Programmable Phase-Cut Dimmer Operation

• US 20150028778A1
• Filed: 04/29/2014
• Published: 01/29/2015
• Est. Priority Date: 07/24/2013
• Status: Active Grant

• Current Assignee: Dialog Semiconductor GmbH (Renesas Electronics Corporation)
• Original Assignee: Dialog Semiconductor GmbH (Renesas Electronics Corporation)
• Inventors: Zudrell-Koch, Stefan
• Granted Patent: US 9,307,603 B2
• Time in Patent Office: Days
• US Class Current: 315/308
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/60 Circuit arrangements for operating LEDs comprising organic material, e.g. for operating organic light-emitting diodes [OLED] or polymer light-emitting diodes [PLED]

Abstract

The present document relates to solid state lighting (SSL) devices. A driver circuit for phase-cut dimmable SSL based lighting assemblies is described. A control circuit for a power converter is provided. The power converter is configured to convert an input power derived from a mains power supply into a drive power for a light source. The control circuit comprises a dimmer mode detection unit to determine a first dimmer mode. The first dimmer mode indicates if the input power has been derived from the mains power supply using a dimmer. The control circuit comprises a state processor configured to determine a first operation mode of the power converter. The pre-determined first state information is dependent on the first dimmer mode. The control circuit comprises a first control unit configured to generate a first control signal for operating the power converter in accordance to the first operation mode.

Claims

1. ) A control circuit for a power converter;

wherein the power converter is configured to convert an input power derived from a mains power supply into a drive power for a light source;

wherein the control circuit comprises

a dimmer mode detection unit configured to determine a first dimmer mode from a plurality of pre-determined dimmer modes, based on one or more sensor signals sensed at corresponding one or more nodes of the power converter;

wherein the first dimmer mode is indicative of whether or not the input power has been derived from the mains power supply using a dimmer;

a state processor configured to determine a first operation mode of the power converter based on pre-determined first state information;

wherein the pre-determined first state information is dependent on the first dimmer mode; and

a first control unit configured to generate a first control signal for operating the power converter in accordance to the first operation mode.

2. ) The control circuit of claim 1, wherein the plurality of pre-determined dimmer modes comprise one or more of:

a mode which indicates that the input power has been derived from the mains power supply without a dimmer;

a mode which indicates that the input power has been derived from the mains power supply using a leading edge phase-cut dimmer;

a mode which indicates that the input power has been derived from the mains power supply using a trailing edge phase-cut dimmer; and

/or

a mode which indicates that the input power has been derived from the mains power supply using an intelligent phase-cut dimmer.

3. ) The control circuit of claim 1, wherein

the control circuit further comprises a storage unit configured to store a plurality of dimmer mode tables for the corresponding plurality of pre-determined dimmer modes;

and

a first dimmer mode table from the plurality of dimmer mode tables, which corresponds to the first dimmer mode, is indicative of the first state information for operating the power converter in accordance to the first operation mode.

4. ) The control circuit of claim 3, wherein

The first dimmer mode table comprises a plurality of state information records;

and

a first of the plurality of state information records comprises the first state information defining the first operation mode of the power converter.

5. ) The control circuit of claim 4, wherein

the first operation mode corresponds to a first state specifying the first state information.

the first state information record is associated with the first state and is indicative of one or more future states and one or more events which trigger a transition from the first state to the one or more future states;

the control circuit comprises an event detection unit configured to detect the occurrence of a first event, based on the one or more sensor signals; and

the state processor is configured to determine a second state from the one or more future states, based on the detected first event.

6. ) The control circuit of claim 5, wherein

a second state identifies a second of the plurality of state information records;

a second state information record comprises second state information defining a second operation mode of the power converter; and

the second operation mode differs from the first operation mode.

7. ) The control circuit of claim 6, wherein the second state provides a pointer to a storage location of the second state information record within the storage unit.

8. ) The control circuit of claim 4, wherein a state information record comprises one or more of the following:

state information which specifies an operation mode of the power converter;

the state machine information which specifies one or more future states and one or more events which trigger a transition from a current state, associated with the state information record, to the one or more future states;

masking information which allows an event-triggered transition to be disabled; and

/or

timing information which specifies a time interval for an occurrence of a timeout event.

9. ) The control circuit of claim 1, wherein

the input power is an AC power comprising an AC voltage and an AC current;

the one or more sensor signals comprise an input signal indicative of a waveform of the AC voltage; and

the dimmer mode detection unit is configured to determine the first dimmer mode based on the input signal.

10. ) The control circuit of claim 1, wherein

the power converter comprises an energy transfer unit configured to provide an intermediate power from the input power and an SSL device driver unit configured to provide the drive power from the intermediate power;

and

the first control signal is for controlling operation of the energy transfer unit.

11. ) The control circuit of claim 10, wherein the control circuit comprises

a phase-cut angle detection unit configured to determine a dim level based on a phase-cut angle set by the dimmer;

and

a second control unit configured to generate a second control signal based on the dim level for operating the SSL device driver unit to provide the drive power in accordance to the determined dim level.

12. ) The control circuit of claim 10, wherein the energy transfer unit and the SSL device driver unit each comprise a switch mode power converter network comprising at least one power switch, such as a buck converter network, a buck-boost converter network, a SEPIC network, and/or a flyback network.

13. ) The control circuit of claim 12, wherein the control circuit is configured to operate a power switch of the energy transfer unit in a linear operation mode to determine the phase-cut angle set by the dimmer.

14. ) The control circuit of claim 10, wherein the first control unit is configured to generate the first control signal based on a sensor signal indicative of an intermediate voltage at an output of the energy transfer unit.

15. ) A method for controlling a power converter;

wherein the power converter converts an input power derived from a mains power supply into a drive power for a light source;

wherein the method comprises

determining a first dimmer mode from a plurality of pre-determined dimmer modes, based on one or more sensor signals sensed at corresponding one or more nodes of the power converter;

wherein the first dimmer mode is indicative of whether or not the input power has been derived from the mains power supply using a dimmer;

determining a first operation mode of the power converter based on pre-determined first state information;

wherein the pre-determined first state information is dependent on the first dimmer mode; and

generating a first control signal for operating the power converter in accordance to the first operation mode.

16. ) The method for controlling a power converter of claim 15, wherein the plurality of pre-determined dimmer modes comprise one or more of:

a mode which indicates that the input power has been derived from the mains power supply without a dimmer;

a mode which indicates that the input power has been derived from the mains power supply using a leading edge phase-cut dimmer;

a mode which indicates that the input power has been derived from the mains power supply using a trailing edge phase-cut dimmer; and

/or

a mode which indicates that the input power has been derived from the mains power supply using an intelligent phase-cut dimmer.

17. ) The method for controlling a power converter of claim 15, wherein

the control circuit further comprises a storage unit which stores a plurality of dimmer mode tables for the corresponding plurality of pre-determined dimmer modes;

and

a first dimmer mode table from the plurality of dimmer mode tables, which corresponds to the first dimmer mode, is indicative of the first state information for operating the power converter in accordance to the first operation mode.

18. ) The method for controlling a power converter of claim 17, wherein

the first dimmer mode table comprises a plurality of state information records;

and

a first the plurality of state information records comprises the first state information defining the first operation mode of the power converter.

19. ) The method for controlling a power converter of claim 18, wherein

the first operation mode corresponds to a first state specifying the first state information.

the first state information record is associated with the first state and is indicative of one or more future states and one or more events which trigger a transition from the first state to the one or more future states;

the control circuit comprises an event detection unit which detects a occurrence of a first event, based on the one or more sensor signals; and

the state processor determines a second state from the one or more future states, based on the detected first event.

20. ) The method for controlling a power converter of claim 19, wherein

a second state identifies a second of the plurality of state information records;

a second state information record comprises second state information defining a second operation mode of the power converter; and

the second operation mode differs from the first operation mode.

21. ) The method for controlling a power converter of claim 20, wherein the second state provides a pointer to a storage location of the second state information record within the storage unit.

22. ) The method for controlling a power converter of claim 18, wherein a state information record comprises one or more of the following:

state information which specifies an operation mode of the power converter;

the state machine information which specifies one or more future states and one or more events which trigger a transition from a current state, associated with the state information record, to the one or more future states;

masking information which allows an event-triggered transition to be disabled; and

/or

timing information which specifies a time interval for an occurrence of a timeout event.

23. ) The method for controlling a power converter of claim 15 wherein

the input power is an AC power comprising an AC voltage and an AC current;

the one or more sensor signals comprise an input signal indicative of a waveform of the AC voltage; and

the dimmer mode detection unit determines the first dimmer mode based on the input signal.

24. ) The method for controlling a power converter of claim 15, wherein

the power converter comprises an energy transfer unit provides an intermediate power from the input power and an SSL device driver unit provides the drive power from the intermediate power;

and

the first control signal is for controlling operation of the energy transfer unit.

25. ) The method for controlling a power converter of claim 24, wherein the control circuit comprises

a phase-cut angle detection unit determines a dim level based on a phase-cut angle set by the dimmer;

and

a second control unit generates a second control signal based on the dim level for operating the SSL device driver unit to provide the drive power in accordance to the determined dim level.

26. ) The method for controlling a power converter of claim 24, wherein the energy transfer unit and the SSL device driver unit each comprise a switch mode power converter network comprising at least one power switch, such as a buck converter network, a buck-boost converter network, a SEPIC network, and/or a flyback network.

27. ) The method for controlling a power converter of claim 26, wherein the control circuit operates a power switch of the energy transfer unit in a linear operation mode to determine the phase-cut angle set by the dimmer.

28. ) The method for controlling a power converter of claim 24, wherein the first control unit generates the first control signal based on a sensor signal indicative of an intermediate voltage at an output of the energy transfer unit.