Abstract: An imaging device includes a fuser assembly including a heat transfer member and a backup member positioned to engage the heat transfer member thereby defining a fusing nip therewith. A motor is coupled to the backup member for rotating the backup member. A controller coupled to the fuser assembly controls the motor using time-based commutation for a period of time to rotate the backup member at a slower speed relative to a speed for performing a toner fusing operation. In memory, at least one lookup table is stored having entries which, when sequentially accessed by the controller during the time-based commutation, are used to generate one or more drive signals for the motor to cause current flowing through windings of the motor to have a substantially sinusoidal waveform.

Abstract: An imaging device includes a fuser assembly including a heat transfer member and a backup member positioned to engage the heat transfer member thereby defining a fusing nip therewith. A motor is coupled to the backup member for rotating the backup member. A controller coupled to the fuser assembly controls the motor using time-based commutation for a period of time to rotate the backup member at a slower speed relative to a speed for performing a toner fusing operation. In memory, at least one lookup table is stored having entries which, when sequentially accessed by the controller during the time-based commutation, are used to generate one or more drive signals for the motor to cause current flowing through windings of the motor to have a substantially sinusoidal waveform.

Abstract: An improved variable speed fan controller for use in devices such as laser printers. The controller automatically adjusts its output signal to fans such that a fan quickly settles into an appropriate operating speed, even if the fan has been newly installed into the equipment. The controller can store values in non-volatile memory, if desired, to keep track of recent changes in the fan's operating parameters and corresponding control signal values. The controller is able to control relatively inexpensive fans that don't necessarily operate at a predictable fan rotating speed under repeatable conditions and control signals, by controlling the fan to an initial or predetermined rotating speed; if the fan isn't running within a suitable range of rotational speeds, then determining whether a fine or coarse adjustment should be made to the fan's rotational speed. The controller makes appropriate adjustments until the fan's rotational speed is within acceptable operating tolerances.