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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66 views

Why does stepper motor not turn properly at different frequencies?

I have an 8 wire stepper motor and an unipolar motor driver. I wired the motor as unipolar connection. On motor 3.15V and 4.2A is written. My connection is above. When I connect V to 24V 14A source ...
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2answers
38 views

Value of omega from forced response V0

Based on figure. Maybe a simple question, but I'd like to know why that if forced response is zero, then $$\omega L = \frac{1}{\omega C}$$ where \$L\$ is the inductance and \$C\$ is the ...
1
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1answer
49 views

How does this inductive musical-keyboard function?

I've been looking to interface with a keyboard that I've removed from a non-functional system, specifically an Ensoniq EPS-16. As luck would have it, I managed to find schematics for the controller ...
10
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2answers
521 views

How does the plastic-tube inductor in this wireless transmitter work?

This single layer PCB (solder side shown here) is from an old fan remote: The inductor in the plastic tube is not connected physically to any components; however, the two loops of wire surrounding ...
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1answer
74 views

Can I make a step up transformer using these components?

I have a step down transformer that converts from 220 volt to 15 volt. I want to connect the secondary coil of this transformer to the output of 555 IC that produces ( 5 volt / 100 KHz ). Is there ...
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1answer
59 views

Current overlap in Inductive Smoothing?

I have the following circuit implemented in the lab : And the output was : Can anyone explain why the current overlaps here ? I can't make sense of this.
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4answers
140 views

Can a current be induced in an HDMI cable that runs parallel to a 120v AC cable for 15 feet?

I just went to go unplug an HDMI cable and got shocked from the end of it! The only possible causes of this that I can think of are that the receiving or sending end of the long (50ft) HDMI cable is ...
1
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1answer
123 views

Can I increase inductance using permanent magnet ?

I know that when I insert a ferromagnetic core inside an air-cored coil, the inductance increases. What if I inserted a permanent magnet with a cylindrical shape into an air-cored coil, does the ...
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1answer
39 views

Inductance in Transformers inductors

How can I find a transformers inductors value by using the derivative formula? If I want to generate high voltage spikes from a square wave generator of 10V p-p with a source resistance of 50Ω. I want ...
3
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2answers
66 views

How to measure coils without Inductance measuring device?

I have a multimeter that can measures Capacitance, Resistors, voltage and current. If I have a known coil and unknown coil. Can I measure the ratio between the inductance of the two coils ? Is it ...
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5answers
164 views

How can the infinite reactance of either primary or secondary in an ideal transformer draw current?

Assumption 1: An "ideal" transformer is said to have very large primary, secondary, and mutual reactance.. (self-inductance/mutual-inductance tending toward infinity), has a unity coupling coefficient ...
2
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2answers
230 views

How to make LC tank circuits oscillate continuously?

An LC tank circuit produces oscillations, when the capacitor is charged and connected to the inductor, but the oscillations decay gradually. How to make it continue, i.e. oscillate continuously? I ...
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1answer
43 views

Testing high power inductors

We are using inductors in 180KVA converter circuits. To measure the inductance value of the inductor we are following the process of pumping the current up to 300A and voltage up to 30V. After ...
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2answers
41 views

Component selections for the ETA3406 DC/DC converter

I was browsing Seeed Studio's Open Parts Library and found the ETA3406, which is a 1.5 MHz 1.2 A Step-Down Converter. It's pretty cheap, and looks very useful for something I want to build, but the ...
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1answer
76 views

How to maximize inductance of a homemade coil?

So how can one maximize inductance of a homemade coil made out of copper wire? I assume adding a ferromagnetic core to the coil increases inductance? Also how can we calculate this inductance ...
2
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4answers
124 views

Do transmission lines induce electric or magnetic fields in towers?

Transmission lines have EM fields around them due to the high amount of current. Do these fields affect transmission towers (metal or otherwise)? If so, would it be possible to estimate the current ...
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2answers
93 views

Toroidal Transformer High Current Output

Can a 28-0-28 amplifier toroidal transformer like this be practically used as a high current supply at low voltages? I plan to put a couple of turns of 4 gauge wire through the centre. I want to use ...
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1answer
45 views

Mutual inductance of two loops

I got to measure inductance of circuit with two loops connected like this: simulate this circuit – Schematic created using CircuitLab simulate this circuit The box measures \$L\$. ...
0
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3answers
186 views

What does an inductor's current stabilize to in DC?

As you can see from the below graph, after an inductor is turned on, the current is stabilized to approximately 6.5mA. My question is: what does the 6.5mA represent? Where did that number come from? ...
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0answers
36 views

Permanent Magnet Synchronous Motor Direct & Quadrature Inductance

I've modeled the following motor (http://www.evo-electric.com/inc/files/AFM-140-Spec-Sheet-V1.1.pdf) assuming a direct & quadrature inductance of 0.2mH. However, I think I may have mistaken this ...
2
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3answers
150 views

LCR meter and iron core inductors

I am trying to wind some coils for a RF transmitter, so to get the values right, I though of using a LCR meter, but there is a problem with the measurements. If I use air core inductors the measured ...
-3
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3answers
81 views

When an inductance is connected to an AC supply, the current in the inductor is [closed]

When an inductance is connected to an AC supply, the current in the inductor is is in phase with the voltage Lags the voltage by 90 degrees. Leads the voltage by 90 degrees. Leads the voltage by 180 ...
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1answer
53 views

How do I place a long wire to make the EMI and inductance minimum?

I'm going to measure high current. After seeing that there is not a lot of low valued sensor resistors in the market and the available ones are very expensive, I decided to make my own current sensing ...
1
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3answers
200 views

How to identify mutual inductance?

I have two coils covered in a box and I don't know the physical arrangement of the two coils and mode of each winding in a magnetically couple DC circuit. How can I make an experiment to determine the ...
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2answers
80 views

Minimal pulse width to actuate a solenoid

I'm powering a solenoid from a battery, so I want to spend the minimum amount of power to get the job done. In this case the solenoid doesn't even have a return spring, so as soon as the armature has ...
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2answers
231 views

How to design an square wave Oscillator Circuit with 1-20 MHz range?

I need a circuit that will generate square waves in a range of 1 to 20MHz. The circuit also should be adjustable in a scale of 0.05MHz for each step. There is no need for adjustments during the ...
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2answers
248 views

RGB LED strip, powered by an ATX PSU and controlled by PWM, makes my speakers buzz with Arduino connected by USB

I've not much idea about electronics, but I managed to do some little projects in the past. Now I'd like to place some RGB LEDs in my desktop PC windowed case. For that, I bought a 5050 SMD strip with ...
2
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2answers
134 views

Calculation of inductance of rectangle coil

I'm currently working on a project about inductance. I want to calculate the inductance of a rectangle-shaped coil with a pitch different from zero. I tried this by applying the law of Biot-Savart. If ...
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0answers
53 views

Check My Inductance Calculation

I'm trying to find the components for a buck step-down converter. I found this equation online to calculate inductance. * L=(Vin-Vout)(Vout/Vin)(1/fsw)(1/(LIR*Iout)) Where L is inductance, fsw is ...
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1answer
60 views

Running single-phase through two or three windings of a three-phase inductor; why does the direction of the middle winding matter?

I have a three-phase inductor, MTE RL-00403, nominal 9 mH. I have some experimental results that don't make sense to me, which appear to be related to the fact that all three chokes share a single ...
3
votes
1answer
54 views

Inductor value given in OHM/Amp

I've been trying to figure out the inductance in Henries from a schematic of a Rabbit Microprocessor development board, however, instead of finding an inductance value over the components in question, ...
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2answers
56 views

EMF due to inductance?

In a DC circuit, current starts to flow, and some time is needed for current to stabilize based on the time constant, there is EMF induced due to current changing over time. As soon as the current ...
1
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1answer
151 views

What could be used to send induced/coupled CAN-BUS signal

My problem I am experiencing is with the circuitry or IC combination to follow. I don't need a answer of what exact IC models I need, as that would be plain stupid. What I asked originally about the ...
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2answers
88 views

Use of inductors vs resistors

Why would we place an inductor in series with a lamp, rather than just a resistor? I'm sort of thinking it has something to do with being able to control voltage to the lamp, without effecting ...
2
votes
4answers
216 views

Estimating Inductance

Here is an inductor I found lying around, and I have no idea what the inductance is. In order to estimate the inductance, I am using the equation \$L=\mu \dfrac{N^2 A}{l}\$. Here are the relevant ...
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0answers
56 views

Compensation of leakage reactance in high frequency transformer

I have a designed a toroidal high-frequency (12/350V, 800VA, 100kHz) transformer with a 50uH magnetization inductance. I measured the leakage inductance by resonating it with a 1uF capacitor. The ...
0
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1answer
150 views

Two-port network: find fundamental parameters

What is the easiest method to find the ABCD parameters? I tried replacing the middle part of the circuit (R2,L,C) with an equivalent impedance and then finding U2 depending on U1, but it is very ...
2
votes
6answers
248 views

Measuring small inductances

I'm working on a small hobby project - a small (230V wall plugged) coreless induction furnace. I generally know what I'm doing, chosen a topology, calculated inverter and coil parameters, desired ...
2
votes
2answers
130 views

Capacitance and Inductance properties of coaxial transmission lines

I'm interested to understand what affect the capacitance (between cable core and shielding) and the inductance have on a signal transmitting down a coaxial cable.
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0answers
65 views

How do I find a Capacitor's SRF from the limited information a supplier gives me?

I have a chip which requires two capacitors connecting the Vcc in and Vss. The two capacitors are a 15nf and 2.2uf. The spec says that the capacitors (at least the 15nf) must have an SRF of 32Mhz. ...
8
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3answers
425 views

Why is inductance (L) proportional with turns-square (N²)?

We start from the Maxwell's Equation $$ \mathbf{\nabla} \times \mathbf{B} = \mu \mathbf{J} + \overbrace{\mu \epsilon \dfrac{\partial \mathbf{E}}{\partial t}}^0. $$ We take surface integration of ...
1
vote
1answer
74 views

Circuit with coupled inductors, need help with mesh equations

Are the mesh eqations in the image below correct? It gets a little tricky with the mutual inductance and my textbook gives no solution (American textbooks..). Click the image below for a larger view. ...
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0answers
43 views

How to understand voltage change between different phases of BLDC?

Actually, it is a question about an application note of BLDC from here. (on page 30 of that material) The question is about calculation of potential of M. What I learned from book is that the ...
3
votes
5answers
2k views

Why does a capacitor act like a short-circuit during a current impulse?

While trying to solve questions involving impulses and step functions, we are supposed to assume that an uncharged capacitor or an uncharged inductor acts as a short circuit and open-circuit ...
0
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1answer
50 views

Measuring self-capacitance of coils

Is there a simple way of measuring the self-capacitance of a coil? There are many estimates out there for self-capacitance based on number of turns and wire specs, but I'm wondering if I can do an ...
1
vote
2answers
106 views

What means coil inductance (h) for relays?

I'm looking at the data-sheet for a Single Coil Latched Relay. In there, i see the Coil Inductance (ref. value)(H) for Armature ON and OFF column. Specs: Rated ...
1
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4answers
132 views

Avoid inductive coupling on two near coils

I have two coils that are placed parallel from each other and separated by a mere 1.5cm, lets say A and B. The core of them is built using soft iron. Right now they are wired and built in the same ...
2
votes
2answers
154 views

How solder inductance affects RF circuits?

I'm assembling a VHF oscillator (90 MHz) and plan to reach UHF and SHF some day. Should I worry about solder inductance affecting an oscillator performance? If no, then when should I take it into ...
3
votes
1answer
181 views

Why do inductors release a high voltage when disconnected

I take a 12 volt battery, take a strong electromagnet, and fire it up. I then touch the two terminals that are currently connected, one terminal of the battery, and one terminal of the electromagnet. ...
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2answers
159 views

RL circuit paradox [closed]

I can't understand why current flow through an inductor in RL circuit if this inductor induces EMF to block it? Well, the current at t=0 is 0 but how the current increases seems to be paradoxal :( ...