Uninterruptible power supply
OverviewTechnologiesCommon power problemsOther designsForm factorsApplicationsHarmonic distortionPower factorThe three general categories of modern UPS systems are on-line, line-interactive and standby: • An on-line UPS uses a "double conversion" method of accepting AC input, rectifying to DC for passing through the rechargeable battery (or battery strings), then inverting back to 120 V/230 V AC for powering the protected equipment.