# US 2014/0152335 A1 · Continuous broken sense lead detection system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152335 A1 - Document ID: US20140152335A1 - Status: Published application - Kind: A1 - Application number: 13/691,738 - Filed: 2012-12-01 - Published: 2014-06-05 - Earliest claimed: 2012-12-01 - Assignees: Agilent Technologies, Inc. - Applicants: Agilent Technologies, Inc. - Inventors: Marko Vulovic - Web page: https://patentgrep.com/patent/US20140152335A1 ## CPC - G01R 31/54: Testing for continuity - G01R 31/52: Testing for short-circuits, leakage current or ground faults - G01R 1/06: Measuring leads; Measuring probes (G01R19/145, G01R19/165 take precedence) - G01R 27/14: Measuring resistance by measuring current or voltage obtained from a reference source (G01R27/16, G01R27/20, G01R27/22 take precedence) - G01R 35/00: Testing or calibrating of apparatus covered by the other groups of this subclass - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract Disclosed is a continuous broken sense lead detection system (“CBSLDS”) for use with a Kelvin-connected device under test (“DUT”), a power source, and detection system stimulus configured to provide a periodic stimulus voltage. The CBSLDS is configured to detect a discontinuity in a first sense lead, second sense lead, or both, that are in signal communication with the DUT. The CBSLDS includes a first transformer, second transformer, first DC-blocker, second DC-blocker, first detection module, and second detection module. ## Claims ### Claim 1 A continuous broken sense lead detection system (“CBSLDS”) for use with a Kelvin-connected device under test (“DUT”), a power source, and detection system stimulus configured to provide a periodic stimulus signal, where the CBSLDS is configured to detect a discontinuity in a first sense lead, second sense lead, or both, that are in signal communication with the DUT, the CBSLDS comprising: a first transformer having a first transformer primary winding and a first transformer secondary winding, wherein the first transformer is in signal communication with the DUT via the first transformer secondary winding and the detection system stimulus via the first transformer primary winding; a first DC-blocker, wherein the first DC-blocker is in signal communication with the first transformer secondary winding and the DUT; a first detection module, wherein the first detection module is in signal communication with the first transformer primary winding and the detection system stimulus, and wherein the first detection module is configured to filter a first reflected voltage signal from the first transformer primary winding, compare the first reflected voltage signal against a predetermined threshold voltage signal, and determine a discontinuity in the first sense lead in response to comparing the first reflected voltage signal against the predetermined threshold voltage signal; a second transformer having a second transformer primary winding and a second transformer secondary winding, wherein the second transformer is in signal communication with the DUT via the second transformer secondary winding and the detection system stimulus via the second transformer primary winding; a second DC-blocker, wherein the second DC-blocker is in signal communication with the second transformer secondary winding and the DUT; and a second detection module, wherein the second detection module is in signal communication with the second transformer primary winding and the detection system stimulus, and wherein the second detection module is configured to filter a second reflected voltage signal from the second transformer primary winding, comparing the second reflected voltage signal against the predetermined threshold voltage signal, and determine a discontinuity in the second sense lead in response to comparing the second reflected voltage signal against the predetermined threshold voltage signal. ### Claim 2 (depends on 1) The CBSLDS of claim 1, wherein the first DC-blocker is configured to block direct current from the first transformer secondary winding to the DUT and the second DC-blocker is configured to block direct current from the second transformer secondary winding to the DUT. ### Claim 3 (depends on 2) The CBSLDS of claim 2, wherein the first DC-blocker includes a first capacitive element and the second DC-blocker includes a second capacitive element. ### Claim 4 (depends on 3) The CBSLDS of claim 3, wherein the first DC-blocker is electrically connected between the first transformer secondary winding and the first sense lead, and wherein the second DC-blocker is electrically connected between the second transformer secondary winding and the second sense lead. ### Claim 5 (depends on 3) The CBSLDS of claim 3, wherein the first transformer secondary winding is in signal communication with the DUT via a first forced lead, wherein the first DC-blocker is electrically connected between the first transformer secondary winding and the first forced lead, wherein the second transformer secondary winding is in signal communication with the DUT via a second forced lead, and wherein the second DC-blocker is electrically connected between the second transformer secondary winding and the second forced lead. ### Claim 6 (depends on 3) The CBSLDS of claim 3, wherein the first DC-blocker further includes a first inductive element and first reactive element, and wherein the second DC-blocker includes a second inductive element and second reactive element. ### Claim 7 (depends on 2) The CBSLDS of claim 2, wherein the first detection module includes a first bandpass filter, a first comparator, and a first digital processor, wherein the first bandpass filter is in signal communication with the first transformer primary winding, wherein the first bandpass filter is configured to filter the first reflected voltage from the first transformer primary winding, and produce a first filtered reflected signal, wherein the first comparator is in signal communication with the first bandpass filter, wherein the first comparator is configured to receive the first filtered reflected signal, receive the predetermined threshold voltage signal, compare the first filtered reflected signal against the predetermined threshold voltage signal, and produce a first comparator signal, wherein the first digital processor is configured to receive the first comparator signal, and determine the discontinuity in the first sense lead, wherein the second detection module includes a second bandpass filter, a second comparator, and a second digital processor, wherein the second bandpass filter is in signal communication with the second transformer primary winding, wherein the second bandpass filter is configured to filter the second reflected signal from the second transformer primary winding, and produce a second filtered reflected signal, wherein the second comparator is in signal communication with the second bandpass filter, wherein the second comparator is configured to receive the second filtered reflected signal, receive the predetermined threshold voltage signal, compare the second filtered reflected signal against the predetermined threshold voltage signal, and produce a second comparator signal, wherein the second digital processor is configured to receive the second comparator signal, and determine the discontinuity in the second sense lead. ### Claim 8 (depends on 7) The CBSLDS of claim 7, wherein the periodic stimulus signal has a stimulus cycle, wherein the first comparator signal is a pulsed signal having a plurality of pulses, wherein the first digital processor is configured to determine when one pulse of the first comparator signal exists within one stimulus cycle, wherein the second comparator signal is a pulsed signal having a plurality of pulses, and wherein the second digital processor is configured to determine when one pulse of the second comparator signal exists within one stimulus cycle. ### Claim 9 (depends on 8) The CBSLDS of claim 8, wherein the first digital processor is configured to determine the discontinuity in the first sense lead when the first digital processor has determined that one pulse of the first comparator signal exists within the one stimulus cycle for a predetermined number of stimulus cycles, and wherein the second digital processor is configured to determine the discontinuity in the second sense lead when the second digital processor has determined that one pulse of the second comparator signal exists within the one stimulus cycle for the predetermined number of stimulus cycles. ### Claim 10 (depends on 9) The CBSLDS of claim 9, wherein the first digital processor is chosen from the group consisting of a field-programmable gate array (“FPGA”), application specific integrated circuit (“ASIC”), digital signal processor (“DSP”), and microprocessor, and wherein the second digital processor is chosen from the group consisting of a FPGA, ASIC, DSP, and microprocessor. ### Claim 11 (depends on 8) The CBSLDS of claim 8, wherein the periodic stimulus signal may be a periodic stimulus voltage signal or periodic stimulus current signal. ### Claim 12 (depends on 11) The CBSLDS of claim 11, wherein the periodic stimulus signal is produced by two separate current sources dependent on the detection system stimulus. ### Claim 13 A method for detecting a discontinuity in a first sense lead or second sense lead for use with a Kelvin-connected device under test (“DUT”), the method comprising: injecting a periodic stimulus signal into both a first transformer primary winding and a second transformer primary winding, wherein the periodic stimulus signal has a stimulus cycle, wherein the first transformer secondary winding is in signal communication with the DUT and the second transformer secondary winding is in signal communication with the DUT; receiving a first reflected voltage signal from the first transformer primary winding and a second reflected voltage signal from the second transformer primary winding; comparing the first reflected voltage signal against a predetermined threshold signal; comparing the second reflected voltage signal against the predetermined threshold signal; determining a discontinuity in the first sense lead in response to comparing the first reflected signal against the predetermined threshold voltage signal; and determining a discontinuity in the second sense lead in response to comparing the first reflected signal against the predetermined threshold voltage signal. ### Claim 14 (depends on 13) The method of claim 13, further including blocking direct current from the first transformer secondary winding to the DUT and blocking direct current from the second transformer secondary winding to the DUT. ### Claim 15 (depends on 14) The method of claim 14, wherein receiving the first reflected signal from the first transformer primary winding includes producing a first filtered reflected signal, wherein comparing the first filtered reflected signal against the predetermined threshold signal includes comparing the first filtered reflected signal against the predetermined threshold voltage signal and producing a first comparator signal, wherein the first comparator signal is a pulsed signal having a plurality of pulses, wherein determining the discontinuity in the first sense lead includes determining when one pulse of the first comparator signal exists within one stimulus cycle, wherein receiving the second reflected signal from the second transformer primary winding includes producing a second filtered reflected signal, wherein comparing the second filtered reflected signal against the predetermined threshold signal includes comparing the second filtered reflected signal against the predetermined threshold voltage signal and producing a second comparator signal, wherein the second comparator signal is a pulsed signal having a plurality of pulses, and wherein determining the discontinuity in the second sense lead includes determining when one pulse of the second comparator signal exists within one stimulus cycle. ### Claim 16 (depends on 15) The method of claim 15, wherein determining the discontinuity in the first sense lead includes determining that one pulse of the first comparator signal exists within the one stimulus cycle for a predetermined number of stimulus cycles and wherein determining the discontinuity in the second sense lead includes determining that one pulse of the second comparator signal exists within the one stimulus cycle for the predetermined number of stimulus cycles. ### Claim 17 A continuous broken sense lead detection system (“CBSLDS”) for use with a Kelvin-connected device under test (“DUT”), a power source, and detection system stimulus configured to provide a periodic stimulus signal, where the CBSLDS is configured to detect a discontinuity in a first sense lead, second sense lead, or both, that are in signal communication with the DUT, the CBSLDS comprising: a first transformer having a first transformer primary winding and first transformer secondary winding, wherein the first transformer secondary winding is in signal communication with the DUT and the first transformer primary winding is in signal communication with the detection system stimulus; means for DC-blocking the first transformer secondary winding, wherein the means for DC-blocking the first transformer secondary winding is in signal communication with the first transformer secondary winding and the DUT; a first detection module, wherein the first detection module is in signal communication with the first transformer primary winding and the detection system stimulus, and wherein the first detection module includes means for filtering a first reflected voltage signal from the first transformer primary winding, means for comparing the first reflected voltage signal against a predetermined threshold voltage signal, and means for determining a discontinuity in the first sense lead in response to comparing the first reflected voltage signal against the predetermined threshold voltage signal; a second transformer having a second transformer primary winding and second transformer secondary winding, wherein the second transformer secondary winding is in signal communication with the DUT and second transformer primary winding is in signal communication with the detection system stimulus; means for DC-blocking the second transformer secondary winding, wherein the means for DC-blocking the second transformer secondary winding is in signal communication with the second transformer secondary winding and the DUT; and a second detection module, wherein the second detection module is in signal communication with the second transformer and the detection system stimulus, and wherein the second detection module includes means for filtering a second reflected voltage signal from the second transformer primary winding, means for comparing the second reflected voltage signal against the predetermined threshold voltage signal, and means for determining a discontinuity in the second sense lead in response to comparing the second reflected voltage signal against the predetermined threshold voltage signal. ### Claim 18 (depends on 17) The CBSLDS of claim 17, wherein the means for DC-blocking the first transformer secondary winding includes blocking direct current from the first transformer secondary winding to the DUT and the means for DC-blocking the second transformer secondary winding includes blocking direct current from the second transformer secondary winding to the DUT. ### Claim 19 (depends on 18) The CBSLDS of claim 18, wherein the means for DC-blocking the first transformer secondary winding is electrically connected between the first transformer secondary winding and the first sense lead, and wherein the means for DC-blocking the second transformer secondary winding is electrically connected between the second transformer secondary winding and the second sense lead. ### Claim 20 (depends on 3) The CBSLDS of claim 3, wherein the first transformer is in signal communication with the DUT via a first forced lead, the means for DC-blocking the first transformer secondary winding is electrically connected between the first transformer secondary winding and the first forced lead, wherein the second transformer secondary winding is in signal communication with the DUT via a second forced lead, and wherein the means for DC-blocking the second transformer secondary winding is electrically connected between the second transformer secondary winding and the second forced lead.