Ohm's Law and Reluctance - Revision history

Kevin.Starkey at 03:29, 18 January 2010

2010-01-18T03:29:17Z

← Older revision		Revision as of 20:29, 17 January 2010
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	<center><math>J=\sigma E</math></center>		<center><math>\displaystyle J=\sigma E</math></center>

	==Reluctance==		==Reluctance==
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	<center><math>\Phi=BA</math></center>		<center><math>\displaystyle \Phi=BA</math></center>

Aric.vyhmeister: /* Ohm's Law */

2010-01-11T18:03:07Z

Ohm's Law

← Older revision		Revision as of 11:03, 11 January 2010
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	The SI units for resistance are the Ohm (~~omega~~), voltage is expressed in volts (V) and current is measured in amperes (A).		The SI units for resistance are the Ohm (<math>\Omega</math>), voltage is expressed in volts (V) and current is measured in amperes (A).



	Expressed differently, the current density J (~~amperes~~/m^2) is proportional to the product of conductivity sigma (V/m) and the electric field E (siemens/meter), or		Expressed differently, the current density J (A/<math>m^2</math>) is proportional to the product of conductivity sigma (V/m) and the electric field E (siemens/meter, s/m), or


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	<center><math>J=\sigma E</math></center>		<center><math>J=\sigma E</math></center>

			==Reluctance==

	Now, consider a material of very high permeability with flux ~~phi~~ running through it and separated by a very small gap of area A, where the flux flows through this gap as if it were free space. The flux density crossing this gap is B. Therefore		Now, consider a material of very high permeability with flux <math>\Phi</math> running through it and separated by a very small gap of area A, where the flux flows through this gap as if it were free space. The flux density crossing this gap is B. Therefore



	<center><math>\Phi = BA</math></center>		<center><math>\Phi=BA</math></center>



	The magnetic field intensity can be approximated by H = B/~~muzero~~		The magnetic field intensity can be approximated by <math>H=\frac{B}{\mu_0}</math>

Aric.vyhmeister: /* Ohm's Law */

2010-01-11T16:40:01Z

Ohm's Law

← Older revision		Revision as of 09:40, 11 January 2010
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	R = V/I :<math>~~\R =~~		<center><math>R=\frac{V}{I}</math></center>


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	J = sigma*E.		<center><math>J=\sigma E</math></center>


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	Phi = BA		<center><math>\Phi = BA</math></center>


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	R = F/~~phi~~		<center><math>\R = \frac{F}{\phi}</math></center>

Aric.vyhmeister at 16:28, 11 January 2010

2010-01-11T16:28:07Z

← Older revision		Revision as of 09:28, 11 January 2010
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	~~This article introduces~~ Ohm's Law and reluctance, ~~its magnetic circuit analog.~~		==Ohm's Law==


			Electric circuits share many of the same characteristics as magnetic circuits. One of the most important and fundamental equations describing electric circuits is Ohm’s Law. Georg Ohm, a German physicist, published this famous equation in 1827, drawing significant influence from Fourier’s previous work in heat conduction.



			Ohm’s Law states that the resistance of a conductor is constant and inversely proportional to the current running through the conductor and directly proportional to the voltage across it, or expressed mathematically as



			R = V/I :<math>\R =



			The SI units for resistance are the Ohm (omega), voltage is expressed in volts (V) and current is measured in amperes (A).



			Expressed differently, the current density J (amperes/m^2) is proportional to the product of conductivity sigma (V/m) and the electric field E (siemens/meter), or



			J = sigma*E.



			Now, consider a material of very high permeability with flux phi running through it and separated by a very small gap of area A, where the flux flows through this gap as if it were free space. The flux density crossing this gap is B. Therefore



			Phi = BA



			The magnetic field intensity can be approximated by H = B/muzero



			The reluctance of this gap is analogous to the resistance described by Ohm’s Law, where it is the ratio of the magnetomotive force to the flux, or



			R = F/phi

Aric.vyhmeister: New page: This article introduces Ohm's Law and reluctance, its magnetic circuit analog.

2010-01-11T06:54:17Z

New page: This article introduces Ohm's Law and reluctance, its magnetic circuit analog.

New page

This article introduces Ohm's Law and reluctance, its magnetic circuit analog.