Electronic motor controls, laundry machines including such controls and/or methods of operating such controls

A method for driving an electronically commutated motor cyclically in opposite directions during each of a sequence of half cycles, each half cycle comprising the steps of

• applying electrical power driving the motor in a reverse direction from the prior cycle causing acceleration of the motor towards a desired speed, switching power off to the motor and reducing the speed of the motor to a condition where applying power in the next half cycle will reverse the direction of motor rotation,
• determining resistance to rotation of the motor, and
• adjusting the power applied to the motor in the step of applying power so as to cause acceleration of the motor in accordance with the resistance to motor rotation determined during the prior half cycle.

Electrical control means for cyclically controlling the supply of electrical power to an electric motor having a rotor said control means comprising switching means to switch power on and off to said motor, power on timing means to time the length of power on time when power is switched on, coasting timing means to time the length of coasting time said rotor takes from the time power is switched off thereto to the time when said rotor has slowed to a condition in which the rotor rotation may be reversed (condition for reversing), the control means controlling the amount of power applied to the motor in accordance with the coast time and reversing means to reverse the direction of said rotor when said rotor is in the condition for reversing and to switch power by said switching means when reversing is to be effected.

A method of cyclically controlling power to an electrical motor having a rotor, said method including the steps of starting rotation of said rotor in one direction, setting an initial power on time and applying power to said motor during said power on time, switching off power at the end of said initial power on time, allowing the rotor to slow until the rotor has slowed to a condition in which application of power will cause reversal of rotation (condition to be reversed), checking a ramp down time after power is switched off within which the rotor slows to the condition to be reversed, causing reversal of direction of rotation of said rotor, as soon as the rotor is in the condition to be reversed, and repeating the preceding steps, using the ramp down time to adjust the amount of power applied to the motor while repeating the steps.

A method of electronically cyclically controlling the supply of power to an electric motor using sensing means and actuate adjustment means for adjusting the power to the motor, said method including the steps of setting a desired speed of rotation of the motor, sensing the resistance to rotation of the motor;

• using responses from the sensing means for controlling the adjustment means to adjust the power supplied to the motor to change the motor speed towards said desired speed and then operate the motor within a range of speeds substantially at said desired speed of rotation, switching off the supply of power to the motor following which the motor slows to a stop and applying power to the motor and repeating the recited steps at least once, starting with the step of controlling to thereby cause a change in the adjusted power supplied to the motor in accordance with the sensed resistance to rotation of the rotor that occurred prior to the stop of the motor, with the motor running in the reverse direction.

An electrical control means for cyclically controlling the supply of electrical power to an electrical motor having a rotor said control means comprising:

• switching means to switch power to said motor on and off, coasting timing means to time the length of time said rotor takes from the time power is switched off thereto to the time when said rotor has slowed to a condition in which the rotor direction may be reversed (condition for reversing), reversing means to reverse the direction of said rotor when said rotor is in the condition for reversing and to switch on said switching means when reversing is to be effected and means for controlling the supply of power to said motor in accordance with a desired length of time of coasting to the condition for reversing.

An electrical control means for cyclically controlling the supply of electrical power to an electric motor having a rotor, said electrical control means including setting means operable to set a desired speed of rotation of the rotor of said motor, sensing means to sense resistance to rotation of the rotor prior to a reversal in direction of running of the rotor, adjustment means responsive to the resistance to rotation speed prior to a preceding reversal of running of the rotor for adjusting the power supplied to the motor to accelerate said rotor towards the desired speed and to maintain the rotor speed within a range of speeds substantially at said desired speed of rotation, switching means to switch off the supply of power to said motor after a desired time and reversing means, operable when said rotor has slowed to a condition in which the rotation direction may be reversed (condition for reversing), to reenable the preceding recited means with the rotor running in the reverse direction.

A method of cyclically reversing an electronically commutated motor having a plurality of windings on a stator and a rotor having magnetic poles rotatable relative to said stator, said method comprising the steps of

• (a) removing substantially all the power from the windings and, while the rotor is rotating, allowing the rotor to coast towards zero speed of rotation, and
• (b) when the rotor has slowed to a condition in which application of a reversed commutation will cause reversal of rotation at any time between a still rotating condition of the rotor and substantially the time the rotor has stopped rotation (condition for reversing) and without delay, applying power to the stator windings and effecting entry at the correct sequence of commutations of power to the windings to cause the rotor to change direction and to maintain rotor rotation in the changed direction.