Questions tagged [harmonics]
Questions related to frequencies that are generated by mixing other fundamental frequencies.
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Sideband Production
I am trying to understand exactly how sidebands are made. I've seen the math, but I'm looking for more of a component-level understanding of how they are made and what properties of the mixer ...
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0answers
39 views
What factors cause the harmonic distortion in ADC at high signal amplitudes?
I have been studying about the ADC's SNR vs amplitude relation. A sample curve is shown below:
I am interested in the region rounded (orange) of the gray curve. At that region, we expect to see ...
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1answer
13 views
how to avoid harmonic on intrrupt for proximity sensor in NodeMcu
i have 5v IR proximity sensor for measuring pulse output attached in NodeMCu
using intrrupt pin but it gets a random counter on the harmonic environment.
it is working fine in Normal situation what ...
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3answers
64 views
Tektronix function generator THD
I am confused by the datasheet of the AFG3021C: https://www.tek.com/link-click-count?nid=75006&url=https%3A//download.tek.com/datasheet/AFG3000C-Arbitrary-Function-Generator-Datasheet-75W282817....
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1answer
78 views
Generating a realistic sine wave in MATLAB
I'm working on a simulation on MATLAB and I need a realistic sine wave which has harmonics. So I know there would be harmonics at 2f,3f... but I am not sure how to determine their amplitude. I tried ...
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1answer
86 views
Harmonic resonance calculation in power-factor correction
Eaton's Power factor correction:
a guide for the plant engineer states,
Capacitors and transformers can create dangerous resonance
conditions when capacitor banks are installed at the service
...
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1answer
34 views
If I use a CAT 2 10x probe does my DSO need to be CAT 2?
I need to measure the harmonic distortion on a solar inverter (power output). I need to buy all the equipment from scratch and was wondering if my DSO needs to be CAT 2 rated if I use a CAT2 10x probe....
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2answers
68 views
Filter harmonics in AC power line [closed]
I run a Toshiba Digital copier machine in my shop and the machine started showing error codes related to power issues a few days ago. This happens randomly during daytime. There were no problems at ...
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1answer
44 views
Harmonic mixing in spectrum analyzers
I'm having a pretty difficult time understanding how tuning works when using harmonics in spectrum analyzers. I'm reading about the topic from Keysight's AN 150.
Question 1
The following plot is ...
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2answers
451 views
Why is this the maximum dynamic range in a spectrum analyzer?
In Keysight's popular AN 150 there is a plot of noise and harmonics amplitudes versus the level of the input signal at the mixer (page 57).
It's stated there that the maximum n-th dynamic range is ...
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1answer
126 views
How do I calculate THD in proteus?
I know how to plot the Fourier transform, but is there a more precise way to measure the total harmonic distortion?
I have this graph:
As you see, there's only one distinguishable component at 1 kHz ...
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1answer
317 views
Symmetric vs Asymmetric PWM
I am working on Control of Power Converters, I was reading TI's piccolo DSP ePWM guide and came across symmetric vs asymmetric PWM, I have a good basic understanding about converters, DSP and all.
...
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2answers
183 views
Are ripples and harmonics the same thing?
I started working on the "Direct Power Control of Grid Connected Voltage Source Converters", everywhere in the literature, authors state that one of the major drawbacks of this control technique is ...
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2answers
63 views
Switching mode power supply for Power Line Communication
For a Powerline Communication device that uses the frequency band 42 to 89 kHz. I need to choose a power supply that will not add noise in the powerline and kill my communication band. There are two ...
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2answers
330 views
Why is neutral required in three phase charging of Electric vehicles?
Talking about both three-phase AC as well as DC fast charging (wherein 3 phase AC is converted to DC) in EVs, I think that the 3-phase rectifier represents a balanced 'load'. Therefore I want to know ...
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1answer
131 views
Total harmonic distortion (THD) of a circuit
Where \$V_{sin}\$ is sinusoidal with frequency \$f_{1} = 1 kHz\$.
The THD is defined as the sum of the power of all harmonics (except the fundamental) divided by the power of the fundamental harmonic....
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377 views
Power factor and Harmonics associated with Electric Vehicle charging
What is the power factor associated with (typical) DC fast chargers and onboard chargers in electrical vehicles? Also, how much is the harmonic content (especially triple-N harmonics) associated with ...
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1answer
62 views
For induction motors, would one expect harmonics to be different between Delta and Y stator windings?
Given two induction motors with the only difference being that one is wound delta, the other Y, would I expect to see a different behavior if the source is a three phase voltage with harmonics?
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1answer
248 views
How to design filter for inverter for following cases?
I am going to make two pure sine inverters for collage project.
Both inverter uses 24V battery as DC voltage source. Switched to ~360Vdc and ~180Vd by boost converter accordingly.
Both then switched ...
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3answers
59 views
meaning of having harmonic on special signal
my question maybe seems very simple but, I'm not familiar with the answer of that;
what is the meaning of harmonic of the signal exactly?
I know the harmonics of the signal are signals whoes ...
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4answers
109 views
what causes voltage harmonics
People keep telling me that Nonlinear loads causes current harmonics and when i ask them about what causes voltage harmonics, they tell me wherever there is current harmonics there is voltage ...
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1answer
269 views
LVDS clock signal EMI
I am working on a project in which we have an an i.MX53 to driving an LCD through the LVDS connector and we fail the required EMC criteria. There are multiple peaks at 40 MHz intervals (starting at ...
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27 views
Very low network impedance close to 13th harmonic frequency
I carried out a frequency scan of an electrical network model with a proposed 220kV transmission line. Addition of this line lowered the system impedance to very low value (to 3 Ohms) at 13th harmonic ...
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Why harmonics present in a balanced 3-phase voltage are phase shifted by a factor of their harmonic order?
Suppose we have a balanced 3-phase voltage Vr, Vy and Vb that means each phase has same RMS value and is phase shifted by 120-deg from one another. Now, if this supply has harmonics present in it, ...
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0answers
53 views
irritation in LTspice
I have written some measurement commands in LTSpice to calculate the weighted harmonic distortion (PWHD)
.meas a1n INTEG (I(Lgra)*cos(2*n*180*fg*time))
.meas an PARAM a1n*2*fg
....
(if somebody ...
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1answer
388 views
Export error log values from LTspice
I have used .meas expressions to calculate harmonic values in LTSpice. The problem is that these are now in the error log and I cannot export them.
Is there a way to export error log values in a .csv ...
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1answer
102 views
Is my laptop charger is working as harmonic filter and absorbing harmonics?
I have a square wave backup inverter (UPS). Whenever the power goes out, UPS turns on but all the fans run with noise and humming sound. I know it is because of square wave and harmonics. But when I ...
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364 views
Why is the chording angle 30 degrees, in a practical alternator?
So far what i have understood...
Chording angle in Synchronous Generator/ Alternator is introduced to tackle the problem of harmonics that couldn't be taken care of during the design either in -
...
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0answers
46 views
What is the least input current THD that has been attained by researchers using a unidirectional boost PFC rectifier?
The flowchart shows different types of PFC rectifiers classified on the basis of topology. I have been going through the papers available at IEEE but can't find the absolute least input current THD ...
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1answer
165 views
How to control switching of mosfet in PFC boost rectifier using PI controller?
My aim is to reduce THD in the supply current and I wanna use a simple PI controller for that, to make the inductor current more sinusoidal and at the same time keep the output voltage of the ...
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2answers
462 views
High voltage square wave drives induction motor
This is the problem, i'm designing a water pump's universal drive (3 HP Max) controlled by Arduino, so my first vision is to convert 220VAC/50Hz to DC, Then reduce the voltage by DC-DC chopper circuit,...
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2answers
2k views
50/60Hz Noise Harmonics
I want to wirelessly communicate over low frequencies (<1kHz), and I noticed during some tests that 60Hz noise is showing up a bit at 180Hz (3rd harmonic), and also slightly at 300Hz (5th harmonic):...
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1answer
124 views
For Brushless DC Motors would one expect harmonics to be different between Delta and Y stator windings?
Given two 3-phase brushless DC motors with the only difference being that one is wound delta, the other Y with center grounded, would I expect to see high frequency voltage-current harmonics to be ...
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144 views
Is it true that inductors filter current harmonics and Capacitors filter voltage harmonics in SMPS?
In switch mode power supply applications, it is true that inductors filter current harmonics and Capacitors filter voltage harmonics?
Is it true that in most applications we use LC filters due to the ...
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1answer
204 views
AD9850 Harmonics at Lower Frequencies
I am wanting to use the AD9850 for a particular application to generate sine wave signals in the 100Hz to 5kHz range. I've purchased a AD9850 module from ebay which just looks like the standard ones ...
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1answer
72 views
Suppress Certain Overtones In A Musical Instrument's Sound Wave
So, just like the title suggests, my college professor and I are trying to suppress certain overtones of an instrument's sound. I have a microphone hooked up to an oscilloscope, and I'm using the ...
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3answers
315 views
Mixer spurs and IF output filters
I'm designing a simple diode ring mixer for down-conversion from 1.5G to 200k. I want a band-pass LC pi-filter on the mixer IF output.
I've designed the filter for 50R source and load impedance by ...
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1answer
524 views
Long lines: whether or not to treat PCB traces as RF lines
My setup: 53 x 28 mm PCB, uC will run somewhere between 1 MHz and 8MHz. Dual layer PCB design.
From the info I gathered on this site it seems there are two aspects to consider in deciding how to ...
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4answers
819 views
LCR circuit with squarewave input: Why does the output take a decreasing amplitude through each cycle?
I understand a square-wave will be made up of a sum of sine waves in the form $$\frac{1}{n}sin(nf_0)$$
So when a squarewave is input to a LCR circut designed to be a bandpass filter, it will ...
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1answer
68 views
Harmonic simulation of microwave power amplifiers
I am working on microwave power amplifier design for 2.45 GHz, 300 W using LDMOS (part no.:MHT1004N). I am using Agilent's ADS for the simulations. I want to know what exactly is harmonic balance ...
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3answers
789 views
FFT Using Pic Microcontroller [closed]
Good Evening,
I am fairly unfamiliar with DSP and want to engage in a project. I wish to perform a FFT on the source current going into a non-linear load and observe its harmonic content on an LCD. ...
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2answers
763 views
Understanding harmonics of different Amplifier Circuits (A,AB,AB w/OP-Amp)
I have been test the circuits for amplifiers and got somewhat stuck in understanding the results for the FFT's harmonics.
With a standard type B I was able to get this graph for the harmonics
for ...
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1answer
244 views
Why is harmonic voltage flowing to the source
In non-linear loads, Current Harmonic Distortions are created, which in turn creates voltage harmonic distortion that are said to flow from the load to the source ( system ).
My understanding of ...
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3answers
90 views
Some Problems in a power amplifier circuit with THS3091
Recently, I designed a power amplifier circuit with THS3091.
The schematic diagram and PCB of the circuit are just the same as the layout example of the datasheet of THS3091 in page 39. But some ...
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1answer
123 views
What is the rule of the Vdc regulation in a shunt active filter
I understood very well the principals of harmonics identification in an shunt active filter ( PQ theory : Akagi & al for example), but what i don't understand is why do we care about regulating ...
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4answers
3k views
Why are there no “even” harmonics in AC machines?
Why are there no "even" harmonics in AC machines?
In Chapman's book, he says it's because of symmetry of the flux density wave but I don't get it...
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2answers
164 views
Are harmonics going to be introduced if we add capacitor to correct the power factor of a plant?
Suppose there are no harmonics in our installation, will adding capacitors introduce harmonics to our installation ?
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0answers
245 views
RC filter - compute output as a function of input for generating waveform
I'm not so deeply into the theory about all this, I may use strange terminology...
If I put a square wave through a simple lowpass RC filter, the output will be a sort of "rounded sawtooth", well not ...
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3answers
831 views
Fundamental component of Sinusoidal PWM inverter output
It is given in "Ned Mohan Power electronics converters applications and design" that, "sinusoidal PWM output's instantaneous average (over one time period of carrier wave) is same as the fundamental ...
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1answer
288 views
THD calculation using microcontroller
I want to calculate power supply THD (Total Harmonics Distrotion) using microcontroller.
My current sampling rate is 5000 samples per second to measure other parameters.
I have followed some ...
