Mainly divided into two kinds, one kind is pure sine wave inverter, another kind is modified sine wave inverter. Sine wave inverter output is the same as our daily use of power grid and even better sinusoidal alternating current (ac), because it does not exist in the grid electromagnetic pollution.
Square wave inverter output is of poor quality of the square wave ac, the maximum positive to a negative maximum value at the same time almost, in this way, the load and the inverter
itself cause severe instability. At the same time, the load capacity is poor, is only 40-60% of the rated load, cannot take the perceptual load (details see below). As with the load is too large, contains three times square wave current harmonic component will make into the capacitive current in the load increases, serious damage when load power filtering capacitance. According to the above shortcomings, in recent years, the quasi sine wave (or modified sine wave, modified sine wave and sine wave simulation, etc.) inverter, the output waveform from a positive to a negative maximum value has a maximum time interval, use effect is improved, but quasi sinusoidal waveform is still composed of line, belong to the category of square wave, continuity is bad. Generally, the sine wave ac inverter with high quality, can drive any kind of load, but the technical requirements and costs are high.
Quasi sine wave inverter can meet the demand of most of our electricity, high efficiency, low noise, price moderate, thus become the mainstream products in the market. The square wave inverter manufacture easy multivibrator, its technology belongs to the level of the '50 s, will exit the market gradually.