Transistorized magneto ignition system for internal combustion engines

Claim 2

In an internal combustion engine ignition system having a magneto armature provided with at least one winding arranged to be excited by a magnetized rotor driven by tHe engine, and having voltage step-up means coupled with said magneto armature, which means is coupled with a low-voltage winding of said armature and connected by ignition cable to at least one spark plug, an ignition control circuit for connection to said low-voltage winding of said armature, comprising: a controllable semiconductor device (16) having its switching path in circuit with said low-voltage winding; pulse signal means to derive a timing signal for ignition and to supply said signal to the control electrode of said semiconductor device (16); at least one diode (17,18) connected in series with said switching path of said semiconductor device (16) and poled for conduction in the same direction as said switching path, and resistance means (19) for turning on said semiconductor device (16) during positive half waves of the output of said lowvoltage winding, except while said signal is supplied by said pulse signal means as aforesaid, said resistance means (19) having only two terminals connected in said ignition control circuit and being connected by said terminals, between the control electrode of said semiconductor device (16) and the terminal of said diode(s) which is farthest from the connection thereof to said switching path.

Claim 3

An ignition control circuit as defined in claim 1, in which said diode or diodes are connected to the collector end of said switching path of said semiconductor device.

Claim 4

An ignition control circuit as defined in claim 2, in which two diodes (17,18) in series with each other are connected in series between said collector end of said switching path and one end of said primary winding (13), in which, further, the emitter end of said switching path is connected to the other end of said primary winding (13a) and the control electrode of said semiconductor device is connected both to said trigger signal means and, through said resistance means (19), with the end of said primary winding (13a) which is connected to said diodes.

Claim 5

An ignition control circuit as defined in claim 1, in which said pulse signal means includes a circuit having a switching device (20) responsive to a source of control signals and in circuit with the control electrode of said semiconductor device (16).

Claim 6

In an internal combustion engine ignition system having a magneto armature provided with at least one winding arranged to be excited by a magnetized rotor driven by the engine, and having voltage step-means coupled with a low-voltage winding of said armature and connected by ignition cable to at least one spark plug, an ignition control circuit for connection to said low-voltage winding of said armature, comprising: a controllable semiconductor device (16) having its switching path in circuit with said low-voltage winding; pulse signal means to derive a timing signal for ignition and to supply said signal to the control electrode of said semiconductor device (16), said pulse signal means including a switching device (20) responsive to a source of control signals; at least one diode (17,18) connected in series with said switching path of said semiconductor device (16) and poled for conduction in the same direction as said switching path; a capacitor (21) and a charging circuit diode (22) therefor, said capacitor having one terminal connected to the common connection of said semiconductor device (16) and said low-voltage winding (13a) and its other terminal connected to said switching device (20) and to one terminal of said charging circuit diode (22), said charging circuit diode having its other terminal connected to the other end of said low-voltage winding (13a), and being poled in the opposite direction of conduction with respect to said diode(s) (17,18) in circuit with said primary winding (13a) and the switching path of said semiconductor device (16), and resistance means (19) for turning on said semiconductor device (16) during positive half waves of the output of said low-voltage winding except while said signal is supplied by said pulse signal means as aforesaid, said resistance means being connected between the control electrode of said semiconductor device (16) and the terminal of said diode(s) (17,18) which is farthest from the connection thereof to said switching path.

Claim 7

In an internal combustion engine ignition system having a magneto armature provided with at least one winding arranged to be excited by a magnetized rotor driven by the engine, and having voltage step-means coupled with a low-voltage winding of said armature and connected by ignition cable to at least one spark plug, an ignition control circuit for connection to said low-voltage winding of said armature, comprising: a controllable semiconductor device (16) having its switching path in circuit with said low-voltage winding; pulse signal means to derive a timing signal for ignition and to supply said signal to the control electrode of said semiconductor device (16), said pulse signal means including a switching device (20) responsive to a source of control signals; at least one diode (17,18) connected in series with said switching path of said semiconductor device (16) and poled for conduction in the same direction as said switching path; a capacitor (21) and a charging circuit diode (22) therefor, said capacitor having one terminal connected to the common connection of said semiconductor device (16) and said low-voltage winding (13a) and its other terminal connected to said switching device (20) and to one terminal of said charging circuit diode (22), said charging circuit diode having its other terminal connected to the other end of said low-voltage winding (13a), and being poled in the opposite direction of conduction with respect to said diode(s) (17,18) in circuit with said primary winding (13a) and the switching path of said semiconductor device (16), and resistance means (19) for turning on said semiconductor device (16) during positive half waves of the output of said low-voltage winding except while said signal is supplied by said pulse signal means as aforesaid, said resistance means being connected between the control electrode of said semiconductor device (16) and the terminal of said diode(s) (17,18) which is farthest from the connection thereof to said switching path.

Claim 8

An ignition control circuit as defined in claim 1, in which a second resistance means (24) is connected in parallel with the control path of said semiconductor device (16).

Claim 9

An ignition control circuit as defined in claim 1 in which said semiconductor device (16) is a single transistor.

Claim 10

An ignition control circuit as defined in claim 1, in which said semiconductor device (16) is a plurality of transistors in a Darlington circuit combination.

Claim 11

An ignition control circuit as defined in claim 1, in which said pulse signal means includes a control transistor (31) having its collector-emitter path connected in parallel to the control path of said semiconductor device (16).

Claim 12

In an internal combustion engine ignition system having a magneto armature provided with at least one winding arranged to be excited by a magnetized rotor driven by the engine, and having voltage step-up means coupled with a low-voltage winding of said armature and connected by ignition cable to at least one spark plug, an ignition control circuit for connection to said low-voltage winding of said armature, comprising: a Darlington circuit transistor combination (16) having its switching path in circuit with said low-voltage winding; pulse signal means to derive a timing signal for ignition and to supply said signal to the control electrode of said Darlington circuit transistor combination (16), said pulse signal means including a control transistor (31) having its collector-emitter path connected in parallel with the control path of said Darlington circuit transistor combination (16) and including a voltage divider (32) connected across said low-voltage winding (13a), the base of said control transistor (31) being connected to the tap of said voltage divider; at least one diode (17,18) connected in series with said switching path of said semiconductor device (16) and poled for conduction in the same direction as said switching path; resistance means (19) for turning on said Darlington combination (16) during positive half waves of the output of said low-voltage winding except while said signal is supplied by said pulse signal means as aforesaid, said resistance means being connected between the control electrode of said Darlington combination (16) and the terminal of said diode(s) (17,18) which is farthest from the connection thereof to said switching path.

Claim 13

In an internal combustion engine ignition system having a magneto armature provided with at least one winding arranged to be excited by a magnetized rotor driven by the engine, and having voltage step-up means coupled with a low-voltage winding of said armature and connected by ignition cable to at least one spark plug, an ignition control circuit for connection to said low-voltage winding of said armature, comprising: a Darlington circuit transistor combination (16) having its switching path in circuit with said low-voltage winding; pulse signal means to derive a timing signal for ignition and to supply said signal to the control electrode of said Darlington circuit transistor combination (16), said pulse signal means including a control transistor (31) having its collector-emitter path connected in parallel with the control path of said Darlington circuit transistor combination (16) and including a voltage divider (32) connected across said low-voltage winding (13a), the base of said control transistor (31) being connected to the tap of said voltage divider; at least one diode (17,18) connected in series with said switching path of said semiconductor device (16) and poled for conduction in the same direction as said switching path; resistance means (19) for turning on said Darlington combination (16) during positive half waves of the output of said low-voltage winding except while said signal is supplied by said pulse signal means as aforesaid, said resistance means being connected between the control electrode of said Darlington combination (16) and the terminal of said diode(s) (17,18) which is farthest from the connection thereof to said switching path.

Claim 14

An ignition control circuit as defined in claim 10, in which one branch of said voltage divider (32) includes a Zener diode (36) which is so poled that when the Zener voltage is reached, said control transistor (31) receives a potential such as to switch said control transistor (31) into its conductive condition.

Claim 15

An ignition control circuit as defined in claim 11, in which said Zener diode (36) is connected in series with at least one additional diode (34,35).

Claim 16

An ignition system as defined in claim 1, in which said primary winding (13) is bridged by a series combination of an additional resistor (39) and a reverse wave trimming diode (38), said reverse wave trimming diode being poled with its direction of easy conduction opposite to that of the diode or diodes (17, 18) connected between said primary winding (13a) and the switching path of said semiconductor device (16).