A raising wheelchair comprises a wheeled frame and a raising system mounted to the frame and supporting a seat and a backrest. The blower wheel housing comprises a sheet metal scroll and a contiguous sheet metal first side plate having a substantially planar first sidewall portion and a first peripheral portion. The timing-reference signal may be generated from GPS signals when available or generated from TOA and trajectory extrapolations when the GPS signals are not available. The polymerized olefins include ethylene, \u03b1-olefins and functionalized olefins. The contactor sends a test signal from the circuit board to measurement electronics.