Information about Electrical Efficiency

The efficiency of an entity (a device, component, or system) in electronics and electrical engineering is defined as useful power output divided by the total electrical power consumed (a fractional expression).

Efficiency of typical electrical devices

Efficiency should not be confused with effectiveness: a system that wastes most of its input power but produces exactly what it is meant to is effective but not efficient. The term "efficiency" only makes sense in reference to the wanted effect. So a light bulb might have 2% efficiency at emitting light yet still be 98% efficient at heating a room. (In practice it is nearly 100% efficient at heating a room because the light energy will also be converted to heat eventually, apart from the small fraction that leaves through the windows). An electronic amplifier that delivers 10 watts of power to its load (for example a loudspeaker), while drawing 20 watts of power from a power source is 50% efficient. (10/20 × 100% = 50%)
  • Electric kettle: over 90% (comparatively little heat energy is lost during the 2 to 3 minutes a kettle takes to boil water).

Efficiency of devices at point of Maximum Power Transfer

As a result of the Maximum Power Theorem, devices transfer maximum power to a load when running at 50% electrical efficiency. This occurs when the load resistance (of the device in question) is equal to the internal Thevenin equivalent resistance of the power source.

Efficiency of light bulbs

For more details on this topic, see Luminous efficacy.

Discussion

High efficiency is obviously desirable when we wish to design systems that can operate from batteries. Inefficiency has a cost (either paid to the power company or the cost of the required power supply) to be weighed against the cost of attaining greater efficiency (choosing different components or redesigning the system). Also, any difference in the input and output power probably produces heat within the system (though noise and other mechanical vibrations involve at least theoretically separate inefficiencies), and that heat must be removed from the system if it is to remain within its operating temperature range.

See also

External links

Device may refer to:

Computing and electronics

  • Computer hardware
  • Peripheral device, any device attached to a computer that expands its functionality
  • Device file, an interface for a device driver

..... Click the link for more information.
An electronic component is a basic electronic element usually packaged in a discrete form with two or more connecting leads or metallic pads. Components are intended to be connected together, usually by soldering to a printed circuit board, to create an electronic circuit
..... Click the link for more information.
System (from Latin systēma, in turn from Greek σύστημα systēma) is a set of entities, real or abstract, where each entity interacts with, or is related to, at least one other
..... Click the link for more information.
Electronics is the study of the flow of charge through various materials and devices such as, semiconductors, resistors, inductors, capacitors, nano-structures, and vacuum tubes. All applications of electronics involve the transmission of power and possibly information.
..... Click the link for more information.
Electrical engineering (sometimes referred to as electrical and electronic engineering) is an engineering field that deals with the study and/or application of electricity, electronics and electromagnetism.
..... Click the link for more information.
expression must be well-formed. That is, the operators must have the correct number of inputs, in the correct places. The expression 2 + 3 is well formed; the expression * 2 + is not, at least, not in the usual notation of arithmetic.
..... Click the link for more information.
Effectiveness means the capability of producing an effect.

In Physics, an effective theory is, similar to a phenomenological theory, a framework intended to explain certain (observed) effects without the claim that the theory correctly models the underlying (unobserved)
..... Click the link for more information.
incandescent light bulb (also spelled lightbulb) or incandescent lamp is a source of artificial light that works by incandescence. An electrical current passes through a thin filament, heating it until it produces light.
..... Click the link for more information.

..... Click the link for more information.
This article or section needs copy editing for grammar, style, cohesion, tone and/or spelling.
You can assist by [ editing it] now. A how-to guide is available, as is general .
This article has been tagged since February 2007.
..... Click the link for more information.
In electrical engineering, the maximum power (transfer) theorem states that, to obtain maximum power from a source with a fixed internal resistance, the resistance of the load must be made the same as that of the source.
..... Click the link for more information.
In electrical circuit theory, Thévenin's theorem for linear electrical networks states that any combination of voltage sources, current sources and resistors with two terminals is electrically equivalent to a single voltage source V and a single series resistor R.
..... Click the link for more information.
Luminous efficacy is a property of light sources, which indicates what portion of the emitted electromagnetic radiation is usable for human vision. It is the ratio of emitted luminous flux to radiant flux.
..... Click the link for more information.
incandescent light bulb (also spelled lightbulb) or incandescent lamp is a source of artificial light that works by incandescence. An electrical current passes through a thin filament, heating it until it produces light.
..... Click the link for more information.
compact fluorescent lamp (CFL), also known as a compact fluorescent light bulb is a type of fluorescent lamp designed to replace an incandescent lamp. Many CFLs can fit in the existing incandescent light fixtures.
..... Click the link for more information.
light-emitting diode (LED) is a semiconductor diode that emits incoherent narrow-spectrum light when electrically biased in the forward direction of the p-n junction. This effect is a form of electroluminescence.
..... Click the link for more information.
Design, usually considered in the context of the applied arts, engineering, architecture, and other such creative endeavors, is used both as a noun and a verb. As a verb, "to design" refers to the process of originating and developing a plan for a product, structure, system, or
..... Click the link for more information.
System (from Latin systēma, in turn from Greek σύστημα systēma) is a set of entities, real or abstract, where each entity interacts with, or is related to, at least one other
..... Click the link for more information.
battery is a device consisting of one or more electrochemical cells, which store chemical energy and make it available in an electrical form. There are many types of electrochemical cells, including galvanic cells, electrolytic cells, fuel cells, flow cells, and voltaic cells.
..... Click the link for more information.
power supply (sometimes called a power supply unit or PSU) is a device or system that supplies electrical or other types of energy to an output load or group of loads.
..... Click the link for more information.
NOiSE is a one volume manga created by Tsutomu Nihei as a prequel to his acclaimed ten-volume work, Blame!.

It offers some rather sketchy information concerning the Megastructure's origins and initial size, as well as the origins of Silicon life.
..... Click the link for more information.
''For other uses, see oscillator (disambiguation)
Oscillation is the variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states.
..... Click the link for more information.
trillion fold).]]

Temperature is a physical property of a system that underlies the common notions of hot and cold; something that is hotter generally has the greater temperature. Temperature is one of the principal parameters of thermodynamics.
..... Click the link for more information.
In electrical engineering, the maximum power (transfer) theorem states that, to obtain maximum power from a source with a fixed internal resistance, the resistance of the load must be made the same as that of the source.
..... Click the link for more information.
Negawatt power is a term coined for an arbitrage way of supplying additional electrical energy to consumers without increased generation capacity by the creation of a market for trading of increased efficiency. The concept was introduced by Amory Lovins in a 1989 speech.
..... Click the link for more information.
battery is a device consisting of one or more electrochemical cells, which store chemical energy and make it available in an electrical form. There are many types of electrochemical cells, including galvanic cells, electrolytic cells, fuel cells, flow cells, and voltaic cells.
..... Click the link for more information.
Alphabetization has been neglected in some parts of this article (the "b" section in particular). You can help by editing it.


This is a list of communications, computers, electronic circuits, fiberoptics, microelectronics, medical electronics,
..... Click the link for more information.

..... Click the link for more information.
In thermodynamics, the thermal efficiency () is a dimensionless performance measure of a thermal device such as an internal combustion engine, a boiler, or a furnace, for example. The input, , to the device is heat, or the heat-content of a fuel that is consumed.
..... Click the link for more information.
In physics, mechanical efficiency is the effectiveness of a machine and is defined as



To show the effectiveness of a machine one must compare its work input to its work output.
..... Click the link for more information.


This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus


page counter