Ryobi Gen Sine Wave Test

[andytruck]

Have any of you tech geeks put an oscilloscope on the Ryobi 2000W Generator inverter?
It puts out a modified sine wave, but I cannot find out how modified it is. I have some items that will be ruined off a DC inverter, but might work on this type. And, no, not looking for opinions about it, just real data, as I know the obvious things.
My DC inverters are a pretty bad squared-off step, but since the Ryobi gen works off some sort of AC current it might be more round.
thanks

 

[dwh]

Why do you think it puts out modified square wave?

(BTW...There is no such thing as a modified sine wave inverter - that's marketing BS. If it was sine wave, it wouldn't have to be modified. Square waves need to be modified (more steps) to more closely approximate a sine wave - sine waves don't.)

There used to be a few ultra cheapo Chinese inverter gens that had modified square wave inverters. Might still be a few on the market.

I could be wrong, but I'm pretty sure all of the inverter gens that can be ganged and synced have sine wave inverters.

 

[andytruck]

Why do you think it puts out modified square wave?

(BTW...There is no such thing as a modified sine wave inverter - that's marketing BS. If it was sine wave, it wouldn't have to be modified. Square waves need to be modified (more steps) to more closely approximate a sine wave - sine waves don't.)

There used to be a few ultra cheapo Chinese inverter gens that had modified square wave inverters. Might still be a few on the market.

I could be wrong, but I'm pretty sure all of the inverter gens that can be ganged and synced have sine wave inverters.

Thanks for reply. Im not so much interested in semantics or definitions of words, as getting information. They call inverters modified sine wave since it is a square wave modified to more resemble and act like a sin wave. I am not familiar with alternating current inverters, I have only used DC to AC inverters.
So, if anyone knows Id like to also know.

 

[dwh]

They call inverters modified sine wave since it is a square wave modified to more resemble and act like a sin wave.

Right. As I said, marketing BS.

I am not familiar with alternating current inverters, I have only used DC to AC inverters.
So, if anyone knows Id like to also know.

Inverters are all DC to AC.

AC to AC is a transformer.

AC To DC or DC to DC is a converter.

Generators make AC.

Inverter generators make AC, feed it through a rectifier to convert the AC to DC, and then feed the DC into an inverter to make AC.


Now you know.


There is a 99.9% probability that the Ryobi inverter generator has a sine wave inverter.

So I ask again, what makes you think it's got a modified square wave inverter instead?

 

[andytruck]

Right. As I said, marketing BS.






Inverters are all DC to AC.

AC to AC is a transformer.

AC To DC or DC to DC is a converter.

Generators make AC.

Inverter generators make AC, feed it through a rectifier to convert the AC to DC, and then feed the DC into an inverter to make AC.


Now you know.


There is a 99.9% probability that the Ryobi inverter generator has a sine wave inverter.

So I ask again, what makes you think it's got a modified square wave inverter instead?

Something makes me think that probably, and I don't know is why Im asking. I blame Bush, he made me think it.
So the Ryobi turns AC to DC to AC? DC does not alternate the way AC does, so therein lyes the confusion. I dont really care so much about passing a test on it so much as wanting to see the wave it puts off.

 

[dwh]

So the Ryobi turns AC to DC to AC?

Yup. All inverter type generators do that.

Normal (synchronous type) generators have to spin at a fixed RPM to create a steady alternating frequency. In the U.S., 60hz. So the engines have governors to keep them always at the same RPM.

Even if there is no load, they burn along at full speed sucking fuel.


By doing the AC to DC and back to AC thing, the frequency coming out of the inverter will be steady at 60hz no matter what the RPM of the engine/alternator is.

So now you can throttle the engine down when there is less load and save fuel.

DC does not alternate the way AC does, so therein lyes the confusion. I dont really care so much about passing a test on it so much as wanting to see the wave it puts off.

Understandable.

The inverter type generators that are designed to gang together for double the power, have to have the inverters designed to sync the wave form of both inverters to match each other to put out a single wave form when ganged up.

Like I said, I could be wrong, but as far as I know, all the inverter gens designed to be ganged and synced have sine wave inverters.

And the Ryobi is designed to be ganged.

 

[Rickbfried]

Here is an article with what my old boss called a Primary Visual Aid. Cheap inverters put out modified sine wave, better on put out pure sign waves. For anything that needs 60 cycles, better inverters are required.

https://www.altestore.com/blog/2015/10/pure-sine-wave-vs-modified-sine-wave-whats-the-difference/

 

[Ducky's Dad]

To OP, unless you already have the Ryobi unit, think about the current model Yamaha units with pure sine wave output.

The Yamaha EF2000iSv2 Inverter generator supplies clean, high quality power. The EF2000iSV2 – with its inverter system – features Pulse Width Modulation (PWM) so voltage stability is within ± 1%, and frequency stability is ± 0.1 HZ. Its pure sine wave is as clean as or cleaner than public utilities power.

I bought a pair of the previous model Yamahas (without the "v2" suffix) and they seem to be the best small units out there. I looked at several others, including Honda and Ryobi, and the features of the Yamaha made it the obvious choice for me. There are a bunch of threads here about small to mid-size invertor generators.

 

[dwh]

Here is an article with what my old boss called a Primary Visual Aid.

https://www.altestore.com/blog/2015/10/pure-sine-wave-vs-modified-sine-wave-whats-the-difference/

Here is your primary visual aid from that link:

It shows a sine wave and a modified SQUARE wave.

There is NO modified SINE wave in that image.

Alt-E Store lies.

Cheap inverters put out modified sine wave,

Wrong. They put out modified SQUARE waves.

better on put out pure sign waves.

Wrong. They put out sine waves. Not "pure" sine waves, just plain old sine waves.


"Modified sine" and "pure sine' are both nonsense terms thought up by some marketing guy and parroted by every other marketing department so often that even so-called "experts" get fooled into believing it.

But it IS bullsh!t.



Here's a primary visual aid:

http://uenics.evansville.edu/~amr63/equipment/scope/terminology.html

For anything that needs 60 cycles, better inverters are required.

Wrong. Even modified square wave inverters operate at 60hz.

 

[verdesardog]

Semantics....... that squared sine wave form is commonly called a modified sine wave sometimes referred to as a stepped sine wave. Marketing hype sure, but it is what it is called.
A pure sine wave would be one that doesn't have any spurious noise in it, pure sine wave is a correct technical term.
So who has a visual of what the royobi actually puts out???

 

[dwh]

Hmmm.
A Rotary Converter (whats a admirable wonderful thing, If ever one has a chance to play around with one, do it !) can do all of those functions and its still called a converter...

Yea, though the DC to AC units are also often referred to as inverters.

 

[dwh]

Aaaarrrrrgggghhhh!!!!!!

Try to edit to fix a typo (stupid ************** useless retarded "AI" auto correct keeps replacing "sine" with "sign"), and the whole post just gets deleted as soon as I push the edit button.

Jeezus I HATE computer programmers. Biggest bunch of nitwits I've ever seen. If they EVER get anything right it's a full on freaking miracle.

 

[dwh]

Semantics.......

Yes, exactly. Semantics is not a dirty word. Especially in technical subjects where the meanings of words is important.

that squared sine wave form is commonly called a modified sine wave sometimes referred to as a stepped sine wave. Marketing hype sure, but it is what it is called.

Yes exactly, marketing hype. And sure, it's common. Doesn't change the fact that it's bullsh't.

A pure sine wave would be one that doesn't have any spurious noise in it, pure sine wave is a correct technical term.

Yes, exactly. But don't expect to find any pure sine waves in the field. Outside of lab spec power supplies they are pretty rare.

But it also depends on the resolution of the scope. Looked at from across the room, all sine waves seem to be pure.

Grid power often has all sorts of crap in the sine wave if you zoom in. That's one reason why top recording studios pay the price for an isolation transformer for the building.

So who has a visual of what the royobi actually puts out???

I did a quickie search, didn't find anything. But like I said, I'm pretty sure all of the inverter gens that are designed to gang/sync have sine wave inverters, and the Ryobi inverter gen is designed to gang/sync.

 

[dwh]

To the OP's original question...

In another thread, someone posted a link to this:

http://www.homedepot.com/p/Ryobi-1-...-Digital-Inverter-Generator-RYi1000/205536859

In the section of questions and answers, first page, last question, titled 'Inverter', the question is asked:

"Is the inverter a pure sine wave or modified sine wave ? seems strange it;s not stated in the specs, Thanks in advance"

The answer given by what appears to be someone from Ryobi is:

"RYOBIOutdoors
October 26, 2015

Hello Older Yogi! Inverter generators work in a 3 phase using AC/DC then back to AC which can be used by electronic equipment and appliacnes. The output from the inverter generator is often called "clean power" which means a stable and consistent current and a stable sine wave delivery. Hope this helps.



Which seems a bit like doubletalk to me, but maybe it's just some poor sap in India doing the best he can.

 

[dwh]

Also, it should be noted that modified square wave is not a bad thing. There are very few devices that would have a problem with it.

Some people think MSW is not suitable for electronics, but that's BS.

I don't think anyone can legitimitely argue that an APC UPS is bad for electronics. But look at the specs and you'll see this:

"Waveform type
Stepped approximation to a sinewave"

http://www.apc.com/shop/us/en/categ...er-supply-ups-/network-and-server/_/N-15e4jmd


In other words, modified square wave.

APC does make a few products that produce sine wave, but they just tell the truth and call it a sine wave - no mention of "pure".