Ignition system

Claim 1

An ignition circuit for an internal combustion engine comprising (a) an ignition circuit generating an ignition timing signal, (b) an inhibition circuit comprising an r.p.m. detector circuit and a first gating circuit shunting said first gating circuit in response to output from said r.p.m. detector circuit, for inhibiting generation of said ignition timing signal when the r.p.m. of said engine is below a predetermined value; (c) an interruption circuit comprising series connection of a second gating circuit to said inhibition circuit and a time-constant-discharge-circuit comprising a parallel connection of a resistor and a capacitor, and a diode preventing rapid discharge of said capacitor; (d) said time constant discharge circuit shunting said second gating circuit and preventing operation for said inhibition circuit in response to charged voltage in said capacitor when a starter switch is in "ON" position, and continuing to shunt said second gating circuit and to prevent operation of said inhibition circuit in the "ON" position of said starter switch and for a constant time period, just after said starter switch is turned to "OFF" position in response to still charged voltage in said capacitor.