C. D. ignition system with noise rejection means

Claim 2

An engine ignition system comprising a charge capacitor, means for periodically charging said capacitor, first and second ignition coils respectively including first and second primary windings and first and seciond secondary windings connected respectively to first and second spark plugs, first and second electronic switches respectively including first and second anodes connected respectively to said first and second primary windings, first and second cathodes connected to said charge capacitor, and first and second control elements operable, upon application thereto of a trigger pulse, to cause said first and second switches to be conductive, means including a relatively rotatable magnet and coil for generating trigger pulses in response to engine rotation, said coil having first and second ends respectively connected to said first and second control elements, and means for preventing false triggering of said switches comprising a second capacitor having a first plate connected to said first and second cathodes and having a second plate, a resistor having a first end connected to said first and second cathodes in parallel with the connection of the first plate of said second capacitor to said first and second cathodes, said resistor having a second end, a first diode having an anode connected to said second plate of said second capacitor and to said second end of said resistor and a cathode connected to and between said first end of said coil and said first control element, and a second diode having an anode connected to said second plate of said second capacitor and to said second end of said resistor, and a cathode connected to and between said second end of said coil and said second control element.

Claim 3

An engine ignition system in accordance with claim 1 including a third diode having a cathode connected to said first control element and an anode connected to said first end of said coil and to said cathode of said first diode and a fourth diode having a cathode connected to said second control element and an anode connected to said second end of said coil and to said cathode of said second diode.

Claim 4

An engine ignition system in accordance with claim 2 and further including a third capacitor connected to said first control element and to said cathode of said first switch and a fourth capacitor connected to said second control element and to said cathode of said second switch.

Claim 5

An engine ignition system in accordance with claim 2 including a second resistor having a first end connected to said first end of said coil and a second end connected to said cathode of said first diode and to said anode of said third diode and a third resistor having a first end connected to said second end of said coil and having a second end connected to said cathode of said second diode and to said anode of said fourth diode.

Claim 6

An engine ignition system comprising a charge capacitor, means for periodically charging said capacitor, first and second ignition coils respectively including first and second primary windings and first and second secondary windings connected respectively to first and second spark plugs, first and second electronic switches respectively including first and second anodes connected respectively to said first and second primary windings, first and second cathodes connected to said charge capacitor, and first and second control elements operable, upon application thereto of a trigger pulse, to cause said first and second switches to be conductive, a second capacitor having a first plate connected to said first and second cathodes and having a second plate, a first resistor having a first end connected to said first and second cathodes in parallel with the connection of said first plate of said second capacitor to said first and second cathodes, said resistor having a second end, a first diode having a cathode connected to said first control element and an anode, a second diode having a cathode connected to said second control element, and an anode, a third diode having a cathode connected to said anode of first diode and an anode connected to said second plate of said second capacitor and to said second end of said first resistor, a fourth diode having a cathode connected to said anode of said second diode and an anode connected to second plate of said second capacitor and to said second end of said first resistor, a second resistor having a first end connected to said cathode of said third diode and to said anode of said first diode and having a second end, a third resistor having a first end connected to said cathode of said fourth diode and to said anode of said second diode, and means including a relatively rotatable magnet and coil for generating trigger pulses in response to engine rotation, said coil having first and second ends respectively connected to said second ends of said second and third resistors.

Claim 7

An engine ignition system comprising a charge capacitor, means for periodically charging said capacitor, first and second ignition coils respectively including first and second primary windings and first and second secondary windings connected respectively to first and second spark plugs, first and second electronic switches respectively including first and second anodes connected respectively to said first and second primary windings, first and second cathodes connected to said charge capacitor, and first and second control elements operable, upon application thereto of a trigger pulse, to cause said first and second switches to be conductive, a second capacitor having a first plate connected to said first and second cathodes and having a second plate, a first resistor having a first end connected to said first and second cathodes in parallel with the connection of said first plate of said second capacitor to said first and second cathodes, said resistor having a second end, a first diode having a cathode connected to said first control element and an anode, a second diode having a cathode connected to said second control element, and an anode, a third diode having a cathode connected to said anode of first diode and an anode connected to said second plate of said second capacitor and to said second end of said first resistor, a fourth diode having a cathode connected to said anode of said second diode and an anode connected to second plate of said second capacitor and to said second end of said first resistor, a second resistor having a first end connected to said cathode of said third diode and to said anode of said first diode and having a second end, a third resistor having a first end connected to said cathode of said fourth diode and to said anode of said second diode, and means including a relatively rotatable magnet and coil for generating trigger pulses in response to engine rotation, said coil having first and second ends respectively connected to said second ends of said second and third resistors.

Claim 8

An engine ignition system comprising a charge capacitor, means for periodically charging said capacitor, an ignition coil including a primary winding and a secondary winding connected to a spark plug, an electronic switch including an anode connected to said primary winding, a cathode connected to said charge capacitor, and a control element operable, upon application thereto of a trigger pulse, to cause said electronic switch to be conductive, means including a relatively rotatable magnet and trigger coil for generating trigger pulses in response to engine rotation, said trigger coil having a first end connected to said control element and having a second end, means for preventing false triggering of said electronic switch comprising a second capacitor having a first plate connected to said charge capacitor in parallel with connection of said cathode to said charge capacitor and having a second plate, a first resistor having a first end connected to said charge capacitor in parallel with the connection of said cathode and of said first plate of said second capacitor to said charge capacitor, said first resistor having a second end, a first diode having an anode connected to said second plate of said second capacitor and to said second end of said first resistor and a cathode connected to and between said first end of said trigger coil and said control element, and a second diode having an anode connected to said second plate of said second capacitor and to said second end of said first resistor, and a cathode connected to said second end of said trigger coil, and a second resistor having a first end connected to said second end of said trigger coil and to said cathode of said second diode and having a second end connected to said charge capacitor in parallel with the connection of said first plate of said second capacitor, said first end of said first resistor, and said cathode of said switch.

Claim 9

An engine ignition system comprising a charge capacitor, means for periodically charging said capacitor, an ignition coil including a primary winding and a secondary winding connected to a spark plug, an electronic switch including an anode connected to said primary winding, a cathode connected to said charge capacitor, and a control element operable, upon application thereto of a trigger pulse, to cause said electronic switch to be conductive, means including a relatively rotatable magnet and trigger coil for generating trigger pulses in response to engine rotation, said trigger coil having a first end connected to said control element and having a second end, means for preventing false triggering of said electronic switch comprising a second capacitor having a first plate connected to said charge capacitor in parallel with connection of said cathode to said charge capacitor and having a second plate, a first resistor having a first end connected to said charge capacitor in parallel with the connection of said cathode and of said first plate of said second capacitor to said charge capacitor, said first resistor having a second end, a first diode having an anode connected to said second plate of said second capacitor and to said second end of said first resistor and a cathode connected to and between said first end of said trigger coil and said control element, and a second diode having an anode connected to said second plate of said second capacitor and to said second end of said first resistor, and a cathode connected to said second end of said trigger coil, and a second resistor having a first end connected to said second end of said trigger coil and to said cathode of said second diode and having a second end connected to said charge capacitor in parallel with the connection of said first plate of said second capacitor, said first end of said first resistor, and said cathode of said switch.