An inductor is a 2 terminal passive device that stores energy in a magnetic field.

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3
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2answers
196 views

How to calculate the Back-EMF energy on an Inductor?

The Back-EMF generated by an inductor in Volts is: \$V = -L\dfrac{di}{dt}\$ Where \$L\$ is the self-inductance and \$\dfrac{di}{dt}\$ the rate of current change. Now, let's say I want to store those ...
1
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2answers
65 views

Is an LR Phase Shift Oscillator possible?

All the phase shift oscillators I've seen use RC stages each of which produces a 60degree phase-shift. Is it possible to inductors instead of resistors? My understanding is that inductors also cause a ...
4
votes
2answers
633 views

What is this symbol on the schematic?

What is this element on the far right of schematic described as "270 OHM"? Is this some kind of inductor? What is its purpose in this device (this is a reference design of dc-dc power supply of sim900 ...
2
votes
1answer
61 views

Buck converter design problem/confusion

I have problem with designing buck converter. I have tried to design it by using instructions from this site: Buck converter And here are my parameters: V input - 72V max V output - 12 V ...
0
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0answers
31 views

Floating simulated inductor. Simple implementation?

I would like to build an analog delay line (basically many stages of LC filters). To get a long enough delay I need pretty big inductors, in the 500mH+ region and I need many of them (at least 16, ...
1
vote
1answer
138 views

Trying to understand this oscillator… there's no emitter grounding or bias

I dissected and drew up this oscillator circuit from a cassette machine the other night. It's purpose is for biasing the tape. I'm curious though as to how this oscillator functions since the base is ...
6
votes
2answers
108 views

Electrical behavior of holding magnets when you pull them apart

I'm going to buy a holding electromagnet and a strike plate to hold some things, and I want to design my circuit (arduino-controlled) not to fry like bacon. I'm aware that since a holding magnet is ...
1
vote
2answers
46 views

Can this gyrator handle high current and/or high voltage?

Since I first got introduce to the Antoniou Inductor while in university, I've always been amazed at it. I've never built or used one, but I am thinking about using it to simulate an inductor for a ...
0
votes
2answers
78 views

Electric current of inductor

I have a homework problem that was solved by our instructor: "Calculate the electric current of the inductor at \$t=0^+\$." He calculated \$1/30\$ but the answer sheet was says \$-1/30\$. Which ...
0
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1answer
103 views

Coil Winding Sense of Inductor/Transformers and Output Polarity

Given a solenoidal coil, if it is wound in one sense (say clockwise), would the output from it, in terms of polarity, be equivalent to another coil, wound in the opposite sense (counter-clockwise), ...
4
votes
3answers
251 views

When do I twist the wires going to transformer winding terminals, and why do I do it?

I sometimes see the wires of winding are twisted outside of the transformer (or inductor), as seen in the images below. What is the purpose of this? When should I twist winding wires and when ...
1
vote
2answers
116 views

Can a tank circuit store energy for a simple AC system?

If you take the circuit below, with the switch closed, assuming the Tank circuit is tuned to resonate at the same frequency as the source, then I would expect the tank to become charged, and the ...
1
vote
2answers
93 views

How to make a RF Choke?

I am a high school student and am making a project on FM receiver for class 11. I am following this circuit diagram: The L2 in this diagram is a 22µH RF Choke. The part listed in the website has ...
-1
votes
1answer
99 views

why do not we connect inductor in dc circuits. And what are the physical significance of connecting a capacitor or inductor in a circuit [closed]

Why doest an inductor not connected in a dc circuit? What happens? And why it is connected in ac circuits? Explain one more thing that why do we need to connect an inductor or capacitor in a circuit. ...
1
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0answers
81 views

Can I build a high-frequency SMPS choke out of an arbitrary coil of wire?

Suppose I want to build a boost converter that runs at 100 kHz, with an input voltage of 600VDC and an input current of 100 amps. (This is hypothetical, I know the semiconductors involved would be ...
0
votes
1answer
59 views

SMPS Inductor oversized vs properly sized

I am working on an SMPS for boosting an input voltage to drive a single string of LED's. The input voltage range is from 18 to 32 volts. The output voltage needs to be about 60V and the drive current ...
1
vote
1answer
70 views

Inductor held with hands

I have a fairly simple problem, but as I am a newbie in electrical circuits I was hoping someone might help me understand the principles of things. I have a circuit with an inductor of L = 0,102H a ...
0
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0answers
34 views

Is this an antenna or an inductor or both? And does the wire length/core diameter matter?

I have a small transmitter, and attached to it is this device: However, one of the wires attaching the circuit board to to circular red device is broken. I figured that since I have it all taken ...
0
votes
2answers
118 views

Why don't over damped and critically damped circuits oscillate?

The reason underdamped LRC circuits oscillate is because the energy keeps flowing between the inductor and capacitor. The energy is being constantly exchanged between the capacitor and inductor ...
0
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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 ...
2
votes
2answers
61 views

Inductor burning out in a GPS bias tee circuit

I've got a tracking device that uses a Telit GE864-GPS combined GSM/GPS module. The GPS antenna is connected to the Telit module via a bias tee circuit, as shown below: ...
0
votes
1answer
40 views

Is it possible to design cascaded LC filters with inductors sharing the same core?

I want to design an higher order LC filter for filtering out a power signal. In the theoretical design, the inductors are supposed to be on separate cores. But in practice, it will be very costly and ...
0
votes
3answers
99 views

Is Faraday's Law not working?

Faraday-Lenz's law was easy when I was in 12th standard. But it became more complex when I jumped to Engineering. Recently when I was studying about inductors and how they oppose changes in currents, ...
-1
votes
1answer
153 views

What are the failure modes of resistors, inductors, capacitors, diodes, transistors in conditions of overvoltage or overcurrent? [closed]

What are the failure modes of resistors, inductors, capacitors, diodes, transistors in conditions of overvoltage or overcurrent? Example: ...
1
vote
1answer
132 views

How to make a 40mH inductor

We are working on a project that requires us to use a high-valued inductor, with at least 10mH and ideally 40mH inductance. There's nowhere in our area that sells inductors with these values, so we ...
2
votes
1answer
77 views

Rogowski Coil High Frequency Limit

I'd like to do some experiments involving high frequency (1.296GHz to be exact) that involve an 50ohm inductor that has minimal RF losses. The obvious candidate is to drive a Rogowski coil (driven as ...
0
votes
1answer
56 views

Modifying an amp evaluation board to bias the coax?

I'm normally a software guy, but a recent project requires me to dip my toe in the ocean of electrical engineering. I'm trying to (cheaply) capture GPS signals to process in software, and I have an ...
2
votes
2answers
146 views

A simple RL circuit, getting transfer function, matching with results

I'm doing little lab exercise with an RL circuit. I need to check if I did this analysis right, because the numbers I got and the numbers that should theoretically be there are so far off, I figured ...
0
votes
0answers
59 views

Odd MOSFET behaviour (in Multisim)

I have this circuit that's behaving in a strange manner. I am getting a surprisingly low current value flowing through the inductor when the path includes the N-channel MOSFET. Please could someone ...
1
vote
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 ...
0
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0answers
56 views

Calculate equivalent inductance

Here is my task: to calculate the equivalent inductance between A and B; I really don't know how (generally) this is solved. simulate this circuit – Schematic created using CircuitLab ...
0
votes
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 ...
0
votes
3answers
116 views

How to remove energy from inductor using semiconductors?

So I have this coil and I'm driving dc current through it. This coil has inductance and thus stores energy from the dc current. I have to remove this energy before I can change the polarity of my ...
0
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0answers
58 views

How do I solve for this circuit? (Coupled inductors)

I am trying to solve for the following circuit (mainly getting a function of voltage on capacitor C): However, I tried my best using node voltage method or mesh current method, in time domain and ...
4
votes
2answers
163 views

Inductor selection for obtaining a noiseless analog power rail

I interface an image sensor, and the design schematic for power supply is: How do I choose one from the available 3uH inductors based on the specs? I figured the maximum current and dc resistance ...
0
votes
3answers
185 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? ...
0
votes
1answer
68 views

PMSM inductance in DQ domain

The “abc <-> DQ” transformation matrix used for transforming currents, voltages and magnetic field can they be used for transforming inductances also? as given below-
0
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1answer
99 views

Design steps for a choke inductor

I want to filter out high frequency noise on my power line. At first, I was considering to use an LC filter on the line; but then, I learned about choke filters are used exactly for this purpose. ...
0
votes
3answers
139 views

Can inductor voltage and capacitor current change abruptly?

I understand that inductor current and capacitor voltage cannot change abruptly, but can inductor voltage and capacitor current change abruptly? I have a feeling the answer is no but I cannot explain ...
0
votes
2answers
79 views

Convert a ringing telephone voltage of 90V AC to 3.3V 1000mAh DC current so that it only triggers when the telephone is ringing?

How can I convert and step down a ringing telephone voltage of 90VAC current to 3.3V 1000mAh DC current so that it only triggers when the telephone is ringing? Bridge rectifier? Inductor? Step Down ...
2
votes
1answer
184 views

Re-winding an inductor to decrease inductance

I found a bunch of good size inductors in a bunch of old boards (16 of them, more to desolder). Luckily I had the service manual of said boards and I know the specs of the inductors: 22uH 9A 500V. I ...
0
votes
2answers
124 views

Question with solving for complex power, S, for each component

simulate this circuit – Schematic created using CircuitLab Hi! So I have a couple questions that I have already tried to solve that I think I am going in a little bit of the wrong ...
16
votes
3answers
2k views

What operation could cause the inductor or the capacitor to explode?

In really early days of electronic school, the teacher used to say something about not unplug power too quickly at an inductor or capacitor and we were used to slowly turn the voltage generator from a ...
2
votes
3answers
126 views

Low-DC-resistance inductors?

simulate this circuit – Schematic created using CircuitLab I have a 5V DC source that passes AC noise (alternator whine, spark plug discharge through the smoke-lighter-to-micro-USB ...
2
votes
2answers
81 views

Inductors in series with different currents

I'm having trouble finding the differential equation that describes the circuit, at t=0 10A flow through L1 and 0A through L2, since current can't change instantaneously. But they're in series so ...
2
votes
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 ...
3
votes
2answers
86 views

Quiet inductors?

Are certain types of inductors more likely to create an audible sound than others when under use? Is there any sort of best-practice or guideline to minimize such humming or buzzing sounds? I.E. ...
2
votes
1answer
78 views

Electromagnet for string vibration

I recently read a lot about guitar sustainers, for those who don't know what are they - it is basically an electromagnet with an amplifier. It takes an input from pickup, amplifies it and then ...
0
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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 ...
0
votes
1answer
186 views

What is this inductor-like part?

In a laser printer's power supply board I have desoldered some of these passives. I think it is a inductor, because it's legs aren't exactly aligned and the round body could be the coil. Does ...