Abstract: A method and an arrangement for regulating the signal level in detecting knocking in an internal combustion engine. A transducer, incorporated in a knocking detector, senses a parameter responding to pressure and/or temperature during combustion in the engine and emits a signal representing the degree of knocking. The output signal of the knocking detector controls a knocking-regulating quantity affecting combustion in the engine by being applied to a signal level limiting block which, when knocking sensed by the transducer exceeds a preselected level, limits the output signal level to a level corresponding to said preselected level, whereafter the output signal, at least for a limited time, can only be altered by signals representing a lesser degree of knocking than the preselected degree. Knocking can then be inhibited without delay.

Abstract: A method of avoiding abnormal combustion, so-called knocking, in an internal combustion engine, where a parameter representative of the combustion conditions in the engine is monitored. When abnormal combustion occurs, a signal representing such abnormal combustion is generated and is used to initiate an adjustment of the engine operating conditions by lowering the engine induction pressure so as to reestablish normal combustion. There is also provided an arrangement for avoiding abnormal combustion.