Which device in a power supply converts AC to DC?

Which device in a power supply converts AC to DC?

• A. Inverter
• B. Transformer
• C. Capacitor
• D. Rectifier

Answer: (D)

Converting alternating current to direct current is done by a rectifier. It uses diodes to allow current to flow in only one direction, turning the changing polarity of AC into pulsating DC. In a power supply, the rectifier is typically followed by filtering (often with capacitors) to smooth the pulsating DC into a steadier voltage. An inverter does the opposite, turning DC into AC. A transformer changes the voltage level of AC but does not convert it to DC. A capacitor stores charge and smooths DC but cannot convert AC to DC on its own.

Converting alternating current to direct current is done by a rectifier. It uses diodes to allow current to flow in only one direction, turning the changing polarity of AC into pulsating DC. In a power supply, the rectifier is typically followed by filtering (often with capacitors) to smooth the pulsating DC into a steadier voltage.

An inverter does the opposite, turning DC into AC. A transformer changes the voltage level of AC but does not convert it to DC. A capacitor stores charge and smooths DC but cannot convert AC to DC on its own.