Distributorless ignition system for multicylinder internal-combustion engines

Claim 1

In an ignition system for a multicylinder, spark-ignition, internal-combustion engine, wherein an ignition coil develops voltages in its two opposite directions for causing discharges at first, second, third and fourth spark plugs in timed relation to the revolutions of the engine, the improvement which comprises: (a) a first high-voltage rectifier diode connected in series with the first spark plug to form a first ignition circuit which is connected at one end to one extremity of the ignition coil, the first diode being oriented to permit current flow to the first spark plug in response to the voltage developed in a first direction in the ignition coil; (b) a second high-voltage rectifier diode connected in series with the second spark plug to form a second ignition circuit which is connected at one end to said one extremity of the ignition coil and at the other end to the other end of the first ignition circuit, the second diode being oriented to permit current flow to the second spark plug in response to the voltage developed in a second direction in the ignition coil; (c) a third high-voltage rectifier diode connected in series with the third spark plug to form a third ignition circuit which is connected at one end to the other extremity of the ignition coil and at the other end to said other ends of the first and second ignition circuits, the third diode being oriented to permit current flow to the third spark plug in response to the voltage developed in the second direction in the ignition coil; and (d) a fourth high-voltage rectifier diode connected in series with the fourth spark plug to form a fourth ignition circuit which is connected at one end to said other extremity of the ignition coil and at the other end to said other ends of the first, second and third ignition circuits, the fourth diode being oriented to permit current flow to the fourth spark plug in response to the voltage developed in the first direction in the ignition coil; (e) each diode comprising a stack of square-shaped silicon rectifier diode chips, each having a reverse breakdown voltage in the range of from about 400 to about 850 volts in order to enable the diode to withstand steep overvoltages, the reverse breakdown voltage of each diode ranging from about 27.5 to about 45.0 kilovolts, whereby each diode can function without degradation or rupture even when current flows therethrough in its reverse breakdown region, and can dampen voltages greater than the reverse breakdown voltage thereof.