GB1501621A - Spark ignition systems for internal combustion engines - Google Patents

Abstract

1501621 Ignition systems LUCAS INDUSTRIES Ltd 6 Feb 1975 [8 Feb 1974] 05822/74 Heading F1B A spark ignition system for an internal combustion engine comprises in combination engine driven means for initiating each spark and control means sensitive to one or more engine parameters for prolonging each spark under certain engine conditions. As shown when the contact breaker 32 first opens the spark is initiated by the ignition transformer 15. At the same time the generator 36 starts to operate and turns on the transistor 25 so that energy is stored in the winding 14 at a time well before the normal spark terminates the generator 36 turns the transistor 25 off and the transistor 24 on. The ignition transformer 16 now supplies energy to the plug while full energy is stored in the winding 13 again. Well before all the energy stored in the winding 14 has been dissipated the transistor 24 turns off and the transistor 25 turns on, so that the ignition transformer 15 produces the spark while the ignition transformer 16 restores the full energy level in its primary winding. Thus the spark will be prolonged and will continue to be produced at the plug until the contact breaker 32 closes again unless during the period when the contact breaker 32 is open the central device 37 provides an input to the generator 36 to terminate operation of the generator 36. The device 37 can be a simple logic arrangement receiving inputs from various transducers. In a modification there is a single ignition transformer and two energy storage inductors. During cranking it may be desirable to shortcircuit part or all of the resistor 35 and part of the resistor 31. Although a contact breaker 32 is shown the timing can be purely electronic with a signal from the computor 37 triggering the operation of the signal generator 36. In another modification a capacitor discharges into the primary winding of the ignition transformer to initiate the spark and is then connected in a resonant circuit including the primary winding to prolong the spark under certain engine conditions.