Pure Sine Wave VS Modified Sine Wave Inverter

Click: 454  Date: 19/3/2022 4:24:24 PM

What is a Pure Sine Wave Inverter?

In a sine wave, the voltage rises from zero smoothly until it reaches a peak, and then gradually lowers and changes polarity instantaneously once it reaches zero again. The output voltage in a pure sine wave inverter comes in the form of sine waves.

This smooth output makes pure sine wave inverters suitable for household devices like TVs, fridges, microwaves, washing machine, and more. The power it produces, matches or sometimes exceeds the power supplied to your home, ensuring the safety of devices.

Pure sine wave inverters are essential for audio/video equipment and satellite systems as they work on sine wave output. Other appliances like microwave ovens, motors, and washing machines work on full output only when a pure sine wave is applied making this type of inverter an important choice.

What is a Modified Sine Wave Inverter?

While a pure sine wave inverter produces smooth outputs, a modified sine wave inverter creates a square pattern wave with a stair-step form. The polarity switches from positive to negative abruptly and can affect the sensitive equipment in your home. These inverters also cause a hum in the devices that are connected to them.

While appliances like electronic timers, digital clocks, bread makers, refrigerator motors, fans, and fluorescent lights don’t work properly or don’t work at all on modified sine wave inverters, most commonly used equipment don’t experience any noticeable difference in operation. This is why modified sine wave inverters are cheap and the most common inverter sold by retailers.

Pure Sine vs Modified Sine Wave Inverter – Comparisons

Device Usage

Due to the choppy output voltage, modified sine wave inverters can’t be used for devices with sensitive electronics. It is thus not suited for some appliances like microwaves, compressors, motors, and even some fluorescent lights.

Pure sine wave inverters, on the other hand, match the actual sine wave very closely. This uniformity makes it perfect to be used as a home inverter. It should especially be considered over modified wave for operating medical devices and equipment.


Pure sine wave inverters produce a better output voltage form but cost more upfront. This is because they use more components to smooth out the voltage and achieve higher efficiency.

Modified sine wave inverters are easier to manufacture, use fewer components, and are hence cheaper than pure sine wave inverters.


Modified sine waves reverse polarity abruptly and produce smaller waves of power. If used for appliances with motors, the efficiency will decrease further, and it will use more power. The inverter will run hotter and won’t run for that long.