Questions tagged [inductor]
An inductor is a 2 terminal passive device that stores energy in a magnetic field.
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What kind of magic is energizing the coils in this simple stepper motor driver?
Looking at this web page, i found a simple stepper motor driver circuit
https://www.electronicshub.org/stepper-motor-driver-circuit/
The problem is, i just can't understand how it can work when the ...
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21 views
Transformer/Inductor Bobbin Sizes
I have to design a 150 Ampere, 1.5 mH Inductor for a power supply project assigned to me, and off-the-shelf components are to be used. My instructor is insistent on using a transformer Bobbin to wind ...
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31 views
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30 views
Transformer and Thevenin Theorem
Consider an ideal transformer connected to a real AC voltage source (with output resistance Rg).
Now consider to apply the Thevenin theorem between the output terminals of the secondary circuit. I ...
2
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1answer
52 views
Output Filter Components Breaking Class D Amplifier Chip
Hi I am designing a class D amplifier PCB using the TPA3122D2 amplifier chip. I am planning to base my circuit on the schematic from the evaluation board:
I bought components of the same values given ...
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1answer
27 views
How to Choose Proper Components for Class D Amplifier Circuit
Hi I am designing a class B amplifier PCB using the TPA3122D2 amplifier chip. I am planning to base my circuit on the schematic from the evaluation board (see below).
I have tried building out this ...
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36 views
Calculating current and voltage from RL circuit through differential equation
Our circuit, where R1 = 3 Ohms, R2 = 1 Ohm, R3 = 2 Ohms, L = 5 milliHenry, and I = 0.01 Ampere.
Trying to figure out the differential equation for this circuit, as well as the current for the ...
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2answers
42 views
Metal detection with a coil matrix
I have an 8 x 8 grid and would like to detect where on the grid I place a metal object. I'm currently working with the TDA0161 metal detection IC, and so far have the following setup with detection ...
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3answers
46 views
Modelling the equivalent series resistance's voltage in a circuit
Say a 2H inductor has an equivalent series resistance of 2000 ohm at a particular frequency. Logically to me, that inductor would be modeled as an inductor in series with a resistor. However, that ...
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1answer
31 views
Coil output from variable magnetic field
If I put a coil with X Henry value and N turns in a variable magnetic field of Y Tesla peak value (coming from another coil excited by A sin(wt) signal), how to calculate the output voltage across the ...
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1answer
64 views
Why Ferrites are used as a cores for inductors
Why specifically we use the ferrites as a core for the inductors? For example a NiZn toroid as a core for an inductor?
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48 views
Choosing an inductor value for use as the load in a half bridge inverter circuit
I am making a half-bridge inverter circuit, firstly I have made it in LTSpice to simulate it and plan to build it in the lab.
I will initially use a Vrail of 40V but plan to increase it above this, ...
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0answers
43 views
ASK demodulator not working as expected
I have implemented an ASK modulator and demodulator pair. The modulator works fine, but the demodulator is giving a vague output. Below is the image of the whole circuit and the simulation output.
...
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32 views
How can we make a load that has configurable power factor for 230V AC?
We are hoping to create a lab for students at our university that requires them to measure the power factor and correct for it.
We are working with 230V AC and have a maximum power of 300W.
We were ...
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69 views
Imaginary Capacitance and Imaginary Inductance interpretation and relations with circuit theory
Today I came across with Complex Capacitances and Inductances for the first time:
$$L(j\omega)=L_{real}+jL_{imaginary}$$
$$C(j\omega)=C_{real}+jC_{imaginary}$$
So I started looking at their meaning ...
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1answer
89 views
How do I get rid of vehicle voltage spikes maybe a choke and capacitor filter?
My Question is:
Is this a effecient way of filtering high voltage spikes?
If so is the way I drawn the circuit even correct...
How to size the components to work so that any vehicle high voltage ...
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0answers
32 views
Negative Feedback Operational Amplifiers with Inductors
Wasn't able to find many problems similar to this for reference. I'm studying for my exam next week and am a little lost with some of the material for this section. This is a practice question from an ...
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27 views
Loading an AC generator with DC Chopper + resistor
We're in kind of a bind at work and looking for easiest / cheapest way to load an AC generator (Synchronous permanent magnet machine).
We have access to a big 300A Mosfet module along with it's ...
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32 views
Multiplexer between Capacitor and Inductor (Tank circuit)
I am trying to design an inductance and capacitance meter with multiple scales, to achieve this I thought a multiplexer can do the job, but it didn't.
My question is: What is wrong in this design ...
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2answers
66 views
Why isn't fast decay mode on an h bridge damaging
I'm struggling to understand how fast decay mode works on an h-bridge used for stepper motors . Particularly I've been looking at fast decay mode in this data sheet: http://www.ti.com/lit/an/slva321/...
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2answers
69 views
Why for an inductor part is the RMS current rating is specified at 20°C rise and 40°C rise?
The inductor part from coilcraft (https://www.mouser.in/datasheet/2/597/xal4000-270751.pdf), RMS current rating is specified for 20°C rise and 40°C rise. Is there any specific reason? In note ...
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29 views
Flyback, primary inductance selection for wide output current changes
I would build my first flyback converter.
Converter would be designed for 2A max and load device would draw about 100-200mA for most of the time with 1.8A peaks. Peaks would take a little longer so I ...
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2answers
62 views
Coupled inductor/pulse transformer for very tiny power supply
I need an isolated 24V 3mA supply to activate some optocoupler that will be read by some microcontroller. Its power supply will be the microcontroller's 5V. My first instinct was to use a flyback ...
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4answers
1k views
Why isn't there a non-conducting core wire for high-frequency coil applications
Background
The commonly known skin effect formulas are derived and only apply to solid conductors. The commonly used "skin depth" only applies in these cases. It is for this reason that in some ...
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83 views
Trapezoidal Rule of Complex RLC Circuit using MATLAB
I am having difficulty trying to figure out how to solve this circuit using the trapezoidal rule. I know how to do so in a first and second order RLC circuit however this particular circuit is giving ...
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1answer
86 views
What could cause my boost converter to output below its nominal voltage?
I'm very new to electronics and I'm building things and experimenting as a learning opportunity. I've put together a boost converter circuit and it works OK, but I've noticed that under larger loads ...
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1answer
98 views
Lt-spice switch model
I have a very simple circuit and want to see the current in the inductor.
But I do not know why switch is behaving like that...
Actually, I supposed to get KA range current. but it gives me very ...
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3answers
47 views
Saturation current on chip inductors
Inductors are really not my strong point, and I have been getting a bit confused on the rated current vs saturation current.
I know the rated current is how much current the inductor can handle ...
3
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2answers
149 views
Frequency dependent resistor in real inductor (air coil)?
I tried to measure the resonance frequency of some multi layer air coils. Typical parameters are 0.6 mm copper wire, 3 to 8 layers, and diameter and height are approx 50 mm. I solder a 1 Ohm resistor ...
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2answers
72 views
Series RL current equation
I am trying to derive a inductor current equation for \$i(t)\$ in a series RL circuit when the switch is closed at \$t=0\$, as seen below:
I have posted my attempt so far but I'm having trouble ...
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2answers
64 views
Must the air gap in a transformer always be perpendicular to the magnetic field lines?
The air gap in a transformer seems to always be spaced across the cross section of the core, where the magnetic field in the core has to then flow across it.
Since the core is typically made of ...
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1answer
76 views
Why does duty cycle seem relevant when calculating inductor current in boost converter circuit?
I've been working hard to understand boost converters and the role of inductors in the boost converter circuit. I found a pretty good list of basic calculations from Texas Instruments and I started ...
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1answer
73 views
How do inductor specifications impact their effectiveness in a boost converter circuit?
I've been trying to understand how to select an adequate inductor for a boost converter circuit. I'm a hobbyist so I'm not always sure what to look for, so I haven't been able to find something that ...
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2answers
103 views
Finding the average power dissipated in a resistor
Well, I've a series RL circuit that is powered by a voltage source. The input voltage is given by:
$$\text{V}_{\text{in}}\left(t\right)=50+\frac{400}{\pi}\cdot\sum_{\text{n}=1}^\infty\frac{\sin\left(...
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0answers
48 views
How can an inductor/coil turn a bjt on and off?
I've seen a boost converter circuit on YouTube, and the guy uses a second coil, wound on top of the first coil, and in the same direction, it is connected to the base of a BJT. The BJT acts as a ...
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1answer
3k views
How much time does it take for a switch to go from on to off?
The equation for the voltage across an inductor is v = L di/dt. When a switch changes the circuit from closed to open, it changes the current very quickly. My question is how would one know exactly ...
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2answers
289 views
Buck converter, squeaking/whining inductor
I have a problem with my homemade buck converter. It is based on a TL494 control chip with my discrete MOSFET driver. The problem is that my inductor squeaks and whines, when the output current ...
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0answers
48 views
Series RL Circuit Transient Analysis
I have worked through a question and I am unsure if my answer is correct. It is a series RL circuit with a switch that closes at t=0, supplied by a dc source, which I am trying to derive an expression ...
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25 views
Calculating Currents and Voltages in and AC RL Circuit provided below
I am studying RL Circuits with AC sources. I am trying to solve this circuit
So far, I am only able to calculate the current iL through the inductor as for the other parts I can't grasp the concepts. ...
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2answers
45 views
Can I use this inductor in my boost converter circuit?
I used TI Webench to spec out this boost converter circuit:
The design calls for an inductor that is marked as end of life. Can I use this inductor instead?
My hypothesis is that they are ...
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2answers
54 views
How do I decide which which oscillation frequency and capacitors to use with a boost converter?
I'm working on a few projects where I'll be driving about 8 WS2812B LEDs on a 5V rail with an ATTiny85 (I think the whole circuit is going to draw about .5A; I'm using .75A for my calculations). I'm ...
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2answers
147 views
Why have an inductor between 2 parallel capacitors? (LED driver)
This is the driver for a LED Bulb. I don't understand why there is an inductor between the 2 capacitors C1 and C2? I understand that C1 and C2 are used to handle low frequency ripple and the noise. ...
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1answer
98 views
Simulated inductor for guitar use
Edit: Sorry! Please bear with me, this is my first post! Well, it seems that placing a buffer before certain fuzzes can chance their sound. However, placing an inductor after the buffer cancels this ...
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1answer
40 views
Finding the time constant of an RL circuit
I've the following circuit:
simulate this circuit – Schematic created using CircuitLab
And I've to find the time-constant of the voltage across the inductor.
I did the following:
The voltage ...
2
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1answer
44 views
How to choose RF choke in the biasing circuit of varactor-tuned resonant circuit
I am new to circuit and has a very basic question about how to set biasing circuit of varactor. I need to use varactor to tune the resonance behavior of Split ring resonator (SRR) structure when ...
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1answer
32 views
dual rail DC/DC convertor and CMC
I have a DC/DC convertor that tales 5V and makes + 15V and -15V rails
My question is how to place common mode chokes to reduce common mode noise. Should I place 3 of them (1 on the negative to Gnd , ...
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4answers
495 views
What does a bar symbol in parallel with a single inductor indicate?
Some circuits have parallel bars on their inductor symbols such as:
Does that mean the inductor is wound around a magnetic core instead of air? Is that how a differential choke is represented?
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1answer
63 views
Questions on Inductor Selection guide from TI [closed]
I have been researching on Selecting inductors for Buck Application and came across an Application report from TI.
I have few questions which are listed below:
On ...
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4answers
101 views
Can’t reproduce oscillations using a simple inductor capacitor circuit?
I’m trying to reproduce a simple oscillator conductor / inductor circuit as shown here.
I replicated exactly the same scheme on a breadboard and check all the connections using a led
However when ...
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0answers
67 views
What are the drawbacks of using a ferrite inductor in a boost converter circuit
I have dissected a boost converter so I can remake it on my own PCB. It works fine but I am now experimenting with using different inductors to reduce the overall footprint. I tried installing a ...
