Ignition system with programmable dwell

Claim 2

An engine ignition control system electrically connectible to an ignition circuit which includes a source of electrical energy, an ignition coil, and timing means for repetitively and alternately providing first and second timing signals with the interval between adjacent timing signals being related to engine speed, said control system comprising: means responsive to one of the first timing signals for providing a triggering signal a variable interval after said one timing signal and before the next to occur of the second timing signals subsequent to said one timing signal with the variable interval reducing with increases in engine speed; switch means responsive to said triggering signal for completing a first circuit from the source of electrical energy through the coil to charge the coil; and said switch means including means responsive to the next to occur of the first timing signals subsequent to said one timing signal to open said first circuit to discontinue the charging of the coil whereby the coil can be charged during a charging interval which extends from about the time of the initiation of the triggering signal to about the time of said next to occur of the first timing signals and said coil is not being charged during said variable interval of time.

Claim 3

An engine ignition control system defined in claim 1 wherein said first-mentioned means varies said variable interval so that the ratio of said charging interval to said variable interval is substantially constant over a major range of engine speeds.

Claim 4

An engine ignition control system as defined in claim 1 wherein said switch means is responsive to the triggering signal to complete said first circuit from about the time of the initiation of the triggering signal to about the time of said next to occur of the second timing signals and is responsive to such second timing signal to complete said first circuit during the remainder of the charging interval.

Claim 5

An engine ignition control system as defined in claim 1 wherein the triggering signal is a first triggering signal and said switch means includes electronic switch means responsive to the first triggering signal for providing a second triggering signal and main switch means responsive to the second triggering signal and said next to occur of the first timing signals for completing said first circuit.

Claim 6

An engine ignition control system as defined in claim 1 wherein said first-mentioned means includes first and second impedances couplable to the coil, the timing means and to a reference potential and capacitor means for storing an electrical charge, said impedances and said capacitor means being coupled to a common junction with the first impedance being between said junction and the coil and the second impedance being between the junction and the reference potential, the value of said first impedance being greater than the value of said second impedance.

Claim 7

An engine ignition control system electrically connectible to an ignition circuit which includes a source of electrical energy, an ignition coil, and timing means for repetitively and alternately providing first and second timing signals with the interval between adjacent timing signals being related to engine speed, said control system comprising: first means responsive to the first timing signal for providing a switch control signal which increases in magnitude during a first interval which extends from about the time of the occurrence of the first timing signal at least until a triggering magnitude is reached, said switch control signal having a first magnitude which is the minimum magnitude for said switch control signal; electronic switch means responsive to the switch control signal being of said triggering magnitude for providing a triggering signal with the duration of said triggering signal being approximately coextensive with the period that said switch control signal is of at least said triggering magnitude; said first means includng means responsive to the second timing signal for reducing the magnitude of the switch control signal below the triggering magnitude and gradually reducing the magnitude of the switch control signal toward said first magnitude whereby as engine speed increases the control signal need only increase in magnitude from some value above said first magnitude to said triggering magnitude to thereby reduce said first interval; and main switch means responsive to said triggering signal and said second timing signal for completing a first circuit from the source of electrical energy through the coil to charge the coil from about the time that said switch control signal reaches said triggering magnitude until about the time of the occurrence of the next of the first timing signals.

Claim 8

An engine ignition control system electrically connectible to an ignition circuit which includes a source of electrical energy, an ignition coil, and timing means for repetitively and alternately providing first and second timing signals with the interval between adjacent timing signals being related to engine speed, said control system comprising: first means responsive to the first timing signal for providing a switch control signal which increases in magnitude during a first interval which extends from about the time of the occurrence of the first timing signal at least until a triggering magnitude is reached, said switch control signal having a first magnitude which is the minimum magnitude for said switch control signal; electronic switch means responsive to the switch control signal being of said triggering magnitude for providing a triggering signal with the duration of said triggering signal being approximately coextensive with the period that said switch control signal is of at least said triggering magnitude; said first means includng means responsive to the second timing signal for reducing the magnitude of the switch control signal below the triggering magnitude and gradually reducing the magnitude of the switch control signal toward said first magnitude whereby as engine speed increases the control signal need only increase in magnitude from some value above said first magnitude to said triggering magnitude to thereby reduce said first interval; and main switch means responsive to said triggering signal and said second timing signal for completing a first circuit from the source of electrical energy through the coil to charge the coil from about the time that said switch control signal reaches said triggering magnitude until about the time of the occurrence of the next of the first timing signals.

Claim 9

An engine ignition control system as defined in claim 6 wherein said first means includes first and second resistors coupled to the coil, the timing means and to a reference potential and capacitor means for storing an electrical charge, said resistors and said capacitor means being coupled to a common junction with the first resistor being between said junction and the coil and the second resistor being between the junction and the reference potential, the value of said first resistor being greater than the value of said second resistor.

Claim 10

An engine ignition control system as defined in claim 7 wherein said electronic switch means is coupled to the timing means, said control system includes at least one diode coupled between the electronic switch means and the reference potential.

Claim 11

An engine ignition control system as defined in claim 6 wherein said electronic switch means has a control terminal, said first means includes electrical energy storage means coupled to said control terminal, charging circuit means coupled to the electrical energy storage means for charging the latter during said first interval at least until the charge reaches said triggering magnitude and discharge circuit means responsive to the second timing signal for gradually dishcarging the electrical energy storage means.