Stepless Dimming Control Method of Lighting System

Abstract

A stepless dimming control method of a lighting system is applicable to the situations where a light source for a lighting terminal is a fluorescent lamp and/or an LED lamp. A pulsating voltage regulating device is connected in series with a main power supply circuit of a terminal light source. A dimming control unit is configured for a fluorescent lamp electronic ballast/LED driving unit. The specific method includes: at first, fluctuating a supply voltage value at an input end of the electronic ballast/LED driving unit for a short time by the pulsating voltage regulating device, and then regulating, by the dimming control unit, an output frequency of the electronic ballast and an output current of the LED driving unit according to fluctuation parameters and also in combination with preset system settings, so as to realize dimming. The method can realize remote and stepless dimming, is applicable to the terminal light sources of both fluorescent lamps and LED lamps, has good interference resistance and relatively low system construction/improvement costs, and is extremely suitable for newly-built lighting systems and for use in upgrading existing lighting systems.

Claims

1-10. (canceled)

11. A stepless dimming control method of a lighting system comprising a terminal light source which is a LED light which comprises a LED driving unit arranged therein, a smart pulse voltage adjustment device connected on a power supply circuit of the terminal light source in series, and a dimming control unit comprising a voltage sensing circuit and a single chip microcomputer arranged on the LED driving unit for monitoring a power supply voltage of an input terminal of the LED driving unit and adjusting an output current of the LED driving unit according to a change of a power supply voltage and based on predetermined rules of the lighting system, wherein when dimming is demanded, wherein the method comprises the steps of: causing a value of the power supply voltage of the input terminal of the LED driving unit to generate a first short-time fluctuation by slightly adjusting an output voltage of a smart pulse voltage adjustment device for a first time, wherein the short-time fluctuation is defined as a first signaling, wherein a fluctuation duration of the first signaling is T1; causing the value of the power supply voltage of the input terminal of the LED driving unit to generate a second short-time fluctuation by slightly adjusting the output voltage of the smart pulse voltage adjustment device again after a time duration of T2, wherein the second short-time fluctuation is defined as a second signaling, wherein a fluctuation duration of the second signaling is T3, wherein the fluctuation duration T3 has a predetermined corresponding relation with a target dimming extent; and comparing the durations of T1, T2, and T3 with a predetermined value of the system after the dimming control unit detected the above fluctuations of the value of the power supply voltage of the input terminal of the LED driving unit, wherein if the values are equal, a dimming step of this time is really launched that an output current of the LED driving unit is adjusted to corresponding values according to the target dimming extent obtained by configuring the dimming control unit to check a predetermined value of the system according to the fluctuation duration of T3, wherein if the values are not equal, the dimming step of this time is terminated, wherein the LED driving unit comprises one of a LED inverter power supply and a LED high voltage drive unit, wherein the smart pulse voltage adjustment device is allowed to be replaced by a frequency converter, while the method remain unchanged after such replacement.

12. The method, as recited in claim 11, wherein the interval duration, T2, between the first signaling and the second signaling is predetermined to have a predetermined corresponding relation to the target dimming extent, wherein information including a wave pattern of the second signaling, or the wave pattern of the second signaling plus the fluctuation duration T3, and a wave patterns of the first signaling is regarded as a basis of determination for really launching the dimming step, wherein the durations of T1, T2, and T3 are compared with the predetermined value of the system after the dimming control unit detected the above fluctuations of the value of the power supply voltage of the input terminal of the LED driving unit, wherein if the values are equal, the dimming step of this time is really launched that the output current of the LED driving unit is adjusted to corresponding values according to the target dimming extent obtained by configuring the dimming control unit to check the predetermined value of the system according to the interval duration of T2, wherein if the values are not equal, the dimming step of this time is terminated.

13. The method, as recited in claim 11, wherein the first signaling and the second signaling have one or more times of minor fluctuations on a voltage value respectively, wherein after the dimming control unit detected the fluctuation of the voltage value of the power supply of the input terminal of the LED driving unit, parameters of the specific wave pattern of both or one of the first signaling and the second signaling is also be compared with the predetermined value of the system to provide a basis of determination for really launching this dimming step, wherein compared parameters of the wave pattern comprise one or more parameters selected from the group consisting of an amplitude value of every of the voltage fluctuations, a duration of every of the voltage fluctuations, and every of the interval durations between the voltage fluctuations.

14. The method, as recited in claim 12, wherein the first signaling and the second signaling have one or more times of minor fluctuations on a voltage value respectively, wherein after the dimming control unit detected the fluctuation of the voltage value of the power supply of the input terminal of the LED driving unit, parameters of the specific wave pattern of both or one of the first signaling and the second signaling is also be compared with the predetermined value of the system to provide a basis of determination for really launching this dimming step, wherein compared parameters of the wave pattern comprise one or more parameters selected from the group consisting of an amplitude value of every of the voltage fluctuations, a duration of every of the voltage fluctuations, and every of the interval durations between the voltage fluctuations.

15. The method, as recited in claim 13, further comprising a step of confirming the voltage fluctuation received before the dimming control unit really launches the dimming step to the LED driving unit, wherein the dimming step is really launched only if the first signaling is received again or a specific voltage fluctuation is received in a designated duration of T4.

16. The method, as recited in claim 14, further comprising a step of confirming the voltage fluctuation received before the dimming control unit really launches the dimming step to the LED driving unit, wherein the dimming step is really launched only if the first signaling is received again or a specific voltage fluctuation is received in a designated duration of T4.

17. The method, as recited in claim 15, further comprising a step of detecting if an electric current of a lighting circuit change correspondingly after the dimming step is really launched, wherein if the current is not changed correspondingly, this dimming step is considered failed and the dimming step is going to be launched again.

18. The method, as recited in claim 16, further comprising a step of detecting if an electric current of a lighting circuit change correspondingly after the dimming step is really launched, wherein if the current is not changed correspondingly, this dimming step is considered failed and the dimming step is going to be launched again.

19. The method, as recited in claim 16, wherein the fluctuation extend of the slightly adjusted output voltage of the smart pulse voltage adjustment device is within a range of ±50V and the durations T1, T2, and T3 are 0.2 to 300 seconds.

20. The method, as recited in claim 17, wherein the fluctuation extend of the slightly adjusted output voltage of the smart pulse voltage adjustment device is within a range of ±50V and the durations T1, T2, and T3 are 0.2 to 300 seconds.

21. The method, as recited in claim 16, wherein the dimming control unit comprises a single chip microcomputer, the voltage sensing circuit monitoring the power supply voltage of the input terminal of the LED driving unit, and a PWM signal driving circuit, wherein one of I/O ports or A/D signal receiving ports of the single chip microcomputer is connected with a signal output terminal of the voltage sensing circuit, wherein the single chip microcomputer also comprises a PWM signal output terminal, wherein the PWM signal output terminal is connected with the dimming console of the LED driving unit via the PWM signal driving circuit.

22. The method, as recited in claim 17, wherein the dimming control unit comprises a single chip microcomputer, the voltage sensing circuit monitoring the power supply voltage of the input terminal of the LED driving unit, and a PWM signal driving circuit, wherein one of I/O ports or A/D signal receiving ports of the single chip microcomputer is connected with a signal output terminal of the voltage sensing circuit, wherein the single chip microcomputer also comprises a PWM signal output terminal, wherein the PWM signal output terminal is connected with the dimming console of the LED driving unit via the PWM signal driving circuit.

23. The method, as recited in claim 11, wherein when the pulse voltage adjustment device is replaced by a frequency converter, the voltage sensing circuit of the dimming control unit is replaced by a frequency sensing circuit, such that the dimming control unit becomes monitoring a frequency variation of the power supply voltage of the input terminal of the LED driving unit and adjusting the output current of the LED driving unit according to predetermined rules of the system, wherein a dimming method employing the following contents and rules: (1) providing a corresponding relation between a frequency of an output voltage of the frequency converter and the target dimming extent, or providing a corresponding relation between the target dimming extent and a difference between a frequency of the output voltage of the frequency converter and a rated operating frequency; and (2) when dimming is required, adjusting the frequency of the output voltage of the frequency converter to a corresponding value according to a predetermined corresponding relation of said step (1) and the target dimming extent; and configuring the dimming control unit to detect a frequency variation of the power supply voltage of the input terminal of the LED driving unit, to obtain a target dimming extent by checking with the predetermined corresponding relation, and to adjust an output current of the LED driving unit to corresponding values.

24. The method, as recited in claim 12, wherein when the pulse voltage adjustment device is replaced by a frequency converter, the voltage sensing circuit of the dimming control unit is replaced by a frequency sensing circuit, such that the dimming control unit becomes monitoring a frequency variation of the power supply voltage of the input terminal of the LED driving unit and adjusting the output current of the LED driving unit according to predetermined rules of the system, wherein a dimming method comprising employing the following contents and rules: (1) providing a corresponding relation between a frequency of an output voltage of the frequency converter and the target dimming extent, or providing a corresponding relation between the target dimming extent and a difference between a frequency of the output voltage of the frequency converter and a rated operating frequency; and (2) when dimming is required, adjusting the frequency of the output voltage of the frequency converter to a corresponding value according to a predetermined corresponding relation of said step (1) and the target dimming extent; and configuring the dimming control unit to detect a frequency variation of the power supply voltage of the input terminal of the LED driving unit, to obtain a target dimming extent by checking with the predetermined corresponding relation, and to adjust an output current of the LED driving unit to corresponding values.

25. The method, as recited in claim 11, wherein when the pulse voltage adjustment device is replaced by a frequency converter, the voltage sensing circuit of the dimming control unit is replaced by a frequency sensing circuit, such that the dimming control unit becomes monitoring a frequency variation of the power supply voltage of the input terminal of the LED driving unit and adjusting the output current of the LED driving unit according to predetermined rules of the system, wherein a dimming method employing the following contents and rules: (1) providing a corresponding relation between a parameter of a frequency fluctuation of the output voltage of the frequency converter and a target dimming extent, wherein the parameter of the frequency fluctuation comprises one or more parameters selected from the group consisting of a amplitude value of every of the frequency fluctuations, a duration of every of the frequency fluctuations, and every of the interval times between the frequency fluctuations; and (2) when dimming is required, controlling the frequency of the output voltage of the frequency converter to generate a corresponding fluctuation according to the predetermined corresponding relation of the step (1) and the target dimming extent; and configuring the dimming control unit to detect a frequency variation of the power supply voltage of the input terminal of the LED driving unit, to obtain a target dimming extent by checking with the predetermined corresponding relation, and to adjust an output current of the LED driving unit to the corresponding values.

26. The method, as recited in claim 12, wherein when the pulse voltage adjustment device is replaced by a frequency converter, the voltage sensing circuit of the dimming control unit is replaced by a frequency sensing circuit, such that the dimming control unit becomes monitoring a frequency variation of the power supply voltage of the input terminal of the LED driving unit and adjusting the output current of the LED driving unit according to predetermined rules of the system, wherein a dimming method employing the following contents and rules: (1) providing a corresponding relation between a parameter of a frequency fluctuation of the output voltage of the frequency converter and a target dimming extent, wherein the parameter of the frequency fluctuation comprises one or more parameters selected from the group consisting of a amplitude value of every of the frequency fluctuations, a duration of every of the frequency fluctuations, and every of the interval times between the frequency fluctuations; and (2) when dimming is required, controlling the frequency of the output voltage of the frequency converter to generate a corresponding fluctuation according to the predetermined corresponding relation of the step (1) and the target dimming extent; and configuring the dimming control unit to detect a frequency variation of the power supply voltage of the input terminal of the LED driving unit, to obtain a target dimming extent by checking with the predetermined corresponding relation, and to adjust an output current of the LED driving unit to the corresponding values.

27. The method, as recited in claim 23, wherein the dimming control unit and the LED driving unit are integrated into a chip or module.

28. The method, as recited in claim 24, wherein the dimming control unit and the LED driving unit are integrated into a chip or module.

29. The method, as recited in claim 25, wherein the dimming control unit and the LED driving unit are integrated into a chip or module.

30. The method, as recited in claim 26, wherein the dimming control unit and the LED driving unit are integrated into a chip or module.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1 is a schematic diagram illustrating a circuit (voltage adjustment type) of a lighting system and a stepless dimming control method thereof according to a first preferred embodiment of the present invention.

[0048] FIG. 2 is a schematic diagram illustrating a circuit (voltage adjustment type) of a lighting system and a stepless dimming control method thereof according to a second preferred embodiment of the present invention.

[0049] FIG. 3 is a schematic diagram illustrating a circuit (voltage adjustment type) of a lighting system and a stepless dimming control method thereof according to a third preferred embodiment of the present invention.

[0050] FIG. 4 is a schematic diagram illustrating a circuit (frequency converter voltage adjustment type) of a lighting system and a stepless dimming control method thereof according to a fourth preferred embodiment of the present invention.

[0051] FIG. 5 is a schematic diagram illustrating a circuit (frequency converter frequency adjustment type) of a lighting system and a stepless dimming control method thereof according to a first preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0052] The following description is disclosed to enable any person skilled in the art to make and use the present invention. Preferred embodiments are provided in the following description only as examples and modifications will be apparent to those skilled in the art. The general principles defined in the following description would be applied to other embodiments, alternatives, modifications, equivalents, and applications without departing from the spirit and scope of the present invention.

[0053] The following will combine the drawings and embodiments to further describe the stepless dimming control method of lighting system according to the present invention.

[0054] 1. Voltage Adjustment Type

[0055] I. Employing Pulse Voltage Adjustment Device to Adjust the Voltage:

[0056] FIGS. 1, 2, and 3 are respectively schematic diagrams illustrating circuits of the lighting systems and their stepless dimming control methods according to the first to third embodiments of the present invention. Referring to FIGS. 1-3, the first to third embodiments of the lighting system corresponded to the stepless dimming control method of lighting system according to the present invention each requires connecting pulse voltage adjustment device to the main power supply circuit of the terminal light source. The terminal light source can employ fluorescent lamp, LED light, or both. The fluorescent lamp and LED light have corresponding electronic ballast or LED driving unit arranged according to regular standard. The system also requires a dimming control unit of a voltage sensing circuit and a single chip microcomputer arranged thereon. The voltage sensing circuit is adapted for monitoring the power supply voltage of the input terminal of the electronic ballast/LED driving unit for the single chip microcomputer to transmit corresponding dimming control signal based on the changes of the power supply voltage and the preset rules of the system to the voltage adjustment terminal of the electronic ballast/LED driving unit, such that the electronic ballast/LED driving unit can adjust the output frequency of the electronic ballast and the output current of the LED driving unit according to the dimming control signal, so as to implement dimming.

[0057] The pulse voltage adjustment device of the first to third embodiments of the present invention may employ mature conventional technology, comprising employing substitutions of autotransformer, compensated voltage regulator, and etc. Here is a specific option for compensated voltage regulator:

[0058] connecting the secondary winding of the compensator transformer in series to the main power supply circuit of the terminal light source, and

[0059] connecting the end tap of the primary winding of the compensator transformer or the end tap and the middle tap of the primary winding of the compensator transformer to the power source via controlling switch.

[0060] When dimming is required, different output voltages are generated in the two ends of the secondary winding of the compensator transformer through the variable ratio relation between the secondary winding and the primary side operating winding rendered by switching between different winding coils of the primary winding of the compensator transformer or the switching of the corresponding controlling switch. In the situation that automatic dimming is demanded, it can then selectively employ the smart control module for the controlling switch.

[0061] The LED driving unit mentioned in the embodiments of the present invention can be configured and setup based on the standards of conventional LED light, comprising employing LED inverter power supply (referring to FIGS. 1 and 2), LED high voltage driving circuit (referring to FIG. 3), and etc.

[0062] Referring to FIG. 1, it also provides an embodiment of the dimming control unit. One of the I/O ports and/or A/D signal receiving ports of the single chip microcomputer is connected with the signal output terminal of the voltage sensing circuit. The single chip microcomputer also comprises a PWM signal output terminal arranged thereon. The PWM signal output terminal is connected with the dimming console of the electronic ballast/LED driving unit via the PWM signal driving circuit. Certainly, if the PWM signal output terminal of a single chip microcomputer is enough to drive the dimming console of the electronic ballast/LED driving unit, the PWM signal driving circuit can also be omitted as illustrated in FIG. 3.

[0063] When dimming is required, it can selectively employ one of the following methods to be cooperated with the actual environment and demand of the operation system:

[0064] 1. First Method, Comprising the Following Utility Method and Procedures:

[0065] (i) causing the value of the power supply voltage of the input terminal of the electronic ballast/LED driving unit to generate a short-time fluctuation by slightly adjusting the output voltage of the pulse voltage adjustment device for the first time, wherein in order to describe easily hereinafter, the short-time fluctuation is defined as first signaling and, besides, the fluctuation duration of the first signaling is T1;

[0066] (ii) causing the value of the power supply voltage of the input terminal of the electronic ballast/LED driving unit to generate a short-time fluctuation by slightly adjusting the output voltage of the pulse voltage adjustment device again after a time interval of T2, wherein this short-time fluctuation is defined as second signaling, and the fluctuation duration of the second signaling is T3, wherein the fluctuation duration T3 has a predetermined corresponding relation with the target dimming extent;

[0067] (iii) comparing the durations of T1, T2, and T3 with the predetermined value of the system after the dimming control unit detected the above fluctuations of the value of the power supply voltage of the input terminal of the electronic ballast/LED driving unit, wherein if the values are equal, the dimming procedure of this time is really launched that the output frequency of the electronic ballast and the output current of the LED driving unit is adjusted to corresponding values according to the target dimming extent obtained by configuring the dimming control unit to check the predetermined value of the system according to the fluctuation duration of T3, wherein if the values are not equal, the dimming procedure of this time is terminated.

[0068] For example, the first signaling is configured to utilize the pulse voltage adjustment device to increase (or decrease) the power supply voltage value of the input terminal of the electronic ballast/LED driving unit for 5V for is (that is the duration T1), to restore it next, to increase (or decrease) the power supply voltage value of the input terminal of the electronic ballast/LED driving unit for 8V for 30 s (that is the duration T3) after an interval time of 0.2 s (that is the duration T2), and then to restore it again.

[0069] Thereafter, the durations of T1, T2, and T3 are compared with the predetermined value of the system after the dimming control unit detected the above fluctuations of the value of the power supply voltage of the input terminal of the electronic ballast/LED driving unit, wherein if the values are equal, the dimming procedure of this time is really launched that the output frequency of the electronic ballast and the output current of the LED driving unit will be adjusted to corresponding values when the corresponding target dimming extent of T3=30 s is obtained by configuring the dimming control unit to check the predetermined value of the system, wherein if the values are not equal, the dimming procedure of this time is terminated.

[0070] 2. Second Method, Comprising the Following Utility Method and Procedures:

[0071] This second method is mostly the same with the above first method, wherein the differences comprise the following: In this second method, the interval time, T2, between the first signaling and the second signaling is predetermined to have predetermined corresponding relation to the target dimming extent, wherein the wave pattern of the second signaling and/or fluctuation duration T3 and the wave patterns of the first signaling are all be regarded as the basis of determination for really launching this dimming procedure.

[0072] That is the durations of T1, T2, and T3 with the predetermined value of the system are compared after the dimming control unit detected the above fluctuations of the value of the power supply voltage of the input terminal of the electronic ballast/LED driving unit, wherein if the values are equal, the dimming procedure of this time is really launched that the output frequency of the electronic ballast and the output current of the LED driving unit will be adjusted to corresponding values according to the target dimming extent obtained by configuring the dimming control unit to check the predetermined value of the system according to the interval time of T2, wherein if the values are not equal, the dimming procedure of this time is terminated,

[0073] For example, the interval time 0.2 s between two fluctuations (which is the duration T2) has a predetermined corresponding relation to the target dimming extent in the system for those examples of the above first method as long as they apply this second method to conduct dimming. When the conditions for really launching the dimming procedure of the time are met, the dimming control unit adjust the output frequency of the electronic ballast and the output current of the LED driving unit to the corresponding values after it checked the predetermined values of the system and learned the corresponding target dimming extent of the interval time of 0.2.

[0074] 3. Third Method, Comprising the Following Utility Method and Procedures:

[0075] This third method is an improvement of the above first and second methods. The differences comprise enhancement of the interference resistance or antijamming performance of dimming. That is this third method employs more complex fluctuation parameters as the basis of determination for the real launching of the dimming procedure.

[0076] That is to say, the first signaling and/or the second signaling have one or more times of minor fluctuation on voltage value, wherein after the dimming control unit detected the fluctuation of the voltage value of the power supply of the input terminal of the electronic ballast/LED driving unit, the parameters of the specific wave pattern of the first signaling and/or the second signaling will also be compared with the predetermined value of the system, wherein the compared parameters of wave pattern comprise the amplitude value of every voltage fluctuation, and/or the duration of every voltage fluctuation, and/or every interval time between the voltage fluctuations.

[0077] For example, if the third method is utilized on the examples of the above first method for conducting dimming, the amplitude value 5V of the fluctuation of the first signaling and the amplitude value 8V of the fluctuation of the second signaling will both be basis of determination for determining if the dimming procedure can really be launched. Apparently, this third method is helpful in preventing risk factors like voltage fluctuation of the power network from possibly rendering interference thereto.

[0078] 4. Fourth Method, Comprising the Following Utility Method and Procedures:

[0079] This fourth method is an improvement on the basis of the above first to third methods. Specifically, it further comprises a step of confirming the received voltage fluctuation before the dimming control unit really launches the dimming procedure to the electronic ballast and the LED driving unit, wherein the dimming procedure is really launched only if first signaling is received again or a specific voltage fluctuation is received in the designated duration of T4. The specific voltage fluctuation can be determined by person skilled in the art. For example, it can be a specific amplitude value and/or one or more small scale fluctuations of the voltage for specific duration.

[0080] 5. Fifth Method, Comprising the Following Utility Method and Procedures:

[0081] This fifth method is an improvement on the bases of the above first to fourth methods. Specifically, it further comprises a step of detecting if the electric current of the lighting circuit change correspondingly after the dimming procedure is really launched. If the current is not changed correspondingly, this dimming is considered failed and the dimming procedure will be launched again.

[0082] II. Employing Frequency Converter to Adjust the Voltage

[0083] The embodiments of the present invention that employ frequency converter to adjust voltage apply program is completely identical to the above implementations that adjust voltage with pulse voltage adjustment device in all aspects, comprising hardware combination, dimming principles, dimming methods, and dimming procedures, except for utilizing frequency converter to directly substitute the pulse voltage adjustment device for voltage adjusting.

[0084] Schematic diagram of the exemplar circuit composition is illustrated in FIG. 4.

[0085] 2. Frequency Adjustment Type

[0086] Referring to FIG. 5, a circuit assembly of the lighting system corresponding to the frequency adjustment type stepless dimming control method of a lighting system according to the present invention is embodied. Comparing FIG. 5 to FIGS. 1 and 4, the hardware combination of this frequency adjustment type solution is mostly the same with it of the above voltage adjustment type solution, wherein the differences comprise the following:

[0087] First, this frequency adjustment type solution in terms of its hardware combination only comprises the situation of utilizing frequency converter, but the situation of utilizing the pulse voltage adjustment device.

[0088] Besides, the voltage sensing circuit of the dimming control unit is replaced with a frequency sensing circuit. The function of the dimming control unit is somewhat different in the present frequency adjustment type embodiment to the voltage adjustment type embodiment. The dimming control unit is altered for monitoring the frequency variation of the power supply voltage of the input terminal of the electronic ballast/LED driving unit, and then adjusting the output frequency of the electronic ballast and the output current of the LED driving unit according to the predetermined rules of the system, so as to implement dimming of the fluorescent lamp/LED light.

[0089] The frequency adjustment type dimming method according to the present invention can be embodied as the following two methods (when dimming is required, it can selectively employ one of the following methods to be cooperated with the actual environment and demand of the operation system):

[0090] 1. First Method, Comprising the Following Utility Contents and Rules:

[0091] (1) providing corresponding relation between the frequency of the output voltage of the frequency converter and the target dimming extent, or providing corresponding relation between the difference between the frequency of the output voltage of the frequency converter and the rated operating frequency and the target dimming extent; and

[0092] (2) When Dimming is Required,

[0093] adjusting the frequency of the output voltage of the frequency converter to the corresponding value according to the predetermined corresponding relation of said step (1) and the target dimming extent; and then

[0094] configuring the dimming control unit to detect the frequency variation of the power supply voltage of the input terminal of the electronic ballast/LED driving unit, to obtain the target dimming extent by checking with the predetermined corresponding relation, and to adjust the output frequency of the electronic ballast and the output current of the LED driving unit to the corresponding values, so as to implement the dimming function.

[0095] For example, if the rated operating frequency is 50 HZ, it can configure the target dimming extent for every ±1 HZ change of the frequency of the output voltage of the frequency converter to be ±10%. Therefore, when the frequency sensing circuit detected that the frequency of the power supply voltage of the input terminal of the electronic ballast/LED driving unit is 55 HZ, the processor can obtain that the target dimming extent is 50% increase after checking with the predetermined value of the system, and then transmit corresponding dimming control signal to adjust the output frequency of the electronic ballast and the output current of the LED driving unit, so as to implement accurate dimming.

[0096] 2. Second Method, Comprising the Following Utility Contents and Rules:

[0097] (1) creating corresponding relation between the parameter of the frequency fluctuation of the output voltage of the frequency converter and the target dimming extent, wherein the parameter of the frequency fluctuation comprises the amplitude value of every frequency fluctuation, and/or the duration of every frequency fluctuation, and/or every interval time between the frequency fluctuations;

[0098] (2) When Dimming is Required,

[0099] controlling the frequency of the output voltage of the frequency converter to generate corresponding fluctuation according to the predetermined corresponding relation of said step (1) and the target dimming extent; and

[0100] configuring the dimming control unit to detect the frequency variation of the power supply voltage of the input terminal of the electronic ballast/LED driving unit to obtain the target dimming extent by checking with the predetermined corresponding relation, and to adjust the output frequency of the electronic ballast and the output current of the LED driving unit to the corresponding values, so as to implement accurate dimming.

[0101] For example, generating one or more times of short-time fluctuations of the frequency of the power supply voltage of the input terminal of the electronic ballast/LED driving unit through slightly adjusting the frequency of the output voltage of the frequency converter. Then, after the dimming control unit detected amplitude value of every frequency fluctuation, every duration, and every interval time, and checked with the predetermined values of the system, it can confirm if the frequency fluctuation is a valid dimming command. If so, it can simultaneously learn the target dimming extent and transmit corresponding dimming control signal to adjust the output frequency of the electronic ballast and the output current of the LED driving unit to corresponding values, so as to implement accurate dimming.

[0102] The above disclosure simply provides some preferred embodiments of the present invention, which shall not be considered as limited implementations of the present invention. The equivalents, alternatives, and improvements according to the technical solutions of the present invention that person skilled in the art can possibly make shall all be within the scope and coverage of the technical solution of the present invention.

INDUSTRIAL UTILITY

[0103] It can be easily noted by person skilled in the art according to the above disclosure that the technical solutions according to the present invention are suitable for being produced in the industry and utilized in the household. Hence, the present invention has industrial utility.

[0104] One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.

[0105] It will thus be seen that the objects of the present invention have been fully and effectively accomplished. The embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.