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 ...

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Finding L and R in AC circuit

Ammeter readings: A1 = 4A A2 = 2A A3 = 3A Voltmeter reading 24V. Circuit is in AC. I have to find R1,R2 and L. While calculating R1 (R1 = 24V/2A= 12 Ohm) seems to be easy, next steps are not ...
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26 views

AL value: nH/N² vs. nH/T²

I'm in the process of sizing some toroidal ferrites. My problem is that I am seeing the AL value on the datasheets shown two different ways as nH/N² or nH/T². Are these two units identical? I believe ...
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41 views

Calculating inductance and capacity of the serial RLC circuit

I've been trying to find a way to complete this task, but can't quite figure out how to solve this circuit. I've attached the picture that should have all the details. Is there a specific way of ...
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2answers
42 views

Meaning of infinite self inductance

I am reading about the characteristics of an ideal transformer and it is mentioned that self inductance of each coil is infinite. Could someone help me to understand the physics behind it? When self ...
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36 views

Why is inductance negative in this triphase mutual inductor?

Suppose I have a threephase circuit with a mutual inductor on the first and second phase (V2 and V3). One way of solving the circuit (ie finding the phase currents) would be the following: convert the ...
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44 views

equivalent inductance

If two circuits 1 and 2, are coupled through the coils of inductance L1 (in circuit 1) and L2 (in circuit 2), how does the inductance value of L2 affect L1 ? and what is the inductance value seen by ...
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44 views

equivalent inductance

I have a basic doubt in understanding the concept of equivalent inductance. When two inductor coils are in series the equivalent inductance is calculated as \$ L_{eq} = L1+L2 \pm 2M \$ (depending on ...
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27 views

Where should I look for transformer inductance discrepancy?

I'm experimenting with this smallish (~15VA) toroidal line transformer as a "lab" exercise as I'm learning about transformers. Right now it has its original 115V primary winding only; I "unwound" and ...
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2answers
61 views

inductance of multi-stranded wire

The inductance of a single loop of wire will increase in inverse proportion to its diameter. Are there exceptions to this rule when applied to multi stranded wire (not litz wire). I should make it ...
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45 views

Welding Transformers?

I was thinking of making a carry handle for two microwave oven transformers in series, and also so that they can share a common ground without having to split the ground wire. I thought about bolting ...
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1answer
89 views

How to choose the correct inductor for my application

I am planning on using induction to power some game pieces in a project I am building. My plan is to use identical coils in board and piece, so they will be small (2" max diameter). My problem is ...
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3answers
70 views

Does mutual inductance change individual inductances?

If I have two inductors, with inductances \$L_1\$ and \$L_2\$. I put them really close to each other to make a transformer. Are their individual inductances still \$L_1\$ and \$L_2\$? Or has the ...
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49 views

Are those calculations for primary coil of a transformer correct?

The calculations in this question are based on my previous quesion: How many turns do I need for the primary coil of a transformer? Marko Buršič said : "B_max shall be between 1.3T and 1.6T, but not ...
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66 views

How many turns do I need for the primary coil of a transformer?

I need to know the number of turns that should be connected to 220 volts AC. I can measure resistance only, I don't have a device that measures inductance. If I need the primary coil to be 220V / 1A ...
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97 views

How to find L value of a coil?

I am a newbie at electronics and was hoping I could find some help. I have a coil with a removable iron core, photo for which is given above. I tried to find L1 or the inductance of the coil. I ...
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20 views

Inductance calc for Edge Coupled Differential Pair?

Apologies up front if this topic has been addressed. I've searched on StackExchange and am concluding that this structure is uncommon as there is no ground return accompanying the differential pair ...
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1answer
37 views

WPC Inductive Power Transfer

I am building an Inductive Power Transfer (IPT) system. As of now I am using a design based on a flyback converter. It works great but I am having issues adding features such as power control feedback ...
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1answer
43 views

Sensing inductance change in high power (20 watts) wireless transmitter

First post here. I have a built a wireless power transmitter that consists of 2 flat spiral coils that transmit about 20 watts across a short distant to power a heating element. The coils inductance ...
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1answer
48 views

critical inductance value when designing a buck converter

From the formula used in this literature from Texas Instruments http://www.ti.com/lit/an/slva057/slva057.pdf - Page 15 Here are my requirements: Vo-Output voltage(v) 98 Vi(max)-Maximum input ...
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147 views

Mutual inductance

Find the value of R such that 10W of power is dissipated by it. The provided answer is R=2.25 kohms. Perhaps it is incorrect?
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45 views

Explanation of Lq, Ld and how it relates to motor inductance

I'm pretty much a novice to motor controls, but I was wondering if any of you could explain the concept of d-axis and q-axis inductance and how it relates to the inductance L that is usually specified ...
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6answers
1k views

LC circuit, bigger L than C, or bigger C than L?

So if I want my LC circuit to resonate at 20MHz, I just use the formula, \$F=\frac{1} {2\pi\sqrt{LC}}\$. Using available inductor and capacitor values, there are lots of different possible ...
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2answers
59 views

how can i choose my inductance? [duplicate]

I calculated my inductance value and current rating but I can't decide which inductance I have use. for example 10uH, max 800mA my inductance values but there is other variables.in this topic I have ...
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115 views

Induction heater circuit problem

I am trying to build induction heater with the help of the following schematics(taken from this page): So I am using 220:10Vrms(15Vpeak) transformer with fullbridge rectifier and a capacitor to get ...
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2answers
41 views

Why does the effective reluctance between two windings change?

The effective reluctance between the two windings should remain same, no matter on which arms they are placed. The pair of arms with less cross sectional area will offer more reluctance as compared ...
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86 views

Rectangular PCB coil

I need someone with great skills in magnetics and coils. I would like to design a PCB coil. This is just a try out so I don't want to study a week to implement it. I have this planar core I would ...
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121 views

Getting resonant frequency in LC circuit with L as air core coil

im trying to find inductance of the air core coil,i read that in LC parallel circuit with known capacitor value we can find unknown inductance value by the formula so need to find 'f' resonant ...
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38 views

Leakage inductance of a transformer

Wikipedia article on Leakage inductance provides a formula for the leakage: These equations can be developed to show that, neglecting associated winding resistances, the ratio of a winding ...
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1answer
94 views

Is my oscilloscope affecting my tuning circuit?

I am building an AM Radio and I have constructed a tuner circuit. See below. simulate this circuit – Schematic created using CircuitLab However, I cannot use this circuit, because even ...
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3answers
164 views

Sensing a Bullet

I am attempting to design a sensor that can non-invasively detect if there is a bullet in the chamber of a gun. To help explain my problem I have put together some models and images for you. First off ...
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1answer
129 views

emitter to base amazing transistor effect

As I'm a beginner I was playing with transistors connecting them parallel, serial, making AND/ OR logic gates and so on. I connected all collectors to + and each transistor emitter to another one's ...
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1answer
56 views

Find the inductance of the copper coil? [closed]

I have copper coil Its length is 20 meter, diameter is 1.66mm. How can I find the inductance of the coil (with out applying the voltage)? I got it, actually. I wound the coil on a hard paper, the ...
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96 views

General Question about Coil wrapped around a transformer core

I had a doubt about how inductance of a wire is calculated if it is wound around a iron rod, and when its wound around a transformer core. Case 1 : Considering an iron rod at first , or in other ...
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406 views

Dependence of Inductance of a Coil on the gap between turns?

I was wondering how does inductance of a coil say wrapped around a core change by increasing the gap between turns ? Usually it shouldn't depend on it from the Formula of L being equal to (uN^2A)/L ...
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1answer
147 views

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: ...
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1answer
177 views

Why inductors lose inductance when connected in parallel?

Generally I can't arrive due to why inductance lose inductance when connected in parallel. If two capacitors are connected in series, the distance between the plates of a capacitor increase and thus ...
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3answers
622 views

What's the easy way to measure a DC hobby motor's inductance?

When using simulations(SPICE), I need to model a DC motor or an electromagnet, relay ect. as an RL in series. I can measure the R resistance by an ohmmeter. But I couldn't find an easy way to find ...
2
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1answer
95 views

Solenoid circuit current issue

I have been working on a circuit go make a solenoid switch polarity with arduino. I originally used transistors (NPN) rated for 1A and 625mW in between the ends of the solenoid and ground. These all ...
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1answer
59 views

What is the difference between a magnetized nail and a coil?

When I was a child, I brought a nail (metal bar) and I made some turns around the nail. It was something like a coil and the nail was the core of that coil. When I applied DC on the coil using 1.5 V ...
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2answers
126 views

Modeling long wires in circuits

What's the proper way to model really long wires in circuits (18ga, ~1500 ft)? I'm aware that over long lengths start to accrue non-ignorable resistances. I'm wondering if they start to get other ...
2
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2answers
370 views

Why are some common-mode chokes rated in ohms instead of henries?

Some common-mode chokes, including this one, are rated in ohms instead of in henries. Why? Isn't the impedance injected by the common-mode choke entirely frequency dependent? Is there an assumed ...
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78 views

Inductor in transformer

In an inductor, a current waveform 90° out of phase with the voltage waveform creates a condition where power is alternately absorbed and returned to the circuit by the inductor. If the inductor ...
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1answer
50 views

Why isn't number of loops included in the EMF equation?

The following is a snapshot from (http://www.electronics-tutorials.ws/inductor/inductance.html). I understand the first equation which relates inductance, number of wraps, and current. But since EMF ...
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3answers
134 views

Series LCR experiment

i am doing a series LCR experiment for measuring the resonant frequency taking, R= 100 ohm; L= 40mH; C=0.1uF. I am using a 10KHz audio oscillator having 10V p-p as the input. I have fixed the input ...
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3answers
81 views

Inductance of toroidal-cylindrical inductor?

If the inductance of a solenoid is \$L_{\text{sol}}=\frac{\mu N^2 A}{l}\$ and the inductance of a toroid is \$L_{\text{tor}}=\frac{\mu N^2 r^2}{D}\$, is it correct to assume that the inductance of a ...
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1answer
152 views

At what input frequency of an LCR meter should I measure the inductance of a solenoid valve?

I wanted to measure the inductance of a solenoid valve that I have: Airtec 2P025-08. I took it to the university's electronic valve. There was an LCR meter and I measured this values: @ 120hz : R = ...
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1answer
135 views

pros and cons of replacing a passive inductor by a gyrator

I am studying the construction of some touch sensors, and I need inductances of 10mH, I know I can easily do it, and also purchase them without much difficulty, however I know that it is possible to ...
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2answers
81 views

Induction loop for catching lightning?

Recent thunderstorm, and a big overhead cloud to cloud lightning flash. Coincident with it, sparks jumped from a metal chair in the house. Would it be possible to get a spark from a loop of cable ...
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2answers
80 views

Inductance of a relay coil

I'm using a magnetic latching dpdt relay from Teledyne company. The value of inductance for the coil in the relay is needed and not given in the data sheet. The part number of relay is 422d from ...
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103 views

Why is inductor completely canceling out current?

I used this calculator to determine that my hand-turned inductor has an inductance of approx. .5 uH. simulate this circuit – Schematic created using CircuitLab When I measure this ...