Which device converts direct current to alternating current?

The device that converts direct current (DC) to alternating current (AC) is an inverter. An inverter works by taking a steady input of DC voltage, such as from a battery or solar panel, and converting it to AC voltage, which is necessary for running standard household appliances and for many radio and communication applications.

Inverters use electronic components like transistors to switch the DC inputs on and off rapidly, effectively creating a waveform that resembles an AC signal. This conversion process allows for the use of DC power sources in circuits that require AC, making inverters essential in various applications, including power supplies for ham radio operations.

Other devices mentioned serve different purposes: a rectifier is used to convert AC to DC, a transformer changes the voltage level of AC signals without converting between AC and DC, and a transistor is a semiconductor device used primarily for amplification and switching in electronic circuits rather than direct DC to AC conversion. Understanding these distinctions clarifies why the inverter is the correct choice for converting direct current to alternating current.