There are two major types of inverters are available in the market.
1. Square wave inverters
2. Pure Sine wave inverters.
Square wave inverters
As mentioned in the name itself, the wave form of the output current from this type of inverters is like square. The current we get from grid is neither square wave nor pure sine wave, it’s nearly sine wave. So, our electronic devices like fan and tube light will emit some buzz noise while operating in square wave current. Of course, square wave current won’t spoil your Fan or tube light. In some rare cases, these square wave inverters have spoiled the speed control dimmers of ceiling fans. The main reason for this fault is high voltage output. Normally, voltage output from square wave inverters is 230 volt to 290 volt, hence it is not recommended to sensitive electronic devices like computers. I am just saying “it’s not recommended”, this is some experts opinion. But desktop computers and laptops will operate flawlessly in square wave inverters. As desktop Pc’s are equipped with SMPS, the current from the square wave inverter won’t make any big disturbance in computer.
I have interesting news about square wave inverters.
Computers UPS (15 mins backup) widely available in the market are modified-sine wave inverters, that means square wave inverters. Pure sine wave computer ups are rare in the market, and it’s costly too.
Other Names of Square Wave Inverters
Some inverter UPS manufacturers name their products as digital inverters, modified-sine wave, Trapezoidal waveform, stepped sine wave, quasi sine wave etc., all these are nothing but square wave inverters. So, please carefully read the specification of the inverter before you buy.
Pure Sine Wave inverters
Pure sine wave inverters give the purest form of current to your sensitive devices. Most probably the current from this type inverters are very safe to desktop computers, laptops, camera battery chargers, cell phone chargers, mixie, small house hold water pumping motors etc., .
This type of inverters will save your current bill compared to square wave inverters.
Back up time will be better than square wave inverters.
Today Price of sine wave inverters have come down, the difference between Microtek 600 VA square wave inverter and 600 VA pure sine wave inverter is only Rs.400/- to Rs.500 /- .
No Fan speed Difference and noise
In square wave inverter, when power goes off, the speed of the ceiling fan will increase slightly and make some buzz sound whereas in pure sine wave inverter, the speed of the fan remains same and make no noise. You can’t feel the difference when power goes out.