Power supply

A power supply is an electrical device that supplies <a href="/facts/Electric_power/w61ID9yQ">electric power</a> to an <a href="/facts/Electrical_load/IX0XBAqB">electrical load</a>. The main purpose of a power supply is to convert <a href="/facts/Electric_current/Dc1xdnUX">electric current</a> from a source to the correct <a href="/facts/Voltage/EN2po6N2">voltage</a>, <a href="/facts/Electric_current/Dc1xdnUX">current</a>, and <a href="/facts/Frequency/QUSbPaW8">frequency</a> to power the load. As a result, power supplies are sometimes referred to as <a href="/facts/Electric_power_converter/sKmxxvHx">electric power converters</a>. Some power supplies are separate standalone pieces of equipment, while others are built into the load appliances that they power. Examples of the latter include power supplies found in <a href="/facts/Desktop_computer/edFPINdK">desktop computers</a> and <a href="/facts/Consumer_electronics/cJ8g9NXh">consumer electronics</a> devices. Other functions that power supplies may perform include limiting the current drawn by the load to safe levels, shutting off the current in the event of an <a href="/facts/Electrical_fault/QaCmxu1r">electrical fault</a>, power conditioning to prevent <a href="/facts/Electronic_noise/Izbv38Rr">electronic noise</a> or <a href="/facts/Voltage_surge/XYdAJkje">voltage surges</a> on the input from reaching the load, <a href="/facts/Power-factor_correction/TLKPkptn">power-factor correction</a>, and storing energy so it can continue to power the load in the event of a temporary interruption in the source power (<a href="/facts/Uninterruptible_power_supply/aYD6Yo6L">uninterruptible power supply</a>).
All power supplies have a power input connection, which receives energy in the form of electric current from a source, and one or more power output or power rail connections that deliver current to the load. The source power may come from the <a href="/facts/Electric_power_grid/RkWPqjmG">electric power grid</a>, such as an <a href="/facts/Electrical_outlet/938U5dTF">electrical outlet</a>, <a href="/facts/Energy_storage/9GWtAPeb">energy storage</a> devices such as <a href="/facts/Battery_(electricity)/bqEpm4ue">batteries</a> or <a href="/facts/Fuel_cell/UcMYnCW3">fuel cells</a>, <a href="/facts/Electrical_generators/5sATsUGX">generators</a> or <a href="/facts/Alternator/r9KEPP9d">alternators</a>, <a href="/facts/Solar_power/NpgmEbU2">solar power</a> converters, or another power supply. The input and output are usually hardwired circuit connections, though some power supplies employ <a href="/facts/Wireless_power/V1tkxaCw">wireless energy transfer</a> to power their loads without wired connections. Some power supplies have other types of inputs and outputs as well, for functions such as external monitoring and control.

Power supply open-in-new

Power supply