SYSTEM FOR CONTROLLING AN ELECTROMAGNETIC CLUTCH OF A VEHICLE

摘要

An infinitely variable transmission for a vehicle employs an electromagnetic clutch having a clutch coil (15). The transmission includes a high engine speed drive range (Ds range) which when selected increases the transmission ratio to increase the effectiveness of engine braking. Selection of the drive (D) range opens a switch (55) causing a high level signal to be applied to a transistor (60) in series with the coil (15) and full clutch torque to be obtained. When the Ds rang is selected the switch (55) is closed and the control circuit (50) operates to produce a pulse train which is applied to the clutch coil transistor (60), first to decrease the coil current and hence the clutch torque, and then progressively to increase again the coil current and clutch torque.