JPH03252564A - Environmental electromagnetic noise recordor - Google Patents

Abstract

PURPOSE:To easily detect the frequency and level of a short-time continuing wave by starting a sweep for synchronism when an input wave exceeding a set level arrives and is still inputted even a constant time later. CONSTITUTION:A noise detecting means 13 connected to the communication line 7 and power line 9 of a device to be monitored and an antenna 14 which is installed nearby a device 6 are connected to the environmental noise recording device 12 and the fault occurrence level of the device 6 to noises from respective paths is set previously. Then the entering noises begin to be monitored, and the sweep is started if a noise which has a specific frequency at the time of the arrival of a noise larger than the level and stops the certain time later still exceeds the set level even the constant time later at either or both of capacitance and inductance forming a resonance circuit. Then the frequency and level, and crest value and level are printed out together with the arrival time to know the kind, level, frequency, time, etc., of a noise which causes fault occurrence.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for preventing noise intrusion paths such as communication lines and power lines of the communication equipment when a failure occurs due to external noise in communication equipment such as a telephone connected to two communication lines. This invention relates to a noise monitoring and recording device that monitors noise for a predetermined period of time to quickly identify the cause of a failure.

[Conventional technology]

Conventionally, as this type of monitoring and recording device, a device as shown in FIG. 7, which targets power lines, has been used. That is, in FIG. 7, 1 is a power line installed in an office, user's home, etc., 2 is a device connected to the power line 1 and is subject to failure monitoring, such as a home appliance, office equipment, or OA equipment, and 3 is a power line 1
Reference numeral 4 denotes a noise source installed indoors that transmits noise to the power line 1 by a switching operation or the like during operation of a home appliance or the like different from the failure monitoring target device 2 connected to the .

An outdoor noise source 5 such as a power device connected to the power line 1 outdoors is a power supply noise monitoring and recording device that is connected to the power line 1 of the monitoring target bag f2 and monitors incoming noise when a failure occurs in the monitoring target device 2. be.

FIG. 8(a) shows that in the power line wiring system of FIG. 7, noise from an indoor noise source 3 and an outdoor noise source 4 generated during startup and shutdown is transmitted through the power line 1 and reaches the monitored device 2. This is a typical noise waveform that can cause trouble such as malfunction of two devices.

When a failure occurs in the monitoring target device 2 in the system shown in FIG. A widely used method is to connect to the power line of the device 2 as shown in FIG. 7, monitor it, and print out the incoming data.

[Problem to be Solved by the Invention] However, although this type of monitoring and recording device can detect and record the noise factor when pulse noise as shown in FIG. 8(a) arrives, the incoming noise continues for a short period of time. In such a case, there is a drawback that the frequency and level cannot be detected properly. For example, the noise transmitted during communication when a vehicle equipped with a high-power CB radio device passes by disappears after the vehicle passes, and becomes a short-time continuous wave (duration time tL) as shown in FIG. 8(b). Furthermore, electromagnetic waves as shown in FIG. 8(C) may arrive. If these are devices such as button telephones that are wired with communication lines such as nine office lines or extension lines in addition to power lines, incoming noise may enter the equipment from the office lines or extension cables and cause problems such as malfunctions and line disconnections. to occur. In order to take measures against these noises with equipment, the steps in Figure 8 (b) and (c) are required.
It is necessary to find out early the intrusion route, frequency, level, etc. of short-duration waves such as local lines and extension lines.

The conventional power supply noise monitoring device as shown in FIG. 7 has the drawback of not being able to detect these noise factors.

In order to solve the above-mentioned drawbacks, the present invention aims to solve the problems described in FIGS. 8(b) and 8(C).
) and the frequency and level of short duration waves such as (a
) It is an object of the present invention to provide a monitoring and measuring device capable of independently and automatically detecting the peak value of a pulse wave such as .

[Means to solve the problem]

In order to achieve the above object, the present invention provides a method for noise that has a predetermined frequency and stops arriving after continuing for a certain period of time using either a capacitance element or an inductance element that constitutes a resonant circuit.

Alternatively, if the magnitude of the incoming noise exceeds a predetermined set level and the circuit constant of both elements still exceeds the set level after a certain period of time, the voltage applied to the element is started to be swept. The frequency and peak level of the input noise are detected from the resonance point of the resonant circuit determined by the variable, and are determined by the arrival time and the number of arrivals. In addition, for transient pulses, the peak level, arrival time, and number of arrivals are output.

[Effect]

In the detection of short-term continuous waves in the present invention, when an input wave exceeding a set level arrives, a sweep for tuning is started only when an input exceeding the set level still exists after a certain period of time has elapsed from the arrival time. That's how it is. In addition, as a control signal applied to one or both of the variable capacitance element and variable inductance element of the automatic tuning circuit, a sweep signal with a period shorter than the duration of the short-time continuous wave is used to sweep, and the tuned output is detected and rectified as a DC output. Both frequency and level are obtained based on . These make it possible to easily detect the frequency and level of short duration waves that are normally difficult to detect. In addition to these, the time and number of times (frequency) of arrival noise including transient pulses can be detected independently on the path side. By setting the detection level of this device according to the fault level of the monitored device 6 for each path, you can check the output results and see which route, what noise, and what time the fault came from. It is possible to easily understand the cause, such as "Has the problem occurred?"

〔Example〕

FIG. 1 is a diagram illustrating the incoming noise monitoring state of the environmental electromagnetic noise recording device of the present invention, in which 6 is a monitored device such as a communication device, 7 is a communication line of the monitored device 6, and 8 is an external communication line. 9 is a power line for the monitored device 6, 10 is a noise source equipped with a high-output CB radio, etc., 11 is a radiated disturbance wave from the noise source 10, and 12 is a main 13 is a noise detection means such as a current probe or a high impedance probe for detecting noise arriving at the monitored device 6 from the communication line 7 or the power line 9; 14 is a space around the monitored device 6; 1 is an antenna installed in an environmental noise recording device 6 according to the present invention for detecting noise.

When a failure occurs in the monitored device 6 in FIG. 1, the noise detection means 1 connected to the communication line 7 or power line 9 of the monitored device 6
3. and an antenna 1 installed near the monitored device 6
4 is connected to the environmental noise recording device 12 of the present invention, and after setting in advance the failure occurrence level of the monitored device 6 with respect to the intrusion noise from each path, monitoring of the intrusion noise is started. When noise exceeding each failure occurrence level arrives, by printing out the frequency, level, peak value, and level together with the arrival time of each noise, you can check the cause of the failure when it occurs in the monitored device 6. You can know the type, level, frequency, time, etc. of a certain noise.

FIG. 2 is a block configuration diagram of the environmental noise recording device 12 of the present invention, and 15 is a short-time continuous wave (CW) detection of noise having a constant frequency as shown in FIGS. 8(b) and 8(c). unit, 16 is an input terminal of the CW detection unit 15, 17 is a transient pulse wave (PLS) as shown in FIG.
) detection unit.

18 is the input terminal of the PLS detection unit 17, 19 is the CW
A display unit 20 displays the detection signals of the detection unit 15 and the PLS detection unit 17; 20 is a main control unit that controls the detection signals from each unit and outputs them to the display unit 20;
is the detection signal from each unit 15, 17 and the main control section 20
This is a bus line that connects the display unit 19 and the display unit 19 and exchanges control. 22 is a high frequency amplification circuit for amplifying the input signal from the input terminal 16; 23 is an automatic tuning circuit for extracting the frequency of the output signal 2 of the high frequency amplification circuit 22; 24
25 is a peak hold circuit that holds the maximum value of the DC output Va of the detection rectifier circuit 24, and 26 is a reference voltage using the output Ve of the high frequency amplifier circuit 22. Compared with v0, even after a certain period of time t0 has passed from the input start time of the output Ve, Ve > V
A starting circuit generates an output only when Veo of FIG. 8(b), which becomes o, continues to exist, and 27 is a reference voltage ■.

28 is a tuned frequency detection (V-f conversion) circuit that converts the output ■r of the peak hold circuit 25 into a frequency, and 29 is the output of the tuned scan voltage generation circuit 31 where ■9 is generated. A NAND circuit that outputs the hold value ■ of the peak hold circuit 25 only when
0 is a pulse generation circuit that generates a certain number of pulses at a certain period based on the output of the starting circuit 26, and 31 is a pulse generation circuit 3.
A tuning scan voltage Vv generating circuit for operating the automatic tuning circuit 23 by a generated pulse of zero.

32 is a tuned scan voltage generation circuit 31. Tuning frequency detection circuit 2B, NAND circuit 29. This is a CW control unit that controls each output of the pulse generation circuit 30. 33 is PLS
The preamplifier circuit in the unit 17, 34 is the preamplifier circuit 3
3 is a peak hold circuit that holds the maximum output of 3, 35 is a level comparison circuit that compares the output level of the preamplifier circuit 33 with reference voltage 1, 36 is a variable resistance element for setting the reference voltage 1, and 37 is a A NAND circuit that outputs the output of the peak hold circuit 34 only when there is an output of the level comparison circuit 35;
This is a pulse control unit that controls each output of the ND circuit 37.

Further, FIG. 3 is a diagram showing a specific embodiment of the automatic tuning circuit 23. Figure 3 (a) shows the case where a winding tap changeover switch is used as the inductance variable means of the tuning coil, (b) shows the case where a sliding switch is used, and (C) shows the case where a movable magnetic field inserted into the tuning coil is used. 39 is a tuning coil, 40 is a winding tap changeover switch for the tuning coil 39, 41 is a sliding switch that is slidably movable on the surface of the tuning coil 39, and 42 is a tuning coil 39.
43 is a variable capacitance element such as a variable capacitance diode whose capacitance value changes depending on the magnitude of the applied voltage; 44
is a variable capacitance element such as a variable capacitor, and tuning can be achieved by changing one or both of the tuning coil 39 and the variable capacitance elements 43 and 44 by electrical or mechanical means described below.

FIG. 4 shows an example of generating a tuning scan voltage Vv to be supplied to a variable capacitance element 43 such as a variable capacitance guide in an automatic tuning circuit 23 using continuous pulses from a pulse generator 30. This is a step-like repetitive waveform (period tS) obtained through an n-ary counter circuit in the circuit 31.

FIG. 5 is an explanatory diagram of the operating principle of the automatic tuning circuit 23 of the device of the present invention, in which the tuning scan voltage of the sawtooth wave is shaped into such a step-like repetitive waveform without changing the number of turns of the tuning coil 39. 2 is a conceptual diagram of a tuning output when 9 is applied to the variable capacitance guide 43 of the automatic tuning circuit 23, and a method of converting the frequency using this output in a tuning frequency detection (Vf conversion) circuit to obtain the tuning frequency.

Now, the noise detection means 13 such as current probes are connected to the input terminals 16 and 18 in Fig. 2, and the terminal 16 is connected to the communication line 7 and the terminal 18 to the power line 9 side as shown in Fig. 1. The operation of this monitoring and recording device in the monitoring state will be explained. In this state, on the communication line 7 side, as shown in Fig. 8(b) or (c).
Short duration CW waves such as (duration 1L>1s,
Level VX.

When the frequency f, ) arrives, it is transmitted from the input terminal 16 to C
The signal is input to the high frequency amplification circuit 23 of the W unit 15. Output ■ of the high frequency amplifier circuit 23. is input to both the automatic tuning circuit 23 and the starting circuit 26, and this is the reference setting level (■) of the starting circuit 26. If it is larger than that, operate the starting circuit 26; ■Even after a certain period of time t0 from the input start time. ■Exceed.

An output is generated only when (Veo in FIG. 8(b)) continues to exist. The pulse generating circuit 30 outputs a fixed number of pulses according to the output of the starting circuit 26, and the tuned scan voltage generating circuit 31 performs conversion as shown in FIG. This is then applied to the variable capacitance diode 43 in the automatic tuning circuit 23. This is because the variable capacitance diode 43 is swept only once by the sawtooth wave voltage vv as shown in FIG. 5(a) generated by the tuned scan voltage generating circuit 31.

The capacitance C changes depending on the applied voltage level, and the resonant frequency f is determined by this and the inductance of the tuning coil 39. =1/2πa changes. The tuned output determined by this is converted into a DC output ■7 by the detection rectifier circuit 24, and as shown in FIG. 5(b), its peak voltage ■,
is held by the peak hold circuit 25. This peak voltage (2) is also input to the tuning frequency detection circuit 28, and the tuning frequency detection circuit 28 has a predetermined (2)-f conversion characteristic.
Then, it is converted to the resonance frequency f0 determined from this peak hold value ■ and the time t from the start of the sweep until reaching the peak hold value V, and from this, the frequency f of the short-time continuous wave is
Find x.

On the other hand, regarding the level of such an input wave, when there is an output Vv of the tuning scan voltage generation circuit 31, the output of the automatic tuning circuit 23 is detected and rectified (7) is held, and the NAND circuit 29 is held due to the above Vv. operates and outputs the peak hold value ■. When there are output signals from the tuning frequency detection circuit 28°NAND circuit 29 and tuning scan voltage generation 31, the display section 19 is displayed under control from the main control section 20 via the CW control unit 32.
In addition to outputting the time 1 frequency, peak level, number of arrivals (=number of scans), etc., this information is also output to the printer. These actions result in
If the level of the short-time continuous CW wave as shown in FIGS. 8(b) and 8(c) exceeds the preset reference level V0, the time 2 frequency is reached.

Since the noise factors such as the peak level and the number of times are displayed online on the display unit 19 and sequentially outputted to the printer, the above-mentioned factors of the incoming noise can be easily grasped. In the above explanation, the inductance of the tuning coil 39 is assumed to be constant and the inductance of the tuning coil 39 is constant for automatic tuning of a short-term continuous CW wave, and the explanation is given using an example of sweeping using a sawtooth wave as a method of varying the capacitance of the variable capacitance diode 43. However, if C is changed, If L is also changed at the same time, automatic tuning over a wider frequency range becomes possible. That is, as mentioned above, the tuning frequency f0 in FIG. By switching the switch 40 in (a), sliding in (b), and movably inserting the core 42 in (C), the fo beam becomes maximum when C is minimum, L, and minimum when C is maximum, and these f. It is clear that the range is further expanded compared to when only C is variable.In this way, the automatic tuning method of the present invention is capable of detecting that even after a certain period of time ts has elapsed from the arrival of an input wave that exceeds the set level, there is still an input that exceeds the set level. Sweeping for tuning is started only when the switch is turned on, thereby preventing the erroneous capture of intermittent waves that occur immediately after switching.

FIG. 6 is an embodiment of FIG. 3(c), with 44
-1 is a fixed electrode of the variable capacitor 44.

44-2 is a movable electrode, 45 is an eccentric cam whose radius changes with rotation, 46 is a spring that constantly presses the core 42 against the eccentric cam 45, and 47 is a servo that simultaneously rotates the rotating cam 45 and the movable electrode 44-2. A rotary drive means such as a motor, 48 is a rotating shaft of the rotary drive means 47, and an eccentric cam 45 and a movable electrode 44-2 are fixed thereto. With this configuration, if the rotation drive means 47 is driven by a predetermined rotation angle by the sawtooth wave or a predetermined number of pulse waves (not shown) by the output of the starting circuit 26 as described above, the rotation of the shaft 48 causes The inductance L changes as the core 42 moves within the tuning coil due to the capacitance C between the fixed electrodes and the action of the eccentric cam 45.If these changes are made and a resonant circuit is formed by C, the frequency can be automatically tuned to the incoming noise. It becomes possible.

Next, when a transient pulse wave as shown in FIG. 8(a) arrives at the monitored device 6 from the power line 1 in FIG.
Noise detection means 13 coupled to the power line l of the monitored device 6
A detection signal is input to the input terminal 18 in FIG.

As a result, the input signal is amplified by the preamplifier circuit 33 of the PLS unit 17, and this output is amplified by the peak hold circuit 34.
The output of the peak hold circuit 34 and the output of the level comparator circuit 35 are sent to the C/L/large control unit by the NAND circuit 37 only when the reference level is set and the peak hold circuit 34 exceeds 1. These signals input to the pulse control unit are displayed online on the display unit 19 with the pulse arrival time and level (peak hold value) 1 number of times according to a command signal from the main control unit 2o, and are sequentially output to the printer. ing. As a result of these operations, when a transient pulse as shown in FIG. 8(a) arrives on the power line 1, its level becomes the reference setting level ■1
If it exceeds , you can easily know the arrival time, level, and number of times.

In the above description, the noise detection means 13 is coupled to the communication line and the power line as input waves to the input terminals 16 and 18, respectively.
Although the explanation has been given using an example using , it is clear that if the antenna 14 is connected to these input terminals, arriving waves from space as shown in FIG. 8 can also be detected.

9. Noise detection means 13 used as a means for detecting noise coming from space such as communication lines and power lines, and antennas. It is clear that various combinations other than the above examples are possible for connecting the antenna 14 to the input terminals 16, 18.

〔Effect of the invention〕

As explained above, in the detection of short-term continuous waves in the present invention, when an input wave exceeding a set level arrives, synchronization is performed only when an input exceeding the set level still exists after a certain period of time has elapsed from the arrival time. To start the sweep.

There is an advantage that external noise that arrives due to switching elements being interrupted or the like is not erroneously introduced. Also.

As a control signal to be applied to one or both of the variable capacitance element or the variable inductance element of the automatic tuning circuit, a sweep signal with a period shorter than the duration of the short-time continuous wave is used to sweep the tuning output, and the DC output is detected and rectified. Since both the frequency and level are obtained from the source, unnecessary circuit operations can be omitted and the detection system can be configured easily. This has the advantage that it is possible to easily detect the frequency and level of short-term continuous waves, which are conventionally difficult to detect. In addition, since the time and number of arrival noises (frequency) including transient pulses can be detected independently on each route, the detection level of this device can be adjusted for each route according to the failure occurrence level of the monitored device. By setting , it is advantageous to be able to easily understand the cause of the failure by looking at the output results, such as which route, what type of noise, and what time the noise arrived to cause the failure.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the monitoring state of the environmental electromagnetic noise recording device of the present invention. FIG. 2 is a block diagram of the environmental electromagnetic noise recording device of the present invention. FIG. 3 is an explanatory diagram of a specific example of the automatic tuning circuit of the environmental electromagnetic noise recording device of the present invention. FIG. 4 is an explanatory diagram of an intermediate stage of creating a tuning scan voltage waveform. FIG. 5 is an explanatory diagram of the tuning principle of the automatic tuning circuit. FIG. 6 is a configuration diagram of another embodiment of the tuning circuit. FIG. 7 is a connection diagram of a monitoring system for incoming noise using a conventional electromagnetic noise recording device. FIG. 8 is a typical waveform diagram of incoming external noise. 1... Power line, 2... Fault monitoring target device 3... Indoor noise source, 4... Outdoor noise source. 6... Monitored device, 7... Communication line 8... Indoor rosette, 9... Power line 10... Radiated interference waves. 12...Environmental electromagnetic noise recording device. 13... Noise detection means, 14... Antenna. 15... Short-time continuous (CW) detected unit 17 ・
・ ・ Transient (PLS) wave unit. 18... Input terminal, 19... Display section 20... Main control section, 21... Bus line 22... CWO high frequency amplification circuit. 23... Automatic tuning circuit. 24...Detection rectifier circuit. 25... Peak hold circuit 26... Starting circuit, 27... Variable resistance element 28...
・Tuned frequency detection circuit 29...NAND circuit, 30...Pulse generation circuit,
31... Tuned scan voltage generation circuit 32... CW!
LJ? il unit 33...pulse preamplifier, 3
4...Peak hold circuit 35...Level comparison circuit, 36...Variable resistance element. 38・ 39・ 40・ 41・ 42・ 43・ 44・ Electrode. 45・ 47・ ...NAND circuit. Pulse control unit. Tuning coil changeover switch. sliding switch. Magnetic material core. Variable capacitance diode. Variable capacitor, 44-1...Fixed-2...Variable electrode. Eccentric cam, 46...spring. Rotation drive means, 48...rotation shaft. Figure 7

Claims (1)

[Claims] In a device that monitors noise intrusion paths such as communication lines, power lines, and space when a failure occurs in the communication device due to external noise arriving at the communication device, and records the cause of the incoming noise when noise of a predetermined level or higher arrives, For noise that has a predetermined frequency and stops arriving after continuing for a certain period of time, the circuit constants of either the capacitance element and the inductance element, or both elements that make up the resonant circuit, should be set as follows:
After the magnitude of the incoming noise exceeds a predetermined set level,
If the voltage still exceeds the set level after a certain period of time has elapsed, the voltage applied to the element is varied by a signal that starts sweeping the voltage applied to the element and ends the sweep within the duration of the incoming noise; The frequency and peak level of the input noise are detected from the determined resonance point of the resonant circuit, and these are output together with the arrival time and number of arrivals, and the peak level, arrival time and number of arrivals are output for transient pulses. An environmental electromagnetic noise recording device characterized by comprising: