WO2016015672A1

WO2016015672A1 - Control circuit for starting led lamp and led lighting system

Info

Publication number: WO2016015672A1
Application number: PCT/CN2015/085617
Authority: WO
Inventors: Yongjun Hou; Wenqing Wang
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2014-07-31
Filing date: 2015-07-30
Publication date: 2016-02-04
Anticipated expiration: 2017-01-31
Also published as: CN105307316B; CN105307316A

Abstract

A control circuit (1001) for starting an LED lamp and an LED lighting system are provided. The control circuit (1001) for starting an LED lamp includes: an input module (1), configured to receive an input alternate current and to convert the input alternate current into a direct current; a driving module (2), connected with the input module and configured to generate a driving current for driving the LED lamp (5) according to the direct current; a feedback module (3), connected with the driving module (2) and configured to generate a feedback signal according to the driving current; and a driving chip (4), connected with the driving module (2) and the feedback module (3) respectively, and configured to obtain a starting state of the LED lamp (5) and to adjust the driving current according to the starting state of the LED lamp (5) and the feedback signal so as to control the LED lamp (5) to start.

Description

CONTROL CIRCUIT FOR STARTING LED LAMP AND LED LIGHTING SYSTEM

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority and benefits of Chinese Patent Application No. 201410375142.6, filed with State Intellectual Property Office, P.R.C. on July 31, 2014, the entire content of which is incorporated herein by reference.

FIELD

Embodiments of the present disclosure generally relate to an LED lighting system, and more particularly, to a control circuit for starting an LED lamp and an LED lighting system.

BACKGROUND

With the development of the semiconductor lighting technology and more attention to the energy and the environment, the LED lighting gradually replaces the conventional lighting and accelerates the transition of the world lighting industry. The LED lighting and a drive circuit of the LED lighting have a small size, a lower power consumption and a stable performance and are environmental, which can be widely used in various fields and occasions.

Nowadays, the typical isolated LED drive circuit is widely used, which not only can achieve a constant current output but also can achieve the switch adjusting function. However, the starting speed of the typical isolated LED drive circuit in related art cannot be controlled, and thus the LED lamp cannot achieve a soft starting, or even cannot be started in some applications. And since humans cannot quickly adapt to dramatic changes of the light intensity, they feel a dazzling sense when starting the LED lamp, and thus the user experience is poor.

SUMMARY

Embodiments of the present disclosure seek to solve at least one of the problems existing in the related art to at least some extent.

Embodiments of a first aspect of the present disclosure provide a control circuit for starting an LED lamp, including: an input module, configured to receive an input alternate current and to convert the input alternate current into a direct current； a driving module, connected with the input module and configured to generate a driving current for driving the LED lamp according to the direct current； a feedback module, connected with the driving module and configured to generate a feedback signal according to the driving current； and a driving chip, connected with the driving module and the feedback module respectively, and configured to obtain a starting state of the LED lamp, and to adjust the driving current according to the starting state of the LED lamp and the feedback signal so as to control the LED lamp to start.

With the control circuit for starting the LED lamp according to embodiments of the present disclosure, the input module converts the input alternate current into the direct current, and then the driving module generates the driving current for driving the LED lamp according to the direct current, and after the feedback module samples the driving current of the driving module and generates the feedback signal according to the driving current, the driving chip obtains the starting state of the LED lamp and adjusts the driving current according to the starting state of the LED lamp and the feedback signal so as to control the LED lamp to start. The control circuit for starting the LED lamp not only can achieve the constant current control and the switch dimming, but also can automatically control the starting speed of the LED lamp, such that an accelerated starting of the LED lamp, a reduction in delay between the light switch action and the LED lighting, and the soft starting of the LED lamp may be achieved, and finally the brightness of the LED lamp is controlled to be enhanced gradually so as to ensure the human eye to adapt to the light intensity change, thus accomplishing a more humane and practical lighting design and improving dramatically the user experience.

Embodiments of a second aspect of the present disclosure provide an LED lighting system including the above control circuit for starting the LED lamp.

With the LED lighting system according to embodiments of the present disclosure, the input module converts the input alternate current into the direct current, and then the driving module generates the driving current for driving the LED lamp according to the direct current, and after the feedback module samples the driving current of the driving module and generates the feedback signal according to the driving current, the driving chip obtains the starting state of the LED lamp and adjusts the driving current according to the starting state of the LED lamp and the feedback signal so as to control the LED lamp to start. The control circuit for starting the LED lamp not only can achieve the constant current control and the switch dimming, but also can automatically control the starting speed of the LED lamp, such that an accelerated starting of the LED lamp, a reduction in the delay between the light switch action and the LED lighting, and the soft starting of the LED lamp may be achieved, and finally the brightness of the LED lamp is controlled to be enhanced gradually so as to ensure the human eye to adapt to the light intensity change, thus accomplishing a more humane and practical lighting design and improving dramatically the user experience.

Additional aspects and advantages of embodiments of present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of embodiments of the present disclosure will become apparent and more readily appreciated from the following descriptions made with reference to the accompanying drawings, in which:

Fig. 1 is a circuit diagram of a typical isolated LED drive circuit；

Fig. 2 is a block diagram of a control circuit for starting an LED lamp according to an embodiment of the present disclosure；

Fig. 3 is a circuit diagram of a control circuit for starting an LED lamp according to a first embodiment of the present disclosure；

Fig. 4 is a block diagram of a driving chip according to an embodiment of the present disclosure；

Fig. 5 is a block diagram of a dynamic starting module according to an embodiment of the present disclosure；

Fig. 6 is a circuit diagram of a dynamic starting module according to an embodiment of the present disclosure；

Fig. 7 is a circuit diagram of a control circuit for starting an LED lamp according to a second embodiment of the present disclosure；

Fig. 8 is a signal-wave diagram of a control circuit for starting the LED lamp according to an embodiment of the present disclosure； and

Fig. 9 is block diagram of an LED lighting system according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the present disclosure. Embodiments of the present disclosure will be shown in drawings, in which the same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions. The embodiments described herein according to drawings are explanatory and illustrative, not construed to limit the present disclosure.

Various embodiments and examples are provided in the following description to implement different structures of the present disclosure. In order to simplify the present disclosure, certain elements and settings will be described. However, these elements and settings are only by way of example and are not intended to limit the present disclosure. In addition, reference numerals may be repeated in different examples in the present disclosure. This repeating is for the purpose of simplification and clarity and does not refer to relations between different embodiments and/or settings. Furthermore, examples of different processes and materials are provided in the present disclosure. However, it would be appreciated by those skilled in the art that other processes and/or materials may be also applied. Moreover, a structure in which a first feature is “on” a second feature may include an embodiment in which the first feature directly contacts the second feature, and may also include an embodiment in which an additional feature is formed between the first feature and the second feature so that the first feature does not directly contact the second feature.

In the description of the present disclosure, unless specified or limited otherwise, it should be noted that, terms “mounted, ” “connected” and “coupled” may be understood broadly, such as electronic connections or mechanical connections, inner communications between two elements, direct connections or indirect connections through intervening structures , which can be understood by those skilled in the art according to specific situations.

With reference to the following descriptions and drawings, these and other aspects of embodiments of the present disclosure will become apparent. In the descriptions and drawings, some particular embodiments are described in order to show the principles of embodiments according to the present disclosure, however, it should be appreciated that the scope of embodiments according to the present disclosure is not limited herein. On the contrary, changes, alternatives, and modifications can be made in the embodiments without departing from spirit, principles and scope of the attached claims.

Fig. 1 is a circuit diagram of a typical isolated LED drive circuit. The LED drive circuit is used to achieve the LED lighting. As shown in Fig. 1, an AC flows via the full-wave rectifier bridge (the rectifier bridge is consisted of diodes D1', D2', D4' and D5') , and then is converted by aπ-type filter circuit (consisted of capacitors C2', C3' and an inductor L1') into a high-voltage DC for supplying a starting voltage to a drive control chip IC', and when starting the drive control chip IC', the high-voltage DC supplies the energy for the main power loop. A current of a primary winding L2' of the transformer is converted into a main-side peak voltage signal via a detecting resistor R7', and then the main-side peak voltage signal is outputted to the drive control chip IC' to control a switch Q0' to turn on or turn off, and thus the periodic storage energy of the primary winding L2' is transferred to a secondary winding L3', the secondary winding L3' releases the energy, and the energy is rectified and filtered by the diode D3' and a capacitor C2' to supply the power to the LED lamp, a feedback winding L4' outputs a secondary degaussing time signal and a voltage signal to the drive control chip IC' (a feedback divider network is consisted of resistors R4' and R5') , and supplies the power for the drive control chip IC' via a feedback diode D6' a t the same time, the drive control chip IC' samples the secondary degaussing time signal of the feedback winding L4' to generate a switch control signal of the switch transistor Q0', and controls a conduction cycle of the switch transistor Q0' to be in a fixed proportion to the secondary degaussing time so as to supply a constant current to a secondary-side power loop, thus ensuring the brightness of the LED lamp to be stable. In addition, the drive control ship IC' a djusts a main-side peak current value by sampling the change of a primary-side line voltage signal of the feedback winding L4' to ensure that the output current of the LED drive circuit does not change with the primary-side line voltage signal. The drive control ship IC' also can adjust the main-side peak current value and the proportion of the conduction cycle of the switch transistor Q0' to the secondary degaussing time by sampling the switch control signal of the drive control ship IC' to change the output current value of the LED drive circuit, thus achieving the light adjust function of the switch. However, the starting speed of the typical isolated LED drive circuit in related art cannot be controlled, and thus the LED lamp cannot achieve a soft starting, or even cannot be started in some applications, and humans cannot quickly adapt to dramatic changes of the light intensity, such that they feel a dazzling sense when starting the LED lamp, and thus the user experience is poor.

In the following, a control circuit for starting an LED lamp and an LED lamp are described in detail with reference to drawings.

Fig. 2 is a block diagram of a control circuit for starting an LED lamp according to an embodiment of the present disclosure. As shown in Fig. 2, the control circuit 1001 for starting the LED lamp includes an input module 1, a driving module 2, a feedback module 3, and a driving chip 4. The input module 1 is configured to receive an input alternate current and to convert the input alternate current into a direct current. The driving module 2 is connected with the input module 1 and is configured to generate a driving current for driving the LED lamp 5 according to the direct current. The feedback module 3 is connected with the driving module 2 and is configured to generate a feedback signal according to the driving current. The driving chip 4 is connected with the driving module 2 and the feedback module 3 respectively, and is configured to obtain a starting state of the LED lamp 5, and to adjust the driving current according to the starting state of the LED lamp 5 and the feedback signal so as to control the LED lamp 5 to start.

Fig. 3 is a circuit diagram of a control circuit for starting an LED lamp according to a first embodiment of the present disclosure. As shown in Fig. 3, the input module 1 can include a rectifier bridge consisted of diodes D1, D2, D4 and D5, a π-type filter circuit consisted of capacitors C2, C3 and a first inductor L1, and a starting voltage providing circuit consisted of resistors R5 and R6. The driving module can include a transformer consisted of a primary winding L2, a secondary winding L3 and a feedback winding L4, and the switch transistor Q0.

Fig. 4 is a block diagram of a driving chip according to an embodiment of the present disclosure. As shown in Fig. 4, the driving chip 4 includes a feedback sampling module 41, a dynamic starting module 42, a constant current control module 43, and a driving signal output module 44. The feedback sampling module 41 is configured to generate a feedback sampling signal according to the feedback signal of a feedback terminal FB, the feedback sampling signal includes a feedback voltage sampling signal Vfb and a feedback time sampling signal. The dynamic starting module 42 is connected with the feedback sampling module 41, and is configured to obtain the starting state of the LED lamp 5 according to the feedback sampling signal and to generate a constant parameter signal Vpk-DS according to the starting state of the LED lamp 5, specifically, the dynamic starting module 42 is configured to obtain the starting state of the LED lamp 5 according to the feedback voltage sampling signal Vfb of the feedback sampling signal and to generate the constant parameter signal Vpk-DS according to the starting state of the LED lamp 5. The constant current control module 43 is connected with the feedback sampling module 41 and the dynamic starting module 42 respectively, and is configured to generate a driving signal according to the feedback sampling signal and the constant parameter signal, specifically, the constant current control module 43 is configured to generate the driving signal according to the feedback time sampling signal of the feedback sampling signal and the constant parameter signal Vpk-DS. The driving signal output module 44 is connected with the constant current control module 43, and is configured to output the driving signal to a driving output terminal DRV.

Fig. 5 is a block diagram of a dynamic starting module according to an embodiment of the present disclosure. As shown in Fig. 5, the dynamic starting module 42 includes a voltage detecting sub-module 421, a starting control sub-module 422, and a selecting sub-module 423. The voltage detecting sub-module 421 is configured to obtain the starting state of the LED lamp 5 according to a predetermined voltage threshold Vref and the feedback sampling signal, and to generate a starting state determination signal Select according to the starting state of the LED lamp 5, specifically, the voltage detecting sub-module 421 is configured to obtain the starting state of the LED lamp 5 according to the predetermined voltage threshold Vref and the feedback voltage sampling signal Vfb of the feedback sampling signal, and to generate the starting state determination signal Select according to the starting state of the LED lamp 5. The starting control sub-module 422 is connected with the voltage detecting sub-module 421, and is configured to generate a dynamic constant parameter signal Vpkds according to the starting state determination signal Select, and the dynamic constant parameter signal Vpkds increases from a minimum constant parameter Vpkmin to a maximum constant parameter Vpkmax. The selecting sub-module 423 is connected with the voltage detecting sub-module 421 and the starting control sub-module 422, and is configured to select one of the dynamic constant parameter signal Vpkds and the maximum constant parameter Vpkmax to output according to the starting state determination signal Select. It should be noted that, the dynamic constant parameter signal Vpkds may be the main-side peak current value of the transformer in the driving module 2, may be a ratio of the secondary degaussing time to the conduction cycle of the switch transistor, or may be any other constant parameter or a combination of different constant parameters, which is determined according to different constant principles.

In an embodiment, if the feedback sampling signal is less than the predetermined voltage threshold Vref, and the starting state of the LED lamp 5 is off, the selecting sub-module 423 outputs the maximum constant parameter Vpkmax, specifically, if the feedback voltage sampling signal Vfb of the feedback sampling signal is less than the predetermined voltage threshold Vref, and the starting state of the LED lamp 5 is off, the selecting sub-module 423 outputs the maximum constant parameter Vpkmax. If the feedback sampling signal is larger than the predetermined voltage threshold Vref, and the starting state of the LED lamp 5 is on, the selecting sub-module 423 outputs the dynamic constant parameter signal Vpkds, specifically, if the feedback voltage sampling signal Vfb of the feedback sampling signal is larger than the predetermined voltage threshold Vref, and the starting state of the LED lamp 5 is on, the selecting sub-module 423 outputs the dynamic constant parameter signal Vpkds. Thus, the dynamic starting module 42 can dynamically control the constant parameter signal Vpk_DS during the starting of the LED lamp 5 by determining the feedback voltage sampling signal Vfb having a proportional relationship with the driving current, and thus the constant current control module 43 generates a driving signal according to the constant parameter signal Vpk_DS to adjust the driving current, so as to achieve the dynamic starting of the LED lamp 5.

Fig. 6 is a circuit diagram of a dynamic starting module according to an embodiment of the present disclosure. Fig. 7 is a circuit diagram of a control circuit for starting an LED lamp according to a second embodiment of the present disclosure. As shown in Fig. 6 and Fig. 7, the voltage detecting sub-module 421 includes a comparator 424, the comparator 424 has a first terminal connected with an output terminal of the feedback sampling module 41, a second terminal connected with a providing terminal of the predetermined voltage threshold Vref, and an output terminal configured as an output terminal of the voltage detecting sub-module 421, i.e. the output terminal of the comparator 424 is configured to output the starting state determination signal Select to the selecting sub-module 423.

In an embodiment, as shown in Fig. 6, the starting control sub-module 422 may include a first switch M1, a second switch M2, a third switch M3, a fourth switch M4, a fifth switch M5, a sixth switch M6, a first resistor R1 and a first capacitor C1. The first switch M1 has a first terminal connected with a providing terminal of a first bias current Bias1, a second terminal grounded, and a control terminal connected with the providing terminal of the first bias current Bias1. The second switch M2 has a first terminal grounded, a control terminal connected with the providing terminal of the first bias current Bias1, and a second terminal. The third switch M3 has a first terminal connected with a providing terminal of a first predetermined voltage S1, a second terminal connected with the second terminal of the second switch M2, and a control terminal connected with the second terminal of the third switch M3. The fourth switch M4 has a first terminal connected with the providing terminal of the first predetermined voltage S1, a control terminal connected with the control terminal of the third switch M3, and a second terminal. The first resistor R1 has a first terminal connected with the second terminal of the fourth switch M4, and a second terminal grounded. The fifth switch M5 has a first terminal connected with the providing terminal of the first predetermined voltage S1, a control terminal connected with the control terminal of the third switch M3, and a second terminal. The sixth switch M6 has a first terminal connected with the second terminal of the fifth switch M5, a second terminal connected with the first terminal of the first resistor R1, and a control terminal configured as a first output terminal of the starting control sub-module 422. The first capacitor C1 has a first terminal connected with the first terminal of the first resistor R1 and configured as a second output terminal of the starting control sub-module 422 to output the dynamic constant parameter signal Vpkds, and a second terminal grounded. In an embodiment, the selecting sub-module 423 includes a selector 425, the selector 425 has a first terminal connected with a providing terminal of the maximum constant parameter, a second terminal connected with the second output terminal of the starting control sub-module 422, and a control terminal connected with a first output terminal of the starting control sub-module 422 and the output terminal of the voltage detecting sub-module 421 respectively.

In an embodiment, as shown in Fig. 6, a current mirror circuit is consisted of the first switch M1, the second switch M2, the third switch M3, the fourth switch M4, the fifth switch M5, and is configured to enable the first bias current Bias1 to flow to the first resistor R1 after mirroring the first bias current Bias1 and to generate a bias voltage signal, i.e. the dynamic constant parameter signal Vpkds. When the starting state determination signal Select is at a high level, the sixth switch is turned on, the flowing current of the first resistor R1 increases, the bias voltage signal increases, and the bias voltage signal is filtered and delayed via the first capacitor C1, such that the dynamic constant parameter signal Vpkds increases slowly. It should be noted that, the first bias current Bias1 or the first capacitor C1 can be adjusted to obtain the different delay starting time T according to the various application requirements.

In an embodiment, as shown in Fig. 7, the control circuit 1001 for starting the LED lamp 5 further includes a second capacitor C2 having a first terminal connected with the driving chip 4 and a second terminal grounded.

In an embodiment, as shown in Fig. 7, the starting control sub-module 422 of the driving chip 4 may include a seventh switch M7, an eighth switch M8, a ninth switch M9, a tenth switch M10, a second resistor R2, an eleventh switch M11 and a twelfth switch M12. The seventh switch M7 has a first terminal connected with a providing terminal of a second bias current Bias2, a second terminal grounded, and a control terminal connected with the providing terminal of the second bias current Bias2. The eighth switch M8 has a first terminal grounded, a control terminal connected with the providing terminal of the second bias current Bias2, and a second terminal. The ninth switch M9 has a first terminal connected with a providing terminal of a second predetermined voltage S2, a second terminal connected with the second terminal of the eighth switch M8, and a control terminal connected with the second terminal of the ninth switch M9. The tenth switch M10 has a first terminal connected with the providing terminal of the second predetermined voltage S2, a control terminal connected with the control terminal of the ninth switch M9, and a second terminal. The second resistor R2 has a first terminal connected with the second terminal of the tenth switch M10, and a second terminal grounded. The eleventh switch M11 has a first terminal connected with the providing terminal of the second predetermined voltage S2, a control terminal connected with the control terminal of the ninth switch M9, and a second terminal. The twelfth switch M12 has a first terminal connected with the second terminal of the eleventh switch M11, a second terminal connected with the first terminal of the second resistor R2 and the first terminal of the second capacitor C2 respectively and configured as a second output terminal of the starting control sub-module 422 to output the dynamic constant parameter signal Vpkds, and a control terminal configured as a first output terminal of the starting control sub-module 422.

As shown in Fig. 7, a current mirror circuit is consisted of the seventh switch M7, the eighth switch M8, the ninth switch M9, the tenth switch M10, the eleventh switch M11 and the twelfth switch M12 and is configured to enable the second bias current Bias2 to flow to the second resistor R2 after mirroring the second bias current Bias2, and to generate a bias voltage signal, i.e. the dynamic constant parameter signal Vpkds. When the starting state determination signal Select is at a high level, the twelfth switch is turned on, the flowing current of the second resistor R2 increases, the bias voltage signal increases, and the bias voltage signal is filtered and delayed via the second capacitor C2, such that the dynamic constant parameter signal Vpkds increases slowly. It should be noted that, the second bias current Bias2 or the second capacitor C2 can be adjusted to obtain the different delay starting time T according to the various application requirements. As shown in Fig. 7, since the second capacitor C2 is disposed outside of the driving chip 4, the second capacitor C2 can be adjusted from the outside of the driving chip 4 to obtain the different delay starting time T according to the various application requirements, thus facilitating the debugging of the application terminal.

As shown in Fig. 6 and Fig. 7, each of the first switch M1 to the fifth switch M5 and the seventh switch M7 to the eleventh switch M11 may be a PMOS transistor, each of the sixth switch M6 and the twelfth switch M12 may be an NMOS transistor.

Fig. 8 is a signal-wave diagram of a control circuit for starting the LED lamp according to an embodiment of the present disclosure. Vled is an on-state voltage drop of the load LED lamp, N is a number of the load LED lamp, Vout is a driving voltage for driving the LED lamp 5, and the driving voltage Vout is proportional to the feedback voltage sampling signal Vfb. As shown in Fig. 8, the dynamic starting process have two stages, in a first stage, the feedback voltage sampling signal Vfb of the feedback sampling signal is less than the predetermined voltage threshold Vref, the driving voltage Vout is not high enough for lighting the LED lamp 5, at this time, the starting state determination signal Select is at a low level and the selecting sub-module 423 outputs the maximum constant parameter Vpkmax to the constant current control module 43, such that the driving module 2 in this stage operates in a maximum constant state, generates the maximum driving current, and speeds up the building process of the driving voltage Vout. In a second stage, the feedback voltage sampling signal Vfb of the feedback sampling signal is larger than the predetermined voltage threshold Vref, the driving voltage Vout is high enough for lighting the LED lamp 5, at this time, the starting state determination signal Select is converted into a high level to control the selecting sub-module 423 to output the dynamic constant parameter signal Vpkds, and the starting control sub-module 422 controls the dynamic constant parameter signal Vpkds to increase from the minimum constant parameter Vpkmin to the maximum constant parameter Vpkmax at the same time, and the constant current control module 43 controls the driving module 2 to change gradually from the minimum constant state to the maximum constant state, such that the generated driving current increases gradually from the minimum to the maximum, thus achieving the dynamic starting of the LED lamp 5. Specifically, the different delay starting time T can be set according to the various application requirements.

Specifically, in an embodiment, as shown in Fig. 4, the driving chip 4 further includes a starting module 45, a switch dimming module 46 and an overcurrent protection module 47. The starting module 45 is configured to detect a voltage of a starting capacitor C6 outside the power terminal VDD so as to provide a starting enable signal for the driving chip 4 and to provide a dimming counting signal for the switch dimming module 46. The switch dimming module 46 is configured to determine the dimming level according to the dimming counting signal and to generate a dimming control signal. The overcurrent protection module 47 is configured to detect a main-side peak voltage signal of an overcurrent detecting terminal CS, and to generate an overcurrent protection signal according to the main-side peak voltage signal. The constant current control module 43 controls the conduction period and the main-side peak current value of the switch transistor by processing a feedback time sampling signal of the feedback sampling signal and the overcurrent protection signal, so as to achieve the constant current control. The constant current control module 43 adjusts the constant parameter signal value by processing the dimming control signal, so as to adjust the driving current value and to achieve the switch dimming. Thus, the control circuit for starting the LED lamp 5 not only can achieve the dynamic starting of the LED lamp 5, but also can achieve the constant current control and the switch dimming.

With the control circuit for starting the LED lamp according to embodiments of the present disclosure, the input module converts the input alternate current into the direct current , and then the driving module generates the driving current for driving the LED lamp according to the direct current, and after the feedback module samples the driving current of the driving module and generates the feedback signal according to the driving current, the driving chip obtains the starting state of the LED lamp and adjusts the driving current according to the starting state of the LED lamp and the feedback signal so as to control the LED lamp to start. The control circuit for starting the LED lamp not only can achieve the constant current control and the switch dimming, but also can automatically control the starting speed of the LED lamp, such that an accelerated starting of the LED lamp, a reduction in delay between the light switch action and the LED lighting, and the soft starting of the LED lamp may be achieved, and finally the brightness of the LED lamp is controlled to be enhanced gradually so as to ensure the human eye to adapt to the light intensity change, thus accomplishing a more humane and practical lighting design and improving dramatically the user experience .

Fig. 9 is block diagram of an LED lighting system according to an embodiment of the present disclosure. In an embodiment, the LED lighting system 1000 includes a control circuit 1001 for starting the LED lamp 5.

With the LED lighting system according to embodiments of the present disclosure, the input module converts the input alternate current into the direct current, and then the driving module generates the driving current for driving the LED lamp according to the direct current, after the feedback module samples the driving current of the driving module and generates the feedback signal according to the driving current, the driving chip obtains the starting state of the LED lamp and adjusts the driving current according to the starting state of the LED lamp and the feedback signal, so as to control the LED lamp to start. The control circuit for starting the LED lamp not only can achieve the constant current control and the switch dimming, but also can automatically control the starting speed of the LED lamp, such that an accelerated starting of the LED lamp, a reduction in the delay between the light switch action and the LED lighting and the soft starting of the LED lamp may be achieved, and finally the brightness of the LED lamp is controlled to be enhanced gradually so as to ensure the human eye to adapt to the light intensity change, thus accomplishing a more humane and practical lighting design and improving dramatically the user experience.

Any procedure or method described in the flow charts or described in any other way herein may be understood to comprise one or more modules, portions or parts for storing executable codes that realize particular logic functions or procedures. Moreover, advantageous embodiments of the present disclosure comprises other implementations in which the order of execution is different from that which is depicted or discussed, including executing functions in a substantially simultaneous manner or in an opposite order according to the related functions. This should be understood by those skilled in the art which embodiments of the present disclosure belong to.

The logic and/or step described in other manners herein or shown in the flow chart, for example, a particular sequence table of executable instructions for realizing the logical function, may be specifically achieved in any computer readable medium to be used by the instruction execution system, device or equipment (such as the system based on computers, the system comprising processors or other systems capable of obtaining the instruction from the instruction execution system, device and equipment and executing the instruction) , or to be used in combination with the instruction execution system, device and equipment.

It is understood that each part of the present disclosure may be realized by the hardware, software, firmware or their combination. In the above embodiments, a plurality of steps or methods may be realized by the software or firmware stored in the memory and executed by the appropriate instruction execution system. For example, if it is realized by the hardware, likewise in another embodiment, the steps or methods may be realized by one or a combination of the following techniques known in the art: a discrete logic circuit having a logic gate circuit for realizing a logic function of a data signal, an application-specific integrated circuit having an appropriate combination logic gate circuit, a programmable gate array (PGA) , a field programmable gate array (FPGA) , etc.

Those skilled in the art shall understand that all or parts of the steps in the above exemplifying method of the present disclosure may be achieved by commanding the related hardware with programs. The programs may be stored in a computer readable storage medium, and the programs comprise one or a combination of the steps in the method embodiments of the present disclosure when run on a computer.

In addition, each function cell of the embodiments of the present disclosure may be integrated in a processing module, or these cells may be separate physical existence, or two or more cells are integrated in a processing module. The integrated module may be realized in a form of hardware or in a form of software function modules. When the integrated module is realized in a form of software function module and is sold or used as a standalone product, the integrated module may be stored in a computer readable storage medium.

The storage medium mentioned above may be read-only memories, magnetic disks or CD, etc.

Reference throughout this specification to “an embodiment, ” “some embodiments, ” “one embodiment” , “another example, ” “an example, ” “a specific example, ” or “some examples, ” means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the phrases such as “in some embodiments, ” “in one embodiment” , “in an embodiment” , “in another example, ” “in an example, ” “in a specific example, ” or “in some examples, ” in various places throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that the above embodiments cannot be construed to limit the present disclosure, and changes, alternatives, and modifications can be made in the embodiments without departing from spirit, principles and scope of the present disclosure.

Claims

A control circuit for starting an LED lamp, comprising:

an input module, configured to receive an input alternate current and to convert the input alternate current into a direct current；

a driving module, connected with the input module and configured to generate a driving current for driving the LED lamp according to the direct current；

a feedback module, connected with the driving module and configured to generate a feedback signal according to the driving current； and

a driving chip, connected with the driving module and the feedback module respectively, and configured to obtain a starting state of the LED lamp, and to adjust the driving current according to the starting state of the LED lamp and the feedback signal so as to control the LED lamp to start.
The control circuit for starting the LED lamp of claim 1, wherein the driving chip comprises:

a feedback sampling module, configured to generate a feedback sampling signal according to the feedback signal；

a dynamic starting module, connected with the feedback sampling module, and configured to obtain the starting state of the LED lamp according to the feedback sampling signal and to generate a constant parameter signal according to the starting state of the LED lamp；

a constant current control module, connected with the feedback sampling module and the dynamic starting module respectively, and configured to generate a driving signal according to the feedback sampling signal and the constant parameter signal； and

a driving signal output module, connected with the constant current control module, and configured to output the driving signal.
The control circuit for starting the LED lamp of claim 2, wherein the dynamic starting module comprises:

a voltage detecting sub-module, configured to obtain the starting state of the LED lamp according to a predetermined voltage threshold and the feedback sampling signal, and to generate a starting state determination signal according to the starting state of the LED lamp；

a starting control sub-module, connected with the voltage detecting sub-module, and configured to generate a dynamic constant parameter signal according to the starting state determination signal, wherein the dynamic constant parameter signal increases from a minimum constant parameter to a maximum constant parameter； and

a selecting sub-module, connected with the voltage detecting sub-module and the starting control sub-module, and configured to select one of the dynamic constant parameter signal and the maximum constant parameter to output according to the starting state determination signal.
The control circuit for starting the LED lamp of claim 3, wherein the selecting sub-module is configured to:

select the maximum constant parameter to output, if the feedback sampling signal is less than the predetermined voltage threshold and the starting state of the LED lamp is OFF； or

select the dynamic constant parameter signal to output, if the feedback sampling signal is larger than or equal to the predetermined voltage threshold and the starting state of the LED lamp is ON.
The control circuit for starting the LED lamp of claim 3 or 4, wherein the voltage detecting sub-module comprises:

a comparator, having a first terminal connected with an output terminal of the feedback sampling module, a second terminal connected with a providing terminal of the predetermined voltage threshold, and an output terminal configured as an output terminal of the voltage detecting sub-module.
The control circuit for starting the LED lamp of any one of claims 3-5, wherein the starting control sub-module comprises:

a first switch, having a first terminal connected with a providing terminal of a first bias current, a second terminal grounded and a control terminal connected with the providing terminal of the first bias current；

a second switch, having a first terminal grounded, a control terminal connected with the providing terminal of the first bias current, and a second terminal；

a third switch, having a first terminal connected with a providing terminal of a first predetermined voltage, a second terminal connected with the second terminal of the second switch, and a control terminal connected with the second terminal of the third switch；

a fourth switch, having a first terminal connected with the providing terminal of the first predetermined voltage, a control terminal connected with the control terminal of the third switch, and a second terminal；

a first resistor, having a first terminal connected with the second terminal of the fourth switch, and a second terminal grounded；

a fifth switch, having a first terminal connected with the providing terminal of the first predetermined voltage, a control terminal connected with the control terminal of the third switch, and a second terminal；

a sixth switch, having a first terminal connected with the second terminal of the fifth switch, a second terminal connected with the first terminal of the first resistor, and a control terminal configured as a first output terminal of the starting control sub-module； and

a first capacitor, having a first terminal connected with the first terminal of the first resistor and configured as a second output terminal of the starting control sub-module to output the dynamic constant parameter signal, and a second terminal grounded.
The control circuit for starting the LED lamp of any one of claims 1-5, further comprising:

a second capacitor, having a first terminal connected with the driving chip and a second terminal grounded.
The control circuit for starting the LED lamp of claim 7, wherein the starting control sub-module comprises:

a seventh switch, having a first terminal connected with a providing terminal of a second bias current, a second terminal grounded, and a control terminal connected with the providing terminal of the second bias current；

an eighth switch, having a first terminal grounded and a control terminal connected with the providing terminal of the second bias current, and a second terminal；

a ninth switch, having a first terminal connected with a providing terminal of a second predetermined voltage, a second terminal connected with the second terminal of the eighth switch, and a control terminal connected with the second terminal of the ninth switch；

a tenth switch, having a first terminal connected with the providing terminal of the second predetermined voltage, a control terminal connected with the control terminal of the ninth switch, and a second terminal；

a second resistor, having a first terminal connected with the second terminal of the tenth switch, and a second terminal grounded；

an eleventh switch, having a first terminal connected with the providing terminal of the second predetermined voltage, a control terminal connected with the control terminal of the ninth switch, and a second terminal； and

a twelfth switch, having a first terminal connected with the second terminal of the eleventh switch, a second terminal connected with the first terminal of the second resistor and the first terminal of the second capacitor respectively and configured as a second output terminal of the starting control sub-module to output the constant parameter signal, and a control terminal configured as a first output terminal of the starting control sub-module.
The control circuit for starting the LED lamp of claim 6 or 8, wherein the selecting sub-module comprises:

a selector, having a first terminal connected with a providing terminal of the maximum constant parameter, a second terminal connected with the second output terminal of the starting control sub-module, and a control terminal connected with the first output terminal of the starting control sub-module and the output terminal of the voltage detecting sub-module.
The control circuit for starting the LED lamp of claim 9, wherein each of the first switch to the fifth switch and the seventh switch to the eleventh switch is a PMOS transistor, each of the sixth switch and the twelfth switch is an NMOS transistor.
An LED lighting system, comprising a control circuit for starting the LED lamp according to any one of claims 1-10.