Electronic ignition controller

Claim 2

Apparatus for controlling the anti-dwell firing period of the ignition cycle of an internal combustion engine electrical ignition system having a source of electrical energy, at least one sparking device and an ignition coil having a primary winding connected for energization from said source and another winding for supplying high tension energy to said sparking device; said apparatus including a pickup device driven in synchronism with the engine and developing a triggering signal voltage for each ignition cycle of the engine and an electronic control unit actuated from said pickup device and controlling the energization of said ignition coil from said electrical energy source, said control unit including a first and a second transistor each having emitter, collector and bAse electrodes of which the base and emitter electrodes of the first transistor are coupled to said pickup device; a capacitor connected between the collector of said first transistor and the base of said second transistor; a charging circuit for said capacitor including the base and emitter electrodes of said second transistor connected to one side of said source and a first resistor connected between the collector of said first transistor and the other side of said source; a discharging circuit for said capacitor including a second resistor connected between the emitter and base of said second transistor and a voltage latching conduction device connected across the collector and emitter electrodes of said first transistor to said one side of said source; and a controllable semi-conductor switching device having a pair of output electrodes connected in series with said ignition coil primary winding across said source and an input control electrode coupled to the collector electrode of said second transistor.

Claim 3

Apparatus in accordance with claim 1 wherein the time constant of said capacitor and second resistor is in the order of the period of an ignition cycle at high speed operation of the engine and is less than the period of an ignition cycle at low speed engine operation.

Claim 4

Apparatus according to claim 22 including a third resistor connected between the collector electrode of said second transistor and the said other side of said source and a regenerative d.c. feedback circuit connected between the collector electrode of said second transistor to the base electrode of said first transistor device.

Claim 5

Apparatus in accordance with claim 1 wherein said pick-up device is of a magnetic character and has a stator portion which includes a pick-up coil having a pair of terminals and has a rotor portion which includes a reluctor element for developing a bipolar signal voltage in said pick-up coil for each ignition cycle of the engine, and wherein said control unit further includes a first diode connected across the base-emitter electrodes of said first transistor device and a second diode connected in series from one side of said first diode to one terminal of said pick-up coil, the other terminal of said pick-up coil being connected to the other side of said first diode, said diodes being similarly poled in a direction to oppose current flow in said pick-up coil during one alternation of said signal voltage.

Claim 6

Apparatus in accordance with claim 1 wherein said voltage latching conduction device is an SCR having anode, cathode and gate electrodes of which its anode and cathode electrodes are connected across the collector-emitter electrodes of said first transistor device and its gate electrode is connected to receive a reference potential applied thereto intermediate the potential level of said source.

Claim 7

Apparatus in accordance with claim 5 wherein said reference potential is taken from the junction of a voltage divider connected across said source of energy.

Claim 8

Apparatus in accordance with claim 1 wherein the charging interval of said capacitor is less at high speed than at low speed operation of the engine.

Claim 9

Apparatus in accordance with claim 1 wherein the charging interval of said capacitor determines the anti-dwell firing period and varies inversely with engine speed.

Claim 10

Apparatus in accordance with claim 1 wherein said control unit further includes a third transistor having base, emitter and collector electrodes of which its base electrode is direct current conductively connected to the collector electrode of said second transistor and its emitter electrode is d.c. coupled to the input control electrode of said controllable semi-conductor switching device.

Claim 11

Apparatus in accordance with claim 9 wherein the collector electrode of said second transistor is connected to the base electrode of said thride transistor through a resistor whose ohmic value inversely affects the relation between the triggering senSitivity of the circuit and the source supply voltage.

Claim 12

Apparatus in accordance with claim 9 wherein said controllable semi-conductor switching device is also a transistor of the same conductivity type as said first, second and third transistors.

Claim 13

Apparatus in accordance with claim 11 wherein said transistors are NPN transistors and said voltage conduction latching device is a complementary SCR.

Claim 14

Apparatus in accordance with claim 11 including a Zener diode element connected in circuit between the base electrode and the collector electrode of said controllable semi-conductor transistor switching device.

Claim 15

Apparatus in accordance with claim 11 including a voltage divider connected between the collector electrodes of said third transistor and said controllable semi-conductor transistor switching device and a Zener diode connected between the junction of said voltage divider and the base electrode of said controllable semi-conductor transistor switching device.

Claim 16

Apparatus in accordance with claim 11 wherein each of said first and second transistors and said controllable semi-conductor transistor switching device is connected in a common emitter configuration and said third transistor is connected as an emitter follower.

Claim 17

In a timing circuit for timing the firing period of the ignition system of an internal combustion engine and including a source of electrical energy, at least one sparking device and an ignition coil having a primary winding energizable from said source and a secondary winding coupled to said sparking device, said circuit comprising an output stage semi-conductor device having a control input terminal and a pair of current conducting output terminals connected in series with the primary winding of said ignition coil across said source, a driver stage semi-conductor device having a control input terminal and a pair of output terminals one of which output terminals is conductively connected to one side of said source and the other is conductively connected to the other side of said source and to the control input terminal of said output stage semi-conductor device, and means driven by the engine for supplying control pulses to the control input terminal of said driver stage semi-conductor device to initiate the firing of the engine, means for protecting the output stage semi-conductor device from excessive voltages that may appear at the output terminal thereof during open circuit conditions of the ignition secondary coil including a voltage divider connected between one of the output terminals of each of said devices and a Zener diode connected between the junction of said divider and the input control terminal of said output stage semi-conductor device.

Claim 18

In a timing circuit for timing the firing period of the ignition system of an internal combustion engine and including a source of electrical energy, at least one sparking device and an ignition coil having a primary winding energizable from said source and a secondary winding coupled to said sparking device, said circuit comprising an output stage semi-conductor device having a control input terminal and a pair of current conducting output terminals connected in series with the primary winding of said ignition coil across said source, a driver stage semi-conductor device having a control input terminal and a pair of output terminals one of which output terminals is conductively connected to one side of said source and the other is conductively connected to the other side of said source and to the control input terminal of said output stage semi-conductor device, and means driven by the engine for supplying control pulses to the control input terminal of said driver stage semi-conductor device to initiate the firing of the engine, means for protecting the output stage semi-conductor device from excessive voltages that may appear at the output terminal thereof during open circuit conditions of the ignition secondary coil including a voltage divider connected between one of the output terminals of each of said devices and a Zener diode connected between the junction of said divider and the input control terminal of said output stage semi-conductor device.

Claim 19

Apparatus for controlling the firing of an internal combustion engine ignition system having a source of electrical energy, at least one sparking device and an ignition coil having a primary winding connected for energization from the source and a high tension winding for supplying high tension energy to said sparking device, said apparatus including: a magnetic pickup device operated in synchronism with the engine and having a pair of output terminals across which is developed a signal voltage of alternating polarity; a control transistor having base, emitter and collector electrodes of which one of its emitter and collector electrodes is connected to one side of said source, means connecting the other of the emitter and collector electrodes of said control transistor to the other side of said source; means producing a biasing voltage and applying it to said base electrode of said control transistor to biassthe latter in one state of conduction thereof; a controllable switching device having a pair of output terminals connected in series with said ignition coil primary winding across said source and a control input terminal coupled to the collector electrode of said control transistor; said pickup device connecteD in circuit with the base and emitter electrodes of said control transistor to trigger it to its opposite state of conduction from a pickup signal voltage of one polarity; and a diode connected in series in said pickup and transistor base-emitter circuit and poled in a direction to prevent current flow in the pickup device during the opposite polarity of the signal voltage therefrom and in opposition to the base-emitter junction of said control transistor to compensate for the VBE offset voltage thereof, thereby to reduce the voltage required from the pickup to trigger said control transistor.

Claim 20

Apparatus for controlling the firing of an internal combustion engine ignition system having a source of electrical energy, at least one sparking device and an ignition coil having a primary winding connected for energization from the source and a high tension winding for supplying high tension energy to said sparking device, said apparatus including: a magnetic pickup device operated in synchronism with the engine and having a pair of output terminals across which is developed a signal voltage of alternating polarity; a control transistor having base, emitter and collector electrodes of which one of its emitter and collector electrodes is connected to one side of said source, means connecting the other of the emitter and collector electrodes of said control transistor to the other side of said source; means producing a biasing voltage and applying it to said base electrode of said control transistor to biassthe latter in one state of conduction thereof; a controllable switching device having a pair of output terminals connected in series with said ignition coil primary winding across said source and a control input terminal coupled to the collector electrode of said control transistor; said pickup device connecteD in circuit with the base and emitter electrodes of said control transistor to trigger it to its opposite state of conduction from a pickup signal voltage of one polarity; and a diode connected in series in said pickup and transistor base-emitter circuit and poled in a direction to prevent current flow in the pickup device during the opposite polarity of the signal voltage therefrom and in opposition to the base-emitter junction of said control transistor to compensate for the VBE offset voltage thereof, thereby to reduce the voltage required from the pickup to trigger said control transistor.

Claim 21

Apparatus in accordance with claim 27 including a second transistor having a control input terminal and a pair of output terminals, circuit means coupling the other output terminal of said control transistor to the control input terminal of said second transistor device, and a regenerative feedback connection from one of the output terminals of said second device to the control input terminal of said control transistor.

Claim 22

Apparatus in accordance with claim 17 above further including a second diode connected across the base and emitter electrodes of said control transistor and similarly poled and in series with said first diode.

Claim 23

Apparatus for controlling the anti-dwell firing period of the ignition cycle of an internal combustion engine ignition system having a source of direct current electrical energy, at least one sparking device and an ignition coil having a winding connected for energization from said source and another winding for supplying high tension energy to said sparking device; said apparatus including a pickup device driven in synchronism with the engine and developing a triggering signal for eachignition cycle and an electrical control unit actuated from said pickup device and controlling the energization of said ignition coil from said electrical source; said control unit comprising a charging circuit including first resistor means connected to said source and a capacitor connected to be charged from said source through said resistor means upon application of a triggering signal to said electronic control unit from said pickup device; a conduction latching device connected to said capacitor and said source and responsive to the attainment of a predetermined voltage charge level upon the capacitor; a discharge circuit including second resistor means connected in discharge circuit relation with said capacitor by said conduction latching device when said capacitor has charged to said predetermined level; and a controllable semi-conductor switching device having a pair of output electrodes connected in series with the first mentioned winding of said ignition coil across said source and a control electrode responsive to the charging and the discharging of said capacitor to interrupt the energization of the ignition coil from the source during the charging of said capacitor and restore the energization of the ignition coil from the source during the discharging of said capacitor.

Claim 24

Apparatus for controlling the anti-dwell firing period of the ignition cycle of an internal combustion engine ignition system having a source of direct current electrical energy, at least one sparking device and an ignition coil having a winding connected for energization from said source and another winding for supplying high tension energy to said sparking device; said apparatus including a pickup device driven in synchronism with the engine and developing a triggering signal for eachignition cycle and an electrical control unit actuated from said pickup device and controlling the energization of said ignition coil from said electrical source; said control unit comprising a charging circuit including first resistor means connected to said source and a capacitor connected to be charged from said source through said resistor means upon application of a triggering signal to said electronic control unit from said pickup device; a conduction latching device connected to said capacitor and said source and responsive to the attainment of a predetermined voltage charge level upon the capacitor; a discharge circuit including second resistor means connected in discharge circuit relation with said capacitor by said conduction latching device when said capacitor has charged to said predetermined level; and a controllable semi-conductor switching device having a pair of output electrodes connected in series with the first mentioned winding of said ignition coil across said source and a control electrode responsive to the charging and the discharging of said capacitor to interrupt the energization of the ignition coil from the source during the charging of said capacitor and restore the energization of the ignition coil from the source during the discharging of said capacitor.

Claim 25

Apparatus in accordance with claim 28 above wherein the charging interval of the capacitor determines the anti-dwell firing period of the ignition cycle and the time constant of said capacitor and said second resistor means is in the order of the period of an ignition cycle at high speed operation of the engine and is less than the period of an ignition cycle at low speed engine operation, whereby the charging interval of said capacitor is shorter at high speed than at low speed engine operation.

Claim 26

Apparatus in accordance with claim 20 wherein the discharging interval of said capacitor is greater than the charging interval thereof.

Claim 27

Apparatus in accordance with claim 20 wherein the time constant of said discharge circuit is approximately four times that of said charging circuit.

Claim 28

An electronic control unit for an internal combustion engine ignition system having a direct current source of electriCal energy, at least one sparking device, an ignition coil having a primary winding connected at one side to one side of said source and a secondary winding for supplying high tension electrical energy to said sparking device, and a picup device driven in synchronism with the engine and developing a triggering signal for each ignition cycle of the engine, said electronic control unit having a pair of input terminals for connection to said pickup device; a pair of supply terminals for connection to said energy source; an output terminal for connection to the other side of said ignition coil primary winding; a first and a second transistor device each having base, collector and emitter electrodes of which the base and emitter electrodes of the first transistor are coupled to said input terminals and the emitter electrodes of both said transistors are connected to one of said supply terminals; first resistor means connected between the other of said supply terminals and the collector electrode of said first transistor; a capacitor connected between the collectror of the first transistor and the base of the second transistor; a capacitor charge voltage limiting device connected across the collector and emitter electrodes of said first transistor; second resistor means connected between the base and emitter of the second transistor; and a controllable semi-conductor switching device having a controllable electrode coupled to the collector electrode of said second transistor and a pair of output electrodes connected between said output terminal and the supply terminal which is adapted to be connected to the other side of said source.

Claim 29

An electronic control unit for an internal combustion engine ignition system having a direct current source of electriCal energy, at least one sparking device, an ignition coil having a primary winding connected at one side to one side of said source and a secondary winding for supplying high tension electrical energy to said sparking device, and a picup device driven in synchronism with the engine and developing a triggering signal for each ignition cycle of the engine, said electronic control unit having a pair of input terminals for connection to said pickup device; a pair of supply terminals for connection to said energy source; an output terminal for connection to the other side of said ignition coil primary winding; a first and a second transistor device each having base, collector and emitter electrodes of which the base and emitter electrodes of the first transistor are coupled to said input terminals and the emitter electrodes of both said transistors are connected to one of said supply terminals; first resistor means connected between the other of said supply terminals and the collector electrode of said first transistor; a capacitor connected between the collectror of the first transistor and the base of the second transistor; a capacitor charge voltage limiting device connected across the collector and emitter electrodes of said first transistor; second resistor means connected between the base and emitter of the second transistor; and a controllable semi-conductor switching device having a controllable electrode coupled to the collector electrode of said second transistor and a pair of output electrodes connected between said output terminal and the supply terminal which is adapted to be connected to the other side of said source.

Claim 30

An electronic ignition control unit in accordance with claim 30 wherein said controllable semi-conductor switching device is a transistor having base, emitter and collector electrodes and has a zener diode connected between its base and collector electrodes.

Claim 31

An electronic ignition control unit in accordance with claim 24 including a diode connected in series between one of said input terminals and one of said base and emitter electrodes of said first transistor and poled in a direction opposite the base-emitter junction of said first transistor.

Claim 32

An electronic ignition control unit in accordance with claim 26 including a second diode connected across the base and emitter electrodes of said first transistor and in series with and similarly poled as said first diode.

Claim 33

Apparatus for controlling the anti-dwell firing period of the ignition cycle of an internal combustion engine inductive type ignition system having a source of electrical energy, at least one sparking device and an ignition coil having a primary winding connected for energization from said source and another winding for supplying high tension energy to said sparking device; said apparatus including a triggering device driven in synchronism with the engine and providing a triggering signal voltage for each ignition cycle of the engine and an electronic control unit actuated from said triggering device and controlling the energization of said ignition coil from said electrical energy source, said control unit including a first and a second transistor each having emitter, collector and base electrodes of which the base and emitter electrodes of the first transistor are coupled to said triggering device and the emitter electrodes of both of said transistors are coupled to one side of said source, a charging circuit including a first resistor connected between the collector of said first transistor and the other side of said source and a capacitor connected between the collector of said first transistor and the base of said second transistor to charge from the source upon application of a triggering signal to said first transistor, a discharging circuit for said capacitor including a second resistor connected across the emitter and base electrodes of said second transistor and a voltage latching conduction devicE connected across the collector and emitter electrodes of said first transistor; and a controllable semi-conductor switching device having a pair of output electrodes connected in series with said ignition coil primary winding across said source and an input control electrode coupled to the collector electrode of said second transistor; the charging interval of said capacitor determining the anti-dwell firing period of the ignition cycle and being established at any given speed of the engine by said capacitor and first resistor, the conduction level of said voltage conduction device and any residual charge on the capacitor when said triggering signal is applied to said first transistor.

Claim 34

Apparatus for controlling the anti-dwell firing period of the ignition cycle of an internal combustion engine inductive type ignition system having a source of electrical energy, at least one sparking device and an ignition coil having a primary winding connected for energization from said source and another winding for supplying high tension energy to said sparking device; said apparatus including a triggering device driven in synchronism with the engine and providing a triggering signal voltage for each ignition cycle of the engine and an electronic control unit actuated from said triggering device and controlling the energization of said ignition coil from said electrical energy source, said control unit including a first and a second transistor each having emitter, collector and base electrodes of which the base and emitter electrodes of the first transistor are coupled to said triggering device and the emitter electrodes of both of said transistors are coupled to one side of said source, a charging circuit including a first resistor connected between the collector of said first transistor and the other side of said source and a capacitor connected between the collector of said first transistor and the base of said second transistor to charge from the source upon application of a triggering signal to said first transistor, a discharging circuit for said capacitor including a second resistor connected across the emitter and base electrodes of said second transistor and a voltage latching conduction devicE connected across the collector and emitter electrodes of said first transistor; and a controllable semi-conductor switching device having a pair of output electrodes connected in series with said ignition coil primary winding across said source and an input control electrode coupled to the collector electrode of said second transistor; the charging interval of said capacitor determining the anti-dwell firing period of the ignition cycle and being established at any given speed of the engine by said capacitor and first resistor, the conduction level of said voltage conduction device and any residual charge on the capacitor when said triggering signal is applied to said first transistor.

Claim 35

Apparatus for an inductive type ignition system in accordance with claim 28 wherein the residual charge on said capacitor is determined by the time constant of said capacitor and second resistor as related to the period of the ignition cycle at any given speed of the engine.

Claim 36

For use with an internal combustion engine having a source of direct current potential, at least one sparking device and an ignition coil having a winding connected for energization from said source and another winding for supplying high tension energy to said sparking device, an electronic ignition system of the inductive type producing an ignition cycle characterized by a dwell period during which said ignition coil is energized from said potential source for a time period which varies inversely with engine speed and by an anti-dwell period during which the energization of said coil is interrupted from said source of the remaining portion of said ignition cycle, said electronic ignition system inclding controllable output semi-conductor switching means connected in current controlling energization relation with said ignition coil across said potential source, means driven by the engine providing a triggering signal each igntiion cycle and commencing the anti-dwell period of the ignition cycle, capacitor timing circuit means between said triggering means and said output switching means controlling the duration of the anti-dwell period of the ignition cycle independently of the duration of said triggering signal, and timing circuit modifying means connected to said capacitor timing circuit for decreasing the duration of the anti-dwell period of the ignition cycle with increasing engine speed to correspondingly increase the dwell period of the ignition cycle at higher engine speeds.

Claim 37

For use with an internal combustion engine having a source of direct current potential, at least one sparking device and an ignition coil having a winding connected for energization from said source and another winding for supplying high tension energy to said sparking device, an electronic ignition system of the inductive type producing an ignition cycle characterized by a dwell period during which said ignition coil is energized from said potential source for a time period which varies inversely with engine speed and by an anti-dwell period during which the energization of said coil is interrupted from said source of the remaining portion of said ignition cycle, said electronic ignition system inclding controllable output semi-conductor switching means connected in current controlling energization relation with said ignition coil across said potential source, means driven by the engine providing a triggering signal each igntiion cycle and commencing the anti-dwell period of the ignition cycle, capacitor timing circuit means between said triggering means and said output switching means controlling the duration of the anti-dwell period of the ignition cycle independently of the duration of said triggering signal, and timing circuit modifying means connected to said capacitor timing circuit for decreasing the duration of the anti-dwell period of the ignition cycle with increasing engine speed to correspondingly increase the dwell period of the ignition cycle at higher engine speeds.

Claim 38

An electronic ignition system in accordance with claim 30 wherein said timing circuit modifying means includes capacitor charge limiting means and capacitor discharge prolonging means.