These scanners are required to be fast to achieve realtime image reconstruction while working at low actuation voltage to comply with medical standards. Observe lissajous patterns for different combinations of r and c values. Lissajous pattern trainer experiment setup electronics lab. Lissajous patterns at the dawn of the technological revolution. This property is exploited to produce a set of points, called padua points, at which a function may be sampled in order to compute either a bivariate interpolation or quadrature of the function over the domain. Sinusoidal voltages are applied to the horizontal and vertical deflection plates, they have the form v a sin. A labview based simulation of lissajous pattern using daq. Describe in detail the construction and working of analog type storage oscilloscope. In place of a candle, the modern oscilloscope contains an electron gun in the narrow neck of the tube. As the frequency, amplitude and phase difference are altered, different patterns are seen on the screen of the cro. Approximately 550 900 yards of fingering weight yarn, shown in louet gems fingering.
Originally published in twist collective, the two versions are quite different, with different charts and photography the version includes 4 foot and 8 calf circumference sizes that can be combined for a customized fit. The cro has the cathode ray tube which acts as a heart of the oscilloscope. Lissajous work in the nineteenth century centered around the study of vibrating objects and wave phenomena. The patterns that appear at the cro screen on connecting both pairs of the deflection plates horizontal deflection plates and vertical deflection. Shape of these lissajous pattern changes with changes of phase difference between signal and ration of frequencies applied to the deflection plates. In the system of parametric equations, the variables affect the outcome of the lissajous figure in different ways. Cro setup to obtain lissajous figures figure1 depicts lissajous figure obtained on cro using.
The oscilloscope is a sensitive indicator for frequency and phase measurements. This gun shoots about 6,000,000,000 electrons per second in a concentrated highvelocity beam toward the face of. The relationship between the two signals is shown by the type of display. Figure 8 will aid you in computing a phase angle if a more precise calculation is needed. Lissajous figure on an oscilloscope, displaying a 3. Pdf oscilloscope and its applications researchgate. Lissajous figures are obtained with an oscilloscope when this is operated in xy mode. In order to accurately examine the function of a variable one needs to graph the system of parametric equations below while keeping. Basics of lissajous patterns on an oscilloscope youtube.
Lissajous figures are patterns generated by the junction of a pair of. Shape of these lissajous pattern changes with changes of phase difference between signal and ration of frequencies applied to the. Lissajous 3d can make many beautiful relaxing animations. Lissajous patterns of cro or cathode ray oscilloscope electrical4u. Connect the output of phase shift network to the vertical input as shown in figure. To use this catalogue, adjust the oscilloscope so that the x and y. Cro gives the visual representation of time varying signals.
Lissajous figures are patterns generated by the junction of a pair of sinusoidal waves with axes that are perpendicular to one another. From the shape of lissajous pattern displayed on cro screen, one can determine information about relative phases of signals and frequency ratio of signals too. The frequencies of the motion are in the ratio of two integers. Geometrical and graphical representations analysis of. Labview, daq, lissajous pattern, dso, phase difference, function generator.
We can tell that oscilloscope can measure the phase and. It explores the field of harmony and disorder and let the user dip into an elegant, dreamlike. When this condition is met and when the phase shift is 0, the display consists of a straight line sloping upward from the left side of the screen to the right side. Choosing a backup generator plus 3 legal house connection options transfer switch and more duration. Lissajous figure can be displayed by applying two a. Pdf oscilloscope and its applications find, read and cite all the. The patterns obtained on cro screen and discussed in previous sections are called the lissajous patterns. The figures, sometimes called bowditch curves, were first described in the early 1800s by american mathematician nathaniel bowditch, who experimented with a pendulum undulating around perpendicular axes at the same time. The simplest lissajous patterns appear in the oscilloscope display when the frequencies of the signals are the same, i. If the two waves do not start at the same instant we get different patterns for the same frequency ratio.
Lissajous figures and cro setup to obtain lissajous figures. A lissajous pattern is a pattern which is stationary on the screen of a cro. Osa realtime lissajous imaging with a lowvoltage 2. Lissajous pattern may be constructed in the usual way and a 8 shaped pattern with two loops is obtained.
The pattern of crisscross lines is actually a lissajous figure. Frequency measurements using lissajous figures lissajous pattern also helps to measure. When both pairs of the deflection plates horizontal deflection plates and vertical deflection plates of cro cathode ray oscilloscope are connected to two sinusoidal voltages, the patterns appear at cro screen are called the lissajous pattern. Laser scanning based on microelectromechanical systems mems scanners has become very attractive for biomedical endoscopic imaging, such as confocal microscopy or optical coherence tomography oct. Jules antoine lissajous 18221880 was a french physicist who was interested in waves, and around 1855 developed a method for displaying them optically by reflecting a light beam from a mirror attached to a vibrating object such as a tuning fork. One example 0 12 1 11 10 2 6 7 5 9 3 8 4 the diagram shown is identical to one of the figures you can obtain with the laser lissajous device. Lissajous 3d trace the curves using a ribbon, or a tube, and the dot can oscillate in three or more directions, which takes the patterns. These socks are worked in the round from the top down and feature cables and twisted stitches. Also we try to replace the dso by a labview software. Lissajous figures where a 1, b n n is a natural number and. Lissajous patterns lissajous figures or lissajous curve. The lissajous pattern or lissajous figure is named for the french mathematician jules antoine lissajous 1. In an oscilloscope, the crt produces the electron beam which is accelerated, decelerated and focus with the help of accelerating and focusing anode at a high velocity and brings to the focal point on a fluorescent screen.
Measurement of electrical quantities with a cro notes for. The cathoderay oscilloscope cro is a common laboratory instrument that provides accurate time and amplitude measurements of voltage signals over a wide. Cro cathode ray oscilloscope working electronics club. Frequency measurement by lissajous method basic circuit. Example of an analog oscilloscope lissajous figure, showing a harmonic. The resulting pattern was a function of theratio of the two frequencies. All the values which are obtained by cro or dso can be easily obtained by this effort. If the oscilloscope hasthe xversusy capability, one can apply one signal to the vertical deflection. This pattern include directions for knee high version with calf shaping and shortened sock version. Lissajous patterns, showing the effects of phase relationships. This video takes a fairly detailed look at the basics of lissajous patterns on an oscilloscope. Adjust the vertical and horizontal gains properly for good display. When two sinusoidal signals of same frequency and magnitude are applied two both pairs of deflecting plates of cro, the lissajous pattern. The applet also allows you to apply a signal to modulate the hue of the trace, so you can create colorful designs.
Lissajous patterns are the plane curves traced by a point that executes two independent harmonic motions in perpendicular directions. The lissajous patterns for other frequency ratios can be similarly drawn. Using a scope to display lissajous patterns electrical. The lissajous lab provides you with a virtual oscilloscope which you can use to generate these patterns. A cro is an electronic device with a crt as its main component and other associated circuits consisting of a power supply unit, a sawtoothwave generator, horizon and vertical amplifiers.
Abstractour present work focuses on the beautiful but simple technique for determination of the speed of sound using analysis of the lissajous patterns. The block diagram shows the general purpose of cro internal contraction. Lissajous is a complex audiovideo signal generator built in maxmsp and inspired by the work of jules antoine lissajous. To show how such a figure can be created, consider the diagram to represent a dualaxis amusement park ride. To study the series and parallel lcr circuit and plot the resonance curve at the. We will use the graticule on the oscilloscope, a ratio formula, and sine sin table to compute the angle. Download fulltext pdf discrete lissajous figures and applications article pdf available in ieee transactions on instrumentation and measurement 6312. Phy2028 practical electronics ii information lissajous figures 1 lissajous figures introduction lissajous figures displayed on an oscilloscope can be used to give a quick estimate of the relative phase of two signals at the same frequency. Storage oscilloscopes, capable of high persistence phosphors, have many applications.
Measurement of phase difference between two signals using dual beam cro. This frequency measurement by lissajous method techniques used are simple and dependable, and measurement may be made at any frequency in. Lissajous patterns are derived in the old cathode ray tubes, by feeding one sine wave signal onto the x plates, and another onto the yplates. The light source for lissajous mirrorgenerated patterns was a simple candle. Lissajous figures a lissajous figure is produced by taking two sine waves and displaying them at rightangles to each other. Measurement of the speed of sound in air medium using. Lissajous patterns experiment 3 linkedin slideshare. Inspired by sound, the first lissajous patterns were made by reflecting a beam of light in mirrors attached to two tuning forks to make a dot of light that bounced around following a lissajous curve. Lissajous patterns of cro or cathode ray oscilloscope. The result of these patterns help in analyzing signal parameters. Lissajous figures where a 1, b n n is a natural number and 2 1 s g n n 3 lissajous curves can also be generated using an. Experiments based on cro the wave shapes analysis, measurement of frequency and voltage values peak to peak and rms at different ac.
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