| 摘要 |
A knocking sensor provides output signals which are compared in a comparator (14) with a reference (16), knocking signals (FIG. 3: U17) exceeding the reference (U16); during predetermined cyclically recurring test intervals (FIG. 2: 19), for example after each 1000 ignition events, a test signal is generated at a terminal (15) of a microprocessor (12) and applied to the comparator (14) to lower the reference level (16), so that noise signals will cause a simulated, or pseudo knocking signal to be generated. Simultaneous occurrence of the simulated, or pseudo knocking signal and test signals indicates appropriate function of the knocking system; failure of the pseudo knocking signal to occur with the lowered reference generates control output from the microprocessor, for example by retarding ignition of an ignition system (13). |
