Primary current switching device for ignition module of internal combustion engine, regulates internal control signal so that rate of change of primary current is within limits, if external control signal is erroneous

摘要

A RC circuit monitors the duration of high state of an external control signal. A drive circuit (216) regulates the internal ignition control signal and applies to an IGBT (204), to maintain the rate of change of primary current within limits while reducing to zero, when the external control signal is judged to be erroneous.