Patent ID: 6142130
Filing Date: 2000-11-07
Classification: F02P,H01F

Abstract:
An inductive ignition system operating at a voltage Vc with a high (voltage) end and low end, the ignition system having one or more ignition coils Ti and associated power switches Si, where i=1,2, . . . n, with each coil Ti having a primary winding of inductance Lp and primary turns Np, and a secondary winding with turns Ns, the coil primary and secondary windings defining a turns ratio N equal to Ns/Np,a first end of the primary winding of each coil Ti being interconnected to a common voltage source point and the other (second) ends to separate switch means Si with the low side of the switch means Si returned to a common point on the low end of said voltage source Vc, and the secondary winding of each coil Ti being connected across a spark gap Gi,said connections forming a set of one or more series circuits, each such circuit including at least said voltage source, each of the primary windings of said coil Ti, and corresponding switch means Si, and wherein upon turning on, or closure, of switch means Si in each such series circuit a primary current Ip builds up within the primary winding of the corresponding coil Ti to a maximum value Ipo, which occurs at switch Si opening, to energize the coil to an energy El equal to 1/2.cndot.Lp.cndot.Ipo.sup.2 which is stored in the magnetic core of the coil,the system constructed and arranged to provide:(a) voltage Vc of X times Vb where X is equal to or greater than 2 and Vb is a car battery voltage of peak nominal operating voltage of 14 volts,(b) a peak current Ipo between 16 and 48 amps,(c) a peak spark current Is between 160 ma and 640 ma,(d) a primary inductance Lp no greater than 1.0 mH,(e) a secondary coil winding resistance Rs less than 2.0 k.OMEGA.,(f) a spark current waveform of sufficient peak amplitude and shape so as to have a higher resistance to spark break-up under high flows than standard inductive ignition spark waveforms,the system further constructed and arranged to provide a turns ratio N of sufficiently low ratio, a spark gap Gi of sufficient width, and a dwell time Tdw, during which time switch Si is closed, of sufficiently short duration so that upon switch Si closure the spark gap Gi does not break down, and upon switch Si opening a high voltage of value Vs is produced across the coil secondary winding to electrically breakdown said spark gap Gi and deliver substantially all of said energy El to the spark gap as a high current spark.