Patent ID: 7121967

Claim:
A control circuit for generating a control signal (I) for controlling the transmission ratio of a belt transmission of a vehicle, the belt transmission being adjustable continuously with respect to its transmission ratio, the belt transmission including a drive end, an output end and a primary valve driven by the control signal (I) for adjusting the transmission ratio, the control circuit comprising: means for receiving operating parameters of said vehicle; means for generating said control signal (I) in dependence upon a value (y) for a wanted speed of the transmission ratio change or a quantity derived therefrom; means for calculating said value (y) from said operating parameters transmitted to the control circuit; and, wherein a value (Q p,des ) is calculated as a derived quantity from the value (y) for the wanted speed of the transmission ratio change and, if required, additional operating parameters; the value (Q p,des ) representing a wanted volume flow of a fluid into a primary fluid chamber of the drive end; and, the control signal (I) being generated in dependence upon the value (Q p,des ) for the volume flow.