Generating heat in a movable barrier operator

1. A movable barrier operator apparatus comprising:

a motor configured to couple to a movable barrier;

a control system configured to cause the motor to move the movable barrier by supplying power to the motor; and

a temperature sensor separate from the motor and operatively coupled to the control system and configured to detect a temperature of the motor or its surrounding area;

wherein the control system is further configured to selectively supply nonoperational power to the motor to generate heat in a stop state without moving the movable barrier when the temperature sensor detects a temperature below a predefined threshold associated with a temperature at which a liquid in a movable barrier operator system including the motor loses flow characteristics.

2. The apparatus of claim 1 , wherein the control system is configured to supply nonoperational power to the motor after the motor has been in a stop state for a period of time.

3. The apparatus of claim 1 , wherein the control system is configured to supply nonoperational power to the motor while the movable barrier is in motion to impede movement of the movable barrier.

4. The apparatus of claim 3 , wherein the nonoperational power is supplied in addition to the power supplied to the motor to cause the movable barrier to move.

5. The apparatus of claim 1 , wherein the control system is configured to continuously supply nonoperational power to the motor as the motor transitions from moving the movable barrier to a stop state.

6. The apparatus of claim 5 , wherein the control system is configured to continuously supply nonoperational power to the motor if a detected temperature is below a threshold temperature.

7. The apparatus of claim 1 , wherein the motor comprises an AC induction motor and the control system is configured to supply AC power having a frequency in a first range to the motor to cause the motor to move the movable barrier.

8. The apparatus of claim 7 , wherein nonoperational power comprises at least one of DC power, AC power having a frequency substantially outside of the first range, or AC power with a strong DC component.

9. The apparatus of claim 7 , wherein the control system is configured to supply DC power to the AC induction motor to impede movement of the movable barrier; and

wherein the control system continues to supply DC power to the motor after the movable barrier comes to a stop to generate heat.

10. The apparatus of claim 1 , wherein the motor comprises a DC motor and the nonoperational power comprises AC power having a frequency above a threshold to avoid jitter in the DC motor.

11. A method of heating a movable barrier operator, the method comprising:

determining a state of the movable barrier operator comprising a motor;

detecting a temperature of the motor or its surrounding area with a temperature sensor that is separate from the motor;

selectively, with a control system, supplying nonoperational power to the motor to generate heat without moving a movable barrier when the temperature sensor detects a temperature below a predefined threshold associated with a temperature at which a liquid in a movable barrier operator system including the motor loses flow characteristics; and

moving the movable barrier by supplying operational power to the motor.

12. The method of claim 11 further comprising supplying the nonoperational power to the motor when the movable barrier operator is in a stop state.

13. The method of claim 11 , further comprising the control system supplying nonoperational power to the motor after the motor has been in a stop state for a predetermined period of time.

14. The method of claim 11 , further comprising the control system supplying nonoperational power to the motor while the movable barrier is in motion to impede movement of the movable barrier.

15. The method of claim 14 , further comprising supplying the nonoperational power to the motor to impede the movement of the movable barrier in addition to the power supplied to the motor to cause the movable barrier to move.

16. The method of claim 11 , further comprising continuously supplying nonoperational power to the motor as the motor transitions from moving the movable barrier to a stop state.

17. The method of claim 16 , further comprising continuously supplying nonoperational power to the motor in response to detecting a temperature below a predetermined threshold.

18. The method of claim 11 , wherein the motor comprises an AC induction motor and wherein the method further comprises the control system supplying AC current having a frequency in a first range to the motor to cause the motor to move the movable barrier.

19. The method of claim 18 , wherein the nonoperational power comprises at least one of DC power, AC power having a frequency substantially outside of the first range, or AC power with a strong DC component.

20. The method of claim 18 , wherein the control system is configured supply DC injection to the AC induction motor to impede movement of the movable barrier; and

wherein the control system continues to supply DC power to the motor after the movable barrier comes to a stop to generate heat.

21. The method of claim 11 , wherein the motor comprises a DC motor and the method further comprises providing the nonoperational power comprising AC power having a frequency above a threshold to avoid jitter in the DC motor.

22. A movable barrier operator apparatus comprising:

an AC motor configured to couple to move a movable barrier;

a temperature sensor separate from the AC motor and configured to detect a temperature of the AC motor or its surrounding area; and

a control system;

wherein the control system is configured to cause the AC motor to move the movable barrier by supplying AC power to the motor; and

wherein the control system is configured to selectively supply nonoperational power, comprising one of DC power or AC power having a frequency in a range separate from a frequency range sufficient to drive the AC motor, for the AC motor to generate heat in response to the temperature sensor detecting a temperature below a predefined threshold associated with a temperature at which a liquid in a movable barrier operator system including the motor loses flow characteristics.

23. The apparatus of claim 22 , wherein the control system is further configured to monitor a state of the movable barrier and selectively supply nonoperational power to the motor when the movable barrier is in a stop state.

24. The apparatus of claim 22 , wherein the control system is further configured to supply nonoperational power to the AC motor while the movable barrier is in motion to impede movement of the movable barrier.

25. A movable barrier operator apparatus comprising:

a DC motor configured to couple to move a movable barrier;

a temperature sensor separate from the DC motor and configured to detect a temperature of the DC motor or its surrounding area; and

a control system;

wherein the control system is configured to cause the DC motor to move the movable barrier by supplying DC power to the motor; and

wherein the control system is configured to selectively supply nonoperational power, comprising AC power having a frequency above a threshold to avoid jitter in the DC motor, for the DC motor to generate heat in response to the temperature sensor detecting a temperature below a predefined threshold associated with a temperature at which a liquid in a movable barrier operator system including the motor loses flow characteristics.

26. The apparatus of claim 25 wherein the control system is further configured to monitor a state of the movable barrier and selectively supply nonoperational power to the motor when the movable barrier is in a stop state.