Abstract: A transmitter wheel is used for example to detect speed changes of an internal combustion engine with high precision in order to calculate a running imbalance value from them. A transmitter wheel of this kind has for example three segments, which are ideally the same length, but in reality usually have lengths which differ slightly from one another. In order to prevent measurement errors which are caused by this, it is known to determine the actual lengths by means of an adaption process. The device according to the invention is embodied such that for each segment, it has a plurality of adaption filters to detect different adaption values for different speed ranges. It has namely turned out that in different speed ranges, different lengths are measured, which is an error that must be compensated for since the length of a segment is in fact actually constant.

Abstract: An ignition system for internal combustion engines includes a monitoring circuit (9) which is used for introducing appropriate emergency measures for protecting the catalyst in the case of faulty ignitions. The ignition system includes an evaluation device (10), which subjects the ignition-diagnostic signal (Zund OK) to statistical weighting and, when the weighted ignition-diagnostic value (ZUNTAB) exceeds a specified threshold, introduces appropriate measures, the evaluation being continued steadily so that if the value subsequently falls below the fault threshold (AFSDZU), correction is recognized and the emergency measures are withdrawn.