Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
  • G01R1/20—Modifications of basic electric elements for use in electric measuring instruments; Structural combinations of such elements with such instruments
  • G01R1/203—Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
  • H01C7/001—Mass resistors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
  • H01C7/06—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material including means to minimise changes in resistance with changes in temperature

Definitions

• the invention relates to a current measuring resistor for measuring an electric current, in particular for measuring a battery current in a motor vehicle electrical system.
• EP 0 605 800 A1 discloses such a current measuring resistor which comprises two plate-shaped connection parts made of copper and a low-resistance, likewise plate-shaped resistance element made of a resistance alloy (e.g.
• Such current measuring resistors are used for current measurement according to the known four-wire technique, wherein the current to be measured is passed through the plate-shaped connecting parts through the resistance element. The voltage drop across the resistor element is then a measure of the electrical current to be measured in accordance with Ohm's law.
• the known current measuring resistor therefore has two voltage contacts on the two plate-shaped connection parts, wherein the voltage contacts are arranged close to the resistance element and make it possible to measure the voltage drop across the resistance element.
• the incision in the connecting parts runs parallel to the current flow direction between the two connecting parts and therefore has no particularly advantageous effect on the temperature stability of the current measurement.
• the incisions hardly influence the current flow in the connection parts, since the incisions are aligned parallel to the main current direction.
• the invention is therefore based on the object to improve the temperature stability in the conventional current measuring resistor described above.
• the invention is based on the technical-physical realization that the conductor material (for example copper) of the plate-shaped connection parts has a significantly greater temperature coefficient than the resistance material (e.g.
• the voltage is also influenced by the material of the connection parts.
• the temperature dependence of the voltage measurement is thus not only determined by the temperature coefficient of the voltage derstandsmaterials but also influenced by the temperature coefficient of the conductor material.
• the invention therefore comprises the general technical teaching of providing an incision in at least one of the plate-shaped connection parts in order to reduce the temperature dependence of the measurement.
• the incision preferably runs at least partially transversely (for example at right angles) to the direction of current flow between the two connection parts.
• the cut is thus oriented at least partially transversely (for example at right angles) to the connecting line between the two connecting parts.
• the incision preferably extends at least over part of its length parallel to the connecting line between the resistance element and the adjacent ones
• the current measuring resistor according to the invention differs from the known current measuring resistor described in the introduction according to US Pat. No. 5,999,085, in which the notch is aligned parallel to the current flow direction.
• the current measuring resistor according to the invention largely corresponds to the current measuring resistor described in EP 0 605 800 A1, so that the content of this patent application of the present invention is fully attributable to the description of the design of the current measuring resistor.
• the current measuring resistor according to the invention comprises two plate-shaped connecting parts, which consist of an electrically conductive conductor material (eg
• the current measuring resistor according to the invention has a plate-shaped resistance element which is connected in the current path between the two connection parts and flows through the electrical current to be measured, wherein the resistance element consists of a resistance material (eg Cu84Ni4Mnl2), which is absolutely low-resistance, but a greater resistivity than the conductor material.
• a resistance material eg Cu84Ni4Mnl2
• the current measuring resistor according to the invention preferably has two voltage contacts, which are electrically and mechanically connected to the two plate-shaped connection parts, the two voltage contacts are preferably arranged as close to the resistance element within the plate-shaped connection parts.
• the voltage contacts can be an expression, as described, for example, in DE 10 2009 031 408, so that the content of this patent application can be fully attributed to the present description with regard to the structural design of the voltage contacts.
• the voltage contacts are designed as contacting surfaces, as described, for example, in EP 0 605 800 A1, so that the content of this patent application is fully attributable to the present description with regard to the design of the voltage contacts.
• the two incisions in the two plate-shaped connection parts are in this case preferably arranged so that the streamlines and the equipotential lines in the plate-shaped connection parts are deformed so that the equipotential lines through the voltage contacts in the plate-shaped connection parts extend directly to the contact point (joint) reach the resistance element, ie usually up to the weld between the plate-shaped connection parts and the resistance element.
• This has the advantage that the voltage contacts are then at the same electrical potential as the edges of the resistance element, so that the voltage measurement is not distorted by the conductor material of the plate-shaped connection parts at all.
• the two cuts in the two plate-shaped connection parts are therefore preferably arranged in each case on the side facing away from the resistance element of the respective voltage contact.
• the two cuts run that is to say, preferably between the voltage contacts and the respective current contacts which serve to introduce or dissipate the electrical current to be measured and are electrically and mechanically connected to the respective plate-shaped connection parts.
• the cuts are preferably arc-shaped, wherein the cuts can extend over a sheet angle of more than 30 °, 40 °, 50 °, 60 ° or even 70 °.
• the cuts in the plate-shaped connection parts are each curved or angled away from the current contacts and towards the resistance elements.
• the incision preferably has a width which is substantially constant over the length of the incision.
• the incisions are thus preferably slot-shaped, although other shapes are possible.
• the incision preferably extends inwards starting from an edge of the respective connection part, wherein the incisions in the two connection parts preferably originate from the same edge.
• the recess preferably does not extend to the resistance element or the opposite edge of the respective plate-shaped connection part, so that the voltage contacts can contact the resistance element despite the incision over its entire width via the plate-shaped connection part.
• the temperature coefficient of resistance of the total current sense resistor by at least 30%, 40%, 50% or even 60% is smaller than an otherwise identical current measuring resistor without a such incision.
• the conductor material used for the plate-shaped connecting parts is copper or a copper alloy.
• the invention is not limited to the examples mentioned above with regard to the conductor material used.
• the resistance material for the resistance element is preferably a copper alloy, in particular a copper-manganese-nickel alloy, such as, for example, Cu84Ni4Mn12 (Manganin®).
• the invention is not limited to the above examples in terms of the resistance material used for the resistance element.
• the resistance material of the resistance element preferably has a lower conductivity or a greater specific resistance than the conductor material of the plate-shaped connection parts.
• the resistance element is preferably connected electrically and mechanically to the two connection parts, in particular a welded connection, wherein a connection by electron beam welding is particularly suitable, as already described in detail in EP 0 605 800 A1, so that the content of this patent application the present description with regard to the structure and method of production of the current sense resistor according to the invention is fully attributable.
• connection parts are preferably arranged on opposite sides of the resistance element, so that the resistance element is located between the two connection parts.
• the two connection parts are arranged on the same side of the resistance element.
• Figure 1 is a perspective view of an inventive
• FIG. 2 shows a plan view of the current measuring resistor from FIG. 1,
• FIG. 3 shows a side view of the current measuring resistor from FIGS.
• FIGS. 1 and 2 are identical to FIGS. 1 and 2,
• FIG. 4 shows a detailed view of the current measuring resistor from FIG. 2
• FIG. 5A shows a plan view of a conventional current measuring resistor with the distribution of the current lines and the equipotential lines between the voltage contacts.
• FIG. 6 shows a diagram for illustrating the temperature dependence of the resistance value of the current measuring resistor according to the invention in comparison to a conventional current measuring resistor.
• Figures 1 to 4 and 5B show a preferred embodiment of a current sense resistor 1 according to the invention, which can be used for example for current measurement according to the known four-wire technology in a motor vehicle electrical system.
• the current measuring resistor 1 largely corresponds to a conventional current measuring resistor, as described for example in EP 0 605 800 A1, so that reference is additionally made to this patent application.
• the current measuring resistor 1 consists essentially of two plate-shaped connection parts 2, 3 made of a conductor material (eg copper) and a resistance element 4 made of a low-resistance resistance material (eg Cu84Ni4Mn12) inserted between the two plate-shaped connection parts 2, 3.
• the two plate-shaped connection parts 2, 3 are in this case on opposite sides of the likewise plate-shaped Wider- Standing elements 4 arranged and welded to the plate-shaped resistance element 4.
• the current sense resistor 1 according to the invention two current contacts 5, 6, which are electrically and mechanically connected to the two plate-shaped connection parts 2, 3, the current contact 6 is used to initiate an electrical current I to be measured, while the current contact 5 to Derivation of the measured electric current I is used, as can be seen in particular from the side view in Figure 3.
• the current measuring resistor 1 has two voltage contacts 7, 8, which are electrically and mechanically connected to the two plate-shaped connection parts 2, 3 and serve to measure the voltage drop across the resistance element 4 electrical voltage.
• the two voltage contacts 7, 8 are therefore arranged in the plate-shaped connection parts 2, 3 very close to the resistance element 4, so that the voltage measurement is not distorted by the voltage drop across the connection parts 2, 3 electrical voltage.
• the current measuring resistor 1 according to the invention has an incision 9 laterally in the region of the resistance element 4, which can be used to calibrate or adjust the desired resistance value of the current measuring resistor 1, by making the incision 9 more or less in the course of production less educated.
• an incision 10, 11 is arranged in each of the two plate-shaped connection parts 2, 3 in order to determine the temperature-dependent reduce the speed of the measurement.
• the two incisions 10, 11 extend in each case from the same edge of the plate-shaped connecting part 2 and 3 transversely inwards and are then guided around the respective arcuate voltage contacts 7 and 8, wherein the two incisions 10, 11 via a Arc angle a "70 ° extend, as can be seen in particular from the detailed view in Figure 4.
• the two incisions 10, 11 are slot-shaped and have a width b which is essentially constant over the length of the incisions 10, 11.
• FIGS. 5A and 5B show the course of streamlines 12 and equipotential lines 13 in a conventional current measuring resistor 1
• FIG. 5B shows the course of the current lines 12 and the equipotential lines 13 in the current measuring resistor 1 according to the invention.
• the streamlines 12 in this case define a main flow direction, wherein the incisions 10, 11 are partially aligned transversely to this main flow direction in order to influence the current flow. It can be seen from this comparison that in the conventional current measuring resistor 1 according to FIG. 5A, the equipotential lines 13 passing through the voltage contacts 7, 8 are not exactly at the same electrical potential as the outer edges of the resistance element 4.
• the conductor material (eg copper) of the plate-shaped connecting parts 2, 3 usually has a significantly greater temperature dependence with respect to the specific electrical resistance than the resistance material (eg Manganin®) of the resistive element 4.
• the equipotential lines 13 nestle asymptotically to the welding edge between the plate-shaped connection parts 2, 3 and the resistance element 4 at.

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• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• General Physics & Mathematics (AREA)
• Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
• Details Of Resistors (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (8)

Cited By (9)

Families Citing this family (38)

Citations (4)

Family Cites Families (12)

• 2010
  • 2010-08-26 DE DE102010035485A patent/DE102010035485A1/de not_active Withdrawn
• 2011
  • 2011-08-24 CN CN201180051101.6A patent/CN103180916B/zh active Active
  • 2011-08-24 WO PCT/EP2011/004245 patent/WO2012019784A1/de not_active Ceased
  • 2011-08-24 US US13/819,020 patent/US8884733B2/en active Active
  • 2011-08-24 JP JP2013525182A patent/JP2013536424A/ja active Pending
  • 2011-08-24 EP EP11757765.0A patent/EP2446449B1/de active Active
  • 2011-08-24 ES ES11757765.0T patent/ES2684111T3/es active Active
  • 2011-08-24 KR KR1020137007432A patent/KR101887405B1/ko active Active

Patent Citations (4)

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