What is Waveforms: Definition and 53 Discussions

In electronics, acoustics, and related fields, the waveform of a signal is the shape of its graph as a function of time, independent of its time and magnitude scales and of any displacement in time.In electronics, the term is usually applied to periodically varying voltages, currents, or electromagnetic fields. In acoustics, it is usually applied to steady periodic sounds—variations of pressure in air or other media. In these cases, the waveform is an attribute that is independent of the frequency, amplitude, or phase shift of the signal. The term can also be used for non-periodic signals, like chirps and pulses.
The waveform of an electrical signal can be visualized in an oscilloscope or any other device that can capture and plot its value at various times, with a suitable scales in the time and value axes. The electrocardiograph is a medical device to record the waveform of the electric signals that are associated with the beating of the heart; that waveform has important diagnostic value. Waveform generators, that can output a periodic voltage or current with one of several waveforms, are a common tool in electronics laboratories and workshops.
The waveform of a steady periodic sound affects its timbre. Synthesizers and modern keyboards can generate sounds with many complicated waveforms.

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  1. I

    A little help understanding 3 phase waveforms and summation

    Hello all, I'm in the process of learning about 3 phase power and how to wire loads to a generator. I've searched high and low with as many sentence structures as I could think of in the google search bar and I can't seem to find the answers I'm looking for. I'm really hoping you guys can...
  2. Q

    I Why is Photon Energy Quantized in Terms of Sine Wave Frequency?

    Hello everyone, I've been grappling with a concept for years, diving into internet resources and pestering professors, yet I still find myself tangled in confusion. I'm reaching out in hopes that someone here can shed light on a question that has been haunting my thoughts regarding the nature...
  3. S

    A Help with IPTA Gravitational Waveforms Detected

    Hi All. I am interested in finding out if the International Pulsar Timing Array team have detected specific waveform types. The waves I am particularly interested in (if they exist) would be low frequency and would be triggered at a minimum amplitude. Example below: There may be waves detected...
  4. PhysicsTest

    Phase currents of Trapezoidal switching

    For trapezoidal switching or 180 degree switching these are the waveforms when i referred to the website 180 switching when i calculated the RMS value of the phase voltage it is Vp = 0.4714Vs so assuming the Vs = supply voltage = 20V and each phase - phase resistance as per the data sheet is...
  5. J

    Engineering Sketching output waveforms while considering slew rate

    1. Using the frequency equation I know the time period is 1 millisecond. 2. The duty cycle (50%) equation tells me that the pulse width and the amplitude is 1 V. 3. Thus the input waveform looks like this : (?) 4. As the slew rate is 0.5 volts per microsecond, the output voltage would take...
  6. J

    Engineering Combining these two AC waveforms

    I have calculated V3 to be 294.62sin(1800 pi t + -0.56)V I am confident this is correct but I now need to work out the frequency of the waveform, I believe it may be 900 but I am not too sure if my calculations are correct and I can't find anywhere on line that aids me in this particular instance.
  7. M

    Sketching Waveforms to represent Transient Responses

    i am completely unsure on what is being asked by this question. i know the word sketch suggests a rough drawing and google shows up roughly what the waveforms should look like but what's thrown me off is the fact that the equation 'b' has twice the frequency as the other two. this is a topic...
  8. dvscrobe

    RMS and DC Value Displays of Waveforms on LTspice

    I hope I am posting this in correct forum section. I just downloaded LTspice for my Power Electronics course. Does anyone know if the software can display the DC component of a waveform such as found by determining the Fourier series of a waveform?
  9. R

    Adding Two Waveforms to find the final Phasor

    v(t) = 2cos(8t+180) + 10cos(8t+30) volts polar form = 2∠180 + 10∠30 convert to rectangular to add vectors = (2cos180 + i*2sin180) + (10cos30 + i*10sin30) = (-2 + i*0) + (8.66 + i*5) = 6.66 + i*5 find ⦵ and r of sum of vectors ⦵ = arctan(5/6.66) = 0.64 r = sqrt(5^2 + 6.66^2) = 8.33 V =...
  10. J

    Which graphs represent different types of current flow?

    Homework Statement (1) Name the waveform(s) that represent a periodical current flow. (2) Name the waveform(s) that represent a direct current. (3) Name the waveform(s) that represent a non-periodical alternating current. (4) Name the waveform(s) that represent a current with a non-positive...
  11. K

    Plotting the waveforms of the harmonic components

    Homework Statement Hello everyone, I am currently experiencing a problem plotting harmonics in Excel. I'm only able to plot the fundamental wave properly, I can't figure out how to plot the 3rd and 5th harmonic as they have a different frequency. Can you point me in the right direction...
  12. ADDA

    Carrier Signals and demodulation of audio waveforms

    Is the failure to remove the carrier frequencies the problem with the audio output in the following videos?
  13. W

    Monostable Waveforms: Solutions & Resources

    Homework Statement [/B] Homework Equations T = Time constant x ln [span/remainder] The Attempt at a Solution a)[/B] The trigger pulse must have a negative polarity and an amplitude greater than 1V. V+ is at 0V in the stable state. By using these conditions for a triggering pulses, it...
  14. J

    KCL for AC Waveforms: Can I Get the Right Answer?”

    Homework Statement [/B]Homework Equations Can I use KCL at the central node? The Attempt at a Solution I tried KCL and got: 5cos0 + j 5sin0 + 10 cos 60 + j 10 sin 60 = (-I1) 5 + 5 + j 10 *1.732 / 2 = (-I1) 10 + j 5 * 1.732 = -I1 This gives 13.33 angle (220.89) Book answer is A Is the 5 and...
  15. A

    Actuating Pencil To Draw Waveforms

    I am looking to make a pencil whose tip moves to create a waveform as you move it across the paper.In essence, I want to be able to record a sound and then play the sound through the pencil whilst I draw with it, of course, I will use software to lower the frequency to make it more of a waveform...
  16. R

    Allowed EM Waveforms: Which Ones?

    Homework Statement which of the following proposed space-time dependent electric fields in vacuum is/are allowed by the equations of EM theory? a) $$E_x=E_1\sin(kz-wt),E_y=E_2\sin(kz-wt),E_z=0$$ b) $$E_x=E_1\sin(kz-wt),E_y=2E_1\cos(kz-wt),E_z=0$$ c)...
  17. J

    Help understanding NMOS waveforms

    Hello, I have doing an example simulation on microwind of an nmos device. This has a clock signal at the gate and at the drain, though they are at difference frequencies. I'm not sure what the S1 is referring to in this diagram http://imgur.com/a/B9Nes Is it the current through the device, it...
  18. R

    Show graphically/vector addition adding two waveforms

    Homework Statement We've been given an assignment in civil engineering with this question which we can't solve as the tutor hasn't explained it and has subsequently gone off sick with no replacement! The question is to show graphically and by vector addition, the result of adding the two...
  19. T

    How do you work out wave envelopes and asymmetries?

    Hi Say I took one or all of the four waves here: How would I go about working out the envelope around their peaks, or finding the exponential time constant from start to steady state? Cheers!
  20. STEMucator

    Output waveforms with a clamped capacitor

    Homework Statement For the circuits shown, each utilizing an ideal diode (or diodes), sketch the output for the input shown. Label the most positive and most negative output levels. Assume ##CR > T##. The input waveform is given by: I have re-drawn all of the circuits in my solution, which...
  21. N

    Engineering Effect of Cell on circuit half-wave rectifier circuit waveforms

    Homework Statement a) http://i.imgur.com/LrWxrEX.jpg b) http://i.imgur.com/3YmN3Rv.jpg Homework Equations A halt-wave rectifier(a) is used to charge a battery E.The battery is rated at 12V 100Wh. Average charging current for the battery should be 5A.The primary input voltage is 120v at 60Hz...
  22. A

    Understanding Amplitude and Waveforms

    Homework Statement http://puu.sh/bZQiV/43f7515806.png Homework Equations This is a conceptual conception so no equations[/B]The Attempt at a Solution I believe answer is D since it is the longest and thus can have the highest amplitude. Is it correct?[/B]
  23. STEMucator

    What Are the Average and RMS Values of Waveforms?

    Homework Statement I had two small questions about the following problems. 1. Find the average and RMS values of the following waveform: 2. Show that the average and RMS values of the following sawtooth are independent of the position of the peak and are given by ##0.5## and ##0.577## of...
  24. S

    Exploring Sine Waves: Physical Shape vs. Graph Representation

    Is Sine Wave just a graph of particles that do SHM? A wave on a string is also a Sine wave provided its particles are moving sinusoidally. But its shape also kind of represents a sine wave. So is the wave on a string called a sine wave because of the physical shape that we can see or because...
  25. J

    The Effects of Water on EM Waveforms

    What effect does water have on electromagnetic waveforms? Does metal attract or reflect EM waveforms (specifically rf)?
  26. K

    Relationship between Frequency and Standing Waveforms.

    Hi all, just a quick problem that I really cannot get my head around, any help would be appreciated. Homework Statement State, in detail, how the frequency affects the number of antinodes produced on string with a fixed tension, density and length. Homework Equations The frequency of a...
  27. dexterdev

    What is the difference in the shown waveforms conceptually?

    Hi guys , My present doubt is regarding the waveforms shown in the image. The first plot is a impulse train. what is the difference having δ(t) in one plot and 1 at t=0, (0 else where) in a second case. whether time or frequency is the case...
  28. J

    Drawing 3-Phase Voltage Waveforms

    Homework Statement Draw and label the 3-phase voltage waveforms where VAN= 347∠0° Vrms, VAB= 600∠30° Vrms, Frequency: 50Hz, Volts/Division 200, Time/Division: 2 ms 2. The attempt at a solution Im really not sure how to tackle this one. My prof hardly went over this in lecture, but gave this...
  29. M

    Analyzing Complex Waveforms: Finding Amplitude, Frequency, and Time Period

    Homework Statement A complex waveform is given by the equation: VA=20 sin (50∏t) + 10 sin (100∏t) Determine the amplitude, frequency and time period of the fundamental and harmonic components. Homework Equations The sinusoidal voltage formula is v = V sin(2∏ft). In this formula f...
  30. Z

    Waveforms compatible with transmitting channel?

    why waveforms should be compatible with transmitting channel? What if i send a random wave without having much information about it?
  31. P

    Finding waveforms from Fourier Coefficient Values

    Homework Statement Find the waveforms x1(t) and x2(t) (expressed in a simple form) that are consistent with the sets of Fourier coefficient values provided below. Assume that the period T is equal to 1/10 seconds in both cases (a-1): a(0) = 6, a(-1) = 3 + 4j, a(1) = 3 - 4j, and a(k) = 0 for...
  32. F

    DMA Scope: Affordable PC Oscilloscope for PWM Waveforms

    Hi, i need an oscilloscope but i don't have money to buy one, so i was thinking about some way to use the PC to emulate an osciloscope. I saw on internet people using the sound board, but they say that's a lot of interference... So i found a PC Oscilloscope and i wanted to know if it works. I...
  33. D

    Waveforms, rms, average, offsets

    Hi guys I'm trying to work out average and rms values of two different waveforms. One is a sinusoidal wave, the other a ramped trapezoid (I think that's right). The sinusoidal wave has a peak to peak voltage of 11v and the offset is alleged to be 9-15 = -6v. This is something I've been told...
  34. A

    A.C. Voltage waveforms and harmonics?

    Hi, I have the following question: An A.C. voltage, V comprises of a fundamental voltage of 100V rms at a frequency of 120Hz, a 3rd harmonic which is 20% of the fundamental, a 5th harmonic which is 10% of the fundamental and at a phase angle of 1.2 radians lagging. (1) Write down an...
  35. C

    Engineering Comparing Max. Voltage of Complex Waveforms in Excel and Simulation

    Hi...i have question on RLC circuit. Why my max.voltage of complex sinewave in Excel is different from the simulated complex waveform? which one is right? max.voltage of complex waveform in excel = 106.8V max.voltage of complex waveform in simulation = 126.8V Should it be the same?
  36. T

    Proof of Periodic Sinusoidal waveforms

    Homework Statement Hi, Have completely forgotten how to prove that a sinusoidal waveform is periodic and can't seem to find it anywhere. So was hoping someone could here. I've got the signal x(t)=cos(2t+pi/4) and am trying to prove it is periodic. Homework Equations wt=theta f(x+k)=f(x)...
  37. T

    Analyzing Voltage Waveforms in a Circuit

    Homework Statement In the circuit of Fig. 16(a), the voltage v has the periodic waveform shown in Fig. 16(b) with a period of 4 us and an amplitude of 20 V. Homework Equations i = Cdv/dt v = Ldi/dt The Attempt at a Solution Assuming that x is constant (at its average value)...
  38. M

    Synchronous Buck Converter Vds and Ids Waveforms Analysis

    Hi, I'm simulating the Synchronous Buck Converter as per attached, to obtain the Vds and Ids for the High Side switch and I'm using P-mosfet as the switch and Microsim PSPICE software to simulate the circuit. once it is done, i obtained the Vds and Ids waveforms as per attached. my...
  39. A

    MATLAB Why does this Matlab snippet create biased Fourier waveforms?

    Why does this Matlab snippet create "biased" Fourier waveforms? I'm trying to search through the space of all possible waveforms (or a reasonable approximation of that space), where waveforms are described by 20 parameters: the first 9 Fourier coefficients for sine terms a(1:9), the first 9...
  40. T

    Effective value of complex waveforms?

    how do you determine the effective value for complex waveforms that have different omegas such as 3cos(4t)+4sin(3t)?
  41. D

    Sketch the waveforms of the harmonic components

    Homework Statement Sketch the waveforms of the harmonic components in the output and the resultant output voltage Homework Equations Vo= 0.98sin(1600*pi*t) - 0.1cos(3200*pi*t) + 0.1 The Attempt at a Solution I know that the 0.1 will be a straight line The amplitude of the sin wave...
  42. J

    Are All Waves Sinusoidal, or Are There Non-Sinusoidal Waveforms?

    I have experience with wave mechanics from a undergrad perspective, Modern Physics, etc. I saw the statement the other day, "All waveforms are sinusoidal". I believe this to be not 100% correct. Texts usually show a "nice" looking sine wave for most things "wave". I believe this...
  43. M

    Finding Common period of multiple waveforms

    Hi Everyone, First time poster, longtime viewer of these forums. Love the help that the community gives. Just so you know where I am coming from: I am trying to calculate the average power by first calculating the total energy of my system. Specifically I am looking at the energy...
  44. Z

    Finding Expression for V1 + V2 Waveforms

    say i have the following waveforms V1=10cos(wt) V2=20sin(wt) and i am told to find an analytic expression for the resulting voltage waveform fristly i found the V1+V2 add the two phasors at t= 0 to get 22.4 and then i found theta which is 26.5 (tan^-1(10/20)) but now I am confused will...
  45. F

    Waveforms & Barriers | Physics & Electronics Q&A

    Hello, I have more of a familiarity with electronics than physics, so I came across an unusual idea, or question. Since there are many types of waveforms in electronics, is there any type that can tunnel through a barrier better, or even more perfectly than others? Perhaps some one working in...
  46. N

    Terahertz insulator materials and reflection properties

    Hi, I'm currently perusing ideas for research in the area of Terahertz waveforms. I was wondering if anyone could shed some light on previous works dealing with Terahertz insulator materials and reflection properties. Any guidance would be greatly appreciated! Regards, NW
  47. J

    Why Does Adding Harmonics Not Change the Period of the Fundamental Wave?

    after doing several problems, i keep seeing that when you add the waveform of the fundamental with its higher harmonics, the period of the summed wave is equal to the period of the fundamental wave. Could someone explain conceptually why this happens? that would be much appreciated!
  48. B

    Current waveforms in transformers and rectifiers

    I was wondering why the current waveform in a rectifier circuit that uses transformers, is not out of phase with the voltage waveform. Does the transformer not shift the current waveform out of phase with the voltage waveform? Thanks for any help.
  49. J

    Sinusoidal Waveforms: Answers & Solutions

    Homework Statement Hi, Could you please help me decide on these answers? The question is " Are the following statements Sinusoidal? And are they Periodic? I have produced the waveforms in MathCad The limits are 0 - 4Pi 1.f(x)= sinx + 2sin(x-(Pi/6)) 2.f(x)= sinx +sin2x 3.f(x)= sinx +...
  50. Orion1

    Acoustic vs. seismic waveforms

    Is it possible to correlate the atmospheric acoustic vs. ground seismic waveforms from a charge detonation? Are there any physicists on this forum that recognise the acoustic and seismic waveform signatures from a charge detonation? Acoustic, Seismic wave function equation: \psi (x,t) = A...