Questions tagged [inductance]
Inductance is the property by which a change in current in a conductor induces a voltage both in the conductor itself and nearby inductors, the latter being the basis upon which transformers operate. Discrete inductors are also available that have many applications including filtering and energy storage.
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What plays the stability of inductance value over frequency?
I made a measurement of inductance value over frequency and I got the curve as shown.
I see a high drop of inductance value at high frequency (over several kHz)
I don't really understand why the ...
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What will happen if the Impedance of wireless power power transfer TX coil and RX coil are different
I am new to WPT. Currently I am characterizing the coils to be used used for our WPT.I measured the inductance of TX coil and RX coil at 100Khz.
The impedance of RX coil is 4.5uH @ 100Khz and that of ...
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BLDC HFI Observations
I came here in the hope someone guides me along the steep path of High Frequency Injection.
As a first Test, I connected my motor to a ~2kHz 33% Duty Square Wave, with one Phase switching to positive, ...
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Measurement frequency for indicated coil inductance
This choke inductor has an inductance of 100 µH according to the website.
I know, however, that inductance varies with frequency (due to parasitics). So, I was wondering at which frequency was the ...
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Strange non-linearity in inductor impedance
Recently I've disassembled, and rewound a 12+12 V 2A transformer as an autotransformer for a test in impedance matching, but it ended not being enough for what I wanted (although it did work).
Then I ...
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Testing hook-up wires for inductance
Say a hypothetical question. A seller I'm going to has dubious merchandise & their hook-up wires, in particular, are NOT made out of typical high purity copper, like ordinary hook-up wires. One ...
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Equivalent Loop Inductance
this is a question I believe is straight forward, but for some reason can't wrap my head around it. I am trying to simulate parasitic inductance in a circuit with 2 FETS (Q1, Q2) during a switching ...
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Magnetising Inductance / Primary Inductance
I provided a picture below which shows the transformer calculations and LTspice simulation.
In the 1'st picture L11 = 100.5 µH. This value is the inductance of primary side of the transformer.
In the ...
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Transformer modelling / coupled inductors
I provided a picture which shows the transformer model and related equations.
[Transformer Model and Equations]
Source: https://www.youtube.com/watch?v=VrIfvNVBSyE
I have 2 questions which are as ...
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How should we calculate L (inductance) value for a transformer
I am trying to design a transformer using LTSpice with the following specifications:
Vin = 230 V @ 50 Hz
Vout = 12 V @ 50 Hz
Power = 10 W
The thing I do not understand is how to calculate the ...
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Best method to dampen inductive spiking from pulsing coil with MOSFET?
A simple diode works across the coil to lower the voltage spikes, but I ideally need a way to absorb the inductive spiking as fast as possible. I've heard a Zener diode across the drain and source of ...
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Calculation of transformer inductance value
I am trying to find a way to calculate the primary and secondary inductance of transformer.
I learned that it is changing from one topology to another. My topology is Phase-Shifted Full-Bridge ...
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How would you Improve the Smoothness of a 12V DC Motor Drive with Limited PWM Frequency?
I am developing a control system for a 12VDC brushed motor rated at 500W, which is part of a larger project. Currently, I'm using PWM for motor control, but I'm restricted to a maximum frequency of ...
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What is inside of a typical RF transformer?
I am tempted to decap this 500 MHz transformer, but guessing the internals are typical and well-known by experts here.
I don't understand why many companies don't even spec the two windings' DC ...
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LCR Meter U1733C "rn" Symbol Meaning
I have the Keysight U1733C LCR Meter and when I meausure inductance shows me the "rn" letters in front of the Henry units. Do you know what it means (on the manual I found only the SI units -...
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Determining transformer equivalent circuit components
I have made a PCB based planar transformer with a turns-ratio of 8:6. I am considering the T-model as shown below:
In the T-model, Lp is the primary side leakage inductance, Ls' is the secondary side ...
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Energy stored in a saturating inductor
We all know that the energy stored in an ideal inductor is \$E=\frac{1}{2}LI^2\$. However, real inductors with a ferromagnetic core don't have constant inductance. Particularly, when a specific field ...
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Inductance after core saturation
Looking at the datasheets of some drum core inductors, at higher currents the inductance drops significantly due to ferrite core saturation. But it seems inductance asymptotically approaches a value ...
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When increasing the frequency of an induction motor can't I just add a capacitor to maintain torque instead of increasing the voltage?
When increasing the speed of an induction motor if one wants to maintain the same torque, the voltage has to be increased at the same proportion as the frequency of the AC supply.
This is because the ...
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Can PCB trace inductance be reduced by tinning a trace?
I am creating a circuit for a "high current" buck converter (maybe 40 A), and switch node ringing is giving me a headache trying to find solutions. The circuit schematic I'm using is like ...
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Removing turns from a relay coil to make it work on a lower voltage?
I have a piece of machinery that was moved from a building with 240 V to a building with 208 V and all is well but the contactors don't seem to pull in all the way. Could I remove enough turns from ...
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Equivalent inductance seen from a winding
I would be having a little trouble understanding how to do this problem of magnetic circuits. It asks me to calculate the equivalent inductance seen from winding N2. I know how to calculate the ...
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Graph plot of sinusoidal current/voltage vs displacement of speaker membrane from its resting position
For a very long time I believed that the speaker membrane just moves according to the amplitude of a electrical signal fed to it. Like, If at any instant, the current/voltage is at c% (0 <= c <= ...
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Capacitance Formula derivation
Can anyone help me with how this formula came in the first place (marked in red)? I am not able to understand the denominator term.
This is with reference to Double Pulse Test taken from the book : ...
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Why does the Inductance change on an E-Core Leg when going from Small Copper Wire to Litz Wire?
In the first picture you can see 45 turns of standard 0.4 mm copper wire. The impedance analyzer (e4990) shows an inductance at 20 kHz of 11.5 mH. Which is inside the tolerance of around 12.8 mH +- 20%...
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Why does an inductor's inductance decrease with current?
I am struggling to understand what seems like a fundamental behavior of an inductor. I am looking at a chip mount LQM18PN2R2MFR inductor. One of the diagrams on the manufacturer's website shows a ...
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Using MOV to protect device for heater element
I have a heater element that is controlled by a solid state relay from main power. I know it is customary to place a MOV in parallel when switching inductive loads to clamp the voltage to prevent ...
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Intrinsic safety (IEC60079-11) - assessing spark ignition of RLC circuit, but the L is placed before the zener barrier
My IS circuit contains an inductance, capacitance, and resistance. Shown below is the simplified schematic, with uncountable and countable fault applied, resulting in the most onerous condition:
The ...
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PWM large current, will it kill MOSFET?
We are looking at PWM dimming 2700 LEDs.
3.2V forward voltage
20mA current each
Connected in parallel
This makes 54A in total. The longest stretch of cable is 7 meters (one way). Currently looking ...
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What are the potentials at front and back of inductor when primary DC supply is disconnected in LR circuit?
I have been learning the basics of inductors in simple LR circuits with DC currents. I think I get most of it but I am a bit unclear about the secondary EMF produced by the inductor after the primary ...
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Inductance of solenoid with solid metal core
Consider the solenoid/inductor like in the picture.
There is an air gap between the coil and the inserted solid metal.
The solid metal is from aluminum or copper (Both have a relative magnetic ...
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Could a very high voltage and very low current allow a non-superconducting magnetic energy storage system?
A very low current with very high voltage can travel through high resistant wires without much loss. Could this type of current be used on magnetic energy storage without superconducting materials?
...
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Leakage inductance in a series resonant converter
I know that the leakage inductance is present due to the imperfect linking of flux between the two transformer windings. I have selected a core for the transformer to be used within a series resonant ...
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How to get a smooth operation of multiplexed solenoids
My project involves 100 small solenoids, that I either have drive individually, or hopefully I can drive in a multiplexed configuration, the same way LED displays are driven. Then I only need 20 ...
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Measuring inductance of motor coil with low Q factor
I have a motor coil that I suspect has an inductance outside the nominal range. I wanted to use a Maxwell-Wein bridge to determine the inductance of the bad coil. The main concern I have is that, as I ...
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Help measuring inductance of custom-made coil
I am testing some coils that will be used in a resonant circuit as antennas for very low frequencies (<100 Hz). The coils work great, but the only way I have to tune is trial and error.
If I ...
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Does all the current lag the voltage in an inductor or is it only a small component?
the way I understood a basic inductive circuit (voltage source + inductor) is that all the circuit current (Io) lags the voltage by 90 degrees. However, I am following this blog tutorial to refresh ...
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Why do inductors and capacitors cause phase shifts between current and voltage? [closed]
I am learning about grid level stabilization services.
My native language is German and I am translating the specific terminology. If I use the English terms incorrectly please edit my below sentences....
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Power supply coupling of inductive resonant sensors
I'm working on an array of sensors based on Peltz Oscillators connected to a micro to detect objects based on shifts in resonant frequency when a target object gets close to the inductor. In isolation,...
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Electromagnetic Energy Harvester
It was suggested I make a new post since the topic was growing in complexity.
I am looking into constructing an inductor to utilize electromagnetic induction near a high voltage transmission line. If ...
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Inductor not behaving even close to calculation
I wrapped a coil around a 1/2 inch X 6 inch pure iron rod. The coil is composed of #22 enameled copper and about 393 turns.
393 turn coil around a 0.5 inch (6 inch long) supposed pure iron rod:
This ...
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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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NEMA Coil "Sealed Current"
I am trying to select a relay to interface between a temperature controller output and a NEMA size 4 120VAC contactor coil. According to the NEMA spec, a 120VAC, size 4 has a 8.3A inrush current and ...
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Looking for datasheet of Toshiba T2742 integrated circuit [closed]
I'm looking for datasheet for Toshiba T2742 Integrated circuit. IC is used in old car with tachometer sensor, probably as AFE (Analog Front End). Tachometer sensor is a inductance proximity sensor, ...
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Potential problems with disconnecting resistive load from transformer
Lets say I have a setup where an AC transformer is outputting 50 Amps at 240 volts from the secondary for some other process and I add an additional purely resistive load that pulls 100 amps at 240 ...
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Simulate or Calculate Inductor Flyback Voltage from Component Parameters?
simulate this circuit – Schematic created using CircuitLab
Top circuit can be used to simulate the increase in velocity of the JATO Powered Chevy featured in the first episode (and subsequent ...
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Why will a connector add some inductance if it is soldered or not?
According to this AN :
I do not understand how the inductance can reduce if the connector is soldered or not. I mean the length of the "traces" will not change. I agree that the resistance ...
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When the depth of a conductor is sufficiently large, is the reactance equal to the resistance? [closed]
Is the reactance in a conductor approximately equal to the resistance in a conductor when the depth is very large?
If so, why?
I'm struggling to understand the concepts behind this. I believe it has ...
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How are modern ACDC power supplies desgined?
I wonder about how exactly modern, but mundane ACDC power supplies (your phone power supply) are designed. Maybe my misunderstanding comes from one of the following assumptions:
Modern AC-DCs ...
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Transient analysis with charged and uncharged inductor in series
I have to do transient analysis in the following circuit.
When t<0.
L2 inductor is effectively bypassed and 10A flows through inductor L1.
At t = 0+
L1 behaves as a current source outputting 10A ...
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