# Electrical load > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Electrical_load > Markdown URL: https://mediated.wiki/source/Electrical_load.md > Source: https://en.wikipedia.org/wiki/Electrical_load > Source revision: 1337809623 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Electrical component or portion of a circuit that consumes electric power}} {{Refimprove|date=December 2009}} An '''electrical load''' is an [electrical component](/source/electrical_component) or portion of a [circuit](/source/Electric_Circuit) that consumes (active) [electric power](/source/electric_power),{{cite book | last1 = Karady|first1 = George G.|last2 = Holbert|first2 = Keith E.| url = https://books.google.com/books?id=VzBMPDiCr84C&dq=%22load&pg=SA3-PA18 | doi = | id = | isbn = 978-1118498033 |title = Electrical Energy Conversion and Transport: An Interactive Computer-Based Approach|date = 2013-05-03| publisher=John Wiley & Sons }}{{cite book | last = Glisson | first = Tildon H. | title = Introduction to Circuit Analysis and Design | publisher = Springer | year = 2011 | location = USA | pages = 114–116 | url = https://books.google.com/books?id=7nNjaH9B0_0C&dq=%22load&pg=PA83 | doi = | id = | isbn = 978-9048194421}} such as [electrical appliance](/source/electrical_appliance)s and [lights](/source/Electric_light) inside the home. The term may also refer to the power [consumed](/source/Power_consumption) by a circuit. This is opposed to a [power supply](/source/power_supply) source, such as a [battery](/source/Electric_battery) or [generator](/source/Electric_generator), which ''provides'' power. The term is used more broadly in [electronics](/source/electronics) for a device connected to a [signal](/source/electrical_signal) source, whether or not it consumes power. If an electric circuit has an output [port](/source/port_(circuit_theory)), a pair of terminals that produces an electrical signal, the circuit connected to this terminal (or its input [impedance](/source/Electrical_impedance)) is the ''load''. For example, if a [CD player](/source/CD_player) is connected to an [amplifier](/source/amplifier), the CD player is the source, and the amplifier is the load, and to continue the concept, if loudspeakers are connected to that amplifier, then that amplifier becomes a new, second source (to the loudspeakers), and the loudspeakers will be the load for the amplifier (but not for the CD player, there are two separate sources and two separate loads, chained together in series). Load affects the performance of circuits with respect to output [volt](/source/volt)ages or [current](/source/Current_(electricity))s, such as in [sensor](/source/sensor)s, [voltage source](/source/voltage_source)s, and amplifiers. [Mains](/source/Mains_electricity) [power outlet](/source/Domestic_AC_power_plugs_and_sockets)s provide an easy example: they supply power at constant voltage, with electrical appliances connected to the power circuit collectively making up the load. When a high-power appliance switches on, it dramatically reduces the load [impedance](/source/Electrical_impedance). The voltages will drop if the load impedance is not much higher than the power supply impedance. Therefore, switching on a heating appliance in a domestic environment may cause [incandescent light](/source/incandescent_light)s to dim noticeably. ==A more technical approach== When discussing the effect of load on a circuit, it is helpful to disregard the circuit's actual design and consider only the [Thévenin equivalent](/source/Th%C3%A9venin_equivalent). (The [Norton equivalent](/source/Norton's_theorem) could be used instead, with the same results.{{Cite web |title=Converting Between Thevenin and Norton Equivalent Circuits {{!}} DC Network Analysis {{!}} Electronics Textbook |url=https://www.allaboutcircuits.com/textbook/direct-current/chpt-10/thevenin-norton-equivalencies/ |access-date=2025-07-24 |website=www.allaboutcircuits.com |language=en}}) The Thévenin equivalent of a circuit looks like this: [[image:Electric load0.png|center|thumb|322px|The circuit is represented by an ideal voltage source ''Vs'' in series with an [internal resistance](/source/internal_resistance) ''Rs''.]] With no load (open-circuited terminals), all of V_S falls across the output; the output voltage is V_S. However, the circuit will behave differently if a load is added. Therefore, we would like to ignore the details of the load circuit, as we did for the power supply, and represent it as simply as possible. For example, if we use an [input resistance](/source/Input_impedance) to represent the load, the complete circuit looks like this: center|322px|thumb|The input resistance of the load stands in series with ''Rs''. Whereas the voltage source by itself was an open circuit, adding the load makes a closed circuit and allows charge to flow. This current places a voltage drop across R_S, so the voltage at the output terminal is no longer V_S. The output voltage can be determined by the [voltage division](/source/Voltage_divider_rule) rule: :V_{OUT} = V_S \cdot \frac{R_{L}}{R_{L} + R_S} If the source resistance is not negligibly small compared to the load impedance, the output voltage will fall. This illustration uses simple [resistances](/source/electrical_resistance), but a similar discussion can be applied in [alternating current](/source/alternating_current) circuits using resistive, capacitive, and inductive elements. ==See also== * [Dummy load](/source/Dummy_load) ==References== {{reflist}} {{DEFAULTSORT:Electrical Load}} Category:Electrical circuits --- Adapted from the Wikipedia article [Electrical load](https://en.wikipedia.org/wiki/Electrical_load) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Electrical_load?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.