# 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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52 views

### Emulate impedance response using RLC components

I need to emulate measured impedance response of some blackbox using only RLC components. Measurements: ...
2k views

### What happens if the secondary of an ordinary transformer is left open?

Let's consider a transformer. The ideal transformer equation is: $$\frac{V_1}{V_2} = \frac{I_2}{I_1}$$ Suppose the secondary is open (that means $I_2 = 0$): it will result $I_1 = 0$. How is this ...
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### Confusion Between Dual Capacitor/Inductor Circuits

I'm trying to physically understand the responses of this pair of (dual) circuits: a step current source driving a capacitor and a step voltage source driving an inductor. simulate this circuit &...
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### Finding the total impedance and voltage across open terminals

The question that I'm trying to solve is the following: In the circuit shown below, what is the total impedance in ohms across the open terminals? What is $v_{T}$ if $v_{L}$ is 80 vrms? This is ...
244 views

### Magnetization Inductance vs. Transformer Inductance

what is the difference between transformer inductance and magnetization inductance, as I know transformer inductance is calculated with magnetization current but I've never seen magnetization ...
59 views

### Should via use be used when it is not essential?

I am working on characterising a transistor at approximately Vds=1000V and Ids=100A pulsed at around tON=20ns. Should the power and ground paths (Top and Bottom layers) have vias connected to the ...
149 views

### Transformer at no load [duplicate]

I have been reading about the working of transformers at "no load" condition, that is when no load is connected to secondary side of the transformer. I don't understand why the transformer still draws ...
44 views

### Do metals with different electrical conductivities have different succeptibilities to induction?

If you have an inductive levitation coil and you gradually increase the strength of the AC current to the coils, could you fraction off metal powders by levitating each of them separately due to their ...
146 views

### What is partial inductance?

Some background I have simplified understanding of inductance which is incorrect yet has been a useful falsehood so far. The idea is that a changing flow of current through a loop creates magnetic ...
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### 3-phase inductance calculation homework

This is a homework question where i am stuck. Please help me out in this: Three similar impedances are connected in star across 2000 V, 50 Hz three phase supply. Power absorbed is 300 kW. ...
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### Is there any disadvantage with transmitting the same excitation signal to several resolvers (basically rotating transformers)?

I am considering sending the same excitation signal to multiple resolvers (i.e. transformers of which the secondary rotates with respect to the primary) used as angle sensors in the joints of a ...
287 views

### How do I calculate the equivalent RLC circuit values for a non-ideal capacitor?

The circuit below was constructed and the voltage across Cx measured with an oscilloscope. The measurement is shown below the circuit. The capacitor has a nominal capacitance of 22uF. The square wave ...
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### Air gap variation between metal target and planar Inductor coil changes the coil inductance and oscillating signal's frequency & amplitude?

I am working on planar coil inductive sensor. I noticed if i change the air gap distance between the metal target and sensor coil. the Inductance of the coil changes, frequency and voltage amplitude ...
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### Center tapped transformer equivalent circuit model

What is the correct equivalent circuit model of an arbitrary center tapped transformer? i.e. I simply want the equivalent circuit model with has to look something like this: In center tapped the ...
250 views

### Is my answer correct to this non-ideal capacitor question?

In the picture there are two measurements. The one is of a single 10uF capacitor as shown in the picture. The other measurement is of the 3x 3.3uF capacitors in parallel as shown in the picture below ...
1k views

### Why is wire's inductance inversely proportional to its thickness?

In all the formulas I could find, wire thickness is always in denominator, it seems. Of course thinner wire can have more loops in same space, but even in this monster of a formula for single wire: ...
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### The method and calculation for the total energy that two inductors,which has Mutual inductance, stored in this circuit

The solution for the total energy that two inductors stored in this circuit is $E=\frac{1}{2}\times 4 \times 3^2+\frac{1}{2}\times 6 \times 6^2-1\times 3 \times 6=108J$ I want to ask two things ...
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### What does the black point mean when we are calculate the inductance of several inductors which connected together?

What does this black point mean?i mean because what reason ,so we will say the inductance of the circuit below can be written as this,by the way , $M$ means Mutual inductance. Also,i want to ask ...
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### Inductor with ac and dc

When a dc voltage source is connected with a pure inductor And the switch is closed We get a change in voltage across inductor and along with it a also an attempt to change the current across the ...
74 views

### Circuit analysis Thevenin example in sinusoidal steady-state with dependent and independent ac sources

So I get really confused when I see a dependent source (and serial?) in thevenin-norton problems. Can you help me with these questions? (I think in the question of the figure b the value C is ...
213 views

### Calculating the number of turns for my inductor

so i've calculated that I need an inductance of 0.150mH for my inductor. However, I'm trying to figure out the number of turns I need for it. # I've got an answer of 24 turns but this doesn't feel ...
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### Are there any effects on capacitance and inductance when operating at audio-frequency (i.e. 1kHz - 20kHz)?

At the moment, I study something about audio-frequency track circuits for railway applications and to understand its operation, an accurate model of such a circuit is required. The circuit of audio-...
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### Design coil for rfid chip

I broke an rfid coil which is soldered to a chip. I want to build the coil as it will save me the pain of replacing the chip as it's not something you can find easily. The coil itself was quite ...
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### MOSFET full H bridge, voltage spike protection

Preface, I'm a hobbyist not a electrical engineer, so please be gentle. I was looking for a better than l298N motor control solution for higher currents and one that is similar price and size, but ...
229 views

### how do we get these three formulas from the definition? field strength

I believe these three equation in the figure are not the definition of field strength,and the definition of field strength is $H=\frac{F}{m}$,how do we get these three formulas from the definition? ...
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### Mr. Smeow's loud, annoying robot dog [closed]

I bought my cat a robot dog for Xmas. He loves it! I currently have taken it apart to clean some accumulated hair out from around some of the rotating parts. It plays music that is kind of loud and ...
201 views

### Permeability: is webers per ampere-turn meter (Wb / At.m) equivalent to henrys per meter (H / m)?

Is webers per ampere-turn meter equal to henries per meter? I.e. is $\frac{Wb}{At.m}$ equal to $\frac{H}{m}$? -and if so, is there an easy way to picture the equivalence?
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### Phase difference between source voltage and inductor voltage

What will be the phase difference between the source voltage and the inductor voltage? Will the two voltages be in phase or will be out of phase. How much out of phase they will be? Note that there ...
313 views

### If the self-induced EMF in an inductor is 180° out of phase with source voltage, shouldn't they cancel out and net voltage should become zero?

I know that inductor opposes the change in magnetic flux linked with it. In case of an ac sinusoidal voltage applied across a pure inductor, the emf induced across the inductor is equal and opposite ...
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### Geometric mean versus arithmetic mean or harmoic mean in multiconductor transmission cable inductance?

In the Electrical Power Transmission And Distribution,if we want to know a inductance of inductor,we will use this formula $D_{aa'}$ means the distance between a and a' In the $L_P$.we call the ...
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### Flyback Transformer Primary Inductance Calculation

Can we prove the inductance value of this datasheet using calculation based on it test condition (10kHz,100mV)? Previously I can get almost similar result using LCR meter however I want to know how ...
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### Calculating inductance of inductor that has ferrite core and a large air gap

I'm working on a coil on a PCB that will have a small ferrite core place in the center, with a large gap. I'm trying to come up with a decent equation to estimate the inductance of this inductor. I'...
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### Can an LED be used in paralell of a free wheel diode?

Can an LED be used in paralell of a free wheel diode? All circuit is powered by a 12V alternative. simulate this circuit – Schematic created using CircuitLab I think it can be used like that; ...
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### Why does different antenna inductivity influence LF-RFID performance?

I'm experimenting with LF (125kHz) RFID reader antenna design. And trying two different antennas yields very different results in terms of read sensitivity. Even though one antenna is driven with ...
328 views

### Two-core transformer with three windings?

I am trying to understand how a transformer composed as pictured would function. Basically, two separate cores. Both cores go through the secondary winding. But only one of the cores goes through the ...
1k views

### Center-tapped transformer and inductance calculation for transformer driver

Using a push-pull transformer driver, for example the LT3439 like below with a center-tapped transformer, more precisely this one here So we there is a center tapped transformer (with 1:1.3 ratio ...
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### Is the transformer's secondary winding too large?

I recently took out the windings from an old microwave oven transformer and was planning to use the core for a 120 to 6.3 VAC step-down transformer (total power 160 W max). The secondary winding (...
51 views

### Finding the optimal voltage for a sealed transformer

I stumbled across a sealed transformer (step-up) which i believe came out of a neon power supply. Its completely covered in epoxy like goop and the internals cannot be seen. However,on the tin it ...
106 views

### Back EMF in a transformer with an external power source to the secondary coil

When discussing an ideal transformer, Wikipedia says “varying flux at the secondary winding induces a varying electromotive force (EMF, voltage) in the secondary winding due to electromagnetic ...
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### Evaluation of the primary inductance of a transformer whose core is saturated

I would like to know if it is possible to theoretically estimate reasonably the primary inductance of a transformer when its core is saturated. Otherwise, what is the best way to do it by measurement?...
105 views

### Suppressing the turn off transient for a trailing edge 120V AC dimmer

I am designing an 120V 60 Hz AC trailing edge dimmer based on the reference design above. The gate is driven starting at 0/180 degrees of each cycle and turns off at a programmable phase later in the ...
51 views

### Subtleties of Boost Conver (Step-up Converter)

simulate this circuit – Schematic created using CircuitLab Generally Boost Converter fault happens in my workplace and difficult to find the problem of converter. So I try to understand the ...
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### Are PCB spreading inductance and loop inductance the same thing?

Hi there, there is a mention of power/ground net spreading inductance in the Figure 1. I'm assuming this is the same as PCB spreading inductance. If so, is loop inductance the same thing here? Or ...
962 views

### Measure leakage inductance of flyback transformer with multiple secondary windings

I have a transformer consisting of one primary winding and 3 secondary windings. Now I want to measure the leakage inductance at the primary side, so I need to short the secondary windings. Most of ...
355 views

### Equivalent circuit of a transformer

In equivalent circuit of a transformer, there are two inductances, $L_p$ and $L_s$. These are called Leakage inductances, as the name suggests due to the leakage flux from both the coils. 1) Are ...
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### Permeability Discrepancy of an Inductor

Background: I bought a material 77 ferrite rod for a homemade inductor. The core was 0.5" in diameter and 7.5" long with a claimed initial permeability of 2000. When I recieved it, I tested it out ...
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### Making an Inductor with Proper Inductance

Background I am planning to build a 0.0625 mH inductor, which will be sent about 15 kV max (10 uS pulses, 10 per second). The inductor will be made of 14 AWG copper wire in a tub of mineral oil. The ...
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### Substituting an inductor - cannot find any pieces containing inductance needed

I am a beginner electronics hobbyist trying to follow an old schematic / instructions to build a theremin. I have all of the pieces except one. This piece (Toko 154ANS-T1019Z) calls for a "68 µH, hi-...