There are two major types of inverters. They are sine wave inverters and square wave inverters. Square wave inverters produce a choppy signal which switches levels rapidly and may cause damage to electrical products. The reason behind the hesitancy to buy square wave invertersnowadays lies in the inefficiency of these inverters. An irritating humming noise is produced when devices are connected to square wave inverters and the equipment connected heats up considerably. Most sensitive electrical devices come with warnings on their labels- they shouldn’t be powered by square wave inverters. The best bet is to buy pure sine wave inverter.
About modified sine wave inverters
- Modified sine wave inverters function like a consolation prize to pure sine wave inverters. They are just a cheaper option to lure customers into buying a product that will not give them value for money.
- Modified sine wave inverters produce an output that is the sum of two square waves shifted 90 degrees relative to each other. The 3-step output consists of equidistant peak zero volts, peak positive volts and peak negative volts. This gives a very rough sine wave output.
- It produces a pause between the abrupt switching in square waves.
About pure sine wave inverters
- Modified sine wave inverters have a 30-40% harmonic distortion which is caused by the rapid switching between high to low levels. Pure sine wave inverters have less than 3% harmonic distortion and the curve that transitions between positive to negative is a smooth curve.
- The pure sine wave inverter for the first time in India after realising that cheap square wave inverters were damaging electrical equipment.
- Even though they are expensive, they provide the highest level of safety to electrical devices. This is beneficial for sensitive electronics.
- They are long lasting with a long battery life. They produce a minimal amount of noise and heat, which is a big improvement from square wave inverters. This means that TV sets don’t have lines on them and the light system does not make a humming noise while switched on. The appliances run cooler and more efficiently when connected to sine wave inverters.
- Laser printers, rechargeable battery devices, and pellet stoves get damaged when they are connected to modified sine wave inverters, but they work perfectly well on sine wave inverters.
- A multitude of websites sell sine wave inverter online.
- Devices such as telecommunication equipment run with lesser noise and hum. Motors are driven at their required speed with less heat development. Lesser shut downs and mysterious errors are experienced when computer equipment runs on sine wave inverters.
Achieving the sine wave
- The use of resonant inverters which create sine waves with LC circuits to isolate the harmonic distortion produced by simple square waves has increased considerably.
- Several LC circuits have either a series or parallel resonant combination, which is tuned to a different harmonic in the power line frequency.
- Even though the inductors and capacitors are large and heavy, these circuits simplify the electronics.
- They are popularly adopted by uninterrupted power supplies in data centres.