Transformer - Revision history

Jmdonev: 1 revision imported

2020-04-28T15:32:24Z

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energy>Jmdonev at 18:13, 18 February 2020

2020-02-18T18:13:49Z

← Older revision		Revision as of 18:13, 18 February 2020
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	[[Category:Done ~~2018~~-04-30]]		[[Category:Done 2020-02-29]]
	[[File:4624935949_5d81aacfbe_z.jpg\|300px\|thumb\|Figure 1. Pad mounted transformer for electrical distribution.<ref>sdpitbull via Flickr [Online], Available: https://www.flickr.com/photos/stevestr/4624935949</ref>]]		[[File:4624935949_5d81aacfbe_z.jpg\|300px\|thumb\|Figure 1. Pad mounted transformer for electrical distribution.<ref>sdpitbull via Flickr [Online], Available: https://www.flickr.com/photos/stevestr/4624935949</ref>]]
	<onlyinclude>A '''transformer''' is an electrical device that uses [[electromagnetic induction]] to pass an [[alternating current]] (AC) signal from one [[electric circuit]] to another, often changing (or "transforming") the [[voltage]] and [[electric current]].</onlyinclude> Transformers do not pass [[direct current]] (DC), and can be used to take the DC voltage (the constant voltage) out of a signal while keeping the part that changes (the AC voltage). In the [[electrical grid]] transformers are key to changing the voltages to reduce how much energy is lost in [[electrical transmission]].		<onlyinclude>A '''transformer''' is an [[electrical device]] that uses [[electromagnetic induction]] to pass an [[alternating current]] (AC) signal from one [[electric circuit]] to another, often changing (or "transforming") the [[voltage]] and [[electric current]].</onlyinclude> Transformers do not pass [[direct current]] (DC), and can be used to take the DC voltage (the constant voltage) out of a signal while keeping the part that changes (the AC voltage). In the [[electrical grid]] transformers are key to changing the voltages to reduce how much energy is lost in [[electrical transmission]].

	Transformers change the voltage of the electrical signal coming out of the [[power plant]], usually increasing (also known as "stepping up") the voltage. Transformers also reduce ("step down") the voltage in [[substation]]s, and as [[distribution transformer]]s.<ref name=A>R.T. Paynter, “Basic Electric Components and Meters,” in ''Introduction to Electricity'', 1rst ed. NJ: Prentice-Hall, 2011, ch. 21, sec. 21.1, pp. 903-908.</ref> Transformers are also used as a part of devices, like [[current transformer]]s.		Transformers change the voltage of the electrical signal coming out of the [[power plant]], usually increasing (also known as "stepping up") the voltage. Transformers also reduce ("step down") the voltage in [[substation]]s, and as [[distribution transformer]]s.<ref name=A>R.T. Paynter, “Basic Electric Components and Meters,” in ''Introduction to Electricity'', 1rst ed. NJ: Prentice-Hall, 2011, ch. 21, sec. 21.1, pp. 903-908.</ref> Transformers are also used as a part of devices, like [[current transformer]]s.
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	==How transformers work==		==How transformers work==

	~~The strange ability to keep~~ the total [[power]] the same, ~~but change~~ the current ~~and voltage comes from~~ electromagnetic induction. This ~~ability~~ is ~~often referred to as~~ transformer action, ~~which~~ describes how the transformer changes an AC signal from its primary to its secondary component. When an AC signal is applied to the primary coil, the changing current causes a [[magnetic field]] to change (get bigger or smaller). This changing magnetic field (and associated [[magnetic flux]]) will pass through to the secondary coil inducing a voltage across the secondary coil, thereby effectively coupling the AC input from the primary to secondary component of the transformer. The voltage applied to the primary component will also be present in the secondary component.		It often seems surprising that a transformer keeps the total [[power]] the same when voltage goes up or down. One must keep in mind that when the voltage goes up, the current goes down:

			::<math>P=I_1 V_1 = I_2 V_2 </math>

			Transformers use [[electromagnetic induction]] to change the voltage and current. This change is called transformer action, and describes how the transformer changes an AC signal from its primary to its secondary component (like in the equation above). When an AC signal is applied to the primary coil, the changing current causes a [[magnetic field]] to change (get bigger or smaller). This changing magnetic field (and associated [[magnetic flux]]) will pass through to the secondary coil inducing a voltage across the secondary coil, thereby effectively coupling the AC input from the primary to secondary component of the transformer. The voltage applied to the primary component will also be present in the secondary component.

	As mentioned before, transformers do not allow DC input to flow through. This is known as DC isolation.<ref name=A /> This is because a change in current cannot be generated by DC; meaning that there is no changing magnetic field to induce a voltage across the secondary component.		As mentioned before, transformers do not allow DC input to flow through. This is known as DC isolation.<ref name=A /> This is because a change in current cannot be generated by DC; meaning that there is no changing magnetic field to induce a voltage across the secondary component.

Jmdonev: 1 revision imported

2018-05-11T18:17:04Z

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Jmdonev at 18:00, 9 May 2018

2018-05-09T18:00:55Z

← Older revision		Revision as of 18:00, 9 May 2018
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	[[Category:Done ~~2015~~-08-21]]		[[Category:Done 2018-04-30]]
	[[File:4624935949_5d81aacfbe_z.jpg\|300px\|thumb\|Figure 1. Pad mounted transformer for electrical distribution.<ref>sdpitbull via Flickr [Online], Available: https://www.flickr.com/photos/stevestr/4624935949</ref>]]		[[File:4624935949_5d81aacfbe_z.jpg\|300px\|thumb\|Figure 1. Pad mounted transformer for electrical distribution.<ref>sdpitbull via Flickr [Online], Available: https://www.flickr.com/photos/stevestr/4624935949</ref>]]
	<onlyinclude>A '''transformer''' is an electrical device that uses [[electromagnetic induction]] to pass an [[alternating current]] (AC) signal from one [[circuit]] to another, often changing (or "transforming") the [[voltage]] and [[current]].</onlyinclude> Transformers do not pass [[direct current]] (DC), and can be used to take the DC voltage (the constant voltage) out of a signal while keeping the part that changes (the AC voltage). In the [[electrical grid]] transformers are key to changing the voltages to reduce how much energy is lost in [[electrical transmission]].		<onlyinclude>A '''transformer''' is an electrical device that uses [[electromagnetic induction]] to pass an [[alternating current]] (AC) signal from one [[electric circuit]] to another, often changing (or "transforming") the [[voltage]] and [[electric current]].</onlyinclude> Transformers do not pass [[direct current]] (DC), and can be used to take the DC voltage (the constant voltage) out of a signal while keeping the part that changes (the AC voltage). In the [[electrical grid]] transformers are key to changing the voltages to reduce how much energy is lost in [[electrical transmission]].

	Transformers change the voltage of the electrical signal coming out of the [[power plant]], usually increasing (also known as "stepping up") the voltage. Transformers also reduce ("step down") the voltage in [[substation]]s, and as [[distribution transformer]]s.<ref name=A>R.T. Paynter, “Basic Electric Components and Meters,” in ''Introduction to Electricity'', 1rst ed. NJ: Prentice-Hall, 2011, ch. 21, sec. 21.1, pp. 903-908.</ref> Transformers are also used as a part of devices, like [[current transformer]]s.		Transformers change the voltage of the electrical signal coming out of the [[power plant]], usually increasing (also known as "stepping up") the voltage. Transformers also reduce ("step down") the voltage in [[substation]]s, and as [[distribution transformer]]s.<ref name=A>R.T. Paynter, “Basic Electric Components and Meters,” in ''Introduction to Electricity'', 1rst ed. NJ: Prentice-Hall, 2011, ch. 21, sec. 21.1, pp. 903-908.</ref> Transformers are also used as a part of devices, like [[current transformer]]s.
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	[[File:Transformer operation.png\|thumb\|800px\|center\|Figure 1. A simple operating transformer.<ref> from http://www.kwiznet.com/p/takeQuiz.php?ChapterID=10654&CurriculumID=41&Num=3.15 accessed November 24th, 2014.</ref> [[Current]] <m>I_p</m> comes in with a [[voltage]] <m>V_p</m>. The current passes through the <m>N_p</m> windings creating [[magnetic flux]] in the iron core. This flux is traveling through <m>N_s</m> loops of [[wire]] on the other circuit. This creates a current <m>I_s</m> and a voltage difference in the second circuit of <m>V_s</m>. The [[electric power]] (<m>V\times I</m>) [[conservation of energy\|stays the same]]. ]]		[[File:Transformer operation.png\|thumb\|800px\|center\|Figure 1. A simple operating transformer.<ref> from http://www.kwiznet.com/p/takeQuiz.php?ChapterID=10654&CurriculumID=41&Num=3.15 accessed November 24th, 2014.</ref> [[Current]] <math>I_p</math> comes in with a [[voltage]] <math>V_p</math>. The current passes through the <math>N_p</math> windings creating [[magnetic flux]] in the iron core. This flux is traveling through <math>N_s</math> loops of [[wire]] on the other circuit. This creates a current <math>I_s</math> and a voltage difference in the second circuit of <math>V_s</math>. The [[electric power]] (<math>V\times I</math>) [[conservation of energy\|stays the same]]. ]]

	The fundamental principle that allows ~~for~~ transformers to change the voltage of [[alternating current]] is the direct relationship between the ratio of loops of wire in the primary winding to the secondary winding and the ratio of the primary [[voltage]] to the output voltage. The ratio between the number of turns (or loops) in the primary coil to the number of turns in the secondary coil is known as the turns ratio. The turns ratio establishes the following relationship with voltage:<br />		The fundamental principle that allows transformers to change the voltage of [[alternating current]] is the direct relationship between the ratio of loops of wire in the primary winding to the secondary winding and the ratio of the primary [[voltage]] to the output voltage. The ratio between the number of turns (or loops) in the primary coil to the number of turns in the secondary coil is known as the ''turns ratio''. The turns ratio establishes the following relationship with voltage:<br />

	<center><m>\frac{N_p}{N_s} = \frac{V_p}{V_s}=\frac{I_s}{I_p}</m></center>		<center><math>\frac{N_p}{N_s} = \frac{V_p}{V_s}=\frac{I_s}{I_p}</math></center>
	*<m>N_p</m> = Number of turns in the primary coil		*<math>N_p</math> = Number of turns in the primary coil
	*<m>N_s</m> = Number of turns in the secondary coil		*<math>N_s</math> = Number of turns in the secondary coil
	*<m>V_p</m> = Voltage across the primary		*<math>V_p</math> = Voltage across the primary
	*<m>V_s</m> = Voltage across the secondary		*<math>V_s</math> = Voltage across the secondary
	*<m>I_p</m> = Current through the primary		*<math>I_p</math> = Current through the primary
	*<m>I_s</m> = Current through the secondary<br />		*<math>I_s</math> = Current through the secondary<br />

	From this equation, if the number of turns in the primary coil is greater than the number of turns in the secondary coil (<m>N_p > N_s</m>), then the voltage across the secondary coil will be ''less'' than in the primary coil. This is known as a "step-down" transformer, because it lowers, or steps down, the voltage. The table below shows common types of transformers used on the [[electrical grid]].		From this equation, if the number of turns in the primary coil is greater than the number of turns in the secondary coil (<math>N_p > N_s</math>), then the voltage across the secondary coil will be ''less'' than in the primary coil. This is known as a "step-down" transformer, because it lowers, or steps down, the voltage. The table below shows common types of transformers used on the [[electrical grid]].

	{\| {{table}}		{\| {{table}}
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	\| align="center" style="background:#f0f0f0;"\|'''Power'''		\| align="center" style="background:#f0f0f0;"\|'''Power'''
	\|-		\|-
	\| Step down\|\|input (primary) voltage > output (secondary) voltage\|\|<m>N</m><sub>p</sub>><m>N</m><sub>s</sub>\|\|<m>I</m><sub>p</sub><<m>I</m><sub>s</sub>\|\|<m>P</m><sub>p</sub>=<m>P</m><sub>s</sub>		\| Step down\|\|input (primary) voltage > output (secondary) voltage\|\|<math>N</math><sub>p</sub>><math>N</math><sub>s</sub>\|\|<math>I</math><sub>p</sub><<math>I</math><sub>s</sub>\|\|<math>P</math><sub>p</sub>=<math>P</math><sub>s</sub>
	\|-		\|-
	\| Step up\|\|input (primary) voltage < output (secondary) voltage\|\|<m>N</m><sub>p</sub><<m>N</m><sub>s</sub>\|\|<m>I</m><sub>p</sub>><m>I</m><sub>s</sub>\|\|<m>P</m><sub>p</sub>=<m>P</m><sub>s</sub>		\| Step up\|\|input (primary) voltage < output (secondary) voltage\|\|<math>N</math><sub>p</sub><<math>N</math><sub>s</sub>\|\|<math>I</math><sub>p</sub>><math>I</math><sub>s</sub>\|\|<math>P</math><sub>p</sub>=<math>P</math><sub>s</sub>
	\|-		\|-
	\| One-to-one\|\|input (primary) voltage = output (secondary) voltage\|\|<m>N</m><sub>p</sub>=<m>N</m><sub>s</sub>\|\|<m>I</m><sub>p</sub>=<m>I</m><sub>s</sub>\|\|<m>P</m><sub>p</sub>=<m>P</m><sub>s</sub>		\| One-to-one\|\|input (primary) voltage = output (secondary) voltage\|\|<math>N</math><sub>p</sub>=<math>N</math><sub>s</sub>\|\|<math>I</math><sub>p</sub>=<math>I</math><sub>s</sub>\|\|<math>P</math><sub>p</sub>=<math>P</math><sub>s</sub>
	\|}<br />		\|}<br />

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	To learn more about transformers please see [http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/transf.html#c1 hyperphysics].		To learn more about transformers please see [http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/transf.html#c1 hyperphysics].

			== For Further Reading ==
			For further information please see the related pages below:
			*[[Electrical transmission]]
			*[[Electrical grid]]
			*[[Electrical outlet]]
			*[[Distribution grid]]
			* Or explore a [[Special:Random\| random page!]]

	==References==		==References==
	{{reflist}}[[Category:Uploaded]]		{{reflist}}[[Category:Uploaded]]

J.williams: 1 revision imported

2015-08-26T21:31:55Z

1 revision imported

← Older revision	Revision as of 21:31, 26 August 2015
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J.williams at 18:50, 24 August 2015

2015-08-24T18:50:48Z

New page

[[Category:Done 2015-08-21]]
[[File:4624935949_5d81aacfbe_z.jpg|300px|thumb|Figure 1. Pad mounted transformer for electrical distribution.<ref>sdpitbull via Flickr [Online], Available: https://www.flickr.com/photos/stevestr/4624935949</ref>]]
<onlyinclude>A '''transformer''' is an electrical device that uses [[electromagnetic induction]] to pass an [[alternating current]] (AC) signal from one [[circuit]] to another, often changing (or "transforming") the [[voltage]] and [[current]].</onlyinclude> Transformers do not pass [[direct current]] (DC), and can be used to take the DC voltage (the constant voltage) out of a signal while keeping the part that changes (the AC voltage). In the [[electrical grid]] transformers are key to changing the voltages to reduce how much energy is lost in [[electrical transmission]].

Transformers change the voltage of the electrical signal coming out of the [[power plant]], usually increasing (also known as "stepping up") the voltage. Transformers also reduce ("step down") the voltage in [[substation]]s, and as [[distribution transformer]]s.<ref name=A>R.T. Paynter, “Basic Electric Components and Meters,” in ''Introduction to Electricity'', 1rst ed. NJ: Prentice-Hall, 2011, ch. 21, sec. 21.1, pp. 903-908.</ref> Transformers are also used as a part of devices, like [[current transformer]]s.

==How transformers work==

The strange ability to keep the total [[power]] the same, but change the current and voltage comes from electromagnetic induction. This ability is often referred to as transformer action, which describes how the transformer changes an AC signal from its primary to its secondary component. When an AC signal is applied to the primary coil, the changing current causes a [[magnetic field]] to change (get bigger or smaller). This changing magnetic field (and associated [[magnetic flux]]) will pass through to the secondary coil inducing a voltage across the secondary coil, thereby effectively coupling the AC input from the primary to secondary component of the transformer. The voltage applied to the primary component will also be present in the secondary component.

As mentioned before, transformers do not allow DC input to flow through. This is known as DC isolation.<ref name=A /> This is because a change in current cannot be generated by DC; meaning that there is no changing magnetic field to induce a voltage across the secondary component.

[[File:Transformer operation.png|thumb|800px|center|Figure 1. A simple operating transformer.<ref> from http://www.kwiznet.com/p/takeQuiz.php?ChapterID=10654&CurriculumID=41&Num=3.15 accessed November 24th, 2014.</ref> [[Current]] <m>I_p</m> comes in with a [[voltage]] <m>V_p</m>. The current passes through the <m>N_p</m> windings creating [[magnetic flux]] in the iron core. This flux is traveling through <m>N_s</m> loops of [[wire]] on the other circuit. This creates a current <m>I_s</m> and a voltage difference in the second circuit of <m>V_s</m>. The [[electric power]] (<m>V\times I</m>) [[conservation of energy|stays the same]]. ]]

The fundamental principle that allows for transformers to change the voltage of [[alternating current]] is the direct relationship between the ratio of loops of wire in the primary winding to the secondary winding and the ratio of the primary [[voltage]] to the output voltage. The ratio between the number of turns (or loops) in the primary coil to the number of turns in the secondary coil is known as the turns ratio. The turns ratio establishes the following relationship with voltage: 

<center><m>\frac{N_p}{N_s} = \frac{V_p}{V_s}=\frac{I_s}{I_p}</m></center>
*<m>N_p</m> = Number of turns in the primary coil
*<m>N_s</m> = Number of turns in the secondary coil
*<m>V_p</m> = Voltage across the primary
*<m>V_s</m> = Voltage across the secondary
*<m>I_p</m> = Current through the primary
*<m>I_s</m> = Current through the secondary 

From this equation, if the number of turns in the primary coil is greater than the number of turns in the secondary coil (<m>N_p > N_s</m>), then the voltage across the secondary coil will be ''less'' than in the primary coil. This is known as a "step-down" transformer, because it lowers, or steps down, the voltage. The table below shows common types of transformers used on the [[electrical grid]].

{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Transformer Type'''
| align="center" style="background:#f0f0f0;"|'''Voltage'''
| align="center" style="background:#f0f0f0;"|'''Turns ratio'''
| align="center" style="background:#f0f0f0;"|'''Current'''
| align="center" style="background:#f0f0f0;"|'''Power'''
|-
| Step down||input (primary) voltage > output (secondary) voltage||<m>N</m>p><m>N</m>s||<m>I</m>p<<m>I</m>s||<m>P</m>p=<m>P</m>s
|-
| Step up||input (primary) voltage < output (secondary) voltage||<m>N</m>p<<m>N</m>s||<m>I</m>p><m>I</m>s||<m>P</m>p=<m>P</m>s
|-
| One-to-one||input (primary) voltage = output (secondary) voltage||<m>N</m>p=<m>N</m>s||<m>I</m>p=<m>I</m>s||<m>P</m>p=<m>P</m>s
|} 

The '''one to one''' transformer will have '''equal values for everything''' and is used mainly for the purpose of providing DC isolation.

A '''step down''' transformer will have a '''higher primary voltage''' than secondary voltage, but a '''lower primary current''' value than its secondary component.

In the case of the '''step up''' transformer, the '''primary voltage will be lower''' than the secondary voltage, meaning a '''greater primary current''' than the secondary component.

==Efficiency==
Under ideal conditions the voltage and current change by the same factor for any transformer, which explains why the primary power value is equal to the secondary power value for each case in the above table. As one value decreases the other increases to keep at a constant equilibrium power level.<ref name=A />

Transformers can be extremely efficient. High-power transformers can reach the '''99%''' mark of [[efficiency]], as a result of successes in minimizing [[transformer losses]]. However, a transformer will always output a slightly lower power than its input, as losses cannot be eliminated completely. There is some [[transformer impedance]].

To learn more about transformers please see [http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/transf.html#c1 hyperphysics].

==References==
{{reflist}}[[Category:Uploaded]]