Gated knock detector for internal-combustion engines

Abstract From the Canadian patent

A system for use with an internal combustion engine which reduces, or eliminates, engine knock and attendant engine damage. An audio transducer is placed on an engine cylinder to convert audio signals occurring within the combustion chamber into an electrical signal. This signal is sampled and filtered and the amplitudes of two time-sequenced segments are compared. One of these segments is timed for an interval during which detonation if, any, is likely to occur, and the other of these segments is timed for an interval-during which no detonation is likely to occur. When the amplitude of the sample from the segment of likely detonation exceeds the amplitude of the sample from the segment of …