Method and apparatus for controlling TRIAC dimmable device

• US 9,729,079 B1
• Filed: 05/28/2015
• Issued: 08/08/2017
• Est. Priority Date: 11/15/2011
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Peng, Hao, Choi, Jinho, Zhang, Wanfeng
• Primary Examiner(s): Laxton, Gary L
• Assistant Examiner(s): Sprenger, Kevin H
• Application Number:
  US14/723,649
• Time in Patent Office: 803 Days
• Field of Search: 363 78- 79, 363 84, 363 89, 363125-129
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/335 using semiconductor devices only
• CPC Class Codes: H02M 5/2573 with control circuit
• CPC Class Codes: H02M 7/12 using discharge tubes with control electrode or semiconductor devices with control electrode

Abstract

Aspects of the disclosure provide a method that including receiving a sensed signal corresponding to a current flowing through an energy transfer module in response to an on/off state of a forward-type triode for alternating current (TRIAC), determining the TRIAC on/off state based on the sensed signal, and controlling the energy transfer module based on the determined TRIAC on/off state.

Claims

1. A method for controlling a circuit, comprising:

receiving a sensed signal corresponding to a current flowing through an energy transfer module in response to an on/off state of a triode for alternating current (TRIAC),

providing the sensed signal to a state machine that transitions between a TRIAC on state and a TRIAC off state based on the sensed signal, the TRIAC off state having a first off sub-state and a second off sub-state;

transitioning the state machine from the TRIAC on state to the first off sub-state of the TRIAC off state;

transitioning the state machine from the first off sub-state of the TRIAC off state to the TRIAC on state a first condition of the state machine is satisfied;

transitioning the state machine from the first off sub-state of the TRIAC off state to the second off sub-state of the TRIAC off state when the first condition of the state machine is not satisfied and a time duration condition of the state machine is satisfied; and

transitioning the state machine from the second off sub-state of the TRIAC off state to the TRIAC on state when a second condition of the state machine is satisfied.

2. The method of claim 1, wherein the time duration condition is that the state machine is in the first off sub-state of the TRIAC off state for more than half of a total TRIAC off time.

3. The method of claim 1, further comprising:

determining a total TRIAC off time based on a previous time duration that the state machine is in the TRIAC off state.

4. The method of claim 1, wherein the state machine transitions from the TRIAC on state to the first off sub-state of the TRIAC off state when the sensed signal is lower than a threshold.

5. The method of claim 4, wherein a plurality of pulses, generated by a controller of the circuit, are adjusted based on the sensed signal to control a switch of the energy transfer module.

6. The method of claim 5, therein the sensed signal is lower than the threshold at least over three consecutive pulses in the plurality of pulses.

7. The method of claim 1, further comprising:

controlling the energy transfer module based on states of the state machine.

8. The method of claim 1, further comprising:

implementing, by the TRIAC, at least two phases, a first phase and a second phase;

dedicating the first phase to the TRIAC on state; and

dedicating the second phase to the TRIAC off state, the first and second phases being non-overlapping.

9. The method of claim 8, further comprising:

implementing, by the TRIAC, a third phase, the first, second, and third phases being non-overlapping; and

dedicating the third phase to charge a part of the TRIAC that wirelessly communicates with a control component external to the TRIAC, the third phase occurring at least once per each alternating current cycle of the TRIAC.

10. The method of claim 1, wherein a full range from 0 to 2π

in an alternating current cycle of the TRIAC has a first phase range of an interval from 0 to β

, a second phase range of an interval from β

to α

dedicated to the TRIAC off state, a third phase range of an interval from α

to π

dedicated to the TRIAC on state, a fourth phase range of an interval from π

to (π

+α

) dedicated to the TRIAC off state, and a fifth phase range of an interval from (π

+α

) to 2π

dedicated to the TRIAC on state, the first, second, third, fourth, and fifth phase ranges being non-overlapping.

11. A circuit including a controller configured to:

receive a sensed signal corresponding to a current flowing through an energy transfer module in response to an on/off state of a triode for alternating current (TRIAC);

provide the sensed signal to a state machine that transitions between a TRIAC on state and a TRIAC off state based on the sensed signal, the TRIAC off state having a first off sub-state and a second off sub-state;

transition the state machine from the TRIAC on state to the first off sub-state of the TRIAC off state;

transition the state machine from the first off sub-state of the TRIAC off state to the TRIAC on state when a first condition of the state machine is satisfied;

transition the state machine from the first off sub-state of the TRIAC off state to the second off sub-state of the TRIAC off state when the first condition of the state machine is not satisfied and a time duration condition of the state machine is satisfied; and

transition the state machine from the second off sub-state of the TRIAC off state to the TRIAC on state when a second condition of the state machine is satisfied.

12. The circuit of claim 11, wherein the time duration condition is that the state machine is in the first off sub-state of the TRIAC off state for more than half of a total TRIAC off time.

13. The circuit of claim 11, wherein the controller is further configured to determine a total TRIAC off time based on a previous time duration that, the state machine is in the TRIAC off state.

14. The circuit of claim 11, wherein the state machine transitions from the TRIAC on state to the first off sub-state of the TRIAC off state when the sensed signal is lower than a threshold.

15. The circuit of claim 14, wherein a plurality of pulses, generated by the controller, are adjusted based on the sensed signal to control a switch of the energy transfer module.

16. The circuit of claim 15, wherein the sensed signal is lower than the threshold at least over three consecutive pulses in the plurality of pulses.

17. The circuit of claim 11, wherein the controller is further configured to control the energy transfer module based on states of the state machine.

18. The circuit of claim 11, wherein the controller is further configured to:

implement, by the TRIAC, at least two phases, a first phase and a second phase;

dedicate the first phase to the TRIAC on state; and

dedicate the second phase to the TRIAC off state, the first and second phases being non-overlapping.

19. The circuit of claim 18, wherein the controller is further configured to:

implement, by the TRIAC, a third phase, the first, second, and third phases being non-overlapping; and

dedicate the third phase to charge a part of the TRIAC that wirelessly communicates with a control component external to the TRIAC, the third phase occurring at least once per each alternating current cycle of the TRIAC.

20. The circuit of claim 11, wherein a full range from 0 to 2π

in an alternating current cycle of the TRIAC has a first phase range of an interval from 0 to β

, a second phase range of an interval from β

to α

dedicated to the TRIAC off state, a third phase range of an interval from α

to π

dedicated to the TRIAC on state, a fourth phase range of an interval from π

to (π

+α

) dedicated to the TRIAC off state, and a fifth phase range of an interval from (π

+α

) to 2π

dedicated to the TRIAC on state, the first, second, third, fourth, and fifth phase ranges being non-overlapping.