JPH04116471A - Emi measurement apparatus - Google Patents

Abstract

PURPOSE:To easily and highly accurately measure an electromagnetic interference (EMI) by using a hydraulic motor as a power source of an EMI measurement apparatus of a clamp running device used for moving a machine to be inspected and/or pickup. CONSTITUTION:A clamp running device to be used for moving a machine to be inspected and/or pickup employs a hydraulic motor 17 as a motor for moving an absorbing clamp 14 placed on a leg of the running device. Thus no electromagnetic noise entering the clamp 14 as pickup from the motor 17 will occur. In addition since a hydraulic pump unit 21 and a control box 23 may probably generate noise respectively, they are connected with the motor 17 via tubes 22, 24 each approximately 10m long, so that they can be easily placed sufficiently distant from the clamp 14 or placed at positions where the electromagnetic noise may not easily enter the clamp 14. Therefore EMI of the machine to be inspected can be measured easily with sufficient accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention is applicable to E-M generated from electronic and electrical equipment.
I (Electro-Magnetic Inter
The present invention relates to an EMI measurement device that measures electromagnetic noise that causes electromagnetic interference or electromagnetic interference.

[Prior art] Regarding EMI of electronic and electrical equipment such as televisions, radios, and computers, domestic standards of each country (e.g., VCCI standard of Japan, FCC standard of the United States, and West Germany standard) are based on the Cl5PR standard, which is an international recommendation. VDE standards, etc.) are established and regulated. Equipment regulated by these standards includes computers, information processing equipment such as word processors and facsimile machines, high frequency equipment for industrial, chemical and medical use, televisions, radios and related equipment, and household electrical equipment. In other words, devices with a built-in microprocessor and devices with an oscillation circuit fall under EMI-regulated devices. In particular, recently, microprocessors have come to be used in many devices, and the number of devices subject to regulation has been increasing year by year.
It is subject to MI regulations.

There are two types of EMI: conducted interference, which travels from the target device through electric cables and connection cables and interferes with the operation of other devices, and radiated interference, which is radiated into space and disturbs the operation of other devices.

Measurements of conducted disturbance waves are usually carried out as shown in Figure 4.
The equipment under test 1 is placed on one of the non-metallic stands 2, the power supply coat 3 of the equipment under test 1 is stretched linearly and connected to an AC power source via an auxiliary clamp, and the power cord 3 is connected to an absorber as a pickup. The clamp (current probe) 5 is removed and the high frequency current flowing through the power supply coat 3 is measured using the measuring device 6.

As the measuring device 6, for example, a Svekl~ram analyzer is used. Then, the absorption clamp 5 is moved in the direction of arrow A on the power supply coat 3 to determine the distribution, maximum value, etc. of high frequency current values.

Conventionally, a so-called clamp traveling machine has been proposed in which the absorbing clamp 5 is automatically moved in the direction of arrow A in order to more automatically measure such conducted disturbance waves.

However, when such a ramp traveling machine is used, there is an inconvenience that the measured values tend to fluctuate greatly and become difficult to confuse. In order to run the absorption clamp, an electric motor C as a power source is installed, for example, at the dotted line 7 (j7) of the leg of the stand 2 in FIG. This is because electromagnetic noise is generated in the evening.Especially, when measuring by detecting the peak value in order to speed up the measurement, the influence on the measured value of the electric motor is 1 or larger.

On the other hand, as shown in Figure 5, the radioactive interference waves can be detected by mounting the equipment under test 1 on a turntable 8'' and rotating it, using a pick-up antenna as shown in Figure 5. ] is attached to the lifting device 10 and moved up and down, and the maximum value of the electromagnetic waves emitted from the equipment under test 1 in the water range and vertical direction is measured using this device.

However, in the conventional turntable and antenna elevator used in this conductive disturbance measurement, an electric motor was used as the power source.For this reason, during the conducted disturbance measurement, As explained in the case of using a clamp traveling machine, the noise from the electric motor causes the measurement value to be distorted, and the measurement flow is slow and the noise is insufficient. There was an inconvenience that it was not possible to measure accuracy.

[Problems to be Solved by the Invention] The present invention has been made in view of the problems in the prior art of sub-association, and it is an object of the present invention to provide an EMT measurement device that is easy to measure and has sufficient accuracy.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a clamp travel a, a turntable, and an antenna used for moving the equipment under test and/or the link-up during electromagnetic interference measurement. An EMI measurement device for an elevator or the like is characterized by using a hydraulic motor as a power source.

[Function and Effect] Does the hydraulic motor itself generate electromagnetic noise? <I. Also, even if an electric motor is used for the hydraulic source pump,
By moving the pump away from the pickup or placing the pump and pickup in a position that makes it difficult for the electromagnetic noise from the pump to reach the pickup manually, it is possible to eliminate interference from outside the equipment under test.

It is possible to avoid electromagnetic noise or pick up human power. Therefore, according to the present invention, electromagnetic interference measurements can be easily and sufficiently accurately performed without depending on the electromagnetic noise of the power source for moving the measurement value or the equipment under test and/or the pickup. .

In addition, it is possible to use air pressure as the power source, but if air pressure is used, the speed may be slower than 6, or
There is a problem that the positioning accuracy of the stop position is poor.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A to 1C show the configuration of a clamp traveling machine according to an embodiment of the present invention.

In the figure, 11 is a kite rail, 12 is a suction 11ff clamp stand, and 13 is an auxiliary clamp stand. The absorption clamp stand 12 and the auxiliary clamp stand 13 are each an absorption clamp (for example, KT-10 manufactured by Kyoritsu Electronics Industry Co., Ltd.) 1
4 and auxiliary clamp (for example, manufactured by the same company, KT-20) 1
5 is mounted on the tower and can be moved left and right along the kite rail 11 on A and C in FIG. 16 is a wooden stand for mounting the equipment under test (not shown), 17 is an absorption clamp stand 1
2 in the left and right direction.

FIG. 2 shows the system configuration of the hydraulic system of the clamp traveling machine shown in FIG. In FIG. 2, 21 is a hydraulic pump unit operated by AClooV, and the hydraulic pump unit 21
Hydraulic pressure from the control box 23 is supplied to the control box 23 via the 10 m duplex 22.
3 is further supplied to the hydraulic motor 17 via a 10 m tube 24. control box 2
3 includes a control lever 26 for instructing the position and moving speed of the absorption clamp 12 (FIG. 1) and a digital counter 27 for displaying the position of the absorption clamp 12. ing.

To measure electromagnetic interference using the clamp traveling machine configured as described above, AClooV is supplied to the hydraulic pump unit 21, the equipment under test (not shown) is placed on the stand 16, and the equipment under test is powered on. is connected to a power source (not shown) through the hole 18 provided in the absorption clamp 12 and the auxiliary clamp 13, and the power is turned on. Further, the input cable of a measuring instrument, for example a spectrum analyzer, is connected to the terminal of the absorption clamp 12. Next, the inclination of the lever 26 of the control box 23 is adjusted to move the absorption clamp 12 to a desired position, and the measured value of the measuring device is recorded.

In this clamp traveling machine, a hydraulic motor is used as a motor for moving the absorption clamp disposed on the leg of the traveling machine, so that no electromagnetic noise is generated from the moving motor to the absorption clamp as a pickup. In addition, the hydraulic pump unit 21 and the control box 23 may each generate electromagnetic noise, but since they are connected to the hydraulic motor 17 via tubes 22 and 24 of 10 m each, the absorption clamp 14 Clamp 1 that absorbs electromagnetic noise and is sufficiently far away from the
This makes it easy to arrange them in a positional relationship that is difficult to fit into.

Therefore, the electromagnetic interference of the equipment under test can be measured easily and with sufficient accuracy.

In the above-mentioned embodiment, an example was explained in which the present invention was applied to a clamp traveling machine that moves an absorption clamp, but the present invention is also applicable to the positional relationship between the equipment under test and the pickup when EMI is fixed. Applicable to devices for changing the antenna, such as turntables used to rotate the equipment under test during radiated interference measurements, and antenna lifting devices used to change the angle and height of the antenna used as a pickup. is also possible.

[Brief explanation of drawings]

1A to 1C are a front view, a side view, and a plan view showing the configuration of a clamp traveling machine according to an embodiment of the present invention, and FIG. 2 is a hydraulic system of the clamp traveling machine shown in FIG. 1. 3 is an external view of the control box in the system diagram of FIG. 2, FIG. 4 is an explanatory diagram of the conducted interference measurement method, and FIG. 5 is an explanatory diagram of the radiated interference measurement method. 1: Equipment under test 5.14 Absorption clamp (pickup) 6/Spectrum analyzer 8: Turntable 9: Antenna (pickup) 10; Antenna elevator 17: Hydraulic motor

Claims (1)

[Claims] (1) In an EMI measurement device for measuring electromagnetic interference emitted from a device under test, a hydraulic motor is used as a power source for varying the relative position between the device under test and a pickup for measuring electromagnetic interference. An EMI measurement device characterized by: