Transformer with test circuit

Patent metadata

Field	Value
Publication number	US-2021190546-A1
Application number	US-201917268671-A
Country	US
Kind code	A1
Filing date	Jul 17, 2019
Priority date	Aug 16, 2018
Publication date	Jun 24, 2021
Grant date	—

Abstract

A transformer including a primary circuit with a primary inductor, a first secondary circuit with a first secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor, a second secondary circuit with a second secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor. The second secondary inductor is implemented redundantly with respect to the first secondary inductor, in particular such that the first secondary inductor encloses the second or the second encloses the first. The first and second secondary inductors are connected to one, or each to one, DC voltage source as well as each to a test circuit with a tapping point for tapping off a test voltage.

First claim

1 . A transformer, comprising:
a primary circuit with a primary inductor, a first secondary circuit with a first secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor, and a second secondary circuit with a second secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor, wherein the second secondary inductor is implemented redundantly with respect to the first secondary inductor, in particular such that the first secondary inductor encloses the second or the second encloses the first, wherein the first and second secondary inductors are connected to one, or each to one, DC voltage source as well as each to a test circuit with a tapping point for tapping off a test voltage.

2 . The transformer as claimed in claim 1 , wherein the respective test circuit comprises two resistors between which the tapping point is arranged, so that the resistors form a voltage divider, wherein in particular the respective secondary inductor is connected in series between the two resistors.

3 . The transformer as claimed in claim 2 , wherein the resistors are dimensioned such that the division ratios of the respective voltage dividers are different.

4 . The transformer as claimed in claim 1 , further comprising a third secondary circuit with a third secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor, a fourth secondary circuit with a fourth secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor, wherein the fourth secondary inductor is implemented redundantly with respect to the third secondary inductor, such that the third secondary inductor encloses the fourth or the fourth encloses the third,
wherein the third and fourth secondary inductors are each connected to a DC voltage source or to the DC voltage source of the first and second secondary inductors, as well as each to a test circuit with a tapping point for tapping off a test voltage.

5 . The transformer as claimed claim 1 , wherein the secondary inductors each comprise their own ground connection and each comprise a galvanic isolation from the ground connection, in particular in the form of a capacitor.

6 . The transformer as claimed in claim 1 , wherein the primary circuit comprises a DC voltage source, so that a specific DC voltage potential can be applied to the primary inductor.

7 . The transformer as claimed in claim 1 , wherein the electrical components of the test circuits are dimensioned such that in the case of different defective states, in particular short circuits between different combinations of components, the size of the difference between the test voltage in the fault-free state and the test voltage in the case of a particular one of the various defective states is as large as possible in each case for at least one of the test voltages, taking into account the respective maximum component tolerances.

8 . The transformer as claimed in claim 1 , further comprising an analysis apparatus for further processing of the test voltages that is attached to the respective tapping points, wherein the analysis apparatus is configured to compare the respective test voltage with at least one threshold voltage and, depending thereon, to output information as to whether the transformer has a defective state, in particular also as to what type of defective state is involved.

9 . The transformer as claimed in claim 8 , wherein the tapping points are connected to the analysis apparatus through an analog/digital converter in each case.

10 . The transformer as claimed in claim 9 , wherein the respective analog/digital converters are connected to the common DC voltage source of the secondary inductors as the reference voltage source.

11 . A sensor comprising a transformer as claimed in claim 1 , wherein the sensor is designed to register the distance covered by an encoder on the basis of a coupling between the primary inductor and the secondary inductors, wherein the encoder influences the coupling depending on the distance, in particular as a result of local saturation of a soft-magnetic core.

Assignees

• Continental Teves Ag & Co Ohg

Inventors

• Lehmann Sören

Classifications

• G01D18/00 Primary

  Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00 · CPC title

• H01F27/29

  Terminals; Tapping arrangements {for signal inductances} · CPC title

• G01D5/2291 Primary

  Linear or rotary variable differential transformers (LVDTs/RVDTs) having a single primary coil and two secondary coils · CPC title

• G01D2218/10

  Testing of sensors or measuring arrangements · CPC title

• H01F21/06

  by movement of core or part of core relative to the windings as a whole · CPC title