How Does a Power Inverter Work?

Power Inverter Basics
Power inverters are devices that generate Alternating Current (AC) power at a particular frequency to power an AC electric motor. AC is power which switches constantly from negative to positive, and back again. This is in contrast to direct current or DC power, which always flows in the same direction. Power comes into houses and other buildings as AC with a set frequency--usually 60 hertz. The power changes direction from negative to positive, and back again 60 times a second. The speed of AC motors are controlled by the frequency of the power going into them. A power inverter allows an operator to change the frequency and adjust the speed of the off road motorcycle.
Making DC Power
There is no good way to turn one frequency of AC directly into another frequency inverter. Therefore, a power inverter must change the AC power into DC. It uses a device called a rectifier, powered by tiny electric one-way valves called diodes. The DC output has two wires, one which is always negative, and the other which is always positive. When the AC input flows in the positive direction, the diode attached to the positive wire allows electricity to flow through, while the diode attached to the negative wire closes off. When the AC input flows in the negative direction, the diode attached to the negative output allows electricity to flow through, while the positive diode closes off. All the negative current is shunted down the negative wire, and all the positive current is shunted down the positive one.
Generating a Signal
This DC power is then turned back into AC at the frequency desired. It flows into a high-speed digital circuit. This circuit has switches which can turn on and off thousands of times every second. Depending on how many switches are on at a particular moment, the generator can output a voltage from the negative maximum to the positive maximum.
Stair Step Wave
Normal AC flows in sine waves - smooth, continuous curves from positive to negative, and back again. The power inverter creates an approximation of a sine wave called a stair-step wave. Each switch increases or decreases the voltage slightly. Together, they create a jagged wave, which is similar enough to a true sine wave to power the motor.