초록 ▼

A corona ignition system for maintaining a drive frequency approximately equal to the resonant frequency of a corona igniter is provided. The system includes a current sensor, at least two cascaded timers which are electrically independent of a controller, and at least two switches. During operation

A corona ignition system for maintaining a drive frequency approximately equal to the resonant frequency of a corona igniter is provided. The system includes a current sensor, at least two cascaded timers which are electrically independent of a controller, and at least two switches. During operation, the current sensor measures the current at an input of the corona igniter. A conditioned current signal including information related to the zero crossings of the current ultimately activates a pair of the timers which in turn control and drive one of the switches. The conditioned current signal is not processed by the controller before driving the switch.

대표청구항 ▼

1. A corona ignition system, comprising: a corona igniter receiving current at a radio frequency and providing a radio frequency electric field;a current sensor obtaining an unfiltered current signal including information about the current received by the corona igniter;at least one of a signal filt

1. A corona ignition system, comprising: a corona igniter receiving current at a radio frequency and providing a radio frequency electric field;a current sensor obtaining an unfiltered current signal including information about the current received by the corona igniter;at least one of a signal filter and a signal conditioner receiving the unfiltered current signal from the current sensor and providing a conditioned current signal, wherein the conditioned current signal includes a falling edge occurring at the end of a first time delay following a first zero crossing of the unfiltered current signal;a first timer receiving the conditioned current signal and initiating a second time delay in response to the falling edge of the conditioned current signal and providing a first timer signal, wherein the first timer signal includes a falling edge at the end of the second time delay and the second time delay ends before a second zero crossing of the unfiltered current signal following the first zero crossing;a second timer receiving the first timer signal from the first timer and providing a first output signal, wherein a third time delay starts at the end of the second time delay at the falling edge of the first timer signal, and the first output signal includes a rising edge at the start of the third time delay; anda first switch receiving the first output signal and being activated at the end of the third time delay, wherein the third time delay ends at or after the second zero crossing of the unfiltered current signal, and the activated first switch allows the current to flow from an energy supply to the corona igniter. 2. The system of claim 1, wherein the second timer initiates a fourth time delay starting at the rising edge of the first output signal and ending at a falling edge of the first output signal, the end of the fourth time delay occurs before a third zero crossing of the unfiltered current signal, the first switch is deactivated at the end of a fifth time delay which starts at the falling edge of the first output signal and ends before or at the third zero crossing. 3. The system of claim 2 including a controller setting the second time delay and the fourth time delay so that the first switch is activated or deactivated at or adjacent one of the zero crossings of the current received by the corona igniter. 4. The system of claim 3, wherein the controller receives a voltage, and the controller adjusts at least one of the second time delay and the fourth time delay if zero crossings of the unfiltered current signal are not simultaneous with the zero crossings of the unfiltered current signal. 5. The system of claim 3, wherein the controller initiates an enable signal to one of the timers to activate the first switch and allow the current to flow from the energy supply to the corona igniter before the current sensor obtains the information about the current. 6. The system of claim 3, wherein the timers are electrically independent of the controller. 7. The system of claim 1, wherein the conditioned current signal is conveyed from the signal conditioner to the first timer without the controller acting as an intermediary. 8. The system of claim 1, wherein the conditioned current signal includes a rising edge occurring at the end of a sixth time delay following a fourth zero crossing of the unfiltered current signal, wherein the sixth time delay is equal to the first time delay; a third timer receives the conditioned current signal and initiates a seventh time delay in response to a rising edge of the conditioned current signal and provides a second timer signal, wherein the seventh time delay is equal to the second time delay, the second timer signal includes a rising edge at the end of the seventh time delay and the seventh time delay ends before a fifth zero crossing of the unfiltered current signal following the fourth zero crossing; a fourth timer receives the first timer signal from the third timer and provides a second output signal, wherein an eighth time delay starts at the end of the seventh time delay at the rising edge of the first timer signal, the eighth time delay is equal to the third time delay, and the second output signal includes a falling edge at the start of the eighth time delay; anda second switch receives the second output signal and is activated at the end of the eighth time delay, wherein the eighth time delay ends at or after the fifth zero crossing of the unfiltered current signal, and the activated second switch allows the current to flow from the energy supply to the corona igniter. 9. The system of claim 8, wherein the fourth timer initiates a ninth time delay starting at the falling edge of the second output signal and ending at a rising edge of the second output signal, the ninth time delay is equal to the fourth time delay, the end of the ninth time delay occurs before a sixth zero crossing of the unfiltered current signal, the second switch is deactivated at the end of a tenth time delay which starts at the rising edge of the second output signal and ends before or at the sixth zero crossing, and the tenth time delay is equal to the fifth time delay. 10. The system of claim 9 including a controller setting the seventh time delay and the ninth time delay so that the switch is activated or deactivated at or adjacent one of the zero crossings of the unfiltered current signal. 11. The system of claim 10, wherein the corona igniter receives a voltage and the controller adjusts at least one of the second time delay and the fourth time delay if zero crossings of the voltage received by the corona igniter are not simultaneous with the zero crossings of the unfiltered current signal. 12. The system of claim 10, wherein the first, third, fifth, sixth, eighth, and tenth time delays are fixed and based at least in part on design of the current sensor, the signal filter and/or the signal conditioner, the timers, and the switches. 13. A method of controlling a corona discharge system, comprising the steps of: providing energy to a corona igniter at a radio frequency;obtaining an unfiltered current signal including information about the current received by the corona igniter;providing a conditioned current signal which includes a falling edge occurring at the end of a first time delay following a first zero crossing of the unfiltered current signal;initiating a second time delay in response to the falling edge of the conditioned current signal and providing a first timer signal, wherein the first timer signal includes a falling edge at the end of the second time delay and the second time delay ends before a second zero crossing of the unfiltered current signal following the first zero crossing;providing an output signal which includes a rising edge at the start of a third time delay, wherein the third time delay starts at the end of the second time delay at the falling edge of the first timer signal; andactivating a first switch by the first output signal at the end of the third time delay, wherein the third time delay ends at or after the second zero crossing of the unfiltered current signal, and the activated first switch allows the current to flow from an energy supply to the corona igniter. 14. The method of claim 13 including initiating a fourth time delay starting at the rising edge of the first output signal and ending at a falling edge of the first output signal, the end of the fourth time delay occurs before a third zero crossing of the unfiltered current signal, and deactivating the first switch at the end of a fifth time delay which starts at the falling edge of the first output signal and ends before or at the third zero crossing. 15. The method of claim 13 including setting the second time delay and the fourth time delay so that the first switch is activated or deactivated at or adjacent one of the zero crossings of the current received by the corona igniter. 16. The method of claim 13 including adjusting at least one of the second time delay and the fourth time delay if zero crossings of the unfiltered current signal are not simultaneous with the zero crossings of the unfiltered current signal. 17. The method of claim 13 including initiating an enable signal to one of the timers to activate the first switch and allow the current to flow from the energy supply to the corona igniter before the current sensor obtains the information about the current. 18. The method of claim 13, wherein the conditioned current signal is conveyed from the signal conditioner to the first timer without a controller acting as an intermediary. 19. The method of claim 13, wherein the conditioned current signal includes a rising edge occurring at the end of a sixth time delay following a fourth zero crossing of the unfiltered current signal, wherein the sixth time delay is equal to the first time delay; initiating a seventh time delay in response to a rising edge of the conditioned current signal and providing a second timer signal, wherein the seventh time delay is equal to the second time delay, the second timer signal includes a rising edge at the end of the seventh time delay and the seventh time delay ends before a fifth zero crossing of the unfiltered current signal following the fourth zero crossing;providing a second output signal including a falling edge at the start of an eighth time delay, wherein the eighth time delay starts at the end of the seventh time delay at the rising edge of the second timer signal, the eighth time delay is equal to the third time delay;activating a second switch by the second output signal at the end of the eighth time delay, wherein the eighth time delay ends at or after the fifth zero crossing of the unfiltered current signal, and the activated second switch allows the current to flow from the energy supply to the corona igniter;initiating a ninth time delay starting at the falling edge of the second output signal and ending at a rising edge of the second output signal, wherein the ninth time delay is equal to the fourth time delay, and the end of the ninth time delay occurs before a sixth zero crossing of the unfiltered current signal; anddeactivating the second switch at the end of a tenth time delay which starts at the rising edge of the second output signal and ends before or at the sixth zero crossing, wherein the tenth time delay is equal to the fifth time delay. 20. The method of claim 19, including adjusting at least one of the eighth and tenth time delays if zero crossings of the voltage received by the corona igniter are not simultaneous with the zero crossings of the unfiltered current signal.