What device is used to convert power from AC to DC?

The device that is specifically designed to convert alternating current (AC) to direct current (DC) is a rectifier. Rectifiers function by allowing current to flow in only one direction, thus transforming the alternating waveform of AC into a unidirectional waveform, which is characteristic of DC. This process is crucial in various applications, such as in power supply units for electronic devices, where DC is typically required for operation.

The functionality of a rectifier can be achieved using diodes or combinations of diodes in a specific configuration, such as a full-wave or half-wave rectifier. The efficiency and effectiveness of this conversion are critical in ensuring that the electrical energy is suitable for devices that only operate on DC.

Transformers, while involved in changing AC voltage levels, do not convert AC to DC; they solely work with AC currents. Circuit breakers are safety devices designed to interrupt current flow in the case of overloads or faults, and inverters are used for the opposite purpose, converting DC back into AC. Therefore, the rectifier is uniquely positioned to fulfill the requirement of converting AC into DC, making it the correct choice.