# US 2009/0260607 A1 · Overcurrent threshold correction for ignition control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260607 A1 - Document ID: US20090260607A1 - Status: Published application - Kind: A1 - Application number: 12/106,988 - Filed: 2008-04-21 - Published: 2009-10-22 - Earliest claimed: 2008-04-21 - Inventors: Matthew T. LaDuke; Jack B. Marshall; Dirk Swanson; Clyde A. Marlow - Web page: https://patentgrep.com/patent/US20090260607A1 ## CPC - F02P 7/035: {without mechanical switching means} - F02P 3/0552: {Opening or closing the primary coil circuit with semiconductor devices} - F02P 9/002: {Control of spark intensity, intensifying, lengthening, suppression (by means of current control in the storage devices F02P3/05, F02P3/09, during starting F02P15/12)} - F02D 2041/2058: {using information of the actual current value} - F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00) - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) ## Abstract A system for overcurrent threshold correction in an ignition system. The system includes a control circuit and a current detection circuit. The control circuit has a first and second output. The first output of the control circuit charges a first ignition coil, the second output of the control circuit charges a second ignition coil. The overcurrent detection circuit adjusts the detection of an overcurrent condition, when the charging of the first coil overlaps with the charging of the second coil. Further, the control circuit is in communication with the overcurrent detection circuit to disable the first and second output, when the overcurrent condition is detected. ## Claims ### Claim 1 A system for controlling ignition coils, the system comprising: a control circuit having a first and second output, the first output being configured to control charging of a first coil, the second output being configured to control charging of a second coil; an overcurrent detection circuit configured to adjust detection of an overcurrent condition when charging of a first coil overlaps with charging of the second coil. ### Claim 2 (depends on 1) A system according to claim 1, wherein the control circuit is configured to disable the first and second output when the overcurrent condition is detected. ### Claim 3 (depends on 1) The system according to claim 1, further comprising a first and second switch, the first output being configured to control the first switch and the second output being configured to control the second switch, the first switch being in electrical series connection with the first coil and the second switch being in electrical series connection with the second coil. ### Claim 4 (depends on 3) The system according to claim 3, wherein, the first switch and first coil being in electrical parallel connection with the second switch and the second coil. ### Claim 5 (depends on 3) The system according to claim 3, wherein the first and second switch are in communication with the overcurrent detection circuit at a node, thereby allowing a first current flowing though the first coil and a second current flowing through the second coil to both be provided to the overcurrent detection circuit through the node. ### Claim 6 (depends on 3) The system according to claim 3, wherein the first switch is a first transistor and the base of the first transistor is connected to the first output, the collector of the first transistor is connected to the first coil and the emitter of the first transistor is connected to the node. ### Claim 7 (depends on 6) The system according to claim 6, wherein the second switch is a transistor and the base of the second transistor is connected to the second output, the collector of the second transistor is connected to the second coil and the emitter of the second transistor is connected to the node. ### Claim 8 (depends on 3) The system according to claim 3, wherein the control circuit sends an overlap signal to the overcurrent detection circuit. ### Claim 9 (depends on 8) The system according to claim 8, wherein the overcurrent detection circuit compares an overcurrent threshold to the signal to detect the overcurrent condition. ### Claim 10 (depends on 9) The system according to claim 9, wherein the overcurrent detection circuit adjusts the overcurrent threshold while the charging of the first coil overlaps charging of the second coil. ### Claim 11 (depends on 10) The system according to claim 10, wherein the overcurrent detection circuit provides an overcurrent signal to the control circuit to disable the first and second output. ### Claim 12 (depends on 1) The system according to claim 1, wherein the overcurrent detection circuit provides a feedback loop to the control circuit based on whether the charging of the first coil and charging of the second coil overlap. ### Claim 13 A system for controlling ignition coils, the system comprising: a control circuit having a first and second output, the first output being configured to control charging of a first coil, the second output being configured to control charging of a second coil; an overcurrent detection circuit configured to adjust detection of an overcurrent condition when charging of a first coil overlaps with charging of the second coil; a first and second switch, the first output being configured to control the first switch and the second output being configured to control the second switch, the first switch being in electrical series connection with the first coil and the second switch being in electrical series connection with the second coil, the first switch and first coil being in electrical parallel connection with the second switch and the second coil, the first and second switch being in communication with the overcurrent detection circuit at a node, thereby allowing a first current flowing though the first coil and a second current flowing through the second coil to both be provided to the overcurrent detection circuit through the node. ### Claim 14 (depends on 13) The system according to claim 13, wherein the control circuit sends an overlap signal to the overcurrent detection circuit. ### Claim 15 (depends on 14) The system according to claim 14, wherein the overcurrent detection circuit compares an overcurrent threshold to the signal to detect the overcurrent condition. ### Claim 16 (depends on 15) The system according to claim 15, wherein the overcurrent detection circuit adjusts the overcurrent threshold while the charging of the first coil overlaps charging of the second coil. ### Claim 17 A method for controlling ignition coils, the method comprising the steps of: generating a first control signal; generating a second control signal; determining if charging of the first coil and charging of the second coil overlap; sensing current through the first and second coil; generating a current signal corresponding to the current through the first and second coil; comparing the current signal to an overcurrent threshold; adjusting the overcurrent threshold based on whether charging of the first coil and charging of the second coil overlap. ### Claim 18 (depends on 17) The method according to claim 17, further comprising generating an overcurrent signal when the current signal exceeds the overcurrent threshold. ### Claim 19 (depends on 17) The method according to claim 17, further comprising disabling the first and second control signal based on the overcurrent signal. ### Claim 20 (depends on 17) The method according to claim 17, wherein the overcurrent threshold is raised during a time period where charging the first time period and charging the second coil overlap.