Different electronic devices are built to run at different voltages and types of current. In the United States, the the voltage of typical wall outlets is 120 volts, also called mains voltage, and it provides an alternating current, which means that the flow of electricity regularly switches direction. Some power sources, however, most notably car batteries, run on a 12-volt direct current. There are times when you may want to run a device built for a mains voltage from a 12-volt power source or the other way around. In order to do this, you need either a power converter or a power inverter. Writer Bio
