JPH0434374A - Method for displaying lissajous' figure - Google Patents

Abstract

PURPOSE:To draw the Lissajous' figure of two signals having arbitrary phase shift difference within the range of 0 - 360 deg. and an arbitrary frequency ratio on a CRT by combining a phase shifter and a frequency multiplier. CONSTITUTION:An oscillator 3 oscillates a sine wave signal of desired frequency (e.g., 1 kHz) to input the same to a phase shifter 1. The phase shifter 1 shifts the sine wave signal (a) inputted from the oscillator 3 in phase by an arbitrary angle within the range of 0 - 360 deg. to form two phase difference signals (b), (c) having certain phase difference. A multiplier 2 multiplies the phase difference signal (b) among the signals (b), (c) to generate a sine wave signal of 2 kHz, 3 kHz or 1.5 kHz synchronous to the phase difference signal (b) and having the same phase as the signal (b) and the frequency ratio of the multiplied phase difference signal (d) and the signal (c) is set to 1:1, 2:1, 3:1 or 3:2, for example. When there is phase shift between the signals (b), (d), the multiplier 2 corrects said phase shift.

Description

Detailed Description of the Invention (Field of Industrial Application) The Lissajous figure display method of the present invention allows a Lissajous figure as shown in FIG. It is used for observation.

(Prior Art) The Lissajous figure shown in Fig. 5a, C, and e allows us to know the phase difference, frequency ratio, etc. between two signals by its shape and inclination. It is used to measure phase differences, frequency ratios, etc.

However, in order to measure phase differences, frequency ratios, etc. using a Lissajous figure, it is necessary to know the meaning of the Lissajous 1 figure in advance, which is why it has traditionally been used in practical training at schools or apprenticeships at companies.

Two sine wave signals with a certain phase difference and frequency ratio are
I was inputting data into a Y oscilloscope and drawing a Lissajous figure on the cathode ray tube for observation.

When observing a Lissajous figure in this way, it is easier to understand the Lissajous figure by drawing various shaped Sarsier figures on a cathode ray tube.To do this, input a single sine wave signal with a known phase difference to an oscilloscope. There is a need to.

(Problems to be Solved by the Invention) The conventional Lissajous figure display method has the following problems.

■ Conventionally, there are various methods of creating two signals with a phase difference (for example, creating a phase difference by inverting the original signal by 180 degrees), but these It was only possible to vary the angle intermittently, and it was not possible to vary the angle continuously in the range of 0 to 360 degrees. For this reason, conventionally it has been difficult to draw Lissajous figures with phase differences other than those phase differences.

■If there is a phase difference between the two sine wave signals input to the oscilloscope (deviation from the specified phase difference), the Lissajous figure drawn on the cathode ray tube will overlap and become two lines, making it very difficult to see. There was a problem. In addition, the Lissage figure drawn on the cathode ray tube changes over time (for example, at one moment it becomes a ring shape, at the next moment the ring shape becomes subdued, at a certain moment after that it becomes a straight line, and these changes are repeated. ), it was difficult to observe the Lissajous figure. To solve this change, an oscillator that can synchronize the two sine wave signals is required, but such oscillators are expensive and in short supply.6 (Object of the Invention) The purpose of the invention is to obtain a desired phase difference (in the range of 0 to 360 degrees)
A Lissajous figure display that can draw a Lissajous figure with a frequency ratio of The purpose is to provide a method.

(Means for Solving the Problems) In order to achieve the above object, the Lissajous figure display method of the present invention uses a phase shifter that can change the phase in the range of 0 to 360 degrees and a frequency that can be multiplied to an arbitrary value. By combining with a multiplier, it is possible to have an arbitrary phase shift difference in the range of 0 to 360° and an arbitrary frequency ratio (for example, 1:1, 2:1,
This invention relates to a Lissajous figure display method that allows Lissajous figures of two signals (3:1.3:2) to be drawn on a CRT.

The Lissajous graphic display method according to claim 1 of the present invention includes:
The phase shifter 1 (Fig. 1), which can change the phase in the range of 0 to 360°, creates two phase difference signals with a desired phase difference based on the input signal. The frequency of the signal is multiplied by a multiplier 2, and the phase difference between the multiplied phase difference signal and the multiplied phase difference signal is corrected,
A method for displaying a J-surge figure, characterized in that a multiplied phase difference signal and an unmultiplied phase difference signal are set to a desired frequency ratio, and a Lissajous figure is drawn on a CRT using these two signals.

A second Lissajous figure display method of the present invention includes:
A falling phase correction circuit 32 provided in the multiplier 2 ensures that the multiplied phase difference signal always has a constant phase relationship with the unmultiplied phase difference signal.

(Function) According to the Lissajous figure display method of claim 1 of the present invention, the phase can be changed in the range of 0 to 360° by the phase shifter 1, and the frequency of one phase difference signal can be changed by the multiplier 2. can be multiplied, so it can be multiplied by 0~360° based on the input signal.
To easily and freely draw a Lissajous figure of two signals having an arbitrary phase shift difference in the range of and an arbitrary frequency ratio (for example, l, ■, 21.3:1.3:2) on a CRT. I can do it.

According to the Lissajous figure display method of the second back claim of the present invention, the multiplied phase difference signal always has a constant phase relationship with the unmultiplied 1i phase difference signal, so that the Lissajous figure is upside down. Never.

(Embodiment) FIG. 1 is an explanatory diagram of the Lissajous figure display method of the present invention, in which numeral 3 represents an oscillator, l represents a phase shifter, and 2 represents a multiplier.

The oscillator 3 oscillates a sine wave signal of a desired frequency (for example, IKH2) and inputs it to the phase shifter 1.

The phase shifter l shifts the phase of the sine wave signal [input signal] a input from the oscillator 3 to an arbitrary angle in the range of 0 to 360°, and generates two phase difference signals having a certain phase difference.
(Figure 1). This phase shifter
The phase shifter X was first developed by Meguro Denpa Kanki Co.
-204 (product name) is available.

The multiplier 2 multiplies the phase difference signal S of the two phase difference signals S and C to generate sine wave signals of 2 kHz, 3 kHz, and 1.5 kHz that are synchronized with and in the same phase as the same phase difference signal S. , thereby setting the frequency ratio of the multiplied phase difference signal d and the unmultiplied phase difference signal C to 1:l, for example.
, 2·l, 3:l, 3:2, etc.

Further, the multiplier 2 is also configured to be able to correct a phase shift when there is a phase shift between the phase difference signal before multiplication and the phase difference signal d after multiplication. Therefore, the multiplier 2 is constructed as shown in FIGS. 2 and 3.

That is, as shown in FIG. 2, the multiplier 2 includes a phase correction/waveform shaping block 1O1PLL block 20, a falling phase correction/Sin converter block 30. It is composed of an output block 40.

As shown in FIG. 2, the phase correction/waveform shaping block 1O is composed of a buffer amplifier 11, a phase correction circuit 12, and a waveform shaping circuit 13.

The PLL block 20 is a general PLL multiplier circuit, and is composed of a phase comparator 2I, a vCO, an auto-reset 22, a first frequency divider 23, and a second frequency divider 24. By the way, when the auto j set circuit 22 praises the oscillation frequency.

This is to prevent the vCO control 11 voltage from deviating from the normal operating range.

The falling phase correction/Sin converter block 3
0 is composed of a third frequency divider 3T, a falling phase correction circuit 32, and a low-pass filter 33. This falling phase correction circuit 32 is used to prevent the Lissajous figure from being turned upside down as shown in Figures 5a, 5c and d when the power is turned on or the frequency is changed. Therefore, as shown in FIG. 6, the falling phase correction circuit 32 includes a NAND circuit 51 and a 0NE-5HOT multi-by-break 52 that can be triggered and whose output pulse period T is sufficiently longer than the period of the PLL reference signal frequency. , E
It is composed of an X-OR circuit 53.

Next, the operation of the multiplier 2 shown in FIGS. 2 and 3 will be explained using the flowchart shown in FIG.

The input signal (one phase difference signal b) input from the phase shifter 1 to the input terminal IN of the multiplier 2 passes through the buffer amplifier 11 in FIG. The phase difference is canceled and the waveform is shaped from a sine wave to a rectangular wave in the next waveform shaping circuit 13. This waveform-shaped signal (FIG. 4A) becomes a reference signal for the PLL of the multiplier 2.

The PLL block 20 receives a rectangular wave input signal (Fig. 4A)
A signal of 100 to 300 KHz is oscillated with reference to
The frequency is divided as follows and sent to the next second frequency divider 24 and sinning block 30.

The signal input to the second frequency divider 24 (FIG. 4C) is frequency-divided by 1, for example, from 1/2 to 1/6 by the same frequency divider 24, and is made into a comparison signal (FIG. 4B). It is fed back to the phase comparison W21.

Signal sent to the sinning block 30 (Fig. 4C)
is frequency-divided by 1/2 by the third frequency divider 31 to become a square wave with a duty 50 as shown in the fourth diagram. The output of the third frequency divider 31 does not always become as shown in Figure 4 (Depending on the state when the power switch is turned on or when the frequency is changed, it becomes D as shown in Figure 4). The output may be inverted.If the waveform is as shown in Figure 4D, there will be no problem, but if the waveform is as shown in the figure, the Lissajous figure drawn on the cathode ray tube may be the Lissajous figure that was originally drawn. Sometimes the figures are upside down (Figure 5 a becomes b, C becomes d)
In this case, the present invention prevents such a phenomenon by using the falling phase correction circuit 32 so that the output of the third frequency divider 31 always has the same phase relationship as Do in FIG. This is so that D is corrected. That is, the signal of FIG. 4B and the signal of FIG. 4 or Do whose rising edge is synchronized with the signal of FIG. 4A are input to the falling phase correction circuit 32. When this signal is B and D, it is NAN
The D circuit 51 outputs the same signal to B and D" as shown in FIG. 4F.
In this case, it is shaped as shown in Fig. 4 F°. The signal thus shaped is input to the 0NE-5HOT multivibrator 52 which is triggered by the rising edge of the input signal, and its output is as shown in FIG. 4G when the signals are B and D. and Do, the result will be as shown in Figure 4 G.

And this output and the signal of the fourth figure or Do are EX-O
After being shaped by the R circuit 53, the signals E and E' in FIG. 4 are output, and both of these signals have the same phase as the signal Do in FIG. 4. This prevents the Lissajous figure from being upside down.

The output signal from this falling phase correction circuit 32 (FIG. 4 E, E' 3 is then fc=:3k) is filtered by a low-pass filter 33 of 1z to cut harmonic components and become a sine wave. This sine wave is sent to the output terminal OUT through the ALC amplifier 41 and buffer amplifier 42 shown in FIG.
With the phase difference set by phase shifter l in the figure, multiplier 2 in figure 1
The frequency ratio glue surge two figures set in are drawn on the CRT.

(Effects of the Invention) The Lissajous figure observation method of the present invention has the following effects.

■.Have an arbitrary phase shift difference in the range of 0 to 360 degrees based on the input signal and have an arbitrary frequency ratio (for example, 1:1.2:1
．． 3:1.3:2) can be easily and freely drawn on a CRT. For this reason, it is useful for understanding Lissajous figures in practical training.

(2) A Lissajous figure drawn on a CRT does not become a double line or change its shape over time, making it easier to see the Lissajous figure.

■Since the sorisage shape is not upside down, you can see the correct sorisage shape.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the Lissajous graphic display method of the present invention, FIG. 2 is an explanatory diagram showing an example of a multiplier used in the present invention, and FIG. 3 is a falling phase correction circuit in FIG. 2. An explanatory diagram showing an example. FIG. 4 is a waveform diagram illustrating the operation of the multiplier in FIG. 2 and the falling phase correction circuit in FIG. 3, and FIGS. 1 is a phase shifter 2 is a multiplier 12 is a phase correction circuit Fig. 4 ■ Indication of the incident Patent application No. 141907/1999 Title of the invention Nosage graphic display method Date of correction instruction Drawings subject to spontaneous correction Figs. 1 and 2 Figure 5: Contents of the amendments as shown in the attached sheet

Claims (2)

[Claims] (1) The phase shifter 1, which can change the phase in the range of 0 to 360°, creates two phase difference signals with a desired phase difference based on the input signal, and The frequency is multiplied by a multiplier 2 to make both phase difference signals have a desired frequency ratio, and the phase difference between the phase difference signal before multiplication and the phase difference signal after multiplication is corrected, and the multiplied phase difference signal and A method for displaying a Lissajous figure, characterized in that a Lissajous figure is drawn on a CRT using a phase difference signal that is not multiplied. (2) Falling phase correction circuit 3 provided in the multiplier 2
2. A Lissajous figure display method according to claim 1 or 2, characterized in that the multiplied phase difference signal always has a constant phase relationship with the unmultiplied phase difference signal.