JPS58144760A - Detector for presence of phase difference - Google Patents

Abstract

PURPOSE:To reduce the detection time by detecting the presence of a phase difference between continuous two signals of a similar waveform the same in the cycle depending on whether the amplitude ratio is the same or not at different two times. CONSTITUTION:Signals of the same phase different in the amplitude is fed to input terminals IN1 and IN2. Clock pulses CK1 and CK2 generated from a pulse generator 8 are applied separately to sample hold circuits 1, 2, 3 and 4 for sampling of input signals and the ratio of sampled values is calculated with dividers 5 and 6. Finally, a difference between outputs of the dividers 5 and 6 is detected with a subtractor 7. This enables easy and quick detection of the presence of a phase difference without depending on the amplitude of the two signals.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phase difference detection device for detecting the presence or absence of a phase difference between two signals having the same period and continuous similar waveforms.

Conventionally, when detecting the presence or absence of a phase difference between two signals as described above, it has been necessary to obtain the Lissajous waveform using an oscilloscope or the like, or to obtain the digital processing result using a counter or the like after shaping the waveform of each signal. I was doing it by method.

In the former case, the operator must directly observe the waveform on the cathode ray tube surface, which is complicated and inefficient, and the reliability of the measurement is also lacking.

Furthermore, in the latter case, the measurement circuit becomes complicated, which is not economical, and it is difficult to easily automate the inspection process and the like.

An object of the present invention is to eliminate the drawbacks of the above-mentioned conventional technology, to detect the presence or absence of a phase difference between two signals as described above in a short time with a simple configuration, and to be suitable for automation of inspection processes, etc. An object of the present invention is to provide a phase difference detection device.

A feature of the present invention is that for two signals having continuous similar waveforms with the same period, each waveform is sampled at different times corresponding to each signal using clock pulses of different phases. a pair of sample-and-hold circuits; a pair of dividers that calculate the ratio of the outputs of each of the sample-and-hold circuits corresponding to each of the different times;
The present invention includes a subtracter for determining the difference between the outputs of the respective dividers, and is configured such that the presence or absence of the output of the subtractor is used as a detection output of the presence or absence of a phase difference between the two signals.

In short, for signals with continuous similar waveforms with the same period (for example, sine wave signals), the amplitude ratio at each corresponding phase is always a constant value, regardless of the availability of the amplitude. Depending on whether the amplitude ratio is the same at least at two different times (phases),
The purpose is to detect the presence or absence of a phase difference.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a phase difference detection device according to the present invention, and FIG. 2 is a time chart thereof.

In FIG. 1, 1.2Fi, a sample hold circuit that samples the signal input to the input terminal INI, 3, 4
This is a sample hold circuit that samples the signal input to the U input terminal IN2, and each output of the circuit 1.3 is as follows.
It is input to the divider 5, and the outputs of the same circuits 2 and 4 are
The outputs of the dividers 5 and 6 are input to a subtracter 7. 8 is sample hold circuit 1~
4, a pulse generator that generates clock pulses CKI and CK2 for the dividers 5 and 6 and the subtracter 7;

The operation of this embodiment will be explained in detail below.

First, it is assumed that the input signal a shown in FIG. 2 is inputted to the input terminal INI, and at the same time, the input signal a shown in the above figure having the same phase and different amplitude is inputted to the input terminal IN2.

The clock pulse CK1 from the pulse generator 8 is at time t,
When applied to the sample and hold circuit 1.3 at
Respectively, its output val + vat is sent out.

Similarly, when clock pulse CK2 is applied to sample-and-hold circuit 2.4 at time t2, its output vallvbl is respectively delivered. Here the clock pulse CK2 drives the divider 5.6 and the subtracter 7.

The divider 5 performs division processing on the input signals val r vbl and outputs the ratio V, 1 /va 1 .

Similarly, the divider 6 outputs the ratio vb2/v,2. These signals are respectively input to the subtracter 7, and the difference signal is sent out from the output terminal OUT.

In this case, since the input signals a and b are in phase, the divider 5
The output VbI/v, , and the output v,2/v,2 of the divider 6
are equal due to the similarity of their waveforms, so the output of the subtracter 7 becomes O, and it is detected that there is no phase difference between the input signals a and b.

Next, it is assumed that an input signal C having a phase difference with respect to the input signal a is inputted to the input terminal IN2, and in the same manner as above, at time 1
1 w ” Pulling value v of input signals a and c at t
, ,v, ,andv,2. Find v,2. In this case, since the phases of the input signals a and c are different, the divider 5,
The outputs v, , /v, , v, 2/v, 2 of 6 are not equal, and the subtracter 7 obtains an output corresponding to the difference between them, and there is a phase difference between input signals a and C. presence is detected.

In this way, the presence or absence of a phase difference between the two signals can be easily detected in a short time without depending on the amplitudes of the two signals, so that the inspection process can be automated easily by using the detection signal.

As described in detail above, according to the present invention, it is possible to realize a phase difference detection device that can detect the presence or absence of a phase difference between two signals in a short time with a simple configuration. Application to automatic inspection related to phase difference becomes possible, and remarkable effects can be obtained in improving the efficiency and reliability of this type of inspection process.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of a phase difference detection device according to the present invention, and FIG. 2 is a time chart thereof.

Claims (1)

[Claims] 1. For two signals with the same period and continuous similar waveforms, each clock pulse with a different phase can be used to
A pair of sample-and-hold circuits sample each waveform at different times corresponding to each signal, and a pair of sample-and-hold circuits that calculates the ratio of the outputs of each sample-and-hold circuit at different times. and a subtracter for determining the difference between the outputs of each of the dividers, and is configured such that the presence or absence of the output of the subtractor is used as the detection output of the presence or absence of a phase difference between the two signals. A phase difference detection device.