Questions tagged [mutual-inductance]
The mutual-inductance tag has no usage guidance.
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What precisely is the numerical (or any) meaning of mutual inductance and, is it useful, representative (of something) or important?
When we consider two inductors that are magnetically coupled, we sometimes talk about mutual inductance. As an example, consider two inductors (such as 9 μH and 4 μH) that are 100% coupled and produce ...
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If I used the primary coil as an inductor, does the secondary coil affect it?
I've read this question. It's about how to obtain the maximum inductance from a transformer:
How do I use a transformer as an inductor?
Now, I would like to use the primary coil only as an inductor ...
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Parallel decoupling capacitors: Is inductance reduced?
Background
In general, when placing decoupling capacitors in parallel, their capacitances add and their compound ESR is reduced (like for parallel resistors). But I am a bit uncertain if/how this ...
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Circuit feedback with mutual inductance on a toroid
I have been reviewing a circuit for the past few days and I am hoping to get some feedback to verify my thoughts as to how the circuit is working. This is a driving circuit for an ultrasonic cleaner ...
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Problem finding voltage in a circuit with mutual inductance
I'm trying to solve an example from Hayt's Engineering Circuit Analysis:
let \$i_1=4i_2= 20\cos(500t-20°) \mathrm{\ mA}\$. Determine \$v_1(0)\$.
Using \$k=\frac{M}{\sqrt{L_1L_2}}\$, I got \$M=0.6\ \...
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How to achieve mutual inductance and CM choke simulation in CircuitLab?
This site is using CircuitLab. In some SPICE programs it is possible to simulate CM choke. For example:
Mutual Inductance is designated in a SPICE netlist by beginning the
first word (label) of a ...
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Induced voltages and flux within a transformer and their polarities
This is a multifaceted question, and is more to see if I understand what happens inside a transformer. I understand the general idea behind transformers: Alternating voltage that is applied to the ...
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Resonant Coupling for Optimal Power Transfer
I am trying to read the following paper:
B. L. Cannon, J. F. Hoburg, D. D. Stancil and S. C. Goldstein, "Magnetic Resonant Coupling As a Potential Means for Wireless Power Transfer to Multiple ...
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What happens when primary and secondary coil of an isolating(1:1) transformer are connected together(in parallel)?
I am considering the case of an isolating transformer because both the coils are identical. If we connect both of these in parallel, they will act as mutually linked inductors if they are connected in ...
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limit of mutual coupling
The two inductors are in parallel and are coupled magnetically. The equivalent inductance of the arrangement is,
$$L_{eq}=\frac{L_1L_2-M^2}{L_1+L_2+2M}$$
This would obviously be zero when \$M=\sqrt{...
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Coaxial Cable with signal applied to shield and center conductor grounded
The standard way to drive a signal through a coaxial cable is to have the shield grounded, and a single-ended signal applied to the center conductor.
(Throughout, I will assume that \$R_{term}\$ and \...
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Mutual inductance dot convention
I have a question regarding the dot convention, or more-so want to find out where I am getting it wrong. I start by defining the currents I1, I2, and I3. I1 goes through R1 and L1, while I2 is the ...
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Thevenin equivalent with mutual inductance
I was practicing for the exam I found a problem in the book as follow :
I want to find the voltage Vth so here is what I did :
When finding the Vth I didn't ignore the dependant voltage source in ...
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How to avoid mutual inductance at UHF frequencies?
I know that keeping inductors at right angles helps to avoid mutual inductance. But I can't find any information minimal spacing between inductors such that they have no mutual inductance. In my ...
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Two questions about an AC electric circuit: Have I interpreted the dots correctly and where does the negative sign come from?
I asked this question over at the Physics Stack Exchange (https://physics.stackexchange.com/q/549814/263454) and I thought that it might stand a better chance of being answered here.
So I am looking ...
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Closed loop shapes with zero mutual inductance?
I have done numerous searches trying to find any mention of theory or experimentation done on determining closed current loop shapes that have zero mutual inductance and...no dice!
Of course you can ...
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Mutual Inductance Practical Explanation
I can't understand why the Mutual Inductance is measured in Henry. The self inductance of a coil is the abillity that has a coil to create a magnetic field that produses a voltage on itself so to ...
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A problem of ideal transformer
I am studying Fundamental of Electric Circuits by Alexander and Sadiku, and I am not able to solve a practice problem 13.9 about ideal transformer in Chapter 13 of the textbook. My answer is different ...
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Mutual inductance vs coupling coefficient
Question regarding this and this question about mutual inductance and coupling coefficient.
I'm trying to analyse a two coil system:
It consists of two coils like in the picture with 2 cm air gap ...
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How to emulate effect of mutual inductance?
Background
I don't have any background in electrical engineering. My knowledge is very superficial. I am simulating a circuit which has mutual inductance between two components. However, the software ...
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Does mutual inductance change individual inductances?
If I have two inductors, with inductances \$L_1\$ and \$L_2\$. I put them really close to each other to make a transformer.
Are their individual inductances still \$L_1\$ and \$L_2\$?
Or has the ...
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2
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Mutual inductive coupling in a nodal admittance matrix
I have this question that has been haunting for quite a while now. To compute the nodal admittance matrix \$Y_N\$ of an electrical network, one can make use of the incidence matrix and the branch (or ...
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Resultant voltage function through two opposing coils with mutual inductance
So my question is about the type of relationship in a particular circuit. I would like to know if it is linear or something else like a power.
The circuit in question is a pair of adjacent, mutually ...
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Why is inductance negative in this triphase mutual inductor?
Suppose I have a threephase circuit with a mutual inductor on the first and second phase (V2 and V3). One way of solving the circuit (ie finding the phase currents) would be the following: convert the ...
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Lumped model of a load and source connected by two long paralel wires
I want to understand how to skecth an equivalent circuit model circuit composed of a load (resistor to make it simple) connected to a soruce bia two long paralel wires. Take the following figure as a ...
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Forms of Magnetic Noise Coupling
I was watching a video of Bob Pease discuss magnetic coupling of noise into the ground lead of an oscilloscope probe. See video at 5:40
https://www.youtube.com/watch?v=2vzvWUqUtb8
I noticed another ...
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Taking into account the mutual inductive coupling analytically in LTSPICE
I am trying to take into account the mutual inductive coupling between three turns in LTspice differently. Instead of defining the inductive coupling coefficient K, I am using the analytical ...
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Can someone explain the dependence of coupling coefficient to inductance value to me? It seems counter intuitive
According to the formula \$K=M/\sqrt{L_1 L_2}\$, it seems that k is inversely proportional to the inductance values of the two coils. However, it seems to me that a coupling between two 2uH inductor ...
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Magnetic coupled circuit
I am solving this circuit and according to the dot convension,the j6 ohm and j8 ohm have opposite polarities. Applying kvl to both loops,
I got, 10 = j5I1 - j3I2 + j3I2
Or, I1 = -j2 A
But I am stuck ...
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2
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Analysis of three phase star star connected transformer
What is going on this circuit(below) and what would be current measured by ammeter(zero or non zero)?
Description-
These two transformers winding are star star connected and a balance sinusoidal ...
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Individual Three Phase Potential Transformers vs Three Potential Transformers in one case
If I had to select between Individual Three Phase Potential Transformers vs Three Potential Transformers in one case for a 600V system (which doesn't require many inches of spacing between phases to ...
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In an ideal transformer circuit, how is power transferred?
If I have a system of circuits like this:
where Circuit 2 is providing power the Circuit 1, where does the energy come from? Do the inductors store energy? If not, how is power transferred from the ...
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Calculating Mutual Inductance in Parallel Wires
How would I calculate the mutual inductance (Lm) between parallel wires if I know the inductance per length of the wires and the separation between the wires?
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Equivalent Circuit for the RLC circuit to find the transfer function
I have a series RLC circuit with mutual inductance between the transmitter end and the receiver end.
The circuit is
I am trying to formulate a simple transfer function. I can formulate the ...
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What's the minimum electrical requirements to ac-ac conversion
I bought a 220VAC -> 12VAC (0.3A 3.6VA) cheap power source, and tried to do a simple conversion of the output voltage, with two coils, around a ferrite core, with different length of turns.
simulate ...
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magnetically coupled inductor equations
How come the mutual inductance for the v1(t) equation has a negative sign and the mutual inductance for the v2(t) equation have a positive sign? I don't properly understand how the signs of the self ...
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2
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Constructing Coupled Inductors with Particular Coupling Coefficient
I'm curious about the design of RF transformers with purposely designed non-unity coupling coefficient. I can see how this would be done in an IC, but how feasible is it at the discrete component ...
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Understanding of coupling coefficient and power transfer efficiency
I am a bit confused about my derivation to get power efficiency from the coupling coefficient.
The coupling coefficient \$k=M/\sqrt{L_1L_2}\$.
$$
V_2=M\frac{dI_1}{dt}=L_2\frac{dI_2}{dt}\\
V_1=M\frac{...
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Transformer's Primary and Secondary Voltages
In general, which is the phase relationship between the primary and secondary voltages of an ideal transformer? Does it depends on the dot convention?
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Mutual inductance
I am confused about derivation of the next formula
The question is about Cm term.
We have coupled inductors.
The voltage across first coil is
And I am ok with it. I understand it.
I know ...
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Inductance of planar (spiral) coil near solid copper surface
I'm working on a electromagnetic levitation system, consisting of a flat spiral (planar) inductor positioned above a solid copper surface. The planar coil is parallel to the copper surface. (Consider ...
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Impedance matrix of a transmission line
I'm studying power systems and this question came up: if there are two transmission lines in series and I know the impedance matrix of each one (Zp is self-impedance and Zm is mutual impedance):
...
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How to calculate the induced voltage of two electrically isolated coils (solenoids)?
Suppose I have the following setup:
suppose then that:
Self inductances L1,L2, the radius R, the number of windings (turns) N1, N2 are all given.
V1 is given.
The distance between the coils (...
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Sensing inductance change in high power (20 watts) wireless transmitter
First post here.
I have a built a wireless power transmitter that consists of 2 flat spiral coils that transmit about 20 watts across a short distant to power a heating element. The coils inductance ...
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Mutual Inductance - Self Induced Voltage
When constructing mesh equations for each loop where two coils are linked, I know how to determine the polarity of the induced voltage by use of dot markings, but I need some clarification on the self ...
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Toroidal coil as current sensor
Is there a simple way to estimate the amount of flux that is caught by a toroid coil (filled by some core material, like powder iron for example), which surrounds a straight wire with a current ...
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Loop inside a loop, where is the mutual inductance greatest?
I had a question while working a problem as to where the mutual inductance of a circular loop inside a rectangular loop is greatest.
Is it at the center, because the magnetic field of all four wire ...
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Wirless Power Tansfer Circuit
Hello so my university is closed because of covid. I am allowed one day into their labs to build and test my WPT device.
My Tx is very large compared to my Rx. I have tested their inductance with a ...
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Dot convention inductors in series: equation confusion
So I'm really confused with mutual inductors and dot convention. If your answer is going to be a link to any website I can assure you I read them all and that only left me more confused. So here are ...
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How can I build my own wireless charger for my cellphone? [duplicate]
I am designing a wireless charger for my cellphone, Where my Primary coil is energised with 1.5V and 0.3A, Where I have used a transistor to turn it on and off at a frequency of 1Mhz.
In the secondary ...
