Patent attributes
An electromagnetic clutch includes an armature plate connected to a shaft and being movable axially with respect to the shaft, a rotor being rotatable relative to the shaft, and a plurality of electromagnetic coils, wherein when at least one of the electromagnetic coils are energized a magnetic field will draw the armature plate into contact with the rotor such that the rotor and the shaft are rotatably connected. The magnetic coils are connected to a common power supply providing the magnetic coils a common, non-varying, voltage and a master control switch selectively supplies power from the power supply to the magnetic coils. The magnetic coils are connected to one another in parallel and each coil has a switch to allow each coil to be energized independently of the other coils, individually or in any combination to provide a magnetic field of varying strength.
