Alternating current has a constant voltage, but constantly changes position between positive and negative polarities, producing a wave when represented visually. Electric current is transmitted around the country in the form of alternating current. 120 volts and 60 cycles (position changes between polarities positive to negative to positive) per second (60 Hz) alternating current is what is the most common power source that is supplied to United States residential homes. Alternating current is required to power appliances such as toasters, incandescent light bulbs, and certain components of televisions.
Direct current has a constant voltage that always flows from one polarity to the other, whether it is positive to negative or negative to positive is not significant. Batteries are the primary source of direct current in the learning environment. Direct current is required for all modern electronics; such as computers, certain parts of televisions, mobile phones, and gaming consoles.
Everything that requires electricity in a modern American home is set up either to use 120 volts, 60 Hz ac or to invert ac to dc, so there are many reasons why one would need to use a power inverter in and around the home. A power inverter converts alternating current into direct current or direct current into alternating current. Some examples of an inverter ac to dc are the little box on a mobile phone charger or the box on a printer power cord. There is a power inverter in your television, and the traffic lights at the local intersection function properly through the use of a power inverter.
The most common use of a power inverter dc to ac is solar power. Solar panels produce direct current. Since the common house is set up and wired for alternating current, the solar panels need a power inverter. Using battery power to live on a houseboat is another example of needing a power inverter dc to ac. As previously mentioned, batteries are a good source of direct current. However, in order to use common household appliances on said houseboat, a power inverter dc to ac would be required.