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Uninterruptible power supply
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<p>An uninterruptible power supply (UPS) or uninterruptible power source is a type of <a href="/facts/Continual_power_system/k85dQHSc">continual power system</a> that provides automated backup <a href="/facts/Electric_power/w61ID9yQ">electric power</a> to a <a href="/facts/Electrical_load/IX0XBAqB">load</a> when the input power source or <a href="/facts/Mains_electricity/rjE90Hg0">mains power</a> fails. A UPS differs from a traditional <a href="/facts/Auxiliary_power/dNe5DCH0">auxiliary</a>/<a href="/facts/Emergency_power_system/xlHTYP01">emergency power system</a> or <a href="/facts/Standby_generator/BU7tz22p">standby generator</a> in that it will provide near-instantaneous protection from input power interruptions by switching to energy stored in <a href="/facts/Battery_pack/zElWKqCQ">battery packs</a>, <a href="/facts/Supercapacitor/JuJDlQCA">supercapacitors</a> or <a href="/facts/Flywheel/x6yw1efR">flywheels</a>. The on-battery run-times of most UPSs are relatively short (only a few minutes) but sufficient to "buy time" for initiating a standby power source or properly shutting down the protected equipment. Almost all UPSs also contain integrated <a href="/facts/Surge_protection/o3LqlVNv">surge protection</a> to shield the output appliances from <a href="/facts/Voltage_spike/XYdAJkje">voltage spikes</a>. </p><p>A UPS is typically used to protect hardware such as <a href="/facts/Computer/SQe1aK05">computers</a>, hospital equipment, <a href="/facts/Data_center/DS5wJY41">data centers</a>, <a href="/facts/Telecommunications_equipment/DPnnbpPF">telecommunications equipment</a> or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption or <a href="/facts/Data_loss/oGGosFHt">data loss</a>. UPS units range in size from ones designed to protect a single computer (around 200 <a href="/facts/Volt-ampere/6R2WrK7b">volt-ampere</a> rating) to large units powering entire data centers or buildings. </p>