An inverter is an electrical or electro-mechanical device that converts direct current to alternating current ; the resulting alternating current can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits. An inverter converts the Direct Current electricity from sources such as batteries, solar panels, or fuel cells to Alternative Current electricity.

The electricity can be at any required voltage; in particular it can operate Alternative Current equipment designed for mains operation, or rectified to produce Direct Current at any desired voltage. Inverters convert low frequency main Alternative Current power to a higher frequency for use in induction heating. To do this, Alternative Current power is first rectified to provide Direct Current power.

The inverter then changes the Direct Current power to high frequency Alternative Current power. Three-phase inverters are used for variable –frequency drive applications and for high power applications such as HVDC power transmission. A basic three-phase inverter consists of three single-phase inverter switches each connected to one of the three load terminals. In Inverter air conditioning air conditioners that can continuously regulate its output by altering the compressor speed in response to cooling demand. Uninterruptible power supply, which often are based on an electrical inverter.