Slip ratio calculating device

Claim 1

A slip ratio calculating device for calculating the ratio of two revolutions given in the form of electric voltage signal comprising: a coefficient multiplying circuit for multiplying one voltage signal representing one revolution by 1/n, n being a predetermined constant; a first integrating circuit having a signal input connected to said coefficient multiplying circuit for integrating the output voltage thereof, the first integrating circuit having a reset input; a comparator having one input connected to said first integrating circuit and another input supplied with the other voltage signal representing the other revolution for comparing the two inputs and supplying an output when the two inputs become equal; a constant voltage source for supplying a predetermined Constant voltage; a second integrating circuit having an input connected to said constant voltage source for integrating said constant voltage, the second integrating circuit having a reset input; and a reset pulse generating circuit having an input connected to said comparator and an output connected to both of the reset inputs of said first and second integrating circuit for generating a reset pulse voltage upon reception of an output of said first comparator and supplying the reset pulse output to both the reset inputs of said first and second integrating circuits to reset the two integrating circuits to cause renewed integration by said two integrating circuits upon disappearance of each reset pulse and to effect thereby a representation by the peak voltage of the output of said second integrating circuit of the instantaneous slip ratio of the two revolutions.