Pure sine from converter?

[davidkingham]

I have a very old Honda generator hooked up to my trailer via a 15a/30a adapter, I can't imagine the 110 outlets on this old thing are pure sine. My question is, will the power coming out of the outlets via the converter (not inverter) be pure sine? I have fried a laptop using a modified sine inverter in the past and don't want to do this again! But this is not a question about inverters, just if a modified sine going through a converter is pure sine?

[ABrask]

Originally Posted by davidkingham

I have a very old Honda generator hooked up to my trailer via a 15a/30a adapter, I can't imagine the 110 outlets on this old thing are pure sine. My question is, will the power coming out of the outlets via the converter (not inverter) be pure sine? I have fried a laptop using a modified sine inverter in the past and don't want to do this again! But this is not a question about inverters, just if a modified sine going through a converter is pure sine?

There are some Honda generators that are designed to produce pure sine wave/clean power, but I think you're right that you can't depend on that with an older model. In any event, I'd recommend a surge protector no matter what, and in my experience, you could have problems with appliances or micro-processor based electronics no matter what you do. A laptop should be able to be charged from the output of a generator, however. The battery charging circuit shouldn't require exceptionally clean power.

[lynnmor]

The outlets are not powered by the converter, just the generator. An inverter is used to power the outlets from battery power, but apparently you don't have one.

You might be surprised, but a good generator can produce clean power and an inverter type generator will produce clean power regardless of engine RPM.

If you want to be sure, buy a pure sine wave inverter large enough for the computer and run it off the battery.

[twinboat]

A converter is a 12 volt battery charger, eleminater. It runs off 120 volts to power your 12 volt items and maintain your battery.

An inverter is a different animal. It take your 12 volt power and invertes it to 120 power. They come in modified sine, actually modified square, wave and pure sine wave.

Portable and mounted constant speed generators are sine wave producing devices. Good RPM, controls the volts and cycles.

Inverter generators produce sine wave power electronicly, so RPM is not important for the waveform. (cycles)

[shiggs68]

First, your old generator produces a sine wave output, it is a rotary generator just like the power houses that supply commercial power only a smaller scale. It may also provide some spikes (electrical noise) as a result of the condition of the brushes.

Next, the converter you are speaking of is the 15amp to 30amp RV outlet not the converter in your RV. Therefore the above attempts to clarify the converter/inverter confusion are totally off the subject. In your case, there isn't any cleaning/reconditioning of the power generated, it just a socket conversion.

The comparison of your generator to a newer inverter based generator is that it was discovered that generating low voltage and using a builtin inverter to create the 120vac output is more efficient and lighter to build. The output of those newer inverter based generators is pure sine wave but limited in power. Yes, you can parallel two inverter based generators but 4000 watts is the limit of the efficiency gain. Larger than that returns to the original rotary style generator.


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[wahoonc]

Originally Posted by shiggs68

First, your old generator produces a sine wave output, it is a rotary generator just like the power houses that supply commercial power only a smaller scale. It may also provide some spikes (electrical noise) as a result of the condition of the brushes.

Next, the converter you are speaking of is the 15amp to 30amp RV outlet not the converter in your RV. Therefore the above attempts to clarify the converter/inverter confusion are totally off the subject. In your case, there isn't any cleaning/reconditioning of the power generated, it just a socket conversion.

The comparison of your generator to a newer inverter based generator is that it was discovered that generating low voltage and using a builtin inverter to create the 120vac output is more efficient and lighter to build. The output of those newer inverter based generators is pure sine wave but limited in power. Yes, you can parallel two inverter based generators but 4000 watts is the limit of the efficiency gain. Larger than that returns to the original rotary style generator.


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Honda makes a 7k inverter generator.

Aaron

[davidkingham]

Thanks guys, I was obviously confused about what a converter does exactly, I just didn't want to have it confused with an inverter.

So, what I think you all are saying is that the power coming from the generator should be clean enough to use for my laptop? I've attached a picture of the old (baby) beast.

[Mr_D]

Originally Posted by ABrask

There are some Honda generators that are designed to produce pure sine wave/clean power, but I think you're right that you can't depend on that with an older model. In any event, I'd recommend a surge protector no matter what, and in my experience, you could have problems with appliances or micro-processor based electronics no matter what you do. A laptop should be able to be charged from the output of a generator, however. The battery charging circuit shouldn't require exceptionally clean power.

Surge protector will not stop a MSW inverter from damaging electronics. Maybe that's not what you mean when you say to use one as high voltage can also occur.
Using a PSW inverter shouldn't cause any problems either.
Older genset might if the output wave form isn't PSW.

[wahoonc]

If your laptop charges from a "brick" style adapter it should work just fine with the generator, it acts as sort of a filter. I have not seen that particular model of Honda before and I have a couple of pretty old ones.

Aaron

[nothermark]

FWIW "Pure Sine" inverters are defined as having more than 3 steps in the half cycle. They are not as "pure" as a rotary generator.

I doubt you fried your laptop from using an MSW inverter. You might have killed the brick but that is easily replaceable. If you are worried about it buy the external supply specified for wide range input (120-240VAC, 50-60 Hz) or for 12 VDC input and use that to power your laptop. The internals are designed to handle bad power.

[twinboat]

Originally Posted by nothermark

FWIW "Pure Sine" inverters are defined as having more than 3 steps in the half cycle. They are not as "pure" as a rotary generator.

I doubt you fried your laptop from using an MSW inverter. You might have killed the brick but that is easily replaceable. If you are worried about it buy the external supply specified for wide range input (120-240VAC, 50-60 Hz) or for 12 VDC input and use that to power your laptop. The internals are designed to handle bad power.

Here is a clip that explains it.

Almost all consumer grade inverters that are sold as a "pure sine wave inverter" do not produce a smooth sine wave output at all,*just a less choppy output than the square wave (one step) and modified sine wave (three step) inverters.

In this sense, the phrases "Pure sine wave" or "sine wave inverter" are misleading to the consumer.

*However, this is not critical for most electronics as they deal with the output quite well.

[shiggs68]

Originally Posted by wahoonc

Honda makes a 7k inverter generator.



Aaron

I stand corrected, but that is probably pushing the cost/benefit of inverter based generation. And as mentioned above, the frequency control is much more stable as it is not based on engine rpm.

The physical size is a big factor as I have worked with many large military generators that were rock solid. Today's technology changes the rules.


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[nothermark]

FWIW - "Changes" is the correct term. Not "Improves". The major factor with Inverter style generators is fuel economy because they can vary the speed. In return it costs a lot of money and introduces all the problems of having an inverter in the system.