A cam sensor is provided in a position opposing one surface side of a cam driven sprocket in a valve timing control device. When the valve timing control device is in a high revolution state, a weight is pivoted by centrifugal force caused by the rotation. This allows a projection at the weight to be detected by the cam sensor. In this case, for each rotation of the valve timing control device, the projection of the weight passes the detectable position of the cam sensor and a pulse is generated in a cam signal to be transmitted from the cam sensor to an ECU.