De-jamming device and method
A system and method for automatically applying a de-jamming action in response to a jammed rotating member includes applying a pulsed torque in response to a detected jam, and additionally a reversal in the direction of rotation may be applied.
1. A method for operating a food waste disposer, comprising: automatically determining if a rotating shredder plate of the food waste disposer is jammed and upon determining that the shredder plate is jammed, operating the food waste disposer in a first de-jamming mode by automatically reversing the rotational direction of the shredder plate at least once; and automatically determining whether the shredder plate was de-jammed by operation of the food waste disposer in the first de-jamming mode and if not, operating the food waste disposer in a second de-jamming mode by automatically applying a pulsed torque to the shredder plate by applying a series of positive torque pulses to the shredder plate where the positive torque pulses are at least two times a normal starting torque of a motor driving the shredder plate.
2. The method of claim 1 , wherein automatically determining if the shredder plate is jammed includes determining that it is jammed if the speed of the shredder plate does not reach a predetermined speed during a predetermined time period.
3. The method of claim 1 , wherein automatically determining if the shredder plate is jammed includes determining that it is jammed if the speed of the shredder plate falls below a predetermined speed.
4. The method of claim 1 , wherein the series of torque pulses are applied for a predetermined time period.
5. The method of claim 1 , wherein automatically determining if the shredder plate is jammed includes monitoring current in a winding of a motor driving the shredder plate and determining that the shredder plate is jammed if the current is not below a predetermined level.
6. The method of claim 5 , wherein monitoring the winding includes monitoring a run winding of the motor.
7. The method of claim 5 , wherein monitoring the winding includes monitoring a start winding of the motor.
8. The method of claim 1 , wherein if a jam is determined upon an initial start up of the disposer, reversing the rotational direction of the shredder plate includes energizing a start up winding of the motor.
9. The method of claim 1 , wherein applying the series of positive torque pulses includes activating an SCR.
10. The method of claim 9 , wherein the SCR is activated during a series of positive or negative halfcycles.
11. A method for operating a food waste disposer, comprising: automatically determining if a rotating shredder plate of the food waste disposer is jammed and upon determining that the shredder plate is jammed, automatically reversing the rotational direction of the shredder plate and applying a pulsed torque to the shredder plate by applying a series of positive torque pulses that are at least two times a normal starting torque of a motor driving the shredder plate.
12. The method of claim 11 , wherein automatically determining if the shredder plate is jammed includes determining that the shredder plate is jammed if the speed of the shredder plate does not reach a predetermined speed during a predetermined time period.
13. The method of claim 11 , wherein automatically determining if the shredder plate is jammed includes determining that the shredder plate is jammed if the speed of the shredder plate falls below a predetermined speed.
14. The method of claim 11 , wherein the series of positive torque pulses are applied for a predetermined time period.
15. The method of claim 11 , wherein automatically determining if the shredder plate is jammed includes monitoring a winding of a motor driving the shredder plate.
16. The method of claim 15 , wherein monitoring the winding includes monitoring a run winding.
17. The method of claim 15 , wherein monitoring the winding includes monitoring a start winding.
18. The method of claim 11 , wherein if a jam is detected upon an initial start up of the rotating member, reversing the rotational direction of the shredder plate includes energizing a start up winding of the motor.
19. The method of claim 11 , wherein applying the series of positive torque pulses includes activating an SCR.
20. The method of claim 19 , wherein the SCR is activated during a series of positive or negative halfcycles.