An ignition system for an internal combustion engine.

摘要

The system comprises: at least one spark plug (SP), at least one ignition coil (8) whose secondary winding (9) is connected to the plug (SP) a power transistor (6) whose output path is in series with the primary winding (7) of the coil (8) between the two terminals of a direct-current voltage supply (VB), and a control circuit (13) for switching the transistor (6) from the cut-off condition to the saturated condition to enable current to flow in the primary winding (7) of the coil (8) in order to generate a spark. Conveniently, the control circuit (13) is arranged to switch the transistor (6) progressively from the cut-off condition to the saturated condition, in dependence on the voltage detected between the terminals of its output path by the application of a driver signal (C,P) which is first continuous and then pulsed. <IMAGE>