen TV.
that being said, I also notice that the microwave induction makes a little more noise, and the clock does not keep proper time, but all in all, for half the price of the pure sine wave, I am happy with mine.

I will not that our fridge did take a puke last year, I have no way to tell if it was from the inverter, or just plain rough service, it was about 10 years old so if it was the inverter, it took a long time to effect it.
Jim

[JohnEd]

JimC,

Yours is great news for me.  I have the same inverter as you but in the 3K version.  Thank you for your post.  Till you shared I was only "pretty sure".  Yhat is the only way "pretty' will ever apply to me.

Thanks,

John

[JohnEd]

Boggie man,

Your 1:54 post was terrific.  I ate it up but I fear that 19 out of 20 were dumbfounded and I ain't puttiny any down.  It was a superb expalnation and anything you might have left out would only be of interest to a math major or EE.

Thank you for the info and I wil save your work for the future.

John

[JohnEd]

Jim,

hanks for bringing up the Zantrex DR 3624.  I only researched the 12 volt equip so I missed all the 24 and 48 volt stuff.  Really glad to hear that yours is doing so well....especially since I just bought one.

Thanks,

John

[JohnEd]

It would appear that if you go with a Heart or Trace or Zantrex inv. you stand a good chance of all going well.  Magnum is a good bet but nobody so far has stood up to be counted.

The only info I have on Magnum is from Justin at Dick Wright's shop.  He and Dick are up on Magnum and they carry the product line.  A real biggie to them is that Magnum is very responsive to customer questions and support requests.  The new product that does "power sharing" is not in manufacture at this time and has been in the offing for more than a "while".  Justin left me with the impression that any delay with anything is not typical Magnum behavior.  I don't know but WRICO is a good source.  Justin told me that the only way to be sure that everything you use will perform satisfactorily is to use a Pure Sine Wave inverter.  So far I don't feel the need to be quite that certain.

Those little chargers don't have transformers in them.  I "think" they are called Switching Power Supplies.  I can easily see why a device like that will have problems with a choppy ac power source.  Still, others here are haveing no trouble with their chargers running on Trace/Zantrex inverters.  Time for Boggie and I look forward to the info.

John



John

[junkman42]

As a somewhat aging EE You will have to forgive Me!  I did not say that the transformer would make a pure sine wave!  What I did say was that a isolation transformer would clean up the MSW output, I stand by that.  John

[boogiethecat]

Cool John, I agree.

Everyone else:
Bottom line is kinda this way... use a sine wave inverter = it WILL work, period.
                               Use a Modified sine wave inverter= you takes your chances.  Might work, might not.
As always in busland, whatever is "your way" is always the best!!!

Cheers!
Boog

[DrivingMissLazy]

Cool John, I agree.

Everyone else:
Bottom line is kinda this way... use a sine wave inverter = it WILL work, period.
                               Use a Modified sine wave inverter= you takes your chances.  Might work, might not.
As always in busland, whatever is "your way" is always the best!!!

Cheers!
Boog

I used to convert PWM (pulse wave modulated) inverters to sine wave using a "pie" type LC filter and was able to get the harmonic distortion down to below 6% and a beautiful sine wave.

I experimented with a chopped wave (modified square wave) inverter and was never successful in converting this type inverter to a sine wave output without a significant amount of heat generated in the filter.

Richard