Abstract: An electric heating device in an exhaust gas system, the device having an outer circumferential, circular, housing, wherein a rib structure is arranged in the housing. The rib structure can be heated by applying an electric current. The rib structure is arranged with rib rows parallel to one another in the housing, wherein the parallel-arranged rib rows are arranged such that they are electrically connected to one another in series or in parallel.

Abstract: Systems and methods for mitigating cable twists for underwater cleaners are provided. Cable twist mitigation logic is stored in a memory associated with a pool or spa cleaner, and controls operation of the cleaner in order to mitigate cable twists. A sequence of cleaner orientations is retrieved from memory and compared to one or more pre-defined sequences known to contribute to cable twist. If the sequence of cleaner orientations matches the one or more pre-defined sequences, a twist angle accumulator is incremented by a pre-defined twist angle corresponding to the one or more pre-defined sequences. The system determines whether the cleaner is turning on a surface of a pool or spa, and if so, controls turning of the cleaner using an accumulated angle stored in the twist angle accumulator, in order to mitigate cable twists. A user-definable bias value could also be applied by the system, in order to further mitigate cable twists.

Abstract: The present invention relates to an electric heating device (3) in an exhaust gas system (1), having an outer circumferential, in particular circular, housing (4), wherein a rib structure is arranged in the housing (4), which rib structure can be heated by applying an electric current to it. The rib structure is arranged with rib rows (7) parallel to one another in the housing (4), wherein the parallel-arranged rib rows (7) are arranged such that are electrically connected to one another in series or in parallel.