Solid state magneto ignition switching device

Claim 2

An ignition control circuit for an internal combustion engine having a magnet for magnetically coupling with a stator in synchronism with engine rotation to induce current flow between first and second terminals of a primary winding on the stator followed by interruption of the current to thereby induce a high voltage in a secondary winding that is connected to a spark plug; said control circuit comprising: a solid state switching device having its switching path connected in a circuit between said first and second terminals of the primary winding and having a control terminal to which a control voltage above a predetermined level is applied to switch said device to a conductive state, a programmable unijunction transistor (PUT) having an anode, a cathode and a gate, voltage determining means connected between said first primary winding terminal and said control terminal for developing a voltage and means for applying said voltage between the anode and gate of said PUT, coupling of said magnet and stator causing voltage to be developed in said primary winding to thereby attain said predetermined voltage for switching said switching device to its conductive state whereby to increase current flow in said primary winding, and the concurrent increase in said PUT anode-to-gate voltage causing said PUT to conduct and remove said voltage from said control terminal to thereby switch said switching device to a nonconductive state whereby current flow through said primary winding is interrupted, and diode means connected between said second and first primary winding terminals for conducting the reverse current in said winding.

Claim 3

The control circuit according to claim 1 wherein said switching device comprises transistor means having a base constituting said control terminal, an emitter coupled to said second primary winding terminal and having a collector coupled to said first primary winding terminal.

Claim 4

The control circuit according to claim 1 wherein said voltage determining means is comprised of serially connected resistors, the anode of said PUT being connected to a point intermediate of said resistors, the gate of said PUT being connected to said control terminal and the cathode of said PUT being connected to said primary winding second terminal.

Claim 5

The control circuit according to any of claims 1, 2 or 3 including resistor means in a circuit connecting said switching device control terminal and said gate of the PUT.

Claim 6

The control circuit according to claim 2 including diode means through which said collector is coupled to said first primary winding terminal, said diode means being arranged to conduct in the same direction as said transistor means switching device when said device is in its conductive state.

Claim 7

The control circuit according to claim 2 including resistor means through which said collector is coupled to said first primary winding terminal.

Claim 8

The control circuit according to claim 2 including resistor means in a circuit connecting said control terminal and said gate of the PUT, diode means through which said collector is coupled to said first primary winding terminal, said diode means being arranged to conduct in the same direction as said transistor means switching device when said device is in its conductive state.

Claim 9

The control circuit according to claim 2 including: resistor means in a circuit connecting said control terminal and said gate of the PUT, and resistor means through which said collector is coupled to said first primary winding terminal.

Claim 10

An ignition control circuit for an internal combustion engine having a magnet for magnetically coupling with a stator in synchronism with engine rotation to induce current flow between first and second terminals of a primary winding on the stator followed by interruption of the current to thereby induce a high voltage in a secondary winding that is connected to a spark plug; said control circuit comprising: a solid state switching device having its switching path connected in a circuit between said first and second terminals of the primary winding and having a control terminal to which a control voltage above a predetermined level is applied to switch said device to a conductive state, a programmable unijunction transistor (PUT) having an anode, a cathode and a gate, a first voltage determining circuit connected between said first primary winding terminal and said control terminal, and an intermediate point in said first divider circuit coupled to said anode of the PUT, a second voltage determining circuit connected between said control terminal and said second primary winding terminal, and an intermediate point in said second divider circuit coupled to said gate of the PUT, coupling of said magnet and stator causing voltage to be developed in said primary winding and current to flow in said first voltage determining circuit to thereby attain said predetermined voltage for switching said switching device to its conductive state whereby to increase the current flowing in said primary winding, and the resulting proportional increase in current flowing through said first and second voltage determining circuits causing an increasing voltage at said anode of the PUT relative to said gate of the PUT causing said PUT to conduct and remove the voltage from said control terminal to thereby switch said switching device to a nonconductive state whereby current flow through said primary winding is interrupted, and diode means connected between said second and first primary winding terminals for conducting the reverse current in said primary winding.

Claim 11

An ignition control circuit for an internal combustion engine having a magnet for magnetically coupling with a stator in synchronism with engine rotation to induce current flow between first and second terminals of a primary winding on the stator followed by interruption of the current to thereby induce a high voltage in a secondary winding that is connected to a spark plug; said control circuit comprising: a solid state switching device having its switching path connected in a circuit between said first and second terminals of the primary winding and having a control terminal to which a control voltage above a predetermined level is applied to switch said device to a conductive state, a programmable unijunction transistor (PUT) having an anode, a cathode and a gate, a first voltage determining circuit connected between said first primary winding terminal and said control terminal, and an intermediate point in said first divider circuit coupled to said anode of the PUT, a second voltage determining circuit connected between said control terminal and said second primary winding terminal, and an intermediate point in said second divider circuit coupled to said gate of the PUT, coupling of said magnet and stator causing voltage to be developed in said primary winding and current to flow in said first voltage determining circuit to thereby attain said predetermined voltage for switching said switching device to its conductive state whereby to increase the current flowing in said primary winding, and the resulting proportional increase in current flowing through said first and second voltage determining circuits causing an increasing voltage at said anode of the PUT relative to said gate of the PUT causing said PUT to conduct and remove the voltage from said control terminal to thereby switch said switching device to a nonconductive state whereby current flow through said primary winding is interrupted, and diode means connected between said second and first primary winding terminals for conducting the reverse current in said primary winding.

Claim 12

The ignition control circuit according to claim 9 wherein said switching device comprises transistor means having a base constituting said control terminal, an emitter coupled to said second primary winding terminal and having a collector coupled to said first primary winding terminal.

Claim 13

The ignition control circuit according to claim 9 wherein said first and second voltage determining circuits are comprised of series connected resistors.

Claim 14

The control circuit according to claim 10 including diode means through which said collector is coupled to said first primary winding terminal, said diode means being arranged to conduct in the same direction as said transistor means switching device when said device is in its conductive state.

Claim 15

The control circuit according to claim 10 incuding resistor means through which said collector is coupled to said first primary winding terminal.

Claim 16

An ignition control circuit for an internal combustion engine having a magnet for magnetically coupling with a stator in synchronism with engine rotation to induce current flow between first and second terminals of a primary winding on the stator followed by interruption of the current to thereby induce a high voltage in a secondary winding that is connected to a spark plug; said control circuit comprising: a solid state switching device having its switching path connected in a circuit between said first and second terminals of the primary winding and having a control terminal to which a control voltage above a predetermined level is applied to switch said device to a conductive state, a programmable unijunction transistor (PUT) having an anode, a cathode and a gate, a voltage divider circuit including first resistor means connected on one side to said first primary winding terminal, second resistor means connected on one side to the other side of said first resistor means, a third resistor means and capacitor means connected in a parallel circuit one side of which is connected to the other side of said second resistor means and the other side of which is connected to said control termnal, the anode of said PUT connected intermediately of said first and second resistor means. means for coupling said control terminal to said gate of the PUT, coupling of said magnet and stator causing said voltage to be developed in said primary winding to thereby attain said predetermined voltage for switching said switching device to its conductive state whereby to increase current flow in said primary winding, and the concurrent increase in the anode-to-gate voltage across series connected second resistor means and parallel resistor and capacitor circuit causing said PUT to conduct and remove said voltage from said control terminal to thereby switch said switching device to a nonconductive state whereby current flow through said primary winding is interrupted, and diode means connected between said second and first primary winding terminals for conducting the reverse current in said winding.

Claim 17

An ignition control circuit for an internal combustion engine having a magnet for magnetically coupling with a stator in synchronism with engine rotation to induce current flow between first and second terminals of a primary winding on the stator followed by interruption of the current to thereby induce a high voltage in a secondary winding that is connected to a spark plug; said control circuit comprising: a solid state switching device having its switching path connected in a circuit between said first and second terminals of the primary winding and having a control terminal to which a control voltage above a predetermined level is applied to switch said device to a conductive state, a programmable unijunction transistor (PUT) having an anode, a cathode and a gate, a voltage divider circuit including first resistor means connected on one side to said first primary winding terminal, second resistor means connected on one side to the other side of said first resistor means, a third resistor means and capacitor means connected in a parallel circuit one side of which is connected to the other side of said second resistor means and the other side of which is connected to said control termnal, the anode of said PUT connected intermediately of said first and second resistor means. means for coupling said control terminal to said gate of the PUT, coupling of said magnet and stator causing said voltage to be developed in said primary winding to thereby attain said predetermined voltage for switching said switching device to its conductive state whereby to increase current flow in said primary winding, and the concurrent increase in the anode-to-gate voltage across series connected second resistor means and parallel resistor and capacitor circuit causing said PUT to conduct and remove said voltage from said control terminal to thereby switch said switching device to a nonconductive state whereby current flow through said primary winding is interrupted, and diode means connected between said second and first primary winding terminals for conducting the reverse current in said winding.

Claim 18

The control circuit according to claim 14 wherein said means for coupling said control terminal to the gate of said PUT is a resistor means.

Claim 19

The control circuit according to any of claims 14 or 15 wherein said switching device comprises transistor means having a base constituting said control terminal, an emitter coupled to said second primary winding terminal and having a collector coupled to said first primary winding terminal.

Claim 20

The control circuit according to claim 16 including diode means through which said collector is coupled to said first primary winding terminal, said diode means being arranged to conduct in the same direction as said transistor means switching device when said device is in its conductive state.

Claim 21

The control circuit according to claim 16 including resistor means through which said collector is coupled to said first primary winding terminal.

Claim 22

The control circuit according to claim 14 wherein said switching device comprises transistor means having a base constituting said control terminal, an emitter coupled to said second primary winding terminal and having a collector coupled to said first primary winding terminal, and said means for coupling said control terminal to the gate of said PUT is a resistor means.