• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A contact resistance measuring device has two current probes connected to the terminals of the section to be checked and two voltage probes. The current probes are connected to an A.C. circuit powered by a current generator and the voltage probes are connected to a voltage measuring circuit selectively set to the frequency of the feeding current. The voltage probes (8) and current probes (7) are connected separately in pairs and the conductors (20, 21) of the voltage probes (8) are connected to an area (A) that forms only a fraction of the area (A+B) enclosed by the cables of the current probe (7). A measuring needle for contact resistance measuring devices based on the four-point contact principle has a hollow current electrode (7) fixed in an insulated envelope (6), containing an insulating socket (9) in which the voltage probe can move axially. The voltage probe (8) is insulated from the current electrode (7) and ends with a tip (13), whereas the end of the current electrode (7) is located at a predetermined distance behind the tip (13) and the resilient path of the voltage probe (8) is longer than the said distance. The measuring needles are arranged in pairs in the resistance measuring device. Within each pair, the voltage probe (8) of one measuring needle is connected to the other measuring needle by a cable (18) that passes radially through the insulating screen (19) of the insulated envelope (6), penetrates into the other needle through its insulating screen (19) and extends, together with the conductor (21) connected to its voltage probe (8), up to the sheath of the cable of the current electrode (7).
    公开号:SU1709930A3
    申请号:SU884355556
    申请日:1988-04-01
    公开日:1992-01-30
    发明作者:Санисло Михай；Шретер Имре；Ньикош Йожеф
    申请人:Вилламошэнергиаипари Кутато Интезет (Инопредприятие)；Будапешти Электромош Мювек (Инопредприятие)；
    IPC主号:
    专利说明:

    While maintaining the clamping force, the current probes 7 are also pressed against the wires 3 and 4, as a result of which the current generator circuit is closed. Potential probes 8 detect a voltage drop. If a network current passes through the tested area, then
    when the probe holders 1 and 2 are connected, the voltage is immediately measured, at which the required measurement range is refined, then current probes 7 are connected and the contact resistance is determined. 1 hp f-ly. 1 tab. 4 Il.
    The invention relates to a device for measuring transient resistance and a probe used for this purpose and can be used to test the connections of electrical networks.
    The purpose of the invention is to enhance the functionality by allowing the measurement of transient resistance without disconnecting the operating current in the test section.
    FIG. 1 shows a diagram of the proposed measuring device, a partial section: in FIG. 2 shows the tip of the probe shown schematically. In FIG. 1, enlarged view; in fig. 3 is a transient resistance measurement circuit; in fig. 4 is a block diagram of a device for measuring transient resistance.
    FIG. 1 shows the probe holders 1 and 2 in the initial position (contacting with the monitored area). The controlled area consists of conductors 3 and 4 and a screw clamp 5 connecting them. The probes contain chains 1 and 2 have the same design and consist of springs 8 placed in an insulating shell b and isolated from each other current probe 7 and potential probe 8. 9 and forming the back support of the contact element 10.
    Current zodu 7 inside is made hollow. In this cavity there is an insulating sleeve 11, also inside the hollow, and in it a potential probe 8 is placed with the possibility of axial movement. The latter is provided with an internal thrust bead on which one end of the spring 9 is supported, and the other end of it presses the contact element 10 of the potential probe 8. ensuring its connection. The potential probe 8 is made with a cylindrical rod 12 and the tip 13.
    The front end of the current probe 7 is made in the form of a V-shaped cone with a slot (Fig. 2) and ends with a double tip 14, slightly protruding beyond the front end of the insulating sleeve 11. The distance between the tips 14 and 13 in the initial position the probe 8 is less than the maximum allowable movement of the spring 9. It follows from this condition that when the probe holder 1 is pressed to the wire 3, the tip 13 of the potential probe 8 comes in contact with it, then due to the increased pressing force the pressure spring 9 compresses and dnee edge 14 of the current probe 7 approaches the wire 3 comes to the surface thereof, whereby a current between the probe 7 and the wire 3 in place Ostry expressed electrical contact is created. The potential probe 8 during its movement remains isolated from the current probe 7, the separation space is provided by the presence of an insulating sleeve 11.
    Electrical contact between the current
    the probe 7 and the potential probe 8 are created only via the controlled wires 3 and 4 in the position in which the probe holders 1 and 2 are pressed to the wire. Electrical connection of current probes 7
    Cables 15 and 16 are provided, provided with appropriate insulation and outgoing from the back end of the insulating sheath 6, the probe coder 1 and 2 and connected to the current transformer 17 (Fig. 1).
    The connection of potential probes 8 is also carried out using insulated cables, the wiring of which differs from cables 15 and 16 (Fig. 1). Connected to contact element 10
    probe holder 1 cable 18 is led out radially through the protective washer 19 of the insulating shell 6 and laid inside the insulating sheath of the other probe holder 2. Internal wire 20 of the cable 18
    pass wire 21. providing connection of the potential probe 8 of the probe holder 2, inside the insulation of the cable 16 coming out of the probe probe 2 in the center and protruding from it only to the corresponding distance from the probe holder 2 just before connecting it.
    The operation of the device for measuring transient resistance is based on the device shown in FIG. 3 principle scheme. The contact resistance R of the tested area occurs at the point where wires 3 and 4 are connected. The current probes 7 connected to the last are connected via a current transformer 17 to a current generator 22 that generates a supply current lg (t) Igcos2лf50t of the network l (t). Icos2 i50t passes through the test section of the wire and is preferably about 1 kHz.
    Both potential probes 8 are connected to a voltage transformer 23, which through a band-pass filter 4, which passes the frequency f and strongly damps the mains frequency, is connected to a voltmeter 25, the measured voltage of which U (t) and igWR is proportional to the transition resistance R.
    According to FIG. 4, both potential probes 8 through voltage divider 26 and preamplifier 27 are connected to voltage transformer 23, the output of which is branched and on one side / connected to band-pass filter 24, and on the other side - to low-pass filter 28 transmitting signal with a frequency of 50 Hz and delaying the components with a higher frequency. The output of the low-pass filter 28 is connected to the rectifier 29 and through it to the comparator 30, which is connected to the sound signal device 31. Another output of the low pass filter 28 and the output of the band pass filter 24 are connected to the inputs of the second rectifier 32, the output of which is connected to the voltmeter 25 and a digital display.
    A device for measuring the transient resistance is provided with a switch 33 of operating modes in which modes for measuring voltage and current can be set and which in certain operating modes switches the measurement limits by switching the division factor of voltage divider 26. With the help of the switch of 33 operating modes, it is possible to set the power supply current generator 22 to the discrete step mode.
    The device works as follows.
    Suppose that at the time of measurement a current does not flow through the Tested contact resistance R. Both probe holders 1 and 2 are pressed against wires 3 and 4 on both sides of the test area. At the beginning, the circuit of potential drives 8 closes. While maintaining the clamping force, soon the current probes 7 are also pressed to the wires 3 and 4, as a result of which the current generator circuit 22 closes.
    Potential probes 8 detect a voltage drop, which through the described circuit is read directly into the resistance values in accordance with the final position related to the division factor determined by the voltage divider 26. The measuring current generated in wires 3 and 4 theoretically induces a certain voltage in the measuring circuit of the probe holders 1 and 2, but due to the small size of the flow coupling area A, its action can be neglected. If the current passes through the network, then when the probe holders 1 are connected and 2, the voltage is immediately measured and indicated. The display does not depend on the mode of operation set by the switch 33 modes of operation.
    The voltage at a frequency of 50 Hz arising on potential probes 8 comes from the output of the low-pass filter 28 after rectification into the comparator 30, which has a sweeping voltage of, for example, 200 mV. If the voltage value is greater than the sweep voltage, then this fact is reported by the instrument 31 of the audio signal. This message occurs even before current probes 7 are connected, and thus the operator receives an indication of the appropriateness of first measuring the voltage, such as, for example, screws. Oh, the mode can be open. In this way, short circuits can be avoided when current probes are switched on 7.
    With a large transition resistance, it is impractical to pass an excessively strong current through the current probes 7, therefore the measurement limits and the supply current of the generator 22 are changed to protect the battery.
    The table shows the relationship between the detected voltage with a frequency of 50 Hz and the transient resistance measurement limits.
    When measuring voltage, it is sufficient to set five measurement limits, and when measuring transient resistance, four measurement limits.
    After measuring the transient resistance on the basis of a known value, it is also possible to calculate the current passing through this section of the wire with a frequency of 50 Hz, since the voltage with a frequency of 50 Hz can be measured directly. Without this, the operation mode switch 33 connects the input of the rectifier 32 to the output of the low-pass filter 28.
    With the aid of a device for measuring the transient resistance, it is possible to make measurements even with a measuring limit of 20 mΩ. and the sensitivity of the device allows measurements of transient resistance to 0.1 mΩ. The measurement is not affected if the current with a frequency of 50 Hz in the tested section of the wire varies from 0 to 200 A. A large network current can only be at a lower transient resistance, and the beginning of the transition would be damaged due to thermal effects.
    Using a measuring device according to the invention, it is equally possible to carry out routine and targeted checks of existing low-voltage networks, and measurements can also be carried out on networks under voltage.
    Due to the fast and accurate measurement of transient resistance, energy losses can be reduced due to improper connection (s), as well as the number of fires caused by electrical networks. The usual measurement of electrical connections in places and buildings of high flammability significantly increases safety.
    FORUMUA AND 3 ABOUT AND
    权利要求:
    Claims (2)
    [1]
    1. A device for measuring transient resistance, containing two pairs of current and potential probes with contact vertices, placed with the possibility of contact with a controlled portion of the conductors and connected with connecting wires to a current generator and a potential meter, respectively topics what. In order to expand the functionality by providing transient resistance measurement without disconnecting the operating current in the controlled area, the probes are combined in pairs in holders, each pair contains current and potential probes, while the length of the connecting wires of the potential probes is less than the length of the connecting wires of the current probes.
    [2]
    2. The device according to claim 1, which is based on the fact that in each pair the probes are spaced separately, the current probe is hollow and fixed in the holder, and the potential probe is made in the form of a spring-loaded Center and placed in the cavity of the current electrode with the possibility of conjugation of their contacting peaks in the same plane.
    类似技术:
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    同族专利:
    公开号 | 公开日
    HUT66056A|1994-09-28|
    JPH01500540A|1989-02-23|
    DE3790461D2|1988-09-15|
    WO1988001390A1|1988-02-25|
    CH669853A5|1989-04-14|
    FI881672A0|1988-04-11|
    FR2602874A1|1988-02-19|
    FI881672A|1988-04-11|
    HU210576B|1995-05-29|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR1401531A|1964-05-25|1965-06-04|Westinghouse Electric Corp|Electrical appliance|
    US3416078A|1965-07-08|1968-12-10|Motorola Inc|Method of determining resistivity of a thin layer|
    FR2114303A6|1970-11-19|1972-06-30|Alpave|
    SU400855A1|1971-12-03|1973-10-01|Л. Р. Аугустинас Ленинградское производственное объединение Красна зар|DEVICE FOR MEASUREMENT OF TRANSITION RESISTANCE OF A CONTACT|
    JPS539538B2|1972-06-13|1978-04-06|
    JPS543594B2|1973-10-12|1979-02-24|
    SU529569A1|1974-01-15|1976-09-25|Предприятие П/Я В-2438|Contact device to control the resistance of the metallized holes of printed circuit boards|
    SU617753A1|1975-04-14|1978-07-30|Предприятие П/Я М-5156|Printed circuit board testing arrangement|
    US4228394A|1978-11-16|1980-10-14|Beckman Instruments, Inc.|Digital ohmmeter with electrical continuity tester|
    SU813316A1|1979-04-16|1981-03-15|Восточный Научно-Исследовательскийинститут По Безопасности Работ Вгорной Промышленности|Device for measuring rail joint resistance|
    SU890570A1|1980-02-29|1981-12-15|Предприятие П/Я А-3313|Contact head for testing metallized apertures of printed circuit boards|
    US4496900A|1982-04-30|1985-01-29|International Business Machines Corporation|Nonlinearity detection using fault-generated second harmonic|
    DE3445213A1|1984-12-12|1986-06-12|Degussa Ag, 6000 Frankfurt|Method and device for checking the quality of bonding of contact members|
    SU1269283A1|1985-04-08|1986-11-07|Предприятие П/Я А-7438|Contact device for checking metallized holes of printed circuit boards|AT509489B1|2010-05-07|2011-09-15|Test Fuchs Gmbh|METHOD AND DEVICE FOR MEASURING THE RESISTANCE AT THE TRANSITION POINT OF TWO LADDER|
    FR2989468B1|2012-04-17|2014-05-23|Airbus Operations Sas|METHOD OF CONTROLLING THE PERFORMANCE OF ELECTRICAL JUNCTION IN A CURRENT RETURN NETWORK OF AN AIRCRAFT.|
    CN103575994A|2012-08-08|2014-02-12|成都爱信雅克科技有限公司|Portable automatic resistance tester|
    CN103149442B|2013-02-08|2015-04-29|哈尔滨工业大学|Automatic testing device for contact resistor made of electrical contact material|
    JP6536070B2|2015-02-20|2019-07-03|株式会社Ihi|Battery monitoring device|
    CN105823912B|2016-05-24|2018-10-02|南京协辰电子科技有限公司|Testing impedance probe assembly|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    HU356986A|HU210576B|1986-08-13|1986-08-13|Instrument for measuring contact resistance for checking completness of the mains line connections|
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