A generator arrangement for a wind power plant includes a ring-shaped primary part, a ringshaped secondary part, and a planetary transmission arrangement disposed inside the primary part and the secondary part. In one embodiment of the present invention, a wall unit is located at a customer premises which terminates a single analog phone line and adaptively encodes using Voice over Internet Protocol technology and multiplexes a plurality of telephonic and data calls over the single analog phone line. The vehicle speed determining circuit has a characteristic in which when falling in the dead zone, the determined speed shows zero. The controller is configured to determine an ejection time interval value based on the signal.