# US 10,122,155 B2 · Corona ignition system for an internal combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,122,155 B2 - Document ID: US10122155B2 - Status: Granted - Kind: B2 - Application number: 14/938,534 - Filed: 2015-11-11 - Published: 2016-05-19 - Granted: 2018-11-06 - Earliest claimed: 2014-11-13 - Assignees: BorgWarner Ludwigsburg GmbH - Applicants: BorgWarner Ludwigsburg GmbH - Inventors: Torsten Schremmer; Thomas Holzschuh - Web page: https://patentgrep.com/patent/US10122155B2 ## CPC - H01T 19/00: Devices providing for corona discharge (for charging electrographic elements G03G15/02) - H01T 13/50: having means for ionisation of gap (H01T13/52 takes precedence) - F02P 3/01: Electric spark ignition installations without subsequent energy storage, i.e. energy supplied by an electrical oscillator (with magneto- or dynamo-electric generators F02P1/00; piezoelectric ignition F02P3/12; with continuous electric spark F02P15/10) - H01T: SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES (overvoltage protection circuits H02H) - 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) ## Abstract A corona ignition system is described for igniting fuel in a combustion chamber of an internal combustion engine, with a resonant circuit, which contains an ignition electrode, a high frequency generator connected to the resonant circuit, in order to generate an AC voltage for exciting the resonant circuit, and a direct current voltage source, in order to generate an input voltage for the high frequency generator. According to this disclosure, provision is made that parallel to the direct current voltage source a capacitor is connected to the high frequency generator, which capacitor on transient oscillation of the resonant circuit compensates mismatches between the resonant circuit and the direct current voltage source. ## Claims ### Claim 1 A corona ignition system for igniting fuel in a combustion chamber of an internal combustion engine, comprising: a resonant circuit, which comprises an ignition electrode; a high frequency generator, which is connected to the resonant circuit and configured to generate an AC voltage for exciting the resonant circuit; a direct current voltage source configured to generate an input voltage for the high frequency generator wherein the direct current voltage source is a converter and delivers a voltage between 50 V and 400 V; and a capacitor that is connected to the high frequency generator in parallel to the direct current voltage source, wherein, during transient oscillation of the resonant circuit when the high frequency generator is first activated, the capacitor compensates mismatches between the resonant circuit and the direct current voltage source by reducing the voltage applied to the high frequency generator by the direct current voltage source. ### Claim 2 (depends on 1) The corona ignition system according to claim 1, wherein the capacitor has a capacitance between 20 μF and 100 μF. ### Claim 3 (depends on 1) The corona ignition system according to claim 1, wherein the capacitor and the direct current voltage source are connected to the same voltage input of the high frequency generator. ### Claim 4 (depends on 1) The corona ignition system according to claim 1, wherein the high frequency generator comprises a transformer with a center tap and both the direct current voltage source and also the capacitor are connected to the center tap. ### Claim 5 (depends on 1) The corona ignition system according to claim 1, wherein during the transient process of the resonant circuit the capacitor limits an alteration of the input voltage of the resonant circuit to no more than 5 V/ μs. ### Claim 6 (depends on 1) The corona ignition system according to claim 1, wherein the capacitor reduces the voltage applied to the high frequency generator during transient oscillation of the resonant circuit by a voltage within the range of 10 V to 75 V. ### Claim 7 A corona ignition system for igniting fuel in a combustion chamber of an internal combustion engine, comprising: a resonant circuit, which comprises an ignition electrode; a high frequency generator, which is connected to the resonant circuit and configured to generate an AC voltage for exciting the resonant circuit; a direct current voltage source configured to generate an input voltage for the high frequency generator; and a capacitor that is connected to the high frequency generator in parallel to the direct current voltage source, wherein, during a corona discharge event: (a) during transient oscillation of the resonant circuit when the high frequency generator is first activated the capacitor is being charged whereby less than the full voltage provided by the direct current voltage source is applied to the high frequency generator; (b) after charging the capacitor, the full voltage provided by the direct current voltage source is applied to the high frequency generator with the resonant circuit in a steady state; and (c) after separating the direct current voltage source from the high frequency generator, the capacitor is discharged and the corona discharge is extinguished.