LED driving circuit and luminaire

Abstract

The application provides an LED driving circuit and a lamp. The LED driving circuit comprises a rectifying module, a constant current driving module and a triac signal extraction module; the input end of the rectifying module is connected with the input end of the LED driving circuit, and the output end is connected with the input end of the constant current driving module and the input end of the triac signal extraction module respectively; the first control end of the constant current driving module is connected with the output end of the triac signal extraction module, the second control end is used for inputting a dimming signal, and the output end is connected with the output end of the LED driving circuit; the constant current driving module is used for controlling the output current of the constant current driving module according to the dimming signal and the triac signal. The application controls the constant current by comprehensively using the triac signal and the dimming signal, and is compatible with the triac dimming and intelligent dimming. The application can be directly installed in the power channel with the triac dimmer, and has good compatibility.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED, in particular to an LED driving circuit and a lamp. BACKGROUND

[0002] Triac dimming is a method of controlling LED brightness by adjusting the conduction phase of current, which is simple to realize and low in cost, and has been applied to incandescent lamp and energy-saving lamp dimming mode for a long time, and is also the most widely used dimming mode for LED dimming at present. 2 With the development of LED technology, intelligent dimming products using PWM or I

[0003] In the prior art, since some users have installed triac dimmers in power lines, intelligent dimming products are directly installed in original power lines, and when the user adjusts the triac dimmer to a small angle, the intelligent dimming product will cause problems such as flashing light and non-lighting, and the intelligent dimming product cannot be compatible with the triac dimmer. Therefore, when the intelligent dimming product is installed, the original triac dimmer needs to be removed and the existing power line needs to be modified, which is high in modification cost and is not conducive to the application and promotion of intelligent lighting products. SUMMARY

[0004] Embodiments of the present application provide an LED driving circuit and a lamp to solve the problem that intelligent lighting products in the prior art cannot be compatible with triac dimmers and the original triac dimmer in the power line needs to be removed.

[0005] In a first aspect, embodiments of the present application provide an LED driving circuit, an input end of the LED driving circuit being connected with an AC power supply through a triac dimmer, and an output end of the LED driving circuit being used to drive an LED load; the LED driving circuit comprises a rectifier module, a constant current driving module and a triac signal extraction module;

[0006] An input end of the rectifier module is connected with the input end of the LED driving circuit, and output ends of the rectifier module are respectively connected with an input end of the constant current driving module and an input end of the triac signal extraction module;

[0007] A first control end of the constant current driving module is connected with an output end of the triac signal extraction module, a second control end of the constant current driving module is used to input a dimming signal, and an output end of the constant current driving module is connected with the output end of the LED driving circuit;

[0008] The constant current driving module is used to acquire the dimming signal and a triac signal sent by the triac signal extraction module, and control an output current of the constant current driving module based on the dimming signal and the triac signal.

[0009] Optionally, the control of the output current of the constant current driving module based on the dimming signal and the triac signal comprises:

[0010] The dimming signal and the switching signal are multiplied to obtain a target dimming signal, and the output current of the constant current driving module is controlled according to the target dimming signal.

[0011] Optionally, the LED load comprises at least one LED lamp string; the constant current driving module comprises a positive driving end and at least one negative driving end, the number of the negative driving ends being the same as the number of the LED lamp strings; the positive driving end is connected with the positive poles of the LED lamp strings, and each negative driving end is connected with the negative pole of the corresponding LED lamp string one by one.

[0012] The constant current driving module comprises a first diode, a first resistor and a constant current driving chip.

[0013] The power supply end of the constant current driving chip is connected with the cathode and the positive driving end of the first diode through the first resistor, the first control signal input end of the constant current driving chip is connected with the first control end of the constant current driving module, the second control signal input end of the constant current driving chip is connected with the second control end of the constant current driving module, and each drain driving end of the constant current driving chip is connected with each negative driving end one by one.

[0014] The anode of the first diode is connected with the input end of the constant current driving module.

[0015] The constant current driving chip is used for multiplying the dimming signal and the switching signal to obtain a target dimming signal, and is used for controlling the current of each drain driving end according to the target dimming signal.

[0016] Optionally, the constant current driving chip comprises a switching signal adjusting unit, a dimming signal adjusting unit, at least one dimming control unit, at least one switch driving unit and at least one switch unit; each dimming control unit, each switch driving unit and each switch unit correspond one by one.

[0017] The input end of the switching signal adjusting unit is connected with the first control signal input end of the constant current driving chip, and the output end of the switching signal adjusting unit is connected with the first input end of each dimming control unit; the switching signal adjusting unit is used for converting the switching signal into a PWM signal to obtain an adjusted switching signal.

[0018] The input end of the dimming signal adjusting unit is connected with the second control signal input end of the constant current driving chip, and each output end of the dimming signal adjusting unit is connected with the second input end of each dimming control unit one by one; the dimming signal adjusting unit is used for generating a secondary dimming signal corresponding to each dimming control unit according to the dimming signal; wherein the secondary dimming signal is a PWM signal.

[0019] The output end of any one dimming control unit is connected with the input end of the switch driving unit corresponding to the dimming control unit; the output end of the switch driving unit is connected with the control end of the corresponding switch unit; the first end of the switch unit is connected with the drain driving end corresponding to the dimming control unit, and the second end of the switch unit is grounded; the dimming control unit is used for multiplying the adjusted cutting signal and the secondary dimming signal corresponding to the dimming control unit to obtain the target dimming signal corresponding to the dimming control unit, and generating the reference voltage corresponding to the dimming control unit according to the target dimming signal; the switch driving unit generates the corresponding switch control signal according to the reference voltage corresponding to the dimming control unit, and controls the switch unit to be turned on through the switch control signal to realize the control of the current of the drain driving end corresponding to the dimming control unit.

[0020] Optionally, the switch unit comprises a first switch tube and a second resistor.

[0021] The first end of the first switch tube is connected with the first end of the switch unit, the control end of the first switch tube is connected with the control end of the switch unit, and the second end of the first switch tube is connected with the second end of the switch unit through the second resistor.

[0022] Optionally, the switch driving unit comprises an error amplifier and a driving signal conditioning subunit.

[0023] The positive input end of the error amplifier is connected with the input end of the switch driving unit, the negative input end of the error amplifier is connected with the second end of the first switch tube and the second resistor respectively, and the output end of the error amplifier is connected with the input end of the driving signal conditioning subunit.

[0024] The output end of the driving signal conditioning subunit is connected with the output end of the switch driving unit.

[0025] Optionally, the cutting signal adjusting unit comprises a first comparator and a third resistor.

[0026] The positive input end of the first comparator is connected with the input end of the cutting signal adjusting unit, the negative input end of the first comparator is used for inputting a triangular wave signal, and the output end of the first comparator is connected with the output end of the cutting signal adjusting unit through the third resistor.

[0027] Optionally, the cutting signal extraction module comprises a fourth resistor.

[0028] The first end of the fourth resistor is connected with the input end of the cutting signal extraction module, and the second end of the fourth resistor is connected with the output end of the cutting signal extraction module.

[0029] Optionally, the LED driving circuit further comprises a constant voltage module.

[0030] The input end of the constant-voltage module is connected with the output end of the rectifier module and the input end of the triac signal extraction module respectively, and the output end of the constant-voltage module is connected with the input end of the constant-current drive module.

[0031] The voltage of the output end of the constant-voltage module is constant.

[0032] In the second aspect, the embodiment of the present application provides a lamp, which comprises the LED driving circuit provided in the first aspect of the above embodiment.

[0033] The embodiment of the present application provides an LED driving circuit and a lamp. The input end of the LED driving circuit is connected with an AC power source through a thyristor dimmer, and the output end of the LED driving circuit is used for driving an LED load. The LED driving circuit comprises a rectifier module, a constant-current drive module and a triac signal extraction module. The input end of the rectifier module is connected with the input end of the LED driving circuit, the output end of the rectifier module is connected with the input end of the constant-current drive module and the input end of the triac signal extraction module respectively, the first control end of the constant-current drive module is connected with the output end of the triac signal extraction module, the second control end of the constant-current drive module is used for inputting a dimming signal, and the output end of the constant-current drive module is connected with the output end of the LED driving circuit. The constant-current drive module is used for acquiring the dimming signal and the triac signal sent by the triac signal extraction module, and controlling the output current of the constant-current drive module based on the dimming signal and the triac signal. The LED driving circuit provided in the embodiment of the present application extracts the triac signal, and performs compatible processing on the triac signal and the dimming signal, so that the user can adjust through the thyristor dimmer or intelligent dimming (mobile phone APP or remote controller), and the problem of flashing light does not occur, so that the LED driving circuit can be compatible with the thyristor dimmer, can be directly installed in a power line with the thyristor dimmer, does not need to be reformed on the original power line, and the adaptability and compatibility of the circuit are improved. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative labor.

[0035] Figure 1 is a circuit structure schematic diagram of an LED driving circuit provided by the embodiment of the present application;

[0036] Figure 2 is a circuit structure schematic diagram of another LED driving circuit provided by the embodiment of the present application;

[0037] Figure 3is a circuit schematic diagram of an LED driving circuit provided by an embodiment of the present application;

[0038] Figure 4 is an internal structure block diagram of a constant current driving chip provided by an embodiment of the present application;

[0039] Figure 5 is an internal principle schematic diagram of a constant current driving chip provided by an embodiment of the present application;

[0040] Figure 6 is a circuit structure schematic diagram of another LED driving circuit provided by an embodiment of the present application;

[0041] Figure 7 is a circuit schematic diagram of a constant voltage module provided by an embodiment of the present application;

[0042] Figure 8 is a circuit schematic diagram of another constant voltage module provided by an embodiment of the present application;

[0043] Figure 9 is an internal principle block diagram of a constant voltage control chip provided by an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to make the personnel in the art better understand the present application, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work should fall within the scope of the present application.

[0045] The terms "include", and other any variants such as "comprising", "having", "including", and "containing" in the specification and claims of the present application and the above-described drawings, refer to "including but not limited to", and are intended to cover not exclusive inclusion, and are not limited to the examples listed in the text. In addition, the terms "first" and "second" and the like are used to distinguish different objects, and are not used to describe a specific order.

[0046] The implementation of the present application will be described in detail below with reference to the specific drawings:

[0047] Figure 1 is a structure schematic diagram of an LED driving circuit provided by an embodiment of the present application. Referring to Figure 1 , the input end of the LED driving circuit is connected with an AC power supply AC through a triac dimmer, and the output end of the LED driving circuit is used to drive an LED load;

[0048] The above-mentioned LED driving circuit comprises a rectification module 11, a constant current driving module 12 and a phase-cut signal extraction module 13;

[0049] The input end of the rectifier module 11 is connected with the input end of the LED driving circuit, and the output end of the rectifier module 11 is connected with the input end of the constant current driving module 12 and the input end of the triac signal extraction module 13 respectively;

[0050] The first control end of the constant current driving module 12 is connected with the output end of the triac signal extraction module 13, the second control end of the constant current driving module 12 is used for inputting the dimming signal, and the output end of the constant current driving module 12 is connected with the output end of the LED driving circuit.

[0051] The constant current driving module 12 is used for acquiring the dimming signal and the triac signal sent by the triac signal extraction module 13, and controlling the output current of the constant current driving module 12 based on the dimming signal and the triac signal.

[0052] In the embodiment of the application, the triac signal and the dimming signal are compatible processed by the constant current driving module 12, and the output current of the constant current driving module 12 is controlled based on the dimming signal and the triac signal. Since the constant current driving module 12 considers the triac signal, the triac signal represents the angle of the triac dimmer Triac, and the constant current driving module 12 adjusts the parameters of the constant current driving module 12 according to the angle of the triac dimmer Triac (the triac signal), so that the triac dimmer Triac can accurately perform constant current control whether it is in a large angle or a small angle, and problems such as small-angle flashing light do not occur, and the compatibility of the driving circuit is effectively improved. At the same time, the user can use the triac dimmer Triac and intelligent dimming simultaneously for adjustment, meeting different lighting needs of the user. The driving circuit can also be directly installed for the power line installed with the triac dimmer Triac, without the need to remove the original triac dimmer Triac, and the installation is simple, improving the adaptability of the driving circuit.

[0053] In a possible implementation, the output current of the constant current driving module 12 is controlled based on the dimming signal and the triac signal, including:

[0054] The dimming signal and the triac signal are multiplied to obtain a target dimming signal, and the output current of the constant current driving module 12 is controlled according to the target dimming signal.

[0055] In the embodiment of the present application, the angle of the triac of the triac dimmer is controlled, and the angle of the triac determines the size of the total driving current. In the existing constant current driving architecture, the parameter defaults the maximum total driving current, and when the angle of the triac changes, the size of the total driving current changes. The size of the total driving current is not adapted to the original parameter in the constant current driving module 12, and therefore problems such as small-angle flash light occur. Based on this, in the embodiment of the present application, the dimming signal and the triac signal are multiplied to calculate the size of the actual total driving current, and the parameter of the constant current driving module 12 is dynamically adjusted to adapt the parameter to the size of the actual total driving current, and compatibility design is made to improve the compatibility of the LED driving circuit.

[0056] In a possible implementation, with reference to Figure 2 , the LED load can include at least one LED lamp string; the constant current driving module 12 can include a positive driving end and at least one negative driving end, the number of the negative driving ends being the same as the number of the LED lamp strings; the positive driving end is connected with the positive poles of the LED lamp strings, and each negative driving end is connected with the negative pole of the corresponding LED lamp string one by one;

[0057] With reference to Figure 3 , the constant current driving module 12 can include a first diode D1, a first resistor R1 and a constant current driving chip U1;

[0058] The power supply end of the constant current driving chip U1 is connected with the cathode and the positive driving end of the first diode D1 through the first resistor R1, the first control signal input end of the constant current driving chip U1 is connected with the first control end of the constant current driving module 12, the second control signal input end of the constant current driving chip U1 is connected with the second control end of the constant current driving module 12, and each drain driving end of the constant current driving chip U1 is connected with each negative driving end one by one;

[0059] The anode of the first diode D1 is connected with the input end of the constant current driving module 12;

[0060] The constant current driving chip U1 is used for multiplying the dimming signal and the triac signal to obtain a target dimming signal, and is used for controlling the current of each drain driving end according to the target dimming signal.

[0061] To realize dimming and color adjustment, multiple LED lamp strings are usually set, for example, a warm light lamp string, a neutral light lamp string and a cold light lamp string, and three LED lamp strings are mixed to realize dimming and color adjustment. In the embodiment of the present application, the dimming signal and the triac signal are multiplied in the constant current driving chip U1 to obtain a target dimming signal, and the current of each LED lamp string, that is, the current of each drain driving end, is allocated according to the target dimming signal to realize precise dimming.

[0062] The first diode D1 is used for one-way conduction to avoid the influence of the rear-end signal on the front-end, thereby affecting the accuracy of the triac signal extraction. The first resistor R1 is used to supply power for the constant current driving chip U1.

[0063] Other peripheral devices Figure 3 , which will not be described in detail here, are conventional settings in the art.

[0064] In a possible implementation, the rectifier module 11 can include a rectifier bridge BD1, which is specifically referred to Figure 3 .

[0065] Referring to Figure 3 , a fuse FR1 can also be arranged between the rectifier module 11 and the triac for overcurrent protection.

[0066] In a possible implementation, referring to Figure 4 , the constant current driving chip U1 can include a triac signal adjustment unit 121, a dimming signal adjustment unit 122, at least one dimming control unit 123, at least one switch driving unit 124, and at least one switch unit 125; each dimming control unit 123, each switch driving unit 124, and each switch unit 125 correspond one-to-one;

[0067] The input end of the triac signal adjustment unit 121 is connected with the first control signal input end of the constant current driving chip U1, and the output end of the triac signal adjustment unit 121 is connected with the first input end of each dimming control unit 123 respectively; the triac signal adjustment unit 121 is used for converting the triac signal into a PWM signal to obtain an adjusted triac signal;

[0068] The input end of the dimming signal adjustment unit 122 is connected with the second control signal input end of the constant current driving chip U1, and each output end of the dimming signal adjustment unit 122 is connected with the second input end of each dimming control unit 123 one-to-one; the dimming signal adjustment unit 122 is used for generating a secondary dimming signal corresponding to each dimming control unit 123 according to the dimming signal; wherein the secondary dimming signal is a PWM signal;

[0069] For any one dimming control unit 123, the output end of the dimming control unit 123 is connected with the input end of the switch drive unit 124 corresponding to the dimming control unit 123; the output end of the switch drive unit 124 is connected with the control end of the corresponding switch unit 125; the first end of the switch unit 125 is connected with the drain drive end corresponding to the dimming control unit 123, and the second end of the switch unit 125 is grounded; the dimming control unit 123 is used for multiplying the adjusted phase-cut signal and the secondary dimming signal corresponding to the dimming control unit 123 to obtain the target dimming signal corresponding to the dimming control unit 123, and generating the reference voltage corresponding to the dimming control unit 123 according to the target dimming signal; the switch drive unit 124 generates the corresponding switch control signal according to the reference voltage corresponding to the dimming control unit 123, and controls the switch unit 125 to be turned on through the switch control signal to realize the control of the current of the drain drive end corresponding to the dimming control unit 123.

[0070] For the constant current drive chip U1, the phase-cut signal adjustment unit 121 is used for adjusting the phase-cut signal, for example, converting the phase-cut signal into a PWM signal, facilitating subsequent signal processing; the dimming signal adjustment unit 122 is also used for adjusting the dimming signal, for example, referring to Figure 4 , the dimming signal is I 2 C signal, and the I 2 C signal is also converted into a PWM signal, and then the two PWM signals are multiplied by the dimming control unit 123 to obtain a reference voltage; the reference voltage reflects the size of the current of the drain drive end, and the switch drive unit 124 controls the switch unit 125 to be turned on according to the reference voltage, thereby controlling the size of the current of the drain drive end. The constant current drive chip U1 considers the phase-cut signal, and performs compatibility processing on the dimming signal and the phase-cut signal, so that accurate dimming can be realized, and problems such as too low phase-cut angle flash light can be avoided.

[0071] In a possible implementation, referring to Figure 5 , the switch unit 125 can include a first switch tube Q1 and a second resistor R2.

[0072] The first end of the first switch tube Q1 is connected with the first end of the switch unit 125, the control end of the first switch tube Q1 is connected with the control end of the switch unit 125, and the second end of the first switch tube Q1 is connected with the second end of the switch unit 125 through the second resistor R2.

[0073] The first switch tube Q1 is used to form the switch unit 125 in the constant current drive chip U1, and the chip process is good.

[0074] It should be noted that the above embodiment is only one implementation, and the first switch tube Q1 and the second resistor R2 can also be not integrated in the constant current drive chip U1, and are realized by external connection, which is not limited here.

[0075] In a possible implementation, referring to Figure 5 , the switch driving unit 124 can include an error amplifier EA and a driving signal conditioning subunit 1241 (Control).

[0076] The positive input end of the error amplifier EA is connected with the input end of the switch driving unit 124, the negative input end of the error amplifier EA is connected with the second end of the first switch tube Q1 and the second resistor R2 respectively, and the output end of the error amplifier EA is connected with the input end of the driving signal conditioning subunit 1241.

[0077] The output end of the driving signal conditioning subunit 1241 is connected with the output end of the switch driving unit 124.

[0078] In the embodiment of the application, the current of the drain driving end is controlled by the reference voltage (VRef1, VRef2, VRef3), and the current of the drain driving end is proportional to the reference voltage. When the current of the drain driving end does not reach the preset current, the error amplifier EA amplifies the error and outputs a high level, increases the on-duty ratio of the first switch tube Q1, and increases the current of the drain driving end. Conversely, when the current of the drain driving end does not reach the preset current, the error amplifier EA also amplifies the error, but outputs a low level, reduces the on-duty ratio of the first switch tube Q1, and reduces the current of the drain driving end, thereby realizing the adjustment of the current of each drain driving end.

[0079] In a possible implementation, referring to Figure 5 , the cut-off signal adjusting unit 121 includes a first comparator COMP and a third resistor R3.

[0080] The positive input end of the first comparator COMP is connected with the input end of the cut-off signal adjusting unit 121, the negative input end of the first comparator COMP is used for inputting a triangular wave signal, and the output end of the first comparator COMP is connected with the output end of the cut-off signal adjusting unit 121 through the third resistor R3.

[0081] In the embodiment of the application, the cut-off signal is compared with the triangular wave, and the greater the angle of the cut-off signal converted into the PWM signal of the silicon-controlled rectifier, the greater the duty ratio of the PWM signal after comparison.

[0082] The third resistor R3 is used for buffering; referring to Figure 5 , a buffer can also be arranged between the third resistor R3 and the first comparator COMP, so as to improve the stability and reliability of the signal.

[0083] When the number of LED light strings is greater than 1, the dimming signal can be I 2 The specific circuit of the dimming signal adjusting unit 122 when the dimming signal is a C signal can refer to Figure 5 It is a conventional technical means, and details are not repeated here.

[0084] When the number of LED light strings is 1, the dimming signal can be a PWM signal, and the dimming signal conditioning unit can include a resistor and a buffer, which can refer to part of the circuit in the switching signal adjusting unit 121 in Figure 5 The buffer and the resistor are used for signal buffering.

[0085] Need to explain, Figure 5 It is only the internal principle diagram of the constant current driving chip, and the internal power supply and ground settings are conventional technical means, which are not all shown in Figure 5 .

[0086] In one possible implementation, referring to Figure 3 , the switching signal extraction module 13 can include a fourth resistor R4.

[0087] The first end of the fourth resistor R4 is connected with the input end of the switching signal extraction module 13, and the second end of the fourth resistor R4 is connected with the output end of the switching signal extraction module 13.

[0088] In one possible implementation, referring to Figure 6 , the LED driving circuit can further include a constant voltage module 14.

[0089] The input end of the constant voltage module 14 is connected with the output end of the rectifying module 11 and the input end of the switching signal extraction module 13 respectively, and the output end of the constant voltage module 14 is connected with the input end of the constant current driving module 12.

[0090] Among them, the voltage of the output end of the constant voltage module 14 is constant.

[0091] In the embodiment of the application, the constant voltage module 14 is arranged to control the power supply voltage of the LED, thereby improving the stability of the LED driving circuit. The specific circuit diagram of the constant voltage module 14 can refer to Figure 7 , and details are not repeated here.

[0092] As can be seen from Figure 7 , the constant voltage module 14 realizes constant voltage control through a chip. Referring to Figure 4 or Figure 5 , part of the circuit in Figure 4 or Figure 5 can be realized in the chip of the constant voltage module 14. For example, referring to Figure 8The phase-cut signal extraction module 13 extracts the phase-cut signal through the fourth resistor R4, the phase-cut signal adjustment unit 121 is realized in the constant voltage control chip in the constant voltage module 14, and then the adjusted PWM signal is sent to the constant current driving chip U1, so that the size and process difficulty of the constant current driving chip U1 are reduced.

[0093] Corresponding to Figure 8 The internal structure block diagram of the constant voltage control chip in the constant voltage module 14 is shown in Figure 9 , which is used for realizing constant voltage control and converting the phase-cut signal into a PWM signal, and the specific principle is not described here.

[0094] In a possible implementation, referring to Figure 6 The LED driving circuit can further include a wireless communication module 15 and an auxiliary power supply module 16.

[0095] The input end of the auxiliary power supply module 16 is connected with the output end of the rectifier module 11, for supplying power for the wireless communication module 15.

[0096] The wireless communication module 15 is used for receiving a dimming signal sent by an external mobile phone APP or remote controller, and sending the dimming signal to the constant current driving module 12.

[0097] In a second aspect, the embodiment of the present application provides a lamp, which includes the LED driving circuit provided by any of the above embodiments and has the advantages of the LED driving circuit, and the details are not described here.

[0098] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An LED driving circuit, characterized by, An input end of the LED driving circuit is connected with an AC power supply through a thyristor dimmer, and an output end of the LED driving circuit is used for driving an LED load; The LED driving circuit comprises a rectifying module, a constant current driving module and a triac signal extraction module; An input end of the rectifying module is connected with the input end of the LED driving circuit, and output ends of the rectifying module are respectively connected with an input end of the constant current driving module and an input end of the triac signal extraction module; A first control end of the constant current driving module is connected with an output end of the triac signal extraction module, a second control end of the constant current driving module is used for inputting a dimming signal, and an output end of the constant current driving module is connected with the output end of the LED driving circuit; The constant current driving module is used for acquiring the dimming signal and a triac signal sent by the triac signal extraction module, and controlling an output current of the constant current driving module based on the dimming signal and the triac signal; The controlling of the output current of the constant current driving module based on the dimming signal and the triac signal comprises: multiplying the dimming signal and the triac signal to obtain a target dimming signal, and controlling the output current of the constant current driving module according to the target dimming signal.

2. The LED driving circuit of claim 1, wherein, The LED load comprises at least one LED lamp string, the constant current driving module comprises a positive electrode driving end and at least one negative electrode driving end, the number of the negative electrode driving ends is the same as the number of the LED lamp strings, the positive electrode driving end is connected with positive electrodes of the LED lamp strings, and each negative electrode driving end is connected with a negative electrode of each LED lamp string in one-to-one correspondence; The constant current driving module comprises a first diode, a first resistor and a constant current driving chip; A power supply end of the constant current driving chip is connected with a cathode of the first diode and the positive electrode driving end through the first resistor, a first control signal input end of the constant current driving chip is connected with the first control end of the constant current driving module, a second control signal input end of the constant current driving chip is connected with the second control end of the constant current driving module, and each drain driving end of the constant current driving chip is connected with each negative electrode driving end in one-to-one correspondence; An anode of the first diode is connected with an input end of the constant current driving module; The constant current driving chip is used for multiplying the dimming signal and the triac signal to obtain a target dimming signal, and controlling currents of each drain driving end according to the target dimming signal.

3. The LED driving circuit of claim 2, wherein, The constant current driving chip comprises a triac signal adjustment unit, a dimming signal adjustment unit, at least one dimming control unit, at least one switch driving unit and at least one switch unit, each dimming control unit, each switch driving unit and each switch unit are in one-to-one correspondence; an input end of the triac signal adjustment unit is connected with the first control signal input end of the constant current driving chip, and output ends of the triac signal adjustment unit are respectively connected with first input ends of each dimming control unit; the triac signal adjustment unit is used for converting the triac signal into a PWM signal to obtain an adjusted triac signal; The input end of the dimming signal adjustment unit is connected with the second control signal input end of the constant current driving chip, and each output end of the dimming signal adjustment unit is connected with the second input end of each dimming control unit one by one; the dimming signal adjustment unit is used for generating the secondary dimming signal corresponding to each dimming control unit according to the dimming signal; wherein the secondary dimming signal is a PWM signal. For any one dimming control unit, the output end of the dimming control unit is connected with the input end of the switch driving unit corresponding to the dimming control unit; the output end of the switch driving unit is connected with the control end of the corresponding switch unit; the first end of the switch unit is connected with the drain driving end corresponding to the dimming control unit, and the second end of the switch unit is grounded; the dimming control unit is used for multiplying the adjusted cutting signal and the secondary dimming signal corresponding to the dimming control unit to obtain the target dimming signal corresponding to the dimming control unit, and generating the reference voltage corresponding to the dimming control unit according to the target dimming signal; the switch driving unit generates the corresponding switch control signal according to the reference voltage corresponding to the dimming control unit, and controls the switch unit to be turned on to realize the control of the current of the drain driving end corresponding to the dimming control unit through the switch control signal.

4. The LED driving circuit of claim 3, wherein, The switch unit comprises a first switch tube and a second resistor. The first end of the first switch tube is connected with the first end of the switch unit, the control end of the first switch tube is connected with the control end of the switch unit, and the second end of the first switch tube is connected with the second end of the switch unit through the second resistor.

5. The LED driving circuit of claim 4, wherein, The switch driving unit comprises an error amplifier and a driving signal conditioning subunit. The positive input end of the error amplifier is connected with the input end of the switch driving unit, the negative input end of the error amplifier is connected with the second end of the first switch tube and the second resistor respectively, and the output end of the error amplifier is connected with the input end of the driving signal conditioning subunit. The output end of the driving signal conditioning subunit is connected with the output end of the switch driving unit.

6. The LED driving circuit of claim 3, wherein, The cutting signal adjustment unit comprises a first comparator and a third resistor. The positive input end of the first comparator is connected with the input end of the cutting signal adjustment unit, the negative input end of the first comparator is used for inputting a triangular wave signal, and the output end of the first comparator is connected with the output end of the cutting signal adjustment unit through the third resistor.

7. The LED driving circuit according to any one of claims 1 to 6, wherein The cutting signal extraction module comprises a fourth resistor. The first end of the fourth resistor is connected with the input end of the cutting signal extraction module, and the second end of the fourth resistor is connected with the output end of the cutting signal extraction module.

8. The LED driving circuit according to any one of claims 1 to 6, wherein The LED driving circuit further comprises a constant voltage module. The input end of the constant voltage module is connected with the output end of the rectifying module and the input end of the cutting signal extraction module respectively, and the output end of the constant voltage module is connected with the input end of the constant current driving module. The voltage of the output end of the constant voltage module is constant.

9. A luminaire characterized by, The LED driving circuit comprises any one of claims 1 to 8. The LED driving circuit comprises any one of claims 1 to 8.

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