JPH0726977B2 - Surge classification circuit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a surge classification circuit for obtaining the magnitude of surges such as lightning impulses, cumulative frequency of occurrences, and the like.

[Prior Art] When the magnitude of a surge to be superimposed on a power supply circuit, a temporal generation pattern, and the like are obtained, a sharp rise of the surge requires a high level of technology for the measurement.

FIG. 4 shows such a conventional device for classifying the magnitude of surge. In this device, the voltage of the circuit under test 1 is reduced to 10 V or less by the voltage divider 2, impedance conversion is performed by the high speed amplifier 3, and then surges are detected by a plurality of high speed comparators 4 ₁ to 4 _n having different reference levels. Voltage detection and comparators 4 ₁
The processing circuit 5 performs the voltage classification according to the output of 4 _n . However, with this method, it is necessary to accurately divide the surge waveform of a steep rise (1000 V / μs or more) with the voltage divider 2. Therefore, non-induction high resistance is required, but this kind of resistance must be obtained. Difficult and expensive. Moreover, an ultra-high speed amplifier and an ultra-high speed voltage comparator are required to perform impedance conversion and voltage comparison of a surge having a sharp rise. Therefore, a high level of technology is required to design and manufacture this kind of amplifier and comparator, and it becomes expensive.

[Problems to be Solved by the Invention] The present invention has been made in view of the above points, and an object of the present invention is to classify surges without using a high-performance voltage divider, an amplifier, and a comparator. It is to provide a surge classification circuit capable of performing.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a surge absorbing element such as an arrester, and a current limiting element for preventing continuous discharge of the surge absorbing element when a surge is applied. Resistance,
A power supply circuit, etc., which is configured by connecting in series a surge absorption element and a voltage detection resistance to which a current due to a surge is supplied via a current limiting resistance, has surge absorption elements of different operating voltages, and in which surges are superimposed. A plurality of voltage detection circuits to which the output voltage of the circuit under test is applied, respectively, and a processing circuit that appropriately performs surge classification processing according to the voltage across the voltage detection resistors of each voltage detection circuit. .

(Operation) The present invention includes a surge absorbing element such as an arrester as described above, a current limiting resistor that prevents the surge absorbing element from continuing discharge when a surge is applied, a surge absorbing element and a current limiting element. The output of the circuit under test, such as a power supply circuit, which is configured by connecting in series a voltage detection resistor to which a surge current is supplied via a resistor and has different operating voltages By providing a plurality of voltage detection circuits to which each voltage is applied,
It makes it possible to detect the magnitude of surge using a surge absorbing element and ordinary resistance, which enables classification of surge without using special resistance or ultra-high speed amplifier or comparator. It was made possible.

(Embodiment) FIGS. 1 to 3 show an embodiment of the present invention.

In the present embodiment, as shown in FIG. 1, the surge voltage superimposed on the circuit under test 1 such as a power supply circuit is detected by a surge absorbing element Z such as an arrester, a current limiting resistor r and a voltage detecting resistor R. The voltage detection circuit 6 composed of a series circuit is used for detection. The voltage detection circuits 6 are connected in parallel by the number of classification levels required for the circuit under test 1, and the voltages generated across the respective voltage detection resistors R of these voltage detection circuits 6 are input to the processing circuit 5. The processing circuit 5 performs processing such as classification of surge voltage. FIG. 1 shows the case where the surge voltage is classified into five types. Now, a surge voltage, for example 200V, 300 V, 400V, 500V, if classified into five levels of 600V, the operating voltage of the surge absorbing element Z ₁ to Z ₅ is 20
Select 0V, 300V, 400V, 500V, 600V. by the way,
For example, when an arrester is used as a surge absorber, the arrester must have a fast response (for example, made of ceramic).
Some of them have slow response (made of glass tube), but those of fast response are used in the present invention. That is, when a lightning impulse voltage as shown in FIG. 3 (a) is applied,
The response waveform of the terminal voltage of the arrester having a slow response is as shown in FIG. 3 (c). If the response is slow in this way, the discharge is performed at a voltage higher than the planned voltage, and the error at the time of determination becomes large. . 3 (b) shows the terminal voltage of the arrester having a fast response. The current limiting resistor r ₁ ~r ₅ each, select the one of the resistance value of the discharge of the surge absorber Z ₁ to Z ₅ limits the current so as not to continue to classify the surge voltage as described above In this case, the resistances r _{1 to} r ₅ are, for example, 10
Use one with KΩ to 100KΩ. In addition, the voltage detection resistor R ₁
The to R _5, used of about 1/100 of the current limiting resistor r ₁ ~r ₅ (e.g., about 100Ω~1KΩ).

For example, when a surge of 400V occurs, three surge absorbing elements Z having an operating voltage of 400V or less are discharged, a voltage appears at both ends of each voltage detection resistor R, and the processing circuit 5 responds to this voltage. Perform surge classification processing as appropriate. An example of such a processing circuit 5 is shown in FIG. In this processing circuit 5, a voltage is taken in through the protection circuit 7, and this protection circuit 7 suppresses this voltage to a voltage below which the circuits in the subsequent stages are not destroyed. Then, the pulse width of the voltage signal input by the monostable multi 8 is widened. The output of the monostable multi 8 is amplified by the driver 9 and input to the counter 10. That is, in this processing circuit 5, every time a surge is input, the counter 10
The cumulative number of surge occurrences is calculated by counting at. In the processing circuit 5, the voltage detection resistors R _{1 to} R _{5 are used.}
Voltage across the by obtaining a higher operating voltage of the most surge absorbing element Z in the plurality of voltage detecting circuit 6 _{through 65} generated, it is also possible to classify the surge voltage. Further, a surge generation pattern or the like can be obtained based on the classification of the surge voltage. By the way, even in the case of this embodiment, the monostable multi-8 is required to have a high-speed response.
However, recently, this monostable multi-8 has been integrated into an IC,
Since it is possible to sufficiently respond to the rising of, the monostable multi-8 does not need to use a special one. As described above, in this embodiment, the surge absorbing element Z such as an arrester and the normal resistance are used.
The surge voltage can be detected using r and R, and it is possible to classify surges with a simple circuit without the need for special resistors, ultra-high-speed amplifiers and comparators as in the past.

[Advantages of the Invention] As described above, the present invention provides a surge absorbing element such as an arrester, a current limiting resistor that prevents the surge absorbing element from continuing discharge when a surge is applied, a surge absorbing element, and A circuit to be tested, such as a power supply circuit, which is configured by connecting in series a voltage detection resistor to which a current due to a surge is supplied via a current limiting resistor and has surge absorbing elements of different operating voltages Since it is equipped with a plurality of voltage detection circuits to which each output voltage is applied, it is possible to detect the magnitude of the surge using a surge absorbing element and ordinary resistance. There is an effect that surges can be classified without using an amplifier or a comparator.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a processing circuit of the same, FIG. 3 is an explanatory diagram of characteristics of an arrester of the same, and FIG. 4 is a block of a conventional example. It is a figure. 1 test circuit, 6 _{through 65} the voltage detection circuit, the 5 processing circuit,
Z _{1 to} Z ₅ are surge absorbers, r _{1 to} r ₅ are current limiting resistors, R ₁
~ R ₅ is a resistor for voltage detection.

Claims (1)

[Claims] 1. A surge absorbing element such as an arrester, a current limiting resistor for preventing the discharge of the surge absorbing element from continuing when a surge is applied, and a surge through a surge absorbing element and a current limiting resistor. It is configured by connecting in series a voltage detection resistor to which a current is supplied, and is provided with surge absorbing elements of different operating voltages, and the output voltage of a circuit under test such as a power supply circuit on which surge is superimposed is applied to each. A surge classification circuit comprising: a plurality of voltage detection circuits; and a processing circuit that appropriately performs surge classification processing according to the voltage across the voltage detection resistors of each voltage detection circuit.