JPH0777540A - Multilevel sampling type waveform measuring unit - Google Patents

Abstract

PURPOSE:To make it possible to accurately detect a time waveform having unpredictable maximum strength by providing a plurality of sampling circuits each having a sensitivity level corresponding to different vertical resolution and receiving an identical analog input signal. CONSTITUTION:An analog signal, e.g. an electromagnetic wave propagated through the space or a current induced in a feeder line, is fed to a vertical input section 1 where it is subjected to a predetermined level conversion before being fed to an A/D converting section 2. The digital signals thus converted are sampled by sampling circuits 21, 22,..., 2n at the A/D converting section 2 and transferred sequentially to memories 31, 21,..., 3n at a memory section 3. When a waveform having a level higher than a preset level is fed to the memory 31, 32,..., 3n, update of waveform is stopped for that memory. Data stored in the memory 31, 32,..., 3n is observed by a display means through a digital signal output section 4 or observed on a display section 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring instrument capable of detecting a time waveform of a signal when the signal exceeds a predetermined intensity set in advance, and a waveform whose maximum intensity of the signal cannot be predicted. The present invention relates to a multi-stage level sampling type waveform measuring instrument that can be used for measurement of electromagnetic interference waves that cause interference with electronic devices.

[0002]

2. Description of the Related Art In recent years, electromagnetic pulses caused by lightning discharge, electrostatic discharge, TV broadcast waves, amateur radio, CB radio,
Radio waves caused by radio broadcasting and the like cause troubles such as malfunction of electronic devices. With the increase in speed and power consumption of semiconductor elements, the deterioration of the electromagnetic environment due to the decrease in the resistance of electronic devices to electromagnetic interference waves and the significant increase in electronic devices that cause electromagnetic interference waves has become a problem of this kind. It is spurring.

However, an electromagnetic interference wave that causes a failure of an electronic device is generated by various mechanisms, and the characteristics of the electromagnetic interference wave are often uncertain and poor in reproducibility. Further, since many electromagnetic interference waves are often transient, it is difficult to identify the cause of the interference. For this reason, various measuring instruments have been developed for the purpose of detecting the time waveform and frequency components of electromagnetic interference waves.

[0004]

In order to understand the characteristics of the electromagnetic interference wave that is a cause of interference, it is necessary to clarify the characteristics such as the peak value. However, in the conventional measuring instruments such as storage oscilloscopes that are commercially available, the vertical input sensitivity range is set in advance, but when a waveform that exceeds the set vertical input sensitivity range is input, only a part of the waveform is input. It has the drawback that it cannot be detected and its peak value cannot be grasped.

A first method for solving this drawback is to provide a plurality of input sections on the measuring instrument, set different vertical sensitivity levels for the respective input sections, and branch from one measurement point to a plurality of input sections. To connect. The second method is to set a plurality of waveform measuring instruments and make the vertical sensitivity levels of these waveform measuring instruments different from each other.

However, in the above-mentioned first and second conventional methods, the simplicity and operability at the time of use due to the branching of the connecting cable to the input section is low, the size of the measuring instrument is large, and the cost is high. However, there is a problem that the power consumption is large. That is, in the above-mentioned conventional technique, it is not efficient to detect a time waveform whose peak value cannot be predicted.
Regarding electromagnetic pulse waveforms caused by natural phenomena such as lightning and electrostatic discharge, there is a problem in that there are large variations in characteristics, and electromagnetic pulse waveforms caused by natural phenomena cannot be accurately measured.

In other words, in order to clarify the characteristics of the waveform and the approach route that cause electromagnetic interference, it is necessary to install a plurality of sensors at many locations at the same time. However, in the above-mentioned conventional example, each of the plurality of input units cannot be effectively used, and therefore, the time waveform whose intensity cannot be predicted is accurately and efficiently detected. There is a problem that you cannot do it.

It is an object of the present invention to provide a multi-stage level sampling type waveform measuring instrument capable of accurately and efficiently detecting a time waveform whose maximum intensity cannot be predicted.

[0009]

SUMMARY OF THE INVENTION The present invention comprises a plurality of sampling circuits having sensitivity levels corresponding to different vertical resolutions and receiving the same analog input signal.

[0010]

The present invention has sensitivity levels corresponding to different vertical resolutions and has a plurality of sampling circuits for inputting the same analog input signal. Therefore, the time waveform whose maximum intensity cannot be predicted accurately and efficiently. Can be detected.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the configuration of a multistage level sampling type waveform measuring instrument according to an embodiment of the present invention.

In this embodiment, a vertical input section 1 for level-converting an input analog signal until a level that can be input to a multi-stage level sampling type waveform measuring instrument and an analog signal output by the vertical input section 1 are converted into digital signals. A /
The D conversion unit 2, the memory unit 3 that stores the digital signal output from the A / D conversion unit 2, the digital signal output unit 4 that is the output interface, and the digital signal stored in the memory unit 3 into an analog signal. It has a D / A conversion unit 5 for conversion and a display unit 6.

Only one vertical input unit 1 is provided, and the A / D
The conversion unit 2 includes a plurality of sampling circuits 21, 22, ..., 2n for converting an analog signal into a digital signal, and the plurality of sampling circuits 21, 22 ,.
2n share one vertical input section 1. Each of the sampling circuits 21, 22, ..., 2n has sensitivity levels corresponding to different vertical resolutions, and inputs an analog input signal via the vertical input unit 1.

The memory unit 3 includes memories 31, 32, ...
3n, the digital signal output unit 4 is composed of signal output circuits 41, 42, ... 4n, and each of the sampling circuits 21, 22 ,.
1, 32, ..., 3n are connected to correspond to the memory 3
1, 32, ..., 3n are signal output circuits 41,
42, ..., 4n are connected.

The sampling circuits 21, 22, ...
2n is for updating the input waveform when a waveform having a preset level or less is input, and for stopping the waveform update when a waveform having a preset level or more is input. is there.

FIG. 2 is a block diagram showing the A / D converter 2 in the above embodiment.

The A / D converter 2 includes a sampling circuit 2
In addition to 1, 22, ..., 2n, it has a clock 7 and trigger setting circuits 21t, 22t ,. The sampling circuits 21, 22, ..., 2n start operating when the level of the input signal reaches the trigger level. The trigger setting circuits 21t, 22t, ..., 2nt are circuits for setting the trigger level. is there. Sampling circuit 2
The trigger level of 1, 22, ..., 2n can be set individually. The clock 7 is a sampling circuit 21,
22 ... Controls the synchronization of 2n.

Next, the operation of the above embodiment will be described.

First, an analog signal (temporal waveform) such as an electromagnetic wave propagating in a space or a current induced in a power supply line is input to a vertical input section 1, where a predetermined level (A / D conversion section 2 is input). A / D conversion unit 2
Sent to. The sampling circuit 21 of the A / D converter 2,
Signals (waveforms) sampled at 22, ..., 2n and converted into digital signals are sequentially transferred to the memories 31, 32, ...
When a waveform having a level higher than a preset level is input in each of 2, ..., 3n, the updating of the waveform in the memory is stopped. The data accumulated in the memories 31, 32, ..., 3n can be observed on the display unit (not shown) via the digital signal output unit 4, or can be observed on the display unit 6.

When outputting from the memory section 3 to the D / A conversion section 5 and the display section 6, any recording data can be selected as required (memory 31, 32, ..., 3).
Any of n can be selected and output). Further, from the memory unit 3 to the digital signal output unit 4
3n, any memory may be selected and output, or all memories may be simultaneously selected and output simultaneously.

FIG. 3 shows the memory unit 3 in the above embodiment.
FIG. 6 is a diagram showing an example of a detected waveform displayed on the display unit 6 based on the detection data stored in FIG. 4, corresponding to the case of n = 4, that is, the A / D conversion unit 2 is the sampling circuit 2;
1, 22, 23, 24, and the memory unit 3 is the memory 3
The case having 1, 32, 33, 34 is shown.

The detection waveform display examples shown in FIGS. 3 (1), (2), (3) and (4) are memories 31, 32 and 3 respectively.
The waveform data stored in Nos. 3 and 34 are displayed, and the vertical ranges of the sampling circuits 21, 22, 23, and 24 corresponding to the memories 31, 32, 33, and 34 are sequentially set to be large.

In the detection waveform display examples shown in FIGS. 3A and 3B, the peak value cannot be grasped because the detection waveform exceeds the vertical range preset in the sampling circuits 21 and 22. Here is an example. However, as shown in FIG.
The detection waveform display example shown in (4) is the sampling circuit 2
Since the detected waveform falls within the vertical range set to 3 and 24, the peak value of the detected waveform can be grasped. Further, when comparing (3) and (4) of FIG.
In the detection waveform display example shown in (4), since the vertical range of the detection waveform is too large for the detection waveform, the vertical resolution of the detection waveform is reduced.
The detected waveform shown in FIG. 3 (3) becomes more effective.

According to the above-described embodiment, accurate measurement of a time waveform whose signal strength cannot be predicted can be realized with a higher probability, and moreover, a time waveform whose signal strength cannot be predicted is obtained without increasing the number of input sections 1. Since the measurement can be performed accurately, more efficient measurement can be realized as compared with the conventional example. Then, the measurement of the electromagnetic environment at the time of failure of the electronic device leads to elucidation of the cause of failure of the electronic device due to electromagnetic interference waves and establishment of countermeasure technology against electromagnetic interference.

In the above embodiment, any detected waveform may be selected and recorded, or all detected waveforms may be simultaneously recorded. Further, if a plurality of sets of the vertical input section 1, the A / D conversion section 2, the memory section 3, and the digital signal output section 4 are provided, it is possible to simultaneously perform waveform measurement at different points.

In the above embodiment, a plurality of trigger setting circuits 21t, 22t, ..., 2nt are provided. However, these trigger levels may be set to the same value, and instead of these, one trigger setting circuit may be set. A circuit may be provided.

If the level of the analog input signal (the level of the input signal of the vertical input section 1) in the above embodiment is a level that the A / D conversion section 2 can input, the vertical input section 1 can be omitted. That is, the present invention is a waveform measuring instrument for measuring a time waveform, which has a plurality of sampling circuits having sensitivity levels corresponding to different vertical resolutions and which has a plurality of sampling circuits for inputting the same analog input signal. If so, the time waveform whose maximum intensity cannot be predicted can be detected accurately and efficiently.

[0028]

According to the present invention, it is possible to accurately and efficiently detect a time waveform whose maximum intensity cannot be predicted.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a multistage level sampling type waveform measuring instrument according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an A / D conversion unit 2 in the above embodiment.

FIG. 3 is a diagram showing an example of a detected waveform displayed on a display unit 6 based on the detection data stored in a memory unit 3 in the above embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vertical input part, 2 ... A / D conversion part, 21-2n ... Sampling circuit, 21t-2nt ... Trigger setting circuit, 3 ... Memory part, 31-3n ... Memory, 4 ... Digital signal output part 41-4n ... Signal output circuit, 5 ... D / A converter, 6 ... Display, 7 ... Clock.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G01R 19/00 B 29/08 D

Claims (1)

[Claims] 1. A multi-stage level sampling device, comprising: a waveform measuring device for measuring a time waveform, comprising a plurality of sampling circuits having sensitivity levels corresponding to different vertical resolutions and receiving the same analog input signal. Type waveform measuring instrument.