Abstract In a magneto ignition system where the magneto generator has two windings with a different number of turns, a diode is connected between the winding with the larger number of turns and the capacitor, the discharge of which through the spark coil generates the ignition voltage. The two windings are excited in phase. A second diode is connected between the two windings in such a way that when there is a positive voltage half-wave of the polarity which causes the first diode to conduct, the second diode is blocked so long as the winding with the larger number of turns has a voltage exceeding that across the winding with the smaller number of turns. At higher speeds the second diode conducts, thus preventing the capacitor voltage at ignition time from dropping with increasing speed. During voltage half-waves of the opposite polarity, when both windings are unloaded, the second diode conducts at whatever the speed the engine is running, reducing the peak voltage by the equalizing current that flows and thus protects the first diode against the possibility of excessive back voltage.
A magneto ignition system for an internal combustion engine, comprising: a capacitor; a spark coil having its primary winding in circuit with a semiconductor switch and said capacitor and having its secondary winding in circuit with at least one spark plug of said engine; means for closing said semiconductor switch at the desired ignition time for said engine to produce a spark; said magneto generator having first and second armature windings positioned so as to be excited in phase synchronism, said first winding having a substantially larger number of turns than said second winding; a first diode (19) connected between one end (16b) of said first winding (16) and said capacitor (20) for the charging of said capacitor by said generator; and additional diode rectifying means (18) connected in series with said second armature winding (17), the series combination of said second armature winding (17) and said additional diode rectifying means (18) being connected in parallel with said first armature winding, said additional diode rectifying means being so poled that during a generated half-wave of polarity such that said first diode conducts, said second diode is blocked so long as the voltage across said first winding exceeds the voltage across said second winding.
Claim 2
Dependent Claim
203 words
A magneto ignition system for an internal combustion engine, comprising: a capacitor; a spark coil having its primary winding in circuit with a semiconductor switch and said capacitor and having its secondary winding in circuit with at least one spark plug of said engine; means for closing said semiconductor switch at the desired ignition time for said engine to produce a spark; said magneto generator having first and second armature windings positioned so as to be excited in phase synchronism, said first winding having a substantially larger number of turns than said second winding; a first diode (19) connected between one end (16b) of said first winding (16) and said capacitor (20) for the charging of said capacitor by said generator; and additional diode rectifying means (18) connected in series with said second armature winding (17), the series combination of said second armature winding (17) and said additional diode rectifying means (18) being connected in parallel with said first armature winding, said additional diode rectifying means being so poled that during a generated half-wave of polarity such that said first diode conducts, said second diode is blocked so long as the voltage across said first winding exceeds the voltage across said second winding.
Claim 3
Dependent Claim
40 words
A magneto ignition system as defined in claim 1 in which each of said armature windings is wound on a chord armature arranged within a multiple pole field rotor (11) and supported on opposite halves of an armature plate (13).
Claim 4
Dependent Claim
28 words
A magneto ignition system as defined in claim 1 in which the respective armatures (14,15) carrying the armature windings (16, 17) are magnetically in parallel with each other.
Claim 5
Dependent Claim
19 words
A magneto ignition system as defined in claim 3 in which the two armatures (14,15) are in superimposed arrangement.
Claim 6
Dependent Claim
50 words
A magneto ignition system as defined in claim 1 in which said additional diode rectifying means (18) is a diode connected between one end (17b) of said second armature winding (17) and the common connection of one end (16b) of said first armature winding (16) and said first diode (19).