Patent ID: 7654375

Claim:
A control system for a rotation transmission device, comprising a rotation transmission device comprising a roller clutch unit including an inner member, an outer ring and rollers as engaging elements disposed between said inner member and said outer ring for selectively transmitting torque of a rotary shaft, and an electromagnetic clutch unit including an electromagnetic coil for selectively engaging and disengaging said roller clutch unit by electromagnetic force produced by said electromagnetic coil; a variable setting unit for variably applying current to said electromagnetic coil corresponding to a relative revolving speed between said inner member and said outer ring when said roller clutch unit engages; and a control unit for controlling said variable setting unit; wherein said electromagnetic coil is divided into two portions by connecting a central line to a central portion of said electromagnetic coil, and wherein a switch is provided downstream of said variable setting unit, said switch being operable to effect a change-over between a drive mode in which electric power is applied to said electromagnetic coil through a power supply line and a heating mode in which electric power is applied to said electromagnetic coil through said central line to apply currents that are opposite in direction to each other to said two portions of said coil, respectively, thereby producing magnetic fluxes from said two portions of said electromagnetic coil that cancel each other.