Loading... Please wait...There are two general types of power inverters: Pure sine wave or modified-sine wave (square wave). Pure sine wave inverters produce power that is either identical or sometimes slightly better to power from the public utility power grid system. The power wave when viewed through an oscilloscope is a smooth sine wave. Pure Sine Wave inverters are more suited for sensitive electrical or electronic items such as laptop computers, stereos, laser printers, medical equipment, digital clocks, bread makers with multi-stage timers, and variable speed or rechargeable tools.