Ignition systems for internal combustion engines
AssigneeLumenition Limited
InventorEric H. Ford
Life of this patent
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Abstract
A closed loop electronic ignition system for internal combustion engines, in which a comparison is made between a signal derived from a fixed predetermined crank-shaft angle, and a signal derived from the commencement of the second stage of combustion within a cylinder of the engine, and if non-coincidence is detected between the two signals, the ignition timing is either advanced or retarded so as to maintain coincidence between the signals, so that the second stage of combustion always occurs at the fixed predetermined crank angle, the spark then being extinguished by switching the ignition coil "on" at this predetermined crank-shaft angle, irrespective of engine requirements.
Claims8
An electronic ignition system including:
- means for generating a series of square wave voltage pulses whose mark space ratio is variable, one edge of said waveform always occurring at a fixed predetermined crank-shaft position, whilst the other edge is variable for the purpose of advancing or retarding the ignition;
- means for varying the mark space ratio of the generated square wave voltage pulses in response to engine requirements;
- means for deriving a signal from the second stage of combustion representative of a selected point on the pressure rise curve;
- means operative from a timing comparison between the occurrence of said derived signal and said fixed edge of the square voltage pulses to vary the mark space ratio of said voltage pulses and hence the ignition timing so maintaining coincidence between said derived signal and the fixed edge of the square wave voltage pulses.
Dependencies are inferred from the claim text.