Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [magnetic-flux]

The sum normal component of a magnetic field passing through a surface.

The magnetic flux (represented by Φ or ΦB) through a surface is the surface integral of the normal component of the magnetic field B passing through that surface. The SI unit of magnetic flux is the weber (Wb) and the CGS unit is the maxwell. In EE, electromagnetic phenomenon is applied to transformers and other. For more theoretical details, refer to Physics Stack exchange

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Can a transformer work if the core is not circular?

I am trying to build a transformer to convert 12V AC power to 5V AC. Here is what I have right now: I haven't adjusted the coil ratio yet but I tried it just to see if there would be any output and as a matter of fact there is none. I tested the…
Hadron
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Do all inductors produce 1 weber after one second when 1 volt DC is applied?

A definition of magnetic flux (the weber) is stated here as: - If you take a loop of superconducting wire, and apply 1V to this wire during 1s, then the magnetic flux inside this loop will have changed by 1Wb. Note that this is true regardless of…
Andy aka
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What exactly carries energy in a transformer from primary to secondary?

Suppose we have applied a voltage to a transformer with an open secondary, we will get a certain flux in the core and a certain voltage at the secondary depending upon the turns ratio. Now, suppose we connect resistance to the secondary and…
Anuj Maheshwari
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What happens to parts of induction cooker magnetic field not covered with the pan?

An induction cooker works like this. There's a flat coil of wire under the cooker surface which is connected to a source of high frequency AC and it produces an oscillating magnetic field with field lines oriented vertically. A suitable pan (with…
sharptooth
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Mechanism of transformer secondary current

When a transformer has the secondary open and it's driven by an AC source, the only current that the primary draws is the current needed to produce the flux to magnetize the core (like ferrite) of the transformer. Then we put a load on the…
S. Rotos
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increasing metal detector range

I am working on my senior project. As part of my project I need to use a metal detector. I am using the following circuit schematic. The principle is based on the properties of inductor coil: $$L=N^2\mu \left(\frac{A}{l}\right)$$ Where \$N\$ is…
UserRR
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From a flux point of view, how can we explain that the equivalent inductance is half when identical inductors are connected in parallel?

The equivalent inductance of 2 identical inductance connected in parallel ( ignoring mutual coupling) is half of the orginal . This result is usually derived from the argument of identical voltage across parallel elements->Proof I would like to…
Divya K.S
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How does the length of a transformer's core affect its properties?

I often read mention of a transformer core's "cross-sectional area", of how it affects the transformers VA rating (although I can't find any formulas for that.) I haven't found anything mentioning the length that the magnetic flux must…
Electric-Gecko
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What role does permanent magnet strength play in BLDC/PMSM performance?

It seems to me like stronger permanent magnets are preferred by motor designers, but my current understanding of what role they play in performance is fuzzy at best. I would assume that stronger magnets would imply stronger torque, but I'm not sure…
TheDarkSaint
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How many winding turns in a HV power transformer?

I'm creating a simplified 2D model of 3 three-winding 132/22 kV, 40 MVA transformers that I'll use to calculate the magnetic field surrounding them. Now, the turn ratio is of course 132/22, but is there a typical number of turns for such a…
Stewie Griffin
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Assigning a notion of voltage even when there is a changing magnetic field

In Walter Lewin's lecture, he finds depending on how you keep the lead of the voltmeter for a circuit in a changing magnetic field, you will measure different values]. This experiment is discussed from 49:34 of this lecture and then infers that this…
Reine Abstraktion
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What does the m symbol for magnetic flux mean? Why is it needed when the phi symbol exists?

For reference, I have read the Textbook of Electrical Technology by Theraja and I don't understand how it just uses the mass symbol as a symbol of magnetic flux in poles. Why is it any different from the original phi symbol? Why does the pole thing…
AndroidV11
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How does magnetic flux affects the speed of a DC motor

I'm doing a high school physics project where we need to investigate the relationship between the speed and magnetic flux of a DC motor. We built a simple DC motor which basically looks like this, with brushes and a split-ring commutator. So our…
djaniuiin
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Variable field magnet motor?

See the video in the following link: https://www.youtube.com/watch?v=olnXy-J48SY "Variable field magnet motor" How does this work and is it actually efficient?
FatalSleep
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X-ray back-projection for conversion to hard-field magnetic induction tomography?

This is a question about hard-field back-projection as used in x-ray tomography, but applied to magnetic induction tomography (MIT). Al-Zeibak and Saunders (A feasibility study of in vivo electromagnetic imaging, 1993) have shown that an x-ray…
Brendan Darrer
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