CPC F02P 17/12 (2013.01) [F02P 3/051 (2013.01); H01T 13/58 (2013.01); H01T 13/60 (2013.01); F02P 2017/121 (2013.01)] | 8 Claims |
1. A method of detecting a breakdown voltage between electrodes of a spark plug connected to an ignition coil for a cylinder ignition system in an internal combustion engine, said coil comprising a primary winding and a secondary winding, wherein:
the primary winding is connected to a voltage generator and is provided with a switch that can be switched between an open condition and a closed condition to initiate a breakdown and spark at the spark plug;
the secondary winding is connected to a spark plug;
said method comprising the steps of:
detecting a switching of said switch from the closed condition to the open condition;
detecting a value of a voltage on the primary winding during a time interval following said switching of the switch;
generating a first signal representative of a development of the value of said voltage during said time interval;
integrating said first signal to generate an integrated signal increasing over time during said time interval;
identifying an instant representative of the breakdown at ends of said spark plug when, during said time interval, a second signal representative of a current on the secondary winding exceeds a predetermined threshold value;
determining a breakdown voltage value according to a value of the integrated signal at the instant representative of said breakdown.
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