Questions tagged [inductor]
An inductor is a 2 terminal passive device that stores energy in a magnetic field.
1,602
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2answers
59 views
Transformer with only three wires from an APC UPS
I was taking apart an older APC UPS and found a big transformer in it. The label says CLASS 130(B) NER-B82 430-0144 from Shenzhen Jingquanhua Electronics. DB-E186-3107A E208707. When I looked it up ...
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1answer
82 views
Inductor behavior in DC circuit
An inductor in a pure DC circuit once steady state is reached has a zero volts across it.
In the figure below, the inductor will have a voltage which is not zero
Why isn't VL zero?
1
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1answer
54 views
Inductor selection for POL application
I'd like to add two AP6320x based DC-DC converters to small MCU board, for 3.3V and 5V.
Since inductor is usually a critical component I wanted to do it right. Also, it would be nice to use inductors ...
8
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4answers
858 views
Why common-mode choke on differential-signal serial lines?
I have 2 questions:
Why using a common-mode choke on serial communication lines (like CAN, RS485) if the signal is differential? Wouldn't the common-mode noise simply be cancelled in the receiver?
I ...
0
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0answers
81 views
Can an air core inductor cause a buck converter to malfunction because of EMI?
I am trying to build a buck converter circuit using the LM2596T.
While reading its datasheet, it came to my attention that EMI is a potential problem one should not ignore while designing a buck ...
0
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0answers
25 views
Using a high DCR inductor instead of resistor in LED/Zener voltage reference?
I need a very simple, low noise zener or LED voltage reference that will be fed by a potentially noisy (RF) voltage source.
Focusing on low noise, I was thinking of adding LC filter before or after ...
1
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1answer
76 views
Is there a formula to calculate the saturation current of an inductor or is it only obtained experimentally?
I want to make an inductor for my buck converter since I cannot obtain the recommended inductors for the LM2596.
How do I calculate the saturation current for this inductor if I use a ferrite core?
...
1
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1answer
174 views
How do I stop buck converter voltage from dropping whenever current increases?
I built this buck converter circuit using the LM2596T-5 (5 V OUTPUT, 12 V INPUT) using the exact components mentioned in the datasheet's first page (schematic below), except for the diode.
I used the ...
2
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2answers
417 views
Why are pull-up inductors biasing the power amplifier output of radio transmitters chips needed?
I have seen many designs where the antenna/PA output is fed DC voltage through an inductor. Why not leave it out and feed the DC bias directly? It is L1a in the diagram below:
There are some values ...
0
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0answers
53 views
Can a low side L-spike destroy a turned off microcontroller through its ground pin?
I am working on a low power project involving servo motors and an STM32 Bluepill MCU board and I was wondering if it was necessary to place a free-wheeling diode as shown in the schematic below (D1).
...
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0answers
37 views
Inductor voltage rating for SMPS
I am making a 500 V voltage supply using DC-DC boost converter from 5 V.
Apparently inductors have maximum transient voltage rating to prevent the breakdown of the wire insulation material or the ...
2
votes
3answers
174 views
Is this explanation of a common-mode choke correct?
I am trying to understand how common-mode chokes work. I get the basic concept: the signal lines are joined by a transformer, such that each line will aid or impede current in the other. But I am hazy ...
8
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4answers
2k views
Why might one of these decoupling capacitor schematics also include an inductor and the other not?
I am looking at a third-party schematic (centered around a small IC) and it includes a selection of power schematics. They connect between a general 3.3 V supply and various other users of 3.3 V.
In ...
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2answers
97 views
How do skin-effect and proximity-effect behave for flat-conductor power inductors?
Here is a Digikey search showing flat-conductor power inductors.
And here is a picture of three power inductors found there:
In this answer, by Rohat Kılıç, towards the end of his answer he explains ...
18
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7answers
1k views
What precisely is the numerical (or any) meaning of mutual inductance and, is it useful, representative (of something) or important?
When we consider two inductors that are magnetically coupled, we sometimes talk about mutual inductance. As an example, consider two inductors (such as 9 μH and 4 μH) that are 100% coupled and produce ...
10
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3answers
1k views
Why is the inductor's voltage not specified in the datasheet?
I looked through a few inductors' datasheets and in none of them is the maximum voltage specified. Even Mouser does not let you filter inductors by voltage. Why is that? Is inductor voltage "not ...
3
votes
3answers
415 views
Why does inductor core saturation depend on the temperature?
For example at room temperature (20ºC) the saturation current is 450mA and with 100ºC the saturation current is 350mA. What causes this?
(Edit) The higher inductance with higher temperatures and lower ...
1
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1answer
68 views
How to use an LC stage as a voltage amplifier?
What I have done
From my simulation here, I have tried using a parallel LC stage as a voltage amplifier at resonance.
$$f = \frac{1}{2\pi\sqrt[]{LC}}$$
$$L = 0.001$$
$$C = 10 \cdot 10^{-6}$$
$$\...
0
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0answers
46 views
What are metal composite inductors made of?
I am currently studying different types of inductors and core materials. For most materials I can find a wikipedia page or other sources which describe what kind of alloy is used, for example ...
0
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1answer
27 views
Question about inductors in the form of magnetic fields [closed]
Could you please explain this sentence: Inductors build up energy in the form of magnetic fields, and become more conductive.
0
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1answer
53 views
Thevenin of DC circuits with inductors and capacitors
Can I use Thevenin's theorem for DC circuits containing an inductor or capacitor upon application of Laplace transform - bringing the entire circuit to the \$s\$ frequency?
2
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1answer
95 views
Need help with a resonant frequency question
I DON'T WANT THE SOLUTION
I just don't understand where the "100" (highlighted) came from.
0
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1answer
68 views
Calculating the induced voltage by an inductor
I was given the following problem in a textbook. My teacher reviewed the problem for the class and I was presented with, what I suspect is, a wrong answer. I am asking here to see if my own reasoning ...
1
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2answers
58 views
Time based solution of an LC circuit at resonance
I am trying to solve for the voltage across the capacitor in an LC circuit driven by a sinusoidal voltage at the resonant frequency, \$\sqrt{\frac{1}{LC}}\$. My solution contains a scaling factor of ...
1
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2answers
116 views
What is this flange on an inductor?
Usually I have seen pads beneath inductors. What is the purpose of this flange on an inductor? Why is it constructed like that?
Context: I am looking for low profile inductors (<1.2mm) and ...
0
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0answers
59 views
Inductor identification
Please help; I am not able to identify this inductor from its bandings; I've never had to replace one before. This is from the Toyota SRS Airbag Sensor Array in a 1996 Toyota Granvia. The Sensor has ...
0
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4answers
85 views
Why do diplexer low-pass filter output have more inductors than capacitors and vice versa?
I am reading "Practical Radio Frequency Test & Measurement A Technician's Handbook" by Joseph J. Carr. On page 41, it has a diagram (figure 2.29 shown below). In that figure, why do ...
0
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1answer
57 views
Reason for using small sampling resistors in voltage measurement circuits
The above schematic is of the ZMPT101B module (current type voltage transformer) collected from Arduino Forum. All of the modules available in the market use a similar type of circuit having two ...
0
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0answers
26 views
I’m working with pcf7991at antenna driver ic
Just wondering if you can help me I’m trying to calculate capacitor and resistor values for a 125khz inductor coil . My coil measures 6.8 ohms. I’m not sure how to calculate the capacitor values ...
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2answers
80 views
Why the output voltage of no-load boost converter is increase continuously?
I'm designing the boost converter with 3 mH inductor and 680 uF capacitor 20 kHz fequency. When I try with 12 V, 5 A power supply in the input and fixed 50% duty cycle, I can reach the 24 V output ...
0
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0answers
23 views
What is the definition of ILac in following diagram and calculations?
The attached diagram and calculations refer to following application note:
AN2761 Application note
Solution for designing a transition mode PFC preregulator with the L6562A
I don't have any idea about ...
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0answers
36 views
Calculate Lq and Ld of a motor with HFI
I have seen several papers, where Lq and Ld are calculated by injecting a rotating voltage vector
for Vd or Vq at a fixed frequency. I already made an implementation on a controller and it seems to ...
1
vote
3answers
143 views
Driving a Peltier element with PWM
I'm trying to drive a Peltier element using the VNH2SP30 motor driver, switching at the Arduino's PWM frequency of ~970 Hz (which is extremely low, but I'm planning on increasing the driving frequency ...
0
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3answers
45 views
Multi-phase buck converter inductor selection
This question is regarding the inductor design (uncoupled) in a multiphase buck converter.
In a multiphase converter, the inductance per phase requirement is higher than the corresponding single phase ...
0
votes
1answer
61 views
How we select LC filter for MAX3221?
I have seen a schematic where they used MAX3221IPWRG4 (Texas Instruments), RS232 Driver and Receiver. There they have used LC filter of inductor value 0.68uH and capacitor value of 680pF, but in ...
1
vote
5answers
201 views
Mutual Inductance Practical Explanation
I can't understand why the Mutual Inductance is measured in Henry. The self inductance of a coil is the abillity that has a coil to create a magnetic field that produses a voltage on itself so to ...
0
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2answers
135 views
Flyback transformer size vs. core losses
I'm in the process of compiling some notes on inductor design. I have good hands-on experience in the field (excuse the pun), but I feel this experience hasn't been totally systematic. I have been ...
0
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2answers
73 views
Why does large volt-second product need a large inductance?
This is a buck converter that converts from a high input voltage VIN (60V) to a low output voltage (3V).
I read that because this case has a large voltage-second product we have to use a large ...
0
votes
2answers
73 views
Power supply filtering of ICs
My question is - why in 99% of designs we dont need to provide RC filter to the power supply of IC, just individual capacitor is required? I know, that paths does have some resistance, but still, the ...
4
votes
1answer
171 views
Values at t=0- and t=0+ when closing switch; Circuit Analysis
I have a circuit as shown in the schematic and need to find out the values at t=0- and t=0+ but I don't understand it correctly.
The condition is that the switch was open for a long time and closes at ...
4
votes
2answers
314 views
Reduce coil whine in LED driver
I have designed a PCB to control RGB LEDs at various intensities using the PWM input to an ALW8808WT-7 driver from an STM32RCT MCU.
The 33 uH inductors in my prototype board let off an awful whine ...
0
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2answers
116 views
Ringing in inductively coupled coils
My circuit consists of two inductively coupled inductors. A 40 kHz 600 mV sine voltage is applied to the primary inductor. The induced voltage in the secondary inductor shows some ringing in the area ...
0
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2answers
101 views
Buck converter waveform
It became very hard for me to understand the concepts associated with buck converter waveform. What is the role of capacitor in its output terminal? Is it used for smoothing the voltage ripple? Why ...
5
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2answers
802 views
What is the function of the inductor in the "Dual active bridge" DC/DC converter?
Studying the principle of operation of the DC/DC converter "Dual active bridge", I'm trying to understand what task the inductor (Ls) shown in the diagram performs. The transformer ...
0
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2answers
90 views
Why am I getting a sinewave output from a buck converter with an input of square wave?
I was expecting the output to stay at 1V which is the average value of (2V, 1MHz, 50%) input.
It seems the capacitor is slowly charging to the input peak, and the inductor current is changing based on ...
2
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2answers
75 views
What's the value of an inductor marked "1K" on schematic?
I found this development module datasheet for FTDI FT4232H chip: https://ftdichip.com/wp-content/uploads/2020/07/DS_FT4232H-56Q_Mini_Module.pdf
At page 9, there is the module schematic, and there are ...
0
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0answers
29 views
Bias tee for floating DC supply
I have a floating DC low noise current source driving a load. I also need to drive this load with an RF source but the grounds are not referenced to each other so I don't think I can use a standard ...
0
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0answers
42 views
Antenna connector near a shielded inductor
Is it a bad idea to put a U.FL connector near a shielded inductor?
The connector is for 2.4GHz Wifi signal, the inductor is connected to the output of a buck converter with 700 kHz switching frequency....
0
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0answers
19 views
Coupling coefficient in function of reactance
If there are two coupled inductances L1 and L2, we may want to write k in function of the reactances, that is, in function of Z_L1 and Z_L2. How would you do so?
0
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1answer
48 views
Inductors: Saturation Current or Rated Current?
I am designing a 5V, 5A buck converter, and I am trying to spec my output inductor.
The datasheet specifically mentions that my inductor should have an appropriate current rating, but
I also wonder ...
