JP2790888B2 - Environmental electromagnetic noise recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a noise entry path such as a communication line or a power line of a communication device such as a telephone connected to a communication line when a failure occurs due to external noise. Is monitored for a predetermined period,
The present invention relates to a noise monitoring and recording device for grasping the cause of a failure at an early stage.

[Conventional technology]

Conventionally, as this type of monitoring and recording apparatus, an apparatus as shown in FIG. 7 for power lines has been used. That is, in FIG. 7, 1 is a power line provided in an office, a user's house, etc., 2 is a fault monitoring target device such as a home appliance, office equipment, or OA device connected to the power line 1, and 3 is a power line 1 A noise source installed indoors that transmits noise to the power line 1 by a switching operation or the like when the home appliance is different from the fault monitoring target device 2 connected to the power monitoring device 2 is connected to the power line 1 outdoors. Outdoor noise sources such as power equipment, 5
The power supply noise monitoring and recording device is connected to the power line 1 of the monitored device 2 when a failure occurs in the monitored device 2 and monitors incoming noise.

FIG. 8A shows an indoor noise source 3 and an outdoor noise source 4 generated at the time of starting and stopping in the power line wiring system of FIG.
This shows a waveform in which noise from the device reaches the monitoring target device 2 through the power line 1 and is a representative noise waveform which may be a cause of failure such as malfunction of the device.

In the system shown in FIG. 7, when a failure occurs in the monitoring target device 2, the power supply noise monitoring and recording device 5 is used to monitor the waveform level (pulse peak value), arrival time, frequency and the like at an early stage. A method of connecting to the power line of the device 2 for monitoring as shown in FIG. 7 and printing out these incoming data is widely used.

[Problems to be solved by the invention]

However, this kind of monitoring and recording apparatus can detect and record the noise factor when pulse noise as shown in FIG. 8 (a) arrives. However, when the arrival noise continues for a short time, the frequency and level are changed. There is a disadvantage that it cannot be detected properly.
For example, noise transmitted during communication when a vehicle or the like equipped with a high-power CB radio is passed disappears after passing through the vehicle, and becomes a short-time continuous wave (duration t _L ) as shown in FIG. 8B. . Also, an electromagnetic wave as shown in FIG. 8 (c) may arrive. In equipment such as key telephone equipment, in which communication lines such as office lines and extension lines are wired in addition to power lines, the incoming noise enters the equipment from the office line or extension cable and causes malfunctions such as malfunction or line disconnection. Generate. In order to take countermeasures against these noises with equipment, Fig. 8 (b),
It is necessary to find out the intrusion route, frequency, level, etc. of the short-time continuous wave local line and extension as shown in (c) at an early stage.
The conventional power supply noise monitoring device as shown in FIG. 7 has a drawback that these noise factors cannot be detected.

In order to solve the above-mentioned drawbacks, the present invention relates to a method for generating a failure of a communication device at an irregular time, as shown in FIG.
It is possible to automatically and independently detect the frequency and level of the short-time continuous wave as shown in (c) and the peak value of the pulse wave as shown in (a) and record them together with the arrival time and the number of arrivals. It is an object to provide a simple monitoring and measuring device.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, one or both of a capacitance element and an inductance element constituting a resonance circuit are provided with respect to noise having a predetermined frequency and arriving after continuing for a predetermined time or more. After the magnitude of the incoming noise exceeds a predetermined set level, if the magnitude of the incoming noise still exceeds the set level after a certain period of time, sweeping of the voltage applied to the element is started, The frequency and the peak level of the input noise are detected from the resonance point of the resonance circuit determined by the change, and are output together with the arrival time and the number of arrivals. In addition, a peak level, an arrival time, and the number of arrivals are output for a transient pulse.

[Action]

In the detection of a short-time continuous wave according to 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 is still present after a certain period of time from the arrival time. It is like that. In addition, as a control signal to be applied to one or both of the variable capacitance element and the variable inductance element of the automatic tuning circuit, a sweep signal having a cycle shorter than the duration of the short-time continuous wave is used to perform a sweep, and the tuned output is detected and rectified. And both frequency and level are obtained. These make it possible to easily detect the frequency and level of the short-time continuous wave, which is usually difficult to catch. In addition, the time and the number (frequency) of the incoming noise including the transient pulse can be detected independently for each path. With these, if the detection level of this device is set in accordance with the failure level of the monitoring target device 6 for each path, the output result will be checked, and “from which path, what noise arrives at what time, Cause "or the like can be easily grasped.

〔Example〕

FIG. 1 is a diagram for explaining an incoming noise monitoring state of the environmental electromagnetic noise recording apparatus of the present invention, wherein 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. Indoor rosette for connecting the indoor communication line 7 to the power supply, 9 is a power line of the monitoring target device 6, 10 is a noise source equipped with a high-power CB radio, etc., 11 is a radiated disturbance from the noise source 10, and 12 is a The environmental noise recording device according to the invention, 13 is a noise detecting 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, and 14 is a space around the monitored device 6. 7 is an antenna provided in the 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, a noise detecting means connected to the communication line 7 or the power line 9 of the monitored device 6
13, and an antenna 14 installed near the monitored device 6
Is connected to the environmental noise recording device 12 of the present invention, and after setting a failure occurrence level of the monitoring target device 6 with respect to intrusion noise from each path in advance, monitoring of intrusion noise is started. When noise exceeding each fault occurrence level arrives, its frequency, level, peak value and level are printed out together with the respective arrival times, so that the cause of the fault when the monitoring target device 6 has failed is printed out. It is possible to know the type, level, frequency, time, etc. of a certain noise.

FIG. 2 is a block diagram of the environmental noise recording apparatus 12 of the present invention. Reference numeral 15 denotes 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 the input terminal of CW detection unit 15, 17 is Fig. 8 (a)
Transient pulse wave (PLS) detection unit such as
18 is the input terminal of the PLS detection unit 17 and 19 is the CW detection unit
15 and a display unit for displaying the detection signals of the PLS detection unit 17, 20 is a main control unit for controlling the detection signal from each unit and outputting it to the display unit 20, and 21 is a main control unit for detecting the detection signal from each unit 15, 17. A bus line that connects the main control unit 20 and the display unit 19 and exchanges control. 22 is a high-frequency amplifier for amplifying an input signal from the input terminal 16, and 23 is a high-frequency amplifier 2
Automatic tuning circuit for taking out the frequency of the second output signal V _e,
24 detection rectifier circuit for converting the tuning output of the automatic tuning circuit 23 to a DC, 25 a peak hold circuit for holding the maximum value of the DC output V _T of the detection rectifier circuit 24, 26 based on the output Ve of the high frequency amplifying circuit 22 compared to voltage V _o, only generates an output when the Ve _o of Figure 8 from the input start time of the output Ve becomes constant time t _o after also Ve> V _o (b) is present continuously activated Circuit, 2
Variable resistance element for setting the reference voltage V _o is 7, 28 tuning frequency detection (V-f converter) circuit for converting the output V _P to the frequency of the peak hold circuit 25, 29 of the tuning scan voltage generating circuit 31 gate circuit for outputting the hold value V _p of the peak hold circuit 25 only when the output V _v is generated, 30 pulse generating circuit for generating a fixed number of pulses at a constant period by the output of the starting circuit 26, 31 is a pulse generator the generation pulse circuit 30, the tuning scan voltage V _v generation circuit for operating the automatic tuning circuit 23, 32 is tuned scan voltage generating circuit 3
1, tuning frequency detection circuit 28, gate circuit 29, pulse generation circuit
This is a CW control unit that controls 30 outputs. 33 is PLS
Preamplifier of the unit 17, a peak hold circuit for holding the maximum output of the preamplifier circuit 23 is 34, the level comparator circuit for comparing the reference voltages V ₁ is the output level of the preamplifier circuit 33 35, 36 variable resistance element for setting the reference voltage V _1, 37 is a gate circuit which outputs the output of the peak hold circuit 34 only when there is an output of the level comparator circuit 35, 38 each of the level comparator circuit 35 and a gate circuit 37 It is a pulse control unit that controls the output.

FIG. 3 is a diagram showing a specific embodiment of the automatic tuning circuit 23. FIG. 3 (a) shows a case where a winding tap changeover switch is used as a tuning coil inductance changing means, FIG. 3 (b) shows a case where a sliding switch is used, and FIG. 3 (c) shows a movable magnet inserted into the tuning coil. In the case where a material core is used, 39 is a tuning coil, 40 is a winding tap changeover switch of 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 switch of the tuning coil 39. A magnetic material core inserted inside the winding to change the coil inductance, 4
Reference numeral 3 denotes a variable capacitance element such as a variable capacitance diode whose capacitance value changes according to the magnitude of the applied voltage. Reference numeral 44 denotes a variable capacitance element such as a variable capacitor.
Tuning can be achieved by changing one or both of 3,44 by electrical or mechanical means described below.

Figure 4 is an example of making the tuning scan voltage V _V supplied to the variable capacitance element 43 such as a variable capacitance diode in the automatic tuning circuit 23 using a continuous pulse from the pulse generator 30, the tuning scan voltage Step-like repetitive waveform (period) obtained through an n-ary counter circuit or the like in the generation circuit 31
ts).

FIG. It is an explanatory view of the operation principle of the automatic tuning circuit 23 of the present invention apparatus, automatic tuning the tuning scan voltage V _v of the sawtooth wave shaping such stepped repetitive waveform turns of tuning coil 39 without the variable Variable capacitance diode 43 of circuit 23
FIG. 3 is a conceptual diagram of a tuning output when applied to a, and a method of obtaining a tuning frequency by performing frequency conversion by a tuning frequency detection (V-f conversion) circuit by the output.

Now, the noise detection means 13 such as a current probe is connected to the input terminals 16 and 18 in FIG. 2, respectively, and the terminal 16 is connected to the communication line 7 and the terminal 18 to the power line 9 as shown in FIG. The operation of the monitoring and recording device in the monitoring state will be described. In this state, a short-time continuous CW wave (duration t _L > t _s , level V _x , frequency f _x ) as shown in FIG. 8B or 8C is provided on the communication line 7 side.
Is input from the input terminal 16 to the high-frequency amplifier circuit 23 of the CW unit 15. Although the output V _e of the high frequency amplifier circuit 23 is input to both the automatic tuning circuit 23 starting circuit 26, which operates the starting circuit 26 when the reference greater than the set level V _o of the startup circuit 26, V _e input start time An output is generated only when V _e (V _{e o} in FIG. 8B) exceeding V _o continues for a predetermined time t _o after. Pulse generating circuit 30 by the output of the starting circuit 26 outputs a predetermined number of pulses, performs conversion such as Figure 5 by the tuning scan voltage generating circuit 31, the period generates a sawtooth wave voltage V _v of ts This is applied to the variable capacitance diode 43 in the automatic tuning circuit 23. Since the variable capacitance diode 43 is swept only once by the sawtooth wave voltage V _v, such as in the fifth diagram made by tuning the scan voltage generating circuit 31 such as this (a), the capacitance C by the applied voltage level And the resonance frequency determined by this and the inductance L of the tuning coil 39 Changes. This tuning output depends is converted into DC output V _T by the detection rectifier circuit 24, the peak voltage V _p as shown in FIG. 5 (b) is held by the peak hold circuit 25. The peak voltage V _p is also input to the tuning frequency detection circuit 28, the tuning frequency detection circuit 28 having a V-f converter characteristic predetermined in the peak hold value V _p and sweep start after the peak hold value V _p is converted to the resonance frequency f ₀ which is determined from the time t _p of ranging, than this brief continuation wave of frequency f _x is obtained.

On the other hand, the V _T the output is detected and rectified automatic tuning circuit 23 is held when there is the output Vv of the tuning scan voltage generating circuit 31 for such input signal level of the gate circuit 29 by the above Vv _Operates to output the peak hold value Vp. These tuning frequency detection circuits 28,
When each output signal of the gate circuit 29 and the tuning scan voltage generation 31 is present, the time, frequency, peak level, number of arrivals (= number of scans) are displayed on the display unit 19 under the control of the main control unit 20 via the CW control unit 32. And output such information to a printer. By these operations, FIG. 8 (b), the reference level V _o that such a short time continue CW wave level previously set as (c)
If the frequency exceeds the threshold, noise factors such as time, frequency, peak level, and number of times are displayed on-line on the display unit 19 and are sequentially displayed on the printer, so that the factors of the incoming noise can be easily grasped. Note that in the above description,
For the automatic tuning of the CW wave, the inductance L of the tuning coil 39 is fixed and the example of the sweeping by the sawtooth wave as the method of changing the capacitance of the variable capacitance diode 43 has been described. Automatic tuning over a wider frequency range becomes possible. That is, the tuning frequency f _{o in} FIG.
Is as described above Therefore, when the capacitance C is minimum, L is also minimum, and when the capacitance C is maximum, L is maximum.
If switching of 40, sliding of (b), and movable insertion of the core 42 of (c) are performed, f _o becomes maximum when L and C are minimum, and becomes minimum when L and C are maximum, and the range of these f _o is It is apparent that only C is further enlarged as compared with the case of variable. As described above, the automatic tuning method according to the present invention starts the sweep for tuning only when an input exceeding the set level is still present after a certain time ts has elapsed from the arrival of an input wave exceeding the set level. As a result, intermittent waves generated immediately after switching or the like are prevented from being erroneously taken in.

FIG. 6 shows an embodiment of FIG. 3 (c).
-1 is a fixed electrode of the variable capacitor 44, 44-2 is a movable electrode,
45 is an eccentric cam whose radius changes due to rotation, 46 is a spring that constantly presses the core 42 against the eccentric cam 45, 47 is a rotation drive means such as a servomotor that simultaneously rotates the rotation cam 45 and the movable electrode 44-2, Reference numeral 48 denotes a rotation shaft of the rotation driving means 47, to which the eccentric cam 45 and the movable electrode 44-2 are fixed. In this configuration, if the rotation driving means 47 is driven by the sawtooth wave or a predetermined number of pulse waves (not shown) by a predetermined rotation angle by the output of the starter circuit 26 in the same manner as described above, the rotation The capacitance L between the fixed electrodes and the action of the eccentric cam 45 cause the core 42 to move in the tuning coil, thereby changing the inductance L.
If a resonance circuit is formed by C, automatic tuning of the frequency with respect to the incoming noise 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 of FIG. 1, the noise detecting means coupled to the power line 1 of the monitored device 6
The detection signal from 13 is input to the input terminal 18 in FIG.
As a result, the input signal becomes the preamplifier circuit 33 of the PLS unit 17.
In amplified, the gate circuit only when the output exceeds one reference set level V ₁ held in the peak hold circuit 34
37 outputs the output of the peak hold circuit 34 to the pulse control unit together with the output of the level comparison circuit 35.
These signals input to the pulse control unit are
According to the command signal from 20, the arrival time, level (peak hold value) and number of pulses are displayed on-line on the display unit 19 and sequentially output to the printer. By these operations, when the transient pulse as FIG. 8 (a) to the power line 1 is reached, if it exceeds the level of the reference set level V _1, the arrival time,
The level and the number of times can be easily known.

In the above description, an example was described in which the noise detection means 13 coupled to the communication line and the power line was used as the input waves to the input terminals 16 and 18, respectively. It is clear that an incoming wave as shown in FIG. 8 can be detected.

In addition to the above examples, there are various methods for connecting the noise detection means 13 and the antenna 14 to the input terminals 16 and 18 which are used as means for detecting incoming noise from a space such as a communication line or a power line and an antenna. It is clear that combinations of are possible.

〔The invention's effect〕

As described above, in the detection of a short-time continuous wave according to the present invention, when an input wave exceeding a set level arrives, tuning is performed only when an input exceeding the set level is still present after a certain period of time from the arrival time. Is started, so that there is an advantage that external noise arriving due to switching element switching is not erroneously taken in. In addition, as a control signal to be applied to one or both of the variable capacitance element and the variable inductance element of the automatic tuning circuit, a sweep signal having a cycle shorter than the duration of the short-time continuous wave is used for sweeping, and the tuning output is detected and rectified. Since both frequency and level are obtained based on the output, unnecessary circuit operations can be omitted, and the detection system can be easily configured. Thus, there is an advantage that the frequency and level of a short-time continuous wave, which is conventionally difficult to catch, can be easily detected. In addition, since the time and frequency (frequency) of the incoming noise including the transient pulse can be detected independently for each path, the detection level of this device can be adjusted for each path in accordance with the failure occurrence level of the monitored device. If the setting is made, there is an advantage that the cause such as "from what path, what kind of noise arrived at what time, and the failure occurred" can be easily grasped by looking at the output result.

[Brief description of the drawings]

FIG. 1 is an explanatory view 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, and FIG. 3 is an automatic diagram of the environmental electromagnetic noise recording device of the present invention. FIG. 4 is a diagram illustrating a specific example of a tuning circuit, FIG. 4 is a diagram illustrating a process in the course of generating a tuning scan voltage waveform, FIG. 5 is a diagram illustrating the tuning principle of an automatic tuning circuit, and FIG. 6 is another embodiment of the tuning circuit. FIG. 7 is a connection diagram of an incoming noise monitoring system using a conventional electromagnetic noise recording device, and FIG. 8 is a typical waveform diagram of incoming external noise. 1 power line 2 failure monitoring target device 3 indoor noise source 4 outdoor noise source 6 monitoring target device 7 communication line 8 indoor rosette 9 power line 10 … Radiated interference, 12… Environmental electromagnetic noise recorder, 13… Noise detection means, 14… Antenna, 15… Short duration (CW) wave detection unit, 17… Transient (PLS) wave unit, 18 ... Input terminals, 19 Display unit 20 Main control unit 21, Bus line 22 CW high-frequency amplifier circuit, 23 Automatic tuning circuit, 24 Detection rectifier circuit, 25 Peak hold Circuit 26 Start-up circuit 27 Variable resistor 28 Tuning frequency detecting circuit 29 Gate circuit 30 Pulse generating circuit 31 Tuning scan voltage generating circuit 32 CW control unit 33 … Pulse preamplifier, 34 ……
Peak hold circuit 35 Level comparator circuit 36 Variable resistor element 37 Gate circuit 38 Pulse control unit 39 Tuning coil 40 Switch 41 Slide switch 42 ... magnetic material core, 43 ... variable capacitance diode, 44 ... variable capacitor, 44-1 ... fixed electrode, 44-2 ...
Variable electrode, 45: Eccentric cam, 46: Spring, 47: Rotating drive means, 48: Rotating shaft.

Claims (1)

(57) [Claims] An apparatus for monitoring an external noise intrusion path arriving at a communication device from a communication line, a power line, a space, or the like, and recording a noise factor when the noise has reached a predetermined level or more, comprising a predetermined frequency. After continuing for a certain period of time or more, for the noise that stops arriving, after the magnitude of the arriving noise exceeds a predetermined set level, if the set level still exceeds the set level after a lapse of a certain time Scan voltage generating means for starting the sweep of the sawtooth voltage and ending the sweep within the duration of the incoming noise, and any one of a capacitance element and an inductance element constituting a resonance circuit by supplying the scan voltage, or An automatic tuning means for varying the circuit constants of both elements; and a detection and rectification of a resonance output waveform from the automatic tuning means to which the incoming noise is input, thereby obtaining a peak level of the incoming noise. Means for detecting and holding the signal, means for outputting the output from the peak level detection and holding means when the scan voltage is generated as the peak level of the incoming noise, and output of the resonance output waveform and the scan voltage generating means. Tuning frequency detecting means for outputting a resonance frequency of the incoming noise by inputting a waveform, and detecting and holding a peak level of the input signal for an input signal exceeding a predetermined level for a transient pulse. Means for outputting the peak level, frequency, arrival time and number of arrivals of the incoming noise with respect to the noise whose arrival stops after having the predetermined frequency and continuing for a predetermined time or more, and outputting the transient. Means for outputting the pulse peak level, arrival time and number of arrivals for the pulse. Ambient electromagnetic noise recording apparatus characterized.