Adapter for a current probe and testing system

Abstract

An adapter for a current probe is described, said adapter being configured to be connected with said current probe. Said adapter enables a voltage measurement by using said adapter and said current probe. Said adapter comprises a current loop and at least one transconductance unit. Said transconductance unit transforms the voltage to be measured into a current wherein the current obtained is forwarded by said current loop. Further, a testing system is described.

Claims

1. An adapter for a current probe, said adapter being configured to be connected with said current probe, said adapter enabling a voltage measurement by using said adapter and said current probe, said adapter comprising: a current loop and at least one transconductance unit, said transconductance unit transforming the voltage to be measured into a current, the current obtained being forwarded by said current loop; wherein said current loop forms an adapter interface being configured to be accommodated in said current probe such that said current loop interfaces with said current probe provided that said adapter is installed; wherein said current loop includes a positioning element, said positioning element being established by a carrier, a housing, a printed circuit board or a support, said positioning element positioning said current loop symmetrically within said current probe with respect to nodes of said transconductance unit; and wherein said adapter is configured to enable galvanically isolated voltage measurements by using said current probe.

2. The adapter according to claim 1, wherein said transconductance unit is integrated in said current loop.

3. The adapter according to claim 1, wherein said transconductance unit comprises at least one series resistor.

4. The adapter according to claim 1, wherein said transconductance unit comprises an active transconductance amplifier.

5. The adapter according to claim 1, wherein said current loop is made of a printed circuit board or a wire.

6. The adapter according to claim 1, wherein said adapter comprises two input ports being the ends of said current loop.

7. An adapter for a current probe, said adapter being configured to be connected with said current probe, said adapter enabling a voltage measurement by using said adapter and said current probe, said adapter comprising: a current loop and at least one transconductance unit, said transconductance unit transforming the voltage to be measured into a current, the current obtained being forwarded by said current loop; said transconductance unit being integrated in said current loop, wherein said current loop forms an adapter interface being configured to be accommodated in said current probe such that said current probe is enabled to sense a current signal provided by the adapter interface accommodated in said current probe; and wherein the current signal, which is provided by said adapter interface and sensed by said current probe, relates to a voltage measured across a device under test being contacted by two input ports that are ends of said current loop.

8. An adapter for a current probe, said adapter being configured to be connected with said current probe, said adapter enabling a voltage measurement by using said adapter and said current probe, said adapter comprising: a current loop and at least one transconductance unit, said transconductance unit configured to transform a voltage to be measured into a current, the current obtained by the transconductance unit being forwarded by said current loop, thereby ensuring a determination of the voltage to be measured by galvanically isolated voltage measurements while using the current probe; and wherein the current loop is configured to be accommodated in said current probe such that said current probe is enabled to sense a current signal provided by said current loop accommodated in said current probe, said current signal being obtained by converting a voltage sensed across a device under test by said current loop.

Description

DESCRIPTION OF THE DRAWINGS

(1) The foregoing aspects and many of the attendant advantages of the claimed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawing, wherein

(2) FIG. 1 shows a schematic overview of a testing system according to a first embodiment;

(3) FIG. 2 shows a perspective view of the testing system shown in FIG. 1;

(4) FIG. 3 shows a schematic of a testing system according to a second embodiment;

(5) FIG. 4 shows a schematic of a testing system according to a third embodiment;

(6) FIG. 5 shows a schematic overview of a testing system according to a fourth embodiment; and

(7) FIG. 6 shows a schematic overview of a testing system according to a fifth embodiment.

DETAILED DESCRIPTION

(8) The detailed description set forth below in connection with the appended drawing, where like numerals reference like elements, is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed.

(9) In the following description, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments of the present disclosure. It will be apparent to one skilled in the art, however, that many embodiments of the present disclosure may be practiced without some or all of the specific details. In some instances, well-known process steps have not been described in detail in order not to unnecessarily obscure various aspects of the present disclosure. Further, it will be appreciated that embodiments of the present disclosure may employ any combination of features described herein.

(10) In FIG. 1, a testing system 10 is shown that comprises a measurement device 12 established by an oscilloscope and a current probe 14 that is connected to the oscilloscope 12 via a probe cable 15. Further, the testing system 10 comprises a device under test 16 that is measured via the testing system 10.

(11) The testing system 10 also comprises an adapter 18 that is used in conjunction with the current probe 14 in order to ensure voltage measurements on the device under test 16 even though a current probe 14 is provided. The adapter 18 comprises a current loop 20 that is fed through the current probe 14 being configured to sense a current running through the current loop 20. Further, the adapter 18 has at least one transconductance unit 22 that is configured to transform the voltage to be measured into a current wherein the voltage to be measured corresponds to the voltage across the device under test 16. The current obtained by the transconductance unit 22 is forwarded to the current loop 20 such that the current probe 14 senses the current running through the current loop relating to the voltage to be measured.

(12) Accordingly, the current loop 20 forms an adapter interface 24 that is configured to be connected with the current probe 14. The adapter interface 24 ensures that the current loop 20 can be accommodated in the current probe 14.

(13) In the shown embodiment, the transconductance unit 22 is integrated in the current loop 20 since the transconductance unit 22 is formed by two series resistors 26 that are symmetrically arranged within the current loop 20 with respect to a symmetry axis S of the current probe 14.

(14) In general, the current loop 20 may be made of printed circuit board 28 as shown in FIG. 1, for instance a (semi-)flexible printed circuit board. Thus, the current loop 20 is maintained in its defined position ensuring high accurate measurements.

(15) As already discussed, the adapter 18 is configured to enable galvanically isolated voltage measurements by using the current probe 14 since the voltage to be measured across the device under test 16 is transformed into a current that is forwarded to the current probe 14 by the adapter 18.

(16) For contacting the device under test 16, the adapter 18 comprises two input ports 30 being formed by the ends 32 of the current loop 20 as shown in FIG. 1.

(17) The current probe 14 itself has a current sensing unit 34 that is configured to sense the current running through the current loop 20 of the adapter 18. For instance, the current sensing unit 34 is established by a current probe transformer.

(18) The current sensing unit 34 is positioned in the proximity of a core 36 of the current probe 14 that is configured to accommodate the current loop 20. For instance, the current sensing unit 34 is established by a current probe transformer 38. Alternatively, the current sensing unit 32 can be used by any other suitable unit that is configured to sense a current.

(19) As the current loop 20 of the adapter 18 is fed through the current probe 14, the current loop 20 is fed through the current sensing unit 34 in order to ensure that the current flowing through the current loop 20 is sensed by the current sensing unit 34.

(20) In order to increase the sensitivity of the measurement, the current loop 20 may be fed through that current sensing unit 34 with more than one winding. For instance, this is disclosed in the embodiment shown in FIG. 6.

(21) In FIG. 2, it is also shown that the core 36 of the current probe 14 is at least partly split such that the core has a first portion 40 and a second portion 42 that can be swiveled with respect to each other as the split core 36 is hinged appropriately. Thus, the split core 36 has two different states, namely an open state for receiving the current loop 20 of the adapter 18 and a closed state for performing the measurements. In the closed state, the current sensing unit 34 encircles the current loop 20.

(22) In FIG. 3 a second embodiment of the testing system 10 is shown, in particular the current probe 14 and the adapter 18.

(23) The adapter 18 according to this embodiment comprises a positioning element 44 being established by a carrier, housing or support. Generally, the positioning element 44 ensures that the current loop 20 is positioned symmetrically in the center of the current sensing unit 34 of the current probe 14.

(24) Due to the symmetric positioning of the current loop 20 in the current probe 14, the common-mode rejection (ratio) of the testing system 10 is improved, in particular the common-mode rejection (ratio) of the adapter 18.

(25) The positioning element 44 may also be established by a printed circuit board, and in some embodiments a rigid or semi-flexible one.

(26) Furthermore, the current loop 20 of the adapter 18 is at least partly formed by a wire 46. Thus, the testing system 10 can be used to contact a device under test 16 in a flexible manner due to the flexible wire 46.

(27) In an alternative embodiment, the positioning element 44 is a part of the current probe 14 wherein the current loop 20 is placed on the positioning element 44 such that the current loop 20 is positioned in a defined manner. This ensures that the adapter interface 24 of the current loop 20 is located at the optimal position with regard to the current sensing unit 34. Hence, a high symmetry is guaranteed due to the positioning element 44.

(28) Turning to FIG. 4, a third embodiment of the testing system 10 is shown. The current probe 14 according to this embodiment has a solid core 36 that cannot be opened in order to accommodate the current loop 20. Thus, the current loop 20 cannot be hinged within the core 36 as shown in the embodiment of FIGS. 1 and 2, for instance.

(29) In order to feed the current loop 20 through the current probe 14, in particular the current sensing unit 34, the current loop 20 is separable wherein the current loop 20 is separated for being accommodated in the core 36.

(30) Thus, the current loop 20 has an interface 48 that is established by a plug socket/connection 50, for instance. The current loop 20 is separated via the plug/socket connection 50 such that at least a portion of the current loop 20 can be fed through the solid core 36, for instance the portion having the plug.

(31) Afterwards, both portions of the current loop 20 are connected to each other via the interface 48, and in some embodiments the plug/socket connection 50, in order to provide a closed current loop 20 used for voltage measurement by using the current probe 14.

(32) In addition, the transconductance unit 22 is formed by an active transconductance amplifier 52 in the shown embodiment wherein the active transconductance amplifier 52 is integrated in the current loop 20. This ensures that the voltage to be measured is transformed into a current that can be sensed by the current probe 14 wherein the signal is amplified simultaneously.

(33) Moreover, the adapter 18 comprises a coaxial cable 54 wherein the transconductance amplifier 52 is connected to the center line 56 of the coaxial cable 54. Hence, a cost-efficient connection is established being asymmetric.

(34) Referring to FIG. 5, a fourth embodiment is shown that differs from the one shown in FIG. 3 in that no positioning element 44 is provided. In fact, the current loop 20 is established by the wire 46 that is fed through the current probe 14, in particular the core 36.

(35) The transconductance unit 22 is established by two series resistors 26. Alternatively, the transconductance unit 22 may be established by a single transconductance amplifier such that one end of the wire 46 can be fed through the core 36 being a solid one.

(36) Turning now to FIG. 6, a fifth embodiment is shown. According to this embodiment, the current loop 20 is fed through the core 36 by several windings 58 in order to increase the sensitivity of the testing system 10. The core 36 has enough space to accommodate the several windings 58. Therefore, the adapter interface 24 is established by several windings 58.

(37) Further, it is shown that the transconductance unit 22 is established by a single transconductance amplifier 52 as shown in the embodiment of FIG. 4. Accordingly, the core 36 may be a solid one as one end 32 of the current loop 20 can be fed through the solid core 36 several times in order to provide the several windings 58. For ensuring the flexibility, the current loop 20 is formed by a wire 46 in some embodiments.

(38) Accordingly, a cost efficient possibility is provided to perform galvanically isolated voltage measurements with high bandwidth using an oscilloscope 12 since a current probe 14 is used in combination with the adapter 18.

(39) Due to the adapter 18 the customer has a solution for voltage and current measurements without the need for buying two separately formed probes, namely a current probe and a galvanically isolated voltage probe.

(40) The principles, representative embodiments, and modes of operation of the present disclosure have been described in the foregoing description. However, aspects of the present disclosure which are intended to be protected are not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. It will be appreciated that variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present disclosure. Accordingly, it is expressly intended that all such variations, changes, and equivalents fall within the spirit and scope of the present disclosure, as claimed.