If an electric circuit has a well-defined output terminal, the circuit connected to this terminal (or its input impedance) is the load. (The term 'load' may also refer to the power consumed by a circuit; that topic is not discussed here.) A simple electric circuit made up of a voltage source and a resistor. ... The input impedance or sometimes loading impedance of a circuit or electronic device is the impedance actually experienced by a signal which is connected to its input. ... In physics, power (symbol: P) is the rate at which work is performed or energy is transmitted, or the amount of energy required or expended for a given unit of time. ...

Load affects the performance of circuits that output voltages or currents, such as sensors, voltage sources, and amplifiers. A household's power outlets provide an easy example: they are a voltage source, outputting 120 V AC for example (in USA), with the household's appliances collectively making up the load. When a power-hungry appliance switches on, it dramatically reduces the load impedance, causing the output voltage to drop. This drop is easily observed; for instance, turning on a vacuum cleaner dims the lights. Josephson junction array chip developed by NIST as a standard volt. ... In electricity, current refers to electric current, which is the flow of electric charge. ... Not to be confused with censure, censer, or censor. ... It has been suggested that this article or section be merged with Current source. ... For the British rock band of the same name, see Amplifier (band). ... This article is about plugs and sockets only intended for common domestic (residential) use. ... Josephson junction array chip developed by NIST as a standard volt. ... City lights viewed in a motion blurred exposure. ... Electrical impedance, or simply impedance, is a measure of opposition to a sinusoidal alternating electric current. ... Regular canister vacuum cleaner for home use. ...

A more technical approach

(Two sidenotes on generality, for advanced readers. This discussion will disregard nonlinearity. It will also use simple resistances, but they can be readily generalized to impedances for AC analysis.) In mathematics, a nonlinear system is one whose behavior cant be expressed as a sum of the behaviors of its parts (or of their multiples. ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ...

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. (The Norton equivalent works just as well, but this discussion will use the Thévenin form.) The Thévenin equivalent of a circuit looks like this: It has been suggested that this article or section be merged with Thevenins theorem. ... Nortons theorem for electrical networks states that any collection of voltage sources and resistors with two terminals is electrically equivalent to an ideal current source, I, in parallel with a single resistor, R. For single-frequency AC systems the theorem can also be applied to general impedances, not just...

The circuit is represented by an ideal voltage source Vs in series with an 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. 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. If we use an input resistance to represent the load, the complete circuit looks like this: The output impedance, source impedance, or internal impedance of an electronic device is the opposition exhibited by its output terminals to the flow of an alternating current (AC) of a particular frequency as a result of resistance, induction and capacitance. ... The input impedance or sometimes loading impedance of a circuit or electronic device is the impedance actually experienced by a signal which is connected to its input. ...

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 current 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 rule: Open circuit can mean:- In electronics, where there is nothing connected to a load and no current can flow. ... television cameras for surveillance. ... This article or section does not adequately cite its references or sources. ...

References

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See also

• Dummy load