How Sine wave is better than Square wave and Modified Sine wave?


You might have heard of sine wave, square wave, and modified sine wave inverters – what are these?

Inverter/UPS is a device that takes DC from batteries and converts it into AC because 98% our electrical equipment is made to run on AC.

Direct current (DC) is produced from the source of energy such as batteries or solar panels.

Why AC –alternating current?


Direct current can’t be carried to over long distances – that is why the main electricity supply we get in our houses is in AC – alternating current.

All of our electronic equipment is made to run on AC because that’s what we get in our main power supply.
AC and DC look something like this:

ac dc current

As you can see, direct current is really like its name.

DC is so direct that it just flows in one direction whereas alternating current is more like a sea with waves – it goes high and low.

All inverters/UPS either give square wave or sine wave to power our electrical equipment during power cut.
Simply put, square wave inverters give output in waves that are square looking in shape whereas sine wave looks more like a beautiful sine curve.

wave form

Which wave form looks more like AC?

Yes, you’re right – it is sine wave.

If that is the case which wave is better to power your electrical gadgets?

Answer: Sine wave! Pure Sine Wave inverters/UPS are made to give good quality power to all electrical equipment connected to it.

As you can clearly see, sine wave is very close to the AC power that we get in our main grid supply.

Why Sine Wave is Best?

Sine wave inverters are much better than square wave inverters.

You would hear an irritating humming noise if you are powered with square-wave inverters and may also notice that your equipment gets heated up.

You would also notice that your sensitive electrical devices carry a warning that they shouldn’t be powered on square wave inverters.

Why is that? Because square wave is a bad fit – go for sine wave. 

You’ll be able enjoy power without any noise and your equipment will remain safe.

What about Modified Sine wave? is that Better?

You may have also heard people talking about modified sine wave inverters – what’s that about?

We can tell you that please don’t be fooled into buying modified sine wave inverter thinking that they are like sine wave inverter and cost a little less.

Understand one thing clearly – it is either a sine wave or it is not – how does it matter?

Just like you can’t a little bit pregnant, you can’t have modified sine wave.

Sine wave needs to be pure in order to be a good companion to your sensitive electronics.

Look here and you’ll see that modified sine wave is not very different from square wave so why even bother calling it modified sine wave?

modified sine wave

Just like buggy became obsolete when cars came in. Square wave became ancient when sine wave was launched.

“Why should Indians get this dirty electricity”

Our MD, Kunwer Sachdeva, was the first person in the Indian power backup industry to realize that square wave inverters, although cheap, are actually harming the electronics and are even banned in European countries.

“Why should Indians get this dirty electricity”, he asked.

And then he sat with our R & D engineers to launch sine wave inverters – for the first time ever in India.

Su-kam Sine wave Inverter Series

Su-kam has wide range of models in Pure sine wave inverter series.

You can choose Shiny, Falcon plus, Smiley, Fusion – these are all our sine wave UPS.

They differ in capacity and use.

Check this out for Su-kam Pure sine wave models

falcon plus



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