Ignition-timing apparatus

Claim 1

Ignition timing apparatus for a combustion engine having at least one spark plug, comprising, in combination, ignition coil means including a primary winding, and a secondary winding connected with said spark plug; an electronic switch including a first terminal connected with said primary winding, and a second terminal, said switch being connected in series with said primary winding and having a control electrode responsive to voltage pulses having at least a minimum threshold voltage to actuate said switch for creating an impulse in said primary winding causing a spark; means for applying a voltage to said primary winding and said second terminal of said switch; a control device including two electrically different first and second control circuits respectively including first and second control windings, and diode means connected to said control electrode, said first and second control windings being wound in opposite directions and having a pair of ends connected to each other and to said second terminal, said second terminal being at ground potential, said first and second control windings having a pair of other ends connected with said diode means, said diode means being connected between said other ends of said control windings and said control electrode of said electronic switch; flux generating means; and drive means for moving said flux generating means and said control windings relative to each other in timed relation with the movements of said combustion engine so that said first and second control windings are successively influenced by the flux whereby different voltage pulses are successively generated in said first and second electrically different control circuits and transmitted to said control electrode, the voltage pulse first Generated in said first control winding being below said threshold voltage of said control electrode at starting speeds of said combustion engine and of said drive means and above said threshold voltage at normal speed, and the voltage pulse later generated in said second control winding being above said threshold voltage at starting speeds so that said electronic switch is earlier actuated at said normal speed under the control of said first control circuit and earlier causes a spark of said spark plug than under the control of said second control circuit at the low starting speeds of said combustion engine.