An Uninterruptible Power Supply (UPS) is a device that provides emergency backup power to a load when the main power source fails. It ensures a continuous and stable supply of electricity to sensitive equipment like computers, servers, and industrial devices, preventing sudden shutdowns and potential data loss or equipment damage.

Key functions of a UPS include:

• Instantaneous switch to battery-powered operation during mains failure, ensuring no interruption.
• Voltage regulation to protect against voltage sags, surges, and brownouts.
• Filtering to minimize electrical noise and disturbances.
• Controlled shutdown or bridging time until backup generators start.
• Various system designs including offline, line-interactive, and online (double conversion) UPS options.
• Components typically include rectifiers (to charge batteries), inverters (to convert DC to AC), batteries (energy storage), and control units.