Hitachi Hi-Rel Power Electronics Customer Care Executive Interview Questions and Answers

UPS stands for Uninterruptible Power Supply, which is a device that provides emergency power to a load when the input power source fails.

• UPS takes power from the main electrical supply and stores it in its battery

• It then converts the stored power to the required voltage and frequency to supply to the load

• UPS also provides protection against power surges and spikes

• Example: APC Smart-UPS series

Rectifier and inverter sections are components of power electronics that convert AC to DC and DC to AC respectively.

• Rectifier section converts AC to DC by using diodes

• Inverter section converts DC to AC by using transistors

• Rectifier section is used in power supplies, battery chargers, etc.

• Inverter section is used in solar power systems, UPS, etc.

To convert 230V AC supply into 12V DC supply, a step-down transformer, rectifier, and filter capacitor are used in the circuit.

• Use a step-down transformer to reduce the voltage from 230V AC to a lower voltage level.

• Rectify the AC voltage using a bridge rectifier to convert it into pulsating DC.

• Filter the pulsating DC using a capacitor to smoothen out the ripples and obtain a stable 12V DC output.

• Ensure proper voltage r...read more