Questions tagged [inductor]
An inductor is a 2 terminal passive device that stores energy in a magnetic field.
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How is the voltage across an inductor well defined?
As asked in this question, it seems that certain inductor shapes, like an infinite solenoid or a toroid, produce non-conservative induced E-field outside of them. When doing the line integral of E(dot)...
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48 views
Finding Current in Parallel RLC Circuit with 2 voltage sources?
I've spent sometime learning about step responses for series/parallel RLC circuits, but this problem takes things a step further, since C seems to be in parallel with a series combination of RL and a ...
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1answer
48 views
Practicality of using flat-spiral coil as electromagnet?
For my project, I'm using a 3D magnetic sensor to track the proximity of a local electromagnet at any time, no more than a finger length away.
Ideally, I would like the the electromagnet to be:
...
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29 views
Second - order circuits containing two capacitors or two inductors [on hold]
Why is it that a second order circuit containing either two capacitors or two inductors can never exhibit an underdamped response?
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Small TPA3116D2 amp [closed]
So basically i got this 2x50W+100Wsub Tpa 3116d2 amp
Now my question is since the amp has an issue that it overheats the small orange inductors even when the sound system is idling(no signal) so it ...
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4answers
85 views
Inductor with constant current source
Hii can anyone explain how to do this. Its Given Answer as 6A. What exactly happens when a constant current source in series with inductor? TIA
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2answers
40 views
In a three phase choke, is the rated current per phase or for all 3 together?
In a 3-phase choke, for example here: https://katalog.we-online.de/pbs/datasheet/744839010400.pdf
What is the current rating?
For the inductance it says 3x10.5mH, so its 10.5mH in each phase and if I ...
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0answers
31 views
Solving a driven RL circuit with a current source
I was given a practice problem as listed below. It says that the solution is in the form of a second order differential equation, but I thought that only RLC circuits were 2nd order. Am I missing ...
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35 views
What's the value of this 5 band axial (should be) inductor? (I can't match the color scheme)
I can't find any clue with this inductor:
Grey/Silver, Red, Black, Gold and White
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0answers
91 views
RL Circuit Analysis with 2 sources, how to find current of resistor?
I've been tackling some problems related to natural and step responses for RL & RC circuits, but I think I've hit a major roadblock for this RL circuit. I'm trying to find the time constant and ...
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2answers
30 views
buck converter inductor lm2576
I was curious and looking at the datasheet of the buck converter IC LM2576, looking at the inductor selection guide it feels counter intuitive to me.
Why is the inductor value needed reducing as we ...
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1answer
45 views
How does flux change polarity in full bridge SMPS transformer?
Take a full bridge switching circuit connected to the primary of a transformer.
Assume:
No load on secondary.
Voltage into full bridge is DC.
Duty cycle of switching is 50%.
At t = 0, full bridge ...
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4answers
63 views
Minimum specs before a flyback diode is needed for a relay?
Given a low power signal relay, 3V 140mW coil, controlled by a 2n3904 npn transistor, is a flyback diode required? At what point is a flyback diode needed for any given inductor? Is it total power, ...
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1answer
42 views
Exponential nature of current growth/decay in inductors
Why are the curves for growth and decay of current in inductors of exponential nature i.e $$ 1-e^{-x} $$ and $$ e^{-x} $$ respectively. I understand the mathematical derivation for the current i(t). ...
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0answers
36 views
Small axial inductor for piezo disc buzzer?
I'm planning to operate a 15mm piezo disc as a buzzer at about 5 KHz. Can I use a 5mH 0.5W axial inductor for this? Peak current through the inductor is 70 mA, average current 22 mA, average ...
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2answers
42 views
What are the initial conditions used to find the coefficients in the current equations?
Suppose a RLC series circuit. R, L and C are in series with a battery and a switch. The switch is open. L and C are discharged.
At t=0, the switch is closed and the battery (V1) feeds the circuit.
I ...
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2answers
88 views
How to determine the current rating of Litz wire winding at high frequency?
How can we determine the current rating of a litz wire winding at high frequency?
This is my try:
For example, if we use 660/38 litz at 85kHz, we can see the equivalent AWG is 10 (reference). Then, ...
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1answer
48 views
How do I find the current equations for the RLC Series Circuit?
Let's talk about a RLC series circuit. R, L and C are in series with a battery and a switch. The switch is open. L and C are discharged.
At t=0, the switch is closed and the battery (V1) feeds the ...
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1answer
58 views
Average Inductor Voltage equals Zero?
Okay I already read this post which answers the question mathematically
here,
at the end of the top answer the poster said:
"Thus, the only way to keep current from going to infinity is the ...
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2answers
47 views
How much is the permeability of this attached inductor core?
I want to use this inductor for AC line filter as line reactor. Its inductance value is 6 mH but I don't know the exact value of permeability of the material. It will be used with VFD at the input to ...
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2answers
61 views
Scenarios where Inductor back EMF would result in damage of circuit or component
Let's say that there is a simple circuit with the following components (ignore values):
LEFT: a simple power supply (assume DC)
TOP: load (resistor) and inductor
RIGHT: switch
BOTTOM: load (resistor)
...
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3answers
65 views
Deenergizing Inductor
I am reading through "Practical Electronics for Inventors" and I came upon a chapter about deenergizing inductor. I understand the concept that when you cut the current going into inductor, it will ...
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0answers
32 views
1st order differential circuit RL
Im trying to use KVL to solve the differential equation.
My Attempt so far is the following:
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3answers
607 views
If you have two identical but oppositely wound inductors does the inductance effectively cancel?
I was just curious if the effect inductance of a branch of a circuit would cancel if you put two identical but oppositely wound inductors in series. It's not something I have come across.But looking ...
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2answers
57 views
Derive current through “charging” inductor formula
I don't know if it's just me but I can't find a single resource that derives a general equation for the current through an inductor. My text book just says "assume the equation if of the form ..." but ...
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3answers
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Does this experiment show that Kirchhoff's Law hold when there's a changing magnetic field involved in a circuit?
In this video, the electrical engineer and youtuber Mehdi Sadaghdar (ElectroBOOM) disagrees with another video from professor Walter Lewin.
Basically, professor Lewin shows in an experiment that if ...
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1answer
93 views
Can Induced electromotive force affect itself?
At first, I want to say that I'm not English speaker, so my question might be very hard to understand. And also this question must be a silly question because I can't find any question like this...
I ...
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1answer
53 views
Inductor power choke
I'm looking for this inductor 10 µH.
Need help to recognize series model of this IC's inductor.
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1answer
54 views
Buck converter inductor calculation doesn't agree with typical application schematic
Im trying to play around with some buck converters and have found one that I might want to make a circuit with. The IC I want to use is the the TPS53125 in QFN package. It's a dual output buck ...
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1answer
57 views
DIY transformer (toroid) waveform
Update
Ok, it may be related to the adhesive I'm using to glue the toroids on the 3D prints.. I'll wait till tomorrow for it to cure and test again..
I'm trying to build a portable/battery ...
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0answers
34 views
Calculating distance from magnetometer to electromagnet
I want to calculate distance (and then triangulate to get position) of an electromagnet using multiple magnetometers. It has already been done from the Finexus project
, but the formulas are not well ...
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1answer
41 views
Power over ethernet and common-mode termination
I have a non-standard Power over Ethernet application (connector, and devices are not ethernet standard but we are using ethernet pairs and protocol for communications). On looking at PoE schematics I ...
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1answer
71 views
How to convert Inductor to series transmission line?
My objective is to understand the travelling wave amplifiers, but I am stuck on how to realize inductors in transmission lines.
But, I am basically stuck on how to convert a series inductor to a ...
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1answer
60 views
Curious-looking inductors
I was poking around a video amplifier and — in its dual-rail power supply — saw a pair of inductors unlike any inductors I've come across before:
(These are the two sides of the same inductor; the ...
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2answers
329 views
Impossible to find the energy stored in an inductor without resistance and given a constant DC current source?
Here's my circuit:
simulate this circuit – Schematic created using CircuitLab
After doing some series and parallel inductor combining I get the value $$L_{eq}=20.8 mH$$
My question is, how ...
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2answers
83 views
Transformer magnetizing inductance
I am learning about transformers and in the equivalent circuit the magnetizing inductance of the excitation branch is supposed to represent the current needed to "set up" the flux in the core due to ...
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1answer
114 views
What kind of device in this circuit
It's a power entry part of a DAQ card, the bottom right is a DC jack. The power flow maybe:
Power DC jack -> ferrite bead -> cap -> common mode inductor -> cap -> ?
I guess the bigger black one may ...
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1answer
44 views
When deforming a resonant circuit into an antenna, why can we cut the inductor in half?
The working principle and fields of an antenna can often be shown by considering a parallel LC circuit. The plates can be moved to opposite ends and the inductor can be stretched out, both of which ...
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1answer
57 views
How i can make transmission line from inducor and capacitor [closed]
The questions are:
How can i make an inductor using transmission line?
How can i make a capacitor using transmission line?
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2answers
66 views
What should be the sign of the voltage across the inductors while doing circuit analysis?
I am not able to understand what should be the sign of the voltage across an inductor while doing circuit analysis. I know the voltage across an inductor is given by -Ldi/dt, when the rate of change ...
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1answer
191 views
Undescriptive capacitor and inductor values in audio-amp datasheet
I was learning about audio amplifiers and came across the STA516B IC. To my surprise, the example circuits feature some values for capacitors and inductors which seem a bit high for me. So I wanted to ...
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0answers
65 views
power surge protection
I've seen power protection that uses:
MOV (metal-oxide varistor)
Inductor
TVS diode
Application Note: Transient Voltage Suppressors (TVS Diode)
Applications Overview
I didn't see any design ...
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2answers
81 views
Combining two ideal voltage sources with an impedance between them
Solving a problem, I came across the following source transformation:
My question is:
I know that I can do the following:
&...
2
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1answer
59 views
Source transformation with impedance being inductor or capacitor
I found a presentation that states the following about source transformation when the impedance is capacitive/inductive:
While electrical circuits books, like Nilsson's, says:
If I transform the ...
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2answers
90 views
Inductive kickback
I know this is a very basic concept, and has been described in many places, but I still can't 100% understand inductive kickback.
simulate this circuit – Schematic created using CircuitLab
If ...
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1answer
49 views
How can I change component values in a premade circuit
I do projects quite frequently, but the only problem is that sometimes I don't have the right component, and it takes to long to ship. I heard that some people change the values of their components (...
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1answer
88 views
What will be the behavior of this circuit?
i have a circuit for which i have simulated its output. But i can't seem to understand how it works.
Here is the circuit..
simulate this circuit – Schematic created using CircuitLab
For ...
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0answers
109 views
How to calculate the self capacitance of a flat spiral coil?
I am trying to design a wireless charger and I have to find the resonance frequency of the flat spiral coil. The formula is this one:
ƒr = 1/(2*pi*√(LC)) . So I need to know the inductance of the ...
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1answer
89 views
How do you model differential inductor in LTspice?
I wonder how I can model a differential inductor in LTspice?
I've an inductor that has half the turns on one side and the other half on the other side.
It's intended to be used in a bridge tied ...
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3answers
76 views
Triac Dimmer Supplying a Purely Inductive load
I was asked a question in my lab viva today, on a triac switch supplying a fixed value inductor of 0.2 henry.
How will the current and voltage of the inductor vary, if the triac's firing angle was ...
