CD Ignition with automatic spark retard

A capacitor discharge ignition circuit adapted for use with an internal combustion engine and for connection to an ignition coil primary winding, said circuit comprising a charge capacitor, an ignition SCR, and spark retard circuit means connecting said charge capacitor and said ignition SCR in series relationship with said primary winding and operative for selectively preventing full discharge of said capacitor through said primary winding for a predetermined period of time after said ignition SCR is rendered conductive, thereby providing for automatic spark retard at higher engine rpm, and also operative for selectively isolating the primary winding and said ignition SCR from said charge capacitor to provide for immediate recharging of said charge capacitor after said charge capacitor has discharged through said primary winding to effect an ignition spark.

A capacitor discharge ignition system adapted for use with an internal combustion engine and comprising a charge capacitor, an ignition coil primary winding, an ignition SCR, and spark retard circuit means connected in series relationship with said charge capacitor, said primary winding, and said ignition SCR, said spark retard circuit means operative for selectively preventing full discharge of said capacitor through said primary winding for a predetermined period of time after said ignition SCR is rendered conductive, thereby providing for automatic spark retard at higher engine rpm.

A capacitor discharge ignition system for a four cylinder engine comprising a charge capacitor, a power supply including a full-wave diode rectifying bridge having its output terminals connected across said charge capacitor, four sets of ignition components, each set including an ignition coil primary winding, and an ignition SCR, said system further comprising spark retard circuit means connected in series relationship with said charge capacitor, and operative for selectively preventing full discharge of said capacitor through said primary winding for a predetermined period of time after each of said ignition SCR's is rendered conductive, thereby providing for automatic spark retard at higher engine rpm, and also operative for selectively isolating the primary winding and said ignition SCRs from said charge capacitor to provide for immediate recharging of said charge capacitor after said charge capacitor has discharged through said primary winding to effect an ignition spark.

An automatic spark retard circuit adapted for use with a capacitor discharge ignition system for an engine, said system including a charge capacitor, an ignition coil primary winding, and an ignition SCR, said spark retard circuit comprising a thyristor having a gate, an anode and a cathode, said thyristor having an anode-cathode path adapted for connection in series relationship with the charge capacitor, the primary winding and the ignition SCR, said spark retard circuit further comprising an RC delay network including a capacitor and a resistor with a junction therebetween, said network having one end connected to said thyristor anode and having an opposite end connected to said thyristor gate, said spark retard circuit further comprising voltage threshold means connected between said thyristor gate and said RC delay network junction for selectively preventing full discharge of said capacitor through said primary winding for a predetermined period of time after said ignition SCR is rendered conductive, thereby providing for automatic spark retard at higher engine rpm.