# US 5,708,353 A · Device for detecting the short circuiting of the switches of a converter circuit arrangement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,353 A - Document ID: US5708353A - Status: Granted - Kind: A - Application number: 08/616,589 - Filed: 1996-03-15 - Granted: 1998-01-13 - Earliest claimed: 1995-06-09 - Assignees: Asea Brown Boveri AG - Inventors: Robert Schilling - Web page: https://patentgrep.com/patent/US5708353A ## CPC - H02M 1/38: Means for preventing simultaneous conduction of switches - H02M 7/519: in a push-pull configuration (H02M7/517 takes precedence) - Y10S 323/908: Inrush current limiters - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A device for detecting the short circuiting of the switches of a converter circuit arrangement is disclosed. The device is magnetically coupled to the current limiter coil and comprises a conductor loop which is preferably arranged at the end of the current limiter coil. On short circuiting, a voltage is induced in the conductor loop. This voltage is converted in a detection circuit into a voltage pulse and fed to an evaluation logic circuit. In the evaluation logic circuit, the period of the induced voltage pulse is evaluated and, if appropriate, load-relieval actuation is initiated. ## Claims ### Claim 1 A device for detecting a short circuiting of at least one of a plurality of switches (3) of a converter circuit arrangement (1) having at least one branch (2) with the plurality of switches (3), said branch (2) being connected to at least one of a DC voltage intermediate circuit and a direct current intermediate circuit (4), respective of the plurality of switches (3) corresponding to said branch (2) being protected from excessively steep current edges by a current limiter coil (Lb) connected in series with respective of the switches (3), wherein the device being magnetically coupled to the current limiter coil (Lb), and wherein the device further comprises means (5, 6) for detecting a voltage induced in the current limiter coil (Lb) when a short circuit failure occurs in a respective one of the switches (3). ### Claim 2 (depends on 1) The device as claimed in claim 1, wherein the detection means (5, 6) comprises a conductor loop (5) which is connected to a detection circuit (6). ### Claim 3 (depends on 2) The device as claimed in claim 2, wherein the detection circuit (6) is powered by the induced voltage. ### Claim 4 (depends on 3) The device as claimed in claim 3, wherein the conductor loop (5) is arranged at the end of the current limiter coil (Lb). ### Claim 5 (depends on 2, 3, 4) The device as in one of claims 2-4, wherein the conductor loop (5) is arranged on a printed-circuit board (8). ### Claim 6 (depends on 5) The device of claim 5, further comprising means (7, 13, 14) for electrical screening the detection means, wherein said screening means (7, 13, 14) is arranged on the opposite side of the printed-circuit board (8) from the conductor loop (5). ### Claim 7 (depends on 6) The device of claim 6, wherein the screening means (7) comprises a multiplicity of parallel conductive tracks (14) connected via a main conductor (13), the main conductor (13) electrically forming a reference potential for the detection circuit (6). ### Claim 8 (depends on 5) The device of claim 5, wherein the detection circuit (6) comprises a threshold circuit, (9) which is connected to the conductor loop (5) via a terminating resistor (10), a downstream-connected constant current source (11) and a photodiode (12) powered by the constant current source (11), the photodiode (12) being optically coupled to an evaluation logic circuit. ### Claim 9 (depends on 2, 3, 4) The device as in one of claims 2-4, wherein the detection circuit (6) comprises a threshold circuit (9), which is connected to the conductor loop (5) via a terminating resistor (10), a downstream-connected constant current source (11) and a photodiode (12) powered by the constant current source (11), the photodiode (12) being optically coupled to an evaluation logic circuit. ### Claim 10 (depends on 9) The device of claim 9, further comprising means (7, 13, 14) for electrical screening the detection means, wherein said screening means (7, 13, 14) is arranged on the opposite side of the printed-circuit board (8) from the conductor loop (5). ### Claim 11 (depends on 1, 2, 3, 4) The device as in one of claims 1-4, further comprising means (7, 13, 14) for electrical screening the detection means (5, 6), and wherein the detection means (5, 6) is arranged between the screening means (7, 13, 14) and the end of the current limiter coil (Lb). ### Claim 12 (depends on 11) The device of claim 11, wherein the conductor loop (5) is arranged on a printer-circuit board (8). ### Claim 13 (depends on 11) The device of claim 11, wherein the detection circuit (6) comprises a threshold circuit (9), which is connected to the conductor loop (5) via a terminating resistor (10), a downstream-connected constant current source (11) and a photodiode (12) powered by the constant current source (11), the photodiode (12) being optically coupled to an evaluation logic circuit .