What device converts AC to pulsating DC?

The device that converts alternating current (AC) to pulsating direct current (DC) is a rectifier. A rectifier allows current to flow in only one direction, effectively removing the negative portion of the AC waveform and resulting in a pulsating DC output. This output is not a smooth DC signal; it retains some fluctuations, hence the term "pulsating."

Rectifiers can be either half-wave or full-wave, depending on how they are designed to process the AC waveform. A half-wave rectifier will utilize one half of the AC cycle, while a full-wave rectifier uses both halves. The resulting pulsating DC can then be further processed by filtering components, such as capacitors, to smooth out the signal into a more stable form of DC.

In contrast, an inverter is used to convert DC back into AC. A transformer serves to increase or decrease AC voltage levels without converting it to DC. A capacitor is primarily used for storing electrical energy or filtering signals but does not perform the AC to DC conversion. Thus, the rectifier is uniquely suited for the specific task of transforming AC waveforms into pulsating DC.