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how clean a sine wave..

3322 Views 18 Replies 9 Participants Last post by  triden
Would you say this inverter actually puts out...
The only reason I ask is why are ambulance grade units so much more in cost..?

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There are usually three different types of invertor outputs

1 - Square wave.

2 - Modified sine wave.

3 - Sine wave.

Yours is most likely no 3.
if it wasn't they usually say so.

As for the ambulance types,
Could have better regulation,
Or better protection.
Don't want the de-fibrilator suddenly getting 240v !
 

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There are usually three different types of invertor outputs

1 - Square wave.

2 - Modified sine wave.

3 - Sine wave.

Yours is most likely no 3.
if it wasn't they usually say so.

As for the ambulance types,
Could have better regulation,
Or better protection.
Don't want the de-fibrilator suddenly getting 240v !
Would you place a stepped sine wave under the modified category>
 

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17,035 Posts
There are usually three different types of invertor outputs

1 - Square wave.

2 - Modified sine wave.

3 - Sine wave
The "modified sine wave" is just marketing BS. They make it sound like there's just some minor step preventing it from being a clean sine wave, which is a lot better than the actuality: It's a hard square wave with the corners rounded off.
 

· Certified Organic A-Hole
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1,694 Posts
There are usually three different types of invertor outputs

1 - Square wave.

2 - Modified sine wave.

3 - Sine wave.

Yours is most likely no 3.
if it wasn't they usually say so.

As for the ambulance types,
Could have better regulation,
Or better protection.
Don't want the de-fibrilator suddenly getting 240v !
Defibrilators are battery powered.
 

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Joined
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1,612 Posts
3% THD @ 28 dB ( 10*log(600) ) power output is average for a pure sine inverter and gets within an acceptable threshold. I've seen pure sine waves with MUCH worse. You would never want more than about 5% THD or 3% THD on a single harmonic in your electrical system (IEEE spec). Higher THD ratings create excess power dissipation in tfmr's and excessive heating in motor cores. You probably also wouldn't want to run an audio amplifier off of this device if you are concerned about the sound fidelity. Good inverters will be less than 1% THD.

With that said, you inverter is decent and better than most. I would keep it and not worry too much about it. The price in an inverter all comes down to low THD at the specified power output. Lower the THD or increase the current output and your price starts heading to the sky.
 
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