JPS58171676A - Device for measuring impulse voltage - Google Patents

Abstract

PURPOSE:To measure the approximate value of a impulse voltage easily with a simple means, by differentiating an input signal including the impulse voltage, comparing a differentiated signal with a reference voltage and storing a compared result. CONSTITUTION:Input voltage including the impulse voltage (amplitude Ei) is differentiated by an input circuit 1 and a divided voltage kEi is supplied to a comparator 5, which compares the input voltage with the reference voltage Es of a voltage generating circuit 4. When kEi>Es, the comparator 5 generates an output and stores the output in a memory circuit 6. A display circuit 7 displays the change (stored contents) of the output from the memory circuit 6. Thus the approximate value of the impulse voltage can be easily measured by the simple means.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring the amplitude of impulse voltages in power or signal transfer circuits.

In addition to the power or signal to be transmitted, unintended voltages such as noise may enter the power transmission path or signal transmission path in the form of impulses. This impulse voltage is caused not only by lightning strikes and induced electricity on power transmission lines, but also by electromagnetic loads such as electromagnetic contactors and electromagnetic valves.
It is well known that this problem occurs when operating a drive circuit using an I-switch.In particular, with the spread of electronics, the number of cases in which low-power circuits and high-power circuits are installed close to each other has increased. In this case, the impulse voltage generated at 0N10FF of an inductive load in a strong current circuit may enter the weak current circuit through the capacitance of a conductor or space or by electromagnetic induction, causing it to malfunction.

This impulse voltage is 1 usually from several microseconds to several milliJ
Because it has a pulse width of seconds, it cannot be detected with a normal voltmeter, and a cathode ray tube oscilloscope is usually connected to the target circuit to detect or measure the presence of impulse voltage.

(7) The problem with measurement using an oscilloscope is that it is inconvenient for one person to carry the oscilloscope due to its shape and weight. Furthermore, although an oscilloscope can capture the amplitude of an impulse voltage with considerable accuracy, in general, it is often sufficient to know the approximate value of the magnitude of the impulse voltage. In other words, this type of voltage is generally measured when an impulse voltage t is large enough to cause the electronic circuit to malfunction when installing the electronic circuit; check whether it is occurring or not, and take countermeasures if it is occurring. Therefore, precise measurement of pulse voltage is meaningless.

Measure impulse voltage. Another typical method is to use a circuit shown in FIG. 1, which is a combination of a differentiating circuit 1, a peak hold circuit 2 mainly composed of an operational amplifier, and a voltage indicating circuit 3.

In this circuit, the output of the differentiating circuit is added to the peak hold circuit, the capacitor 22 at the rear end of the peak hold circuit is rapidly charged by the operational amplifier 21, and the voltage of this capacitor is indicated by some display means (for example, a DC voltmeter). However, the operational term 11 for the peak hold circuit
The 11i device 21 is required to have extremely high performance, and this method is generally expensive. This is because the operational amplifier 6 used here must have a high slew rate and be able to provide sufficient output current to quickly charge the load capacitor, reducing capacitor discharge. Therefore, the input bias current is required to be extremely small≠2.The present invention, in view of the above points, provides an inexpensive impulse voltage measuring device for use in groove belts.

The concept of the present invention will be explained using the block diagram shown in FIG. The circuit in Figure 2 is an input that includes a voltage molecule circuit (voltage differential)
Circuit (hereinafter referred to as differential circuit) 1.

A reference voltage ratio generation circuit (hereinafter referred to as a voltage generation circuit) 4, a TLF comparison circuit (hereinafter referred to as a comparison circuit) 5 that compares the magnitude of these voltages, and a memo 11 circuit 6 driven by the output of the comparison circuit. , a display circuit 7 for displaying the output of the memory circuit, a reset circuit 8 for resetting the memory circuit, and a power supply 9 for operating these circuits. It is said that

To explain the operation of this circuit, the impulse voltage (amplitude EEj, i is supplied to the comparator circuit 5, where it is compared with the output voltage Es of the voltage generation circuit 4, and if f13j,>Es, an output of the comparator circuit 5 is generated and stored in the subsequent memory circuit 6, Memo 1 circuit 6
The output change (memory content) is displayed on the display circuit 7. The reset circuit 8 is used to restore the state of the memory circuit 6 to the state before the change.

In this way, the present invention extracts the impulse voltage E1 from the input voltage using the differentiating circuit 1, compares this voltage with the reference voltage Es using the comparator circuit 5, and stores the - instantaneous change in the comparator circuit output in the memory circuit 6. The main idea is to store the state a of the memory circuit and display the state a of the memory circuit on the display circuit 7. 1
The one set circuit 8 and the power supply 9 are auxiliary in the present invention.

When the circuit of FIG. 1 is used, the impulse voltage E1 input to change the display of the display circuit 7 is BEi,
>Es, and the display of the display circuit 7 does not change, since AEi≦Es, for example, by changing the reference voltage 11Gs, when Ks, 1 display does not change, and when Es, the display does not change. If it has changed.

EEs, ≧iE:L)Es, ・・・・・・・・・・・・
. . . (1), and it is possible to know the voltage section where the impulse voltage E1 exists. Even if the reference voltage is fixed and the voltage division ratio is 8t-variable,
It goes without saying that the voltage section of El can also be known in the same way.

As described above, according to the present invention, the impulse voltage range can be determined very easily without using a circuit that combines a peak hold circuit using an operational amplifier and an analog-to-digital converter, which is an analog storage means. obtain.

Among the specific embodiments of the present invention, the simplest one is shown in FIG. In FIG. 3, a circuit to be measured (line) is connected between an input point 11 and a reference point 12. The impulse voltage in the target voltage is differentiated by a differentiating circuit 1 consisting of a capacitor 3 and a resistor 14, and only the pulse component is taken out across the resistor 140 without changing its amplitude. This impulse voltage E1 can be applied to the resistor 14 as necessary.
The voltage is divided by the voltage dividing circuit shown at 1° 142 and applied to the next voltage comparator circuit 5. Here, the reason why a sorting voltage divider is used in the differentiating circuit 1 as necessary is because the impulse voltage is generally larger than the signal voltage used in the electronic circuit in many cases.

The voltage comparator 51 compares the voltage (amplitude) of the signal BEEi input to the voltage comparison circuit 5 with the comparison reference voltage Es in the voltage generation circuit 4, and in this circuit, BKi>E
In the case of Es, the output cap of the voltage comparator 51 is turned ON (logic level 111), and the storage circuit 6 is operated in the memory of the primary stage, and in the case of REi≦Es, the output of the voltage comparator 51 is 0FF (logic level 1o1). ).

The memory circuit 6 is a D type flip 70 tube (hereinafter referred to as D-FF).
The signal input terminal is always connected to the logic level @11 even. The memory circuit input signal 62 is connected to the clock input signal terminal C of the D-FF circuit catfish, and this signal is ON.
Then, the output page 65 of the DJ'F circuit 61 becomes low level (logical level I o I ), and the light emitting diode 71 in the display circuit 7 connected thereto lights up.

The D-F' F circuit 61 has a reset signal terminal 64, and the reset circuit 8 consisting of a resistor 81 and a rebound switch 82 connected to this terminal,
The D-FF circuit 61 is reset in advance before impulse measurement. In the reset state, the D-FF circuit 61
Since the output page 63 of is in the ON state, the light emitting diode 7
1 is in the off state. The main active elements of this circuit are one voltage comparator and one D-FF circuit, and can operate with extremely low power.

In the above embodiment, the memory circuit input signal 62 is connected to the clock input signal terminal C of the D-FF circuit Azusa, which has the following advantages. Normally, a clock pulse CP of one constant period t as shown in FIG. 4(3) is applied to the clock input terminal of this FF' circuit, and the signal input terminal Dv
An input signal to be stored in F'F is applied to c. Then, the input signal applied to the terminal at the timing when the clock pulse CP is input is stored in the FF, and at the same time, the stored contents are output to the output terminal Q. (inverted signal is output).

Assume now that the impulse voltage E1 and the timing of generation of the clock pulse CP are as shown in FIG. Looking at the diagram (1X3), the clock pulse cpI5 is not generated at the timing when the impulse voltage -REi exceeds the reference voltage ESt-. Therefore, even though an impulse voltage exceeding the reference voltage is actually generated.

This fact cannot be stored in the D-FF circuit. Since this embodiment is configured as described above, the output signal of the comparator circuit 5 (input signal 62 of the memory circuit) serves as a clock pulse, and the impulse voltage REi exceeds the reference voltage (the comparator circuit The signal at the input terminal is stored at the timing when a logic level @1'' signal is generated, and at the same time a low level (logic level 101) signal is generated at the output terminal pre-charge.Therefore, the timing at which the impulse voltage exceeds the reference voltage is stored. Regardless of the voltage, you can accurately and instantly display the level of impulse voltage.

No loss of reliability.

In addition, the clock input terminal C can be directly connected to the clock input terminal C without going through the comparison circuit.
This information can also be displayed when noise, such as an impair noise, is input to the device.

The circuit shown in FIG. 3 converts the impulse voltage E1 into the voltage Es/
! ! Although this is done for only one point, if the impulse voltage Ei is input repeatedly, for example, by changing KS in sequence and checking the output of the display circuit each time, You can know the amplitude of the impulse voltage.

FIG. 5 shows another embodiment of the invention. This figure shows a configuration in which a plurality of voltage comparators and D-FF circuits (4 in this example) of the circuit shown in FIG. Here 1gs, −
g, , EES, ~2E, , ES, -3E,
, Es, -4E. These reference voltages can actually be supplied by a voltage divider circuit with a group of resistors that are sufficiently lower than the voltage comparator input resistance.

As is clear from the above explanation, the circuit shown in FIG.
If 714 is not lit, be<sweet Ei≦2E, (3) When the light emitting diodes 711 and 712 are lit, the light emitting diode door 13. If F14 is not lit, 2E, <E1≦3E,
, (4) If the issuing diodes 711 to 713 are lit and the issuing diode 714 is not lit, 31D, (JEi≦4
E.

(5) If all the issuing diodes are lit, a E, (so E
j: The range of the impulse voltage E1 can be divided into five. As you can see, generally the voltage comparator and D-
If N combinations with FF circuits are used, it is possible to know the value of the impulse voltage with the details of 't-N1,100 divisions. In this embodiment, when a certain display circuit is driven, all the display circuits that should be driven with the following voltages are driven, so the impulse voltage can be displayed linearly on the display (light emitting diode). and it becomes easier to see. In addition, the fifth
In the figure, illustration of the reset circuit is omitted.

According to recent integrated circuit manufacturing technology, it is possible to obtain highly integrated voltage comparators and D-FF circuits that operate with extremely low power, so it is possible to obtain a circuit in which the above-mentioned N is approximately 4 and 16, which is practical. Once created, the circuit can be operated with batteries comparable to those used in transistor radios.

FIG. 6 shows a voltage divider circuit used in the differential circuit used in the present invention, which incorporates a block rectifier circuit 143, making it possible to measure impulse voltages for both positive and negative polarity voltages. In the embodiments shown in Figs. 3 and 5, only the positive impulse voltage can be measured; in reality, it is unclear whether the impulse [pressure] is generated with positive or negative polarity, and the polarity of the measured value is also a problem. Therefore, it can be said that the differential circuit having a voltage divider circuit with a bridge circuit shown in FIG. 6 is extremely practical.

Although the purpose of the above embodiment is to measure an impulse voltage having a sudden rise, as shown in FIG. If a terminal 15 for applying voltage is also provided, it will also have the ability to measure the peak values of general DC and AC voltages, as well as the peak values of surge voltages that change extremely slowly and cannot be detected by a differential circuit. Note that this function can be achieved even if only one input terminal 16 is provided, as shown in FIG. remains unchanged. In this case, if the bias voltage of the line to be measured is high, it is safer to use the capacitor 13t.

In the above embodiments, a D-FF circuit is used as the memory circuit, but the memory circuit is not limited to the D-FF circuit. For example, as shown in FIG. 9 and FIG.
AD gates 101-104 and N6R gates 91-94
The gist of the present invention is not lost even if a latch circuit is used in combination. FIG. 9 is an example including a memory circuit for storing the rising edge of the voltage comparator output in the positive direction, similar to FIG. 5.6. g
This is an embodiment in which changes in the voltage comparator output in the negative direction are stored, contrary to the to diagram and the igs diagram. That is, the input terminal of the impulse voltage is the negative input terminal of the comparator in FIG.
In Figure 0, it is the positive input terminal of the comparator.

In the case of the latch circuit described above, since a clock pulse is not used, the output signal of the comparator can be accurately stored because it is stored in the storage circuit at the generation timing of the output signal of the comparator circuit.

FIG. 11 shows a specific circuit diagram when a D-FF is used as a memory circuit. This is configured so that the measured voltage can be divided into eight levels and displayed, and by short-circuiting half of the resistor 142 with the switch S, it is possible to measure up to 520 DV. C,−C,=0.0
22 μF, R, ~R, = I KΩ.

The R15 range is set to Ω at -4 and 7, and the comparator 51
~58, inverter NINN, and D-FF61~6
8 is composed of an IC. Light emitting diode one, 8-D8.
uses an array configuration.

The capacitor 13 that constitutes the differential circuit in the input circuit 1 is 1
000PF, resistor 141 is 100Ω, resistor 142 is 2
It is set to 0 old. Ro is a variable resistor for adjusting the reference voltage.

In the above configuration, impulse voltages are applied to the negative terminals of the comparators 51 to 58, but since the output of each comparator is inverted by the corresponding inverter Nl to N, the memory circuit is connected to the comparator circuit 5. The change in the output of is stored in the positive direction.゛Also, 021 to 028 are for spare purposes and do not necessarily need to be installed. When the switch S is turned on, power is supplied from the power supply IC 17805. When the switch S5 is then pressed, the memory circuit is set to a reset state and the impulse voltage can be measured. If this measurement result shows that the impulse voltage is at a value that causes the electronic device to malfunction, it is necessary to take measures such as changing the installation location or installing a new noise filter, etc. when installing the electronic device. A second specific circuit example will be shown. The same parts as in FIG. 11 are designated by the same reference numerals. In this example, a latch circuit is used as a memory circuit in the same way as shown in FIG. 9/1s10. A protective Zener diode ZD is inserted into the Kugata circuit 1. Memory circuit 91
The positive side of the power supply is applied to the enable terminal E of ~98 (engineering C), the reset input signal is applied to the S terminal, and the output signal of the comparator circuit is applied to the R input terminal. .

The measuring device configured as in each embodiment can be carried as a single unit and checked for the presence or absence of an impulse voltage during maintenance and inspection of other electronic devices. Also.

This measuring device can be made compact and inexpensive.

It can be integrated into other electronic devices (eg sequence controller'y). In this case, regularly every day or
It is possible to temporarily measure the environment around the electronic device (at a time when impulse voltage is most likely to occur considering the operating conditions of other electric machines), thereby improving the operational reliability of the electronic device.

As is clear from the local explanation, according to the present invention, the approximate impulse voltage f contained in any line or circuit is
Since i11r can be measured extremely easily using simple means, appropriate measures can be taken when installing a low power circuit together with a high power circuit, which is highly effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional example, FIG. 2 is a block diagram schematically showing the present invention, FIG. 3 is a block diagram of the first embodiment specifically showing FIG. 2, and FIG. 4 is a block diagram of the first embodiment. Figure 3 is a signal waveform diagram in the number section, Figure 5 is a block diagram of the second embodiment,
Fig. 6 is a circuit diagram showing a modification of the Kugata circuit, Fig. 7 is a circuit diagram showing another modification, Fig. 8 is a circuit diagram showing a modification of Fig. 7, and Fig. 9 is a circuit diagram showing fJg3 implementation. The circuit configuration diagram of the example, FIG. 10 is the circuit configuration diagram of the fourth embodiment, and FIG. 11 shows the actual circuit example #! FIG. 12 is a circuit diagram of the fifth embodiment, and FIG. 12 is a circuit diagram of the sixth embodiment. 1: Input circuit, 4: Reference voltage measurement circuit, 5: Comparison circuit,
6: Memory circuit, 7: Display circuit, D lock pulse application terminal, 13, 14: Differential circuit, 1Z: Switching circuit %146
: Current circuit. Engraving of drawings (no change in content) Fig. 1) $ 2 Fig. 3 Fig. 5 Fig. 6 Fig. 7 Indentation 9 Fig. Ryo IQ Oral procedure amendment (method) - 11 indications Patent application filed in 1988 No. j3825 Name of the invention Impulse voltage measuring device Drawing 11: Person who performs 51 Q mark, Ceremony month 11 Production fee
Table n', [1 win Shigeyo Rihito

Claims (1)

[Claims] t. An input circuit that receives an external signal and performs step-down processing on the signal; and a reference voltage generation circuit that generates a reference voltage. A comparison circuit that compares the output signal from the input circuit with the reference voltage, a memory circuit that receives the output signal of the comparison circuit and stores the comparison result, and a display that displays the stored contents based on the output of the memory circuit. An impulse voltage measuring device comprising a circuit, wherein an output signal of the comparison circuit is stored in the storage circuit at the timing of generation of the output signal. 2. The reference voltage generation circuit is configured to generate a plurality of types of voltages, the comparison circuit is composed of a plurality of circuits each set to a plurality of reference voltages, and the storage circuit is configured to store the output of each comparator. The impulse voltage measuring device according to claim 1, wherein a plurality of impulse voltage measuring devices are arranged corresponding to each comparator. 1 The above memory circuit consists of a memory element that stores data at the application timing of a clock pulse, and the output signal of the above comparison circuit -
3. The impulse voltage measuring device according to claim 1, wherein an output voltage is connected to the clock pulse applying terminal of the memory circuit. 4. Impulse voltage measurement according to claim 1, 2, or 6, wherein the input circuit includes a differentiating circuit and is configured to supply only the alternating current component of the external signal to the comparator. Device. 5. The input circuit according to claim 1, 2, 6, or 4, wherein the input circuit has a changeover switch that receives either a DC component or an AC component of an external signal. Impulse voltage measuring device. & Claim 1 or 2, wherein the input circuit includes a rectifier circuit that rectifies an external signal.