The waveform of the inverter are mainly divided into two categories, one is sine wave inverter, and the other is modified wave inverter. The sine wave inverter is modified to generate a corrected wave output by PWM pulse width modulation. Since there is about 20% harmonic distortion, it is impossible to carry an inductive load such as an air conditioner, but it can be a resistive load such as a lamp. The modified sine wave inverter adopts a non-isolated coupling circuit, and the device is simple and high in efficiency. The pure sine wave inverter adopts the isolated coupling circuit design. The circuit is more complicated and costly. It can be connected to any common electrical equipment (including TV sets, liquid crystal displays, etc., especially inductive loads such as refrigerators) without interference.

(TANFON pure sine wave power frequency inverter for off grid solar system)

The inverter is divided into high frequency machine and power frequency machine according to isolation. The inverter has a 50Hz power frequency isolation transformer behind it, called power frequency inverter. Using high frequency switching technology, high frequency switching components or high frequency isolation. The transformer replaces the power frequency transformer in the inverter, called the high frequency inverter.

The advantage of the power frequency inverter is that the power components are stable and reliable, and the overload capacity and impact resistance are strong. The disadvantages are low efficiency, heavy weight and high price. The high frequency inverter has two types of high-frequency isolation and non-isolation. The advantages are small size, high efficiency, and low price. The disadvantage is that the impact resistance is slightly lower.

(TANFON WSC serise pure sine wave power frequency inverter)

If there are many inductive loading household appliances(air conditioner, fridge, water-pump, washing machine) in the load,  but it does not move frequently, it is recommended to select a power frequency inverter. If the load is a resistive load with less impact, it is necessary to move frequently. It is recommended to select a high frequency inverter.