A dimming and color - adjusting circuit and a lighting fixture

Abstract

A dimming and color mixing circuit and a lighting fixture, which include a thyristor dimmer, a rectifying circuit, a color mixing circuit, and a constant current circuit. Among them, the thyristor dimmer realizes linear dimming by regulating the voltage of the AC signal, and the rectifying circuit rectifies the regulated AC signal into a DC signal to supply power to each light-emitting module. The color mixing circuit adjusts the current ratio flowing through each light-emitting module, and the constant current circuit performs constant current control on the power supply circuit of each light-emitting module. The above dimming and color mixing circuit and lighting fixture control at least two light-emitting modules through a single circuit, and simultaneously realize the two functions of dimming and color mixing, are compatible with thyristors, and use a constant current circuit to control the current in the power supply circuit to be constant. The working efficiency of the circuit is high, the circuit structure is simplified, and it can be widely applied to DOB products.

Description

Technical Field

[0001] This application belongs to the technical field of light-emitting module control, and particularly relates to a dimming and color-tuning circuit and a lighting fixture. Background Art

[0002] The thyristor dimming technology refers to connecting a thyristor dimmer in series between the mains power supply and the light driving power supply. After the thyristor dimmer performs phase-cutting processing on the mains power supply, the output is sent to the light driving power supply, thereby driving the light-emitting module to work. However, when the traditional dimming circuit uses a thyristor for dimming, an additional independent color-tuning circuit is required to achieve the functions of dimming and color-tuning. Therefore, the traditional thyristor dimming technology cannot perform color-tuning while dimming, resulting in low circuit working efficiency and complex circuit structure. In addition, due to low compatibility, the thyristor dimming technology is prone to stroboscopic. To eliminate stroboscopic, an additional electrolytic capacitor is usually added, and the electrolytic capacitor is connected in parallel at the input end of the light driving power supply, thereby eliminating stroboscopic. However, this solution will further reduce the power factor.

[0003] Therefore, the traditional thyristor dimming technology cannot perform color-tuning while dimming, resulting in problems of low circuit working efficiency and complex circuit structure. Summary of the Invention

[0004] The purpose of this application is to provide a dimming and color-tuning circuit and a lighting fixture, aiming to solve the problems that the traditional thyristor dimming technology cannot perform color-tuning while dimming, resulting in low circuit working efficiency and complex circuit structure.

[0005] The first aspect of the embodiment of this application provides a dimming and color-tuning circuit for controlling at least two light-emitting modules to emit light. The dimming and color-tuning circuit includes:

[0006] A thyristor dimmer for accessing an alternating current signal and performing voltage regulation processing on the alternating current signal;

[0007] A rectifier circuit connected to the thyristor dimmer for rectifying the alternating current signal after voltage regulation processing and outputting a direct current signal to supply power to each of the light-emitting modules;

[0008] A color-tuning circuit connected to each of the light-emitting modules for accessing a dimming instruction and correspondingly adjusting the current ratio flowing through each of the light-emitting modules according to the dimming instruction; and

[0009] A constant current circuit connected to the rectifier circuit, the color-tuning circuit and each of the light-emitting modules for performing constant current control on the power supply circuit of each of the light-emitting modules.

[0010] Further, the color-tuning circuit includes:

[0011] A control circuit for accessing the dimming instruction and correspondingly outputting at least two color mixing signals according to the dimming instruction;

[0012] An isolation circuit connected to the control circuit for performing optoelectronic isolation and transmitting the color mixing signal; and

[0013] At least two current regulation circuits connected to the constant current circuit and the isolation circuit, one current regulation circuit corresponding to one light emitting module, the current regulation circuit being configured to receive the corresponding color mixing signal and regulate the current of the corresponding light emitting module according to the received color mixing signal.

[0014] The above color mixing circuit realizes electrical isolation between the control circuit and the current regulation circuit through the isolation circuit, and has high transmission efficiency, so that the overall anti-interference ability of the circuit is strong and the service life of the control circuit is extended.

[0015] Further, the above constant current circuit includes:

[0016] At least two chip select circuits, one of the chip select circuits being connected to at least one of the current regulation circuits, and the other chip select circuit being connected to the light emitting module, each chip select circuit being configured to switch the power supply circuit of each light emitting module; and

[0017] A constant current control circuit connected to the rectification circuit and each chip select circuit for performing constant current control on the power supply circuits of each light emitting module.

[0018] The above constant current circuit switches the power supply circuits of each light emitting module by changing the working state of the chip select circuit, so that a single circuit can perform dimming and color mixing. Moreover, by performing constant current control on the power supply circuits of each light emitting module, a relatively high power factor is ensured.

[0019] Further, the isolation circuit includes:

[0020] At least two optocouplers;

[0021] The light emitter of each optocoupler is connected to the control circuit, and the light receiver of each optocoupler is correspondingly connected to one current regulation circuit.

[0022] In the above isolation circuit, the optocoupler converts the received color mixing signal through electro-optical-electrical conversion and outputs it to the correspondingly connected current regulation circuit to achieve electrical isolation and improve the overall safety of the circuit.

[0023] Further, the dimming and color mixing circuit further includes:

[0024] The control component is connected to the control circuit and is configured to output the corresponding dimming instruction to the control circuit according to the user's operation instruction.

[0025] The above-mentioned control component has multiple options for selection, enabling the user to select the color temperature. The operation is simple and convenient, providing a high user experience.

[0026] Further, the current regulation circuit includes:

[0027] A first resistor, a second resistor, a third resistor, a fourth resistor, a first switching transistor, a second switching transistor, and a first diode;

[0028] A first end of the first resistor is connected to one path of the light-emitting module. A node where a second end of the first resistor, a first end of the second resistor, and a controlled end of the first switching transistor are commonly connected is connected to the isolation circuit. A node where an input end of the first switching transistor and a cathode of the first diode are commonly connected is connected to one path of the light-emitting module. An anode of the first diode, a first end of the third resistor, a first end of the fourth resistor, and a controlled end of the second switching transistor are commonly connected; A second end of the third resistor and an input end of the second switching transistor are both connected to one path of the light-emitting module;

[0029] A node where a second end of the second resistor, a second end of the fourth resistor, an output end of the first switching transistor, and an output end of the second switching transistor are commonly connected is connected to the constant current circuit.

[0030] The above-mentioned current regulation circuit is composed of simple electronic components and is controlled by a dimming signal. When the characteristic parameters of the dimming signal change, the conduction states of its first switching transistor and second switching transistor change accordingly, so as to achieve the purpose of controlling the magnitude of the current flowing through the corresponding light-emitting module. The circuit uses conventional electronic components, with low cost.

[0031] Further, the chip select circuit includes:

[0032] An enable chip, a fifth resistor, a sixth resistor, a seventh resistor, a second diode, and a third diode;

[0033] A first end of the fifth resistor is connected to at least one of the current regulation circuits. A second end of the fifth resistor and an anode of the second diode are commonly connected. A cathode of the second diode is connected to a transmission end or a chip select end of the enable chip; A chip select end of the enable chip, a first end of the sixth resistor, a first end of the seventh resistor, and an anode of the third diode are commonly connected. A second end of the sixth resistor, a second end of the seventh resistor, and a cathode of the third diode are commonly connected.

[0034] The above-mentioned chip select circuit realizes the purpose of changing the power supply circuit of the light-emitting module by changing the working state of the enable chip.

[0035] Further, the constant current control circuit includes:

[0036] A first constant current control chip, a second constant current control chip, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a first capacitor and a second capacitor;

[0037] The current limiting end of the first constant current control chip, the first end of the eighth resistor and the first end of the ninth resistor are commonly connected; the first current limiting end of the second constant current control chip is commonly connected with the first end of the tenth resistor, and the second current limiting end of the second constant current control chip, the second end of the tenth resistor, the first end of the eleventh resistor and the first end of the twelfth resistor are commonly connected; a node commonly connected by the transmission end of the first constant current control chip, the first transmission end of the second constant current control chip and the first end of the first capacitor is connected to one of the chip select circuits; the second transmission end of the second constant current control chip is commonly connected with the first end of the thirteenth resistor, and a node where the second end of the thirteenth resistor is commonly connected with the first end of the fourteenth resistor is connected to the rectifying circuit, the second end of the fourteenth resistor, the first end of the fifteenth resistor and the first end of the sixteenth resistor are commonly connected, and the second end of the fifteenth resistor, the first end of the second capacitor and the power supply end of the first constant current control chip are commonly connected;

[0038] The second ends of the eighth resistor, the ninth resistor, the eleventh resistor, the twelfth resistor, the sixteenth resistor, the second end of the first capacitor and the second end of the second capacitor are grounded.

[0039] Constant current power supply is achieved through the above constant current control circuit.

[0040] Further, it further includes:

[0041] At least two ripple removal circuits, all of which are connected to each of the light emitting modules, one of the ripple removal circuits is further connected to the rectifying circuit, and another ripple removal circuit is further connected to at least one of the chip select circuits. Each of the ripple removal circuits is respectively used for performing ripple removal processing on the current flowing through the light emitting module.

[0042] By adding the ripple removal circuit, stroboscopic elimination can be achieved without adding electrolytic capacitors, avoiding the reduction of the power factor by electrolytic capacitors, thereby achieving the purpose of making the dimming and color mixing circuit compatible with thyristors, improving the power factor and eliminating stroboscopic.

[0043] The second aspect of the embodiments of the present application provides a lamp, including:

[0044] At least two light emitting modules; and

[0045] The above dimming and color - tuning circuit is used to control the light - emitting module to emit light.

[0046] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows: The above dimming and color - tuning circuit and the lamp control at least two light - emitting modules through a single circuit, and simultaneously realize the two functions of dimming and color - tuning, are compatible with thyristors, and use a constant - current circuit to control the current in the power - supply loop to be constant. The working efficiency of the circuit is high, the circuit structure is simplified, and it can be widely applied to DOB products. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the module structure of a dimming and color - tuning circuit provided by an embodiment of the present application;

[0048] Figure 2 For Figure 1 It is a schematic diagram of the specific structure of the dimming and color - tuning circuit shown;

[0049] Figure 3 For Figure 2 It is a schematic diagram of an example circuit principle of the dimming and color - tuning circuit shown;

[0050] Figure 4 It is a schematic diagram of an example circuit principle of the dimming and color - tuning circuit provided by another embodiment of the present application;

[0051] Figure 5 For Figure 3 It is a schematic diagram of the input voltage corresponding to different working states of the dimming and color - tuning circuit described in or 4. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0053] It should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0054] Please refer to Figure 1 , which is a schematic diagram of the module structure of a dimming and color - tuning circuit provided by an embodiment of the present application. For the convenience of description, only the parts related to this embodiment are shown and are described in detail as follows:

[0055] A dimming and color mixing circuit is used to control at least two light-emitting modules 100 to emit light. Specifically, at least two of the light-emitting modules 100 in each path have different light-emitting colors. For example, one light-emitting module 100 emits green light, and the other light-emitting module 100 emits blue light.

[0056] The dimming and color mixing circuit includes a thyristor dimmer 10, a rectifier circuit 20, a color mixing circuit 30, and a constant current circuit 40.

[0057] Among them, the thyristor dimmer 10 is connected to the rectifier circuit 20, the color mixing circuit 30 is connected to each light-emitting module 100, and the constant current circuit 40 is connected to the rectifier circuit 20, the color mixing circuit 30, and each light-emitting module 100.

[0058] The thyristor dimmer 10 is used to access an AC signal and perform voltage regulation on the AC signal.

[0059] Specifically, the thyristor dimmer 10 generates a tangential output voltage waveform after cutting the voltage waveform of the input AC signal through the conduction angle; applying the tangential principle can reduce the effective value of the output voltage, thereby reducing the power of the load, with high adjustment accuracy, enabling linear dimming, and high efficiency.

[0060] After the rectifier circuit 20 rectifies the AC signal after voltage regulation, it outputs a DC signal; this DC signal serves as a power supply signal to supply power to each light-emitting module 100, flows into the power supply circuit of each light-emitting module 100, and is used for the color mixing circuit 30 to adjust the current and for the constant current circuit 40 to perform constant current control.

[0061] Specifically, the rectifier circuit 20 is implemented by a rectifier bridge BD1.

[0062] The color mixing circuit 30, connected to each light-emitting module 100, is used to adjust the current ratio flowing through each light-emitting module 100 according to the received color mixing signal.

[0063] Specifically, the color mixing circuit 30 adjusts the current magnitude flowing through each light-emitting module 100 respectively, so that the current ratio of each light-emitting module 100 reaches the target value. By adjusting the current flowing through each light-emitting module 100, the light-emitting ratio of each light-emitting module 100 is adjusted, and finally the color temperature adjustment is achieved.

[0064] The constant current circuit 40, connected to the rectifier circuit 20, the color mixing circuit 30, and each light-emitting module 100, is used to perform constant current control on the power supply circuit of each light-emitting module 100.

[0065] Specifically, the constant current circuit 40 also has a discharging function. When the voltage in the circuit is at the trough, the discharging function is turned on to maintain the current.

[0066] Please refer to Figure 2 , which is Figure 1 a schematic diagram of the specific structure of the dimming and color mixing circuit shown. For the sake of convenience of explanation, only the parts related to this embodiment are shown and are described in detail as follows:

[0067] In an alternative embodiment, the above-mentioned color mixing circuit 30 includes a control circuit 31, an isolation circuit 32, and at least two current adjustment circuits 33.

[0068] Among them, the control circuit 31 is connected to the isolation circuit 32, and the current adjustment circuit 33 is connected to the constant current circuit 40 and the isolation circuit 32.

[0069] The control circuit 31 is used to access a dimming instruction and correspondingly output at least two color mixing signals according to the dimming instruction.

[0070] Specifically, the above-mentioned color mixing signal is a pulse width modulation signal (PWM, Pulse Width Modulation), and the control circuit 31 correspondingly generates a PWM signal with a certain width according to the dimming instruction and outputs it to the isolation circuit 32.

[0071] The isolation circuit 32, connected to the control circuit 31, is used for optoelectronic isolation and transmission of the color mixing signal.

[0072] Through the isolation circuit 32, electrical isolation between the control circuit 31 and the current adjustment circuit is achieved, and the transmission efficiency is high, making the overall anti-interference ability of the circuit strong and extending the service life of the control circuit 31.

[0073] At least two current adjustment circuits 33, connected to the constant current circuit 40 and the isolation circuit 32, and respectively connected to each path of the light emitting modules 100 one by one, are used to receive the color mixing signals one by one and correspondingly adjust the current flowing through the corresponding light emitting modules 100 according to the color mixing signals received by them respectively.

[0074] Specifically, Figure 2 only a dimming and color mixing circuit with two current adjustment circuits (current adjustment circuit 1 and current adjustment circuit 2) is shown. This dimming and color mixing circuit drives two paths of light emitting modules (light emitting module 1 and light emitting module 2) to emit light, and the light emitting colors of these two paths of light emitting modules are different.

[0075] In an alternative embodiment, the above-mentioned constant current circuit 40 includes a constant current control circuit 42 and at least two chip select circuits.

[0076] Among them, one chip select circuit is connected to at least one current adjustment circuit, another chip select circuit is connected to the light emitting module, and the constant current control circuit 42 is connected to the rectifier circuit 20 and each chip select circuit 41.

[0077] At least two chip select circuits 41, one of the chip select circuits is connected to at least one current adjustment circuit, and the other chip select circuit is connected to the light-emitting module. Each chip select circuit switches the power supply circuit of each light-emitting module.

[0078] Specifically, the chip select circuit 41 switches the power supply circuit of each light-emitting module by changing its own working state, so that a single circuit can perform dimming and color adjustment. The working state of the chip select circuit 41 can be set by writing a program.

[0079] The constant current control circuit 42 performs constant current control on the power supply circuits of each light-emitting module 100.

[0080] Specifically, the constant current control circuit 42 also has a discharging function. When the voltage in the circuit is at the trough, the discharging function is turned on to maintain the current.

[0081] Specifically, Figure 2 Only the constant current circuit 40 with two chip select circuits is shown. The corresponding dimming and color adjustment circuit controls two light-emitting modules (light-emitting module 1 and light-emitting module 2). Each light-emitting module has two power supply circuits according to the working state of the chip select circuit.

[0082] Next, according to Figure 2 Describe the power supply circuit:

[0083] For light-emitting module 1, its first power supply circuit is: thyristor dimmer 10 - rectifier circuit 20 - light-emitting module 1 - current adjustment circuit 1 - chip select circuit 1 - constant current control circuit 42; its second power supply circuit is: thyristor dimmer 10 - rectifier circuit 20 - light-emitting module 1 - current adjustment circuit 1 - chip select circuit 2 - light-emitting module 2 - current adjustment circuit 2 - chip select circuit 1 - constant current control circuit 42.

[0084] For light-emitting module 2, its first power supply circuit is: thyristor dimmer 10 - rectifier circuit 20 - chip select circuit 2 - light-emitting module 2 - current adjustment circuit 2 - chip select circuit 1 - constant current control circuit 42; its second power supply circuit is: thyristor dimmer 10 - rectifier circuit 20 - light-emitting module 1 - current adjustment circuit 1 - chip select circuit 2 - light-emitting module 2 - current adjustment circuit 2 - chip select circuit 1 - constant current control circuit 42.

[0085] According to the above analysis, the second power supply circuits of light-emitting module 1 and light-emitting module 2 are the same. That is, at this time, light-emitting module 1 and light-emitting module 2 emit light in series.

[0086] The first power supply circuit of the light-emitting module 1 and the first power supply circuit of the light-emitting module 2 exist simultaneously, and the second power supply circuit of the light-emitting module 1 and the second power supply circuit of the light-emitting module 2 exist simultaneously. That is, there are two combinations of the operating states of the chip select circuit 1 and the chip select circuit 2. One combination of operating states enables the light-emitting module 1 to have a first power supply circuit and enables the light-emitting module 2 to have a first power supply circuit; the other combination of operating states enables the light-emitting module 1 to have a second power supply circuit and enables the light-emitting module 2 to have a second power supply circuit.

[0087] Please refer to Figure 3 , for Figure 2 the example circuit schematic diagram of the dimming and color mixing circuit shown. For the convenience of description, only the parts related to this embodiment are shown and are described in detail as follows:

[0088] In an alternative embodiment, the above isolation circuit 32 includes at least two optocouplers ( Figure 3 U11 and U13 in

[0089] The light emitter of each optocoupler is connected to the control circuit 31 to receive the adjustment signal output by the control circuit 31.

[0090] The light receiver of each optocoupler is correspondingly connected to a current adjustment circuit 33; after the light emitter converts the adjustment signal into an optical signal, the light receiver receives the optical signal and converts it into an electrical signal, and then outputs it to the corresponding current adjustment circuit 33.

[0091] In the above isolation circuit 32, after the optocoupler performs an electrical-optical-electrical conversion on the received color mixing signal, it outputs it to the correspondingly connected current adjustment circuit 33, achieving electrical isolation and improving the overall safety of the circuit.

[0092] In an alternative embodiment, the above current adjustment circuit 33 includes a first resistor R20, a second resistor R21, a third resistor R23, a fourth resistor R22, a first switching tube Q3, a second switching tube Q2, and a first diode D7.

[0093] Next, taking Figure 3 the current adjustment circuit 2 in

[0094] as an example, the circuit connection structure is described:

[0095] The anode of the first diode D7, the first end of the third resistor R23, the first end of the fourth resistor R22, and the controlled end of the second switching transistor Q2 are commonly connected; the second end of the third resistor R23 and the input end of the second switching transistor Q2 are both connected to a light-emitting module.

[0096] The node commonly connected by the second end of the second resistor R21, the second end of the fourth resistor R22, the output end of the first switching transistor Q3, and the output end of the second switching transistor Q2 is connected to the constant current circuit 40.

[0097] It should be noted that the types, quantities, and connection relationships of the electronic components in the current adjustment circuit 1 are the same as those in the current adjustment circuit 2. For the convenience of introducing the principle below, it is set that the reference numerals of the electronic components in the current adjustment circuit 1 are different from the corresponding electronic components in the current adjustment circuit 1; similarly, the reference numerals of the corresponding electronic components in the following chip selection circuit 1 and chip selection circuit 2 are also different.

[0098] For the current adjustment circuit 1, the reference numerals of its electronic components are respectively: the first resistor R30, the second resistor R29, the third resistor R28, the fourth resistor R27, the first switching transistor Q5, the second switching transistor Q6, and the first diode D9.

[0099] Specifically, Figure 2 The shown isolation circuit 32 has two optocouplers (U11 and U12), and this adjustment circuit has two current adjustment circuits (current adjustment circuit 1 and current adjustment circuit 2). Among them, the output end G1A of the light-receiving device of the optocoupler U11 is connected to the controlled end of the first switching transistor Q3 of the current adjustment circuit 1, and the controlled end G1 of its light-emitting device is connected to the control circuit 31; the output end G2A of the light-receiving device of the optocoupler U12 is connected to the controlled end of the first switching transistor Q3 of the current adjustment circuit 2, and the controlled end G2 of its light-emitting device is connected to the control circuit 31.

[0100] The first switching transistor Q3 and the second switching transistor Q2 adjust their own working states according to the adjustment signal, and can be in a conducting state, a semi-conducting state, a cut-off state, or other conducting states.

[0101] The above-mentioned current adjustment circuit 33 is composed of simple electronic components and is controlled by a dimming signal. When the characteristic parameters of the dimming signal change, the conducting states of its first switching transistor and second switching transistor change accordingly, so as to achieve the purpose of controlling the magnitude of the current flowing through the corresponding light-emitting module. The circuit uses conventional electronic components, and the cost is low.

[0102] In an alternative embodiment, the above-mentioned chip selection circuit 41 includes an enable chip, a fifth resistor, a sixth resistor, a seventh resistor, a second diode, and a third diode.

[0103] Next, taking Figure 3Taking the chip select circuit 1 as an example, the circuit connection structure will be described as follows:

[0104] For the chip select circuit 1, the first end of the fifth resistor R11 is connected to at least one current regulation circuit, the second end of the fifth resistor R11 is commonly connected to the anode of the second diode D2, and the cathode of the second diode D2 is connected to the transmission end or the chip select end of the enable chip U2; the chip select end of the enable chip U2, the first end of the sixth resistor R12a, the first end of the seventh resistor R12, and the anode of the third diode D3 are commonly connected, and the second end of the sixth resistor R12a, the second end of the seventh resistor R12, and the cathode of the third diode D3 are commonly connected.

[0105] Specifically, Figure 2 The shown dimming and color mixing circuit has two chip select circuits (chip select circuit 1 and chip select circuit 2). Among them, the first end of the fifth resistor R11 of the chip select circuit 1 is connected to the output end of the first switching transistor Q3 in the current regulation circuit 1, and the cathode of the second diode D2 of the chip select circuit 1 is connected to the transmission end OUT of the enable chip U2 in this circuit; the first end of the fifth resistor R11 of the chip select circuit 2 is connected to the output end of the first switching transistor Q3 in the current regulation circuit 1, and the transmission end of the enable chip U2 of the chip select circuit 2 is connected to the rectification circuit 20.

[0106] For the chip select circuit 2, the reference numerals of its electronic components are: enable chip U1, fifth resistor R14, sixth resistor R16a, seventh resistor R16, second diode D4, and third diode D6.

[0107] The above-mentioned chip select circuit 1 and chip select circuit 2 switch the power supply circuits of each light emitting module 100 by changing their own working states.

[0108] The enable chip U2 of the chip select circuit 1 and the enable chip U1 of the chip select circuit 2 work simultaneously or do not work simultaneously.

[0109] In an optional embodiment, the above constant current control circuit 42 includes a first constant current control chip U3, a second constant current control chip U4, an eighth resistor R8, a ninth resistor R9, a tenth resistor R2, an eleventh resistor R3, a twelfth resistor R4, a thirteenth resistor R1, a fourteenth resistor R5, a fifteenth resistor R7, a sixteenth resistor R6, a first capacitor C2, and a second capacitor C1.

[0110] The current limiting terminal REXT of the first constant current control chip U3, the first terminal of the eighth resistor R8, and the first terminal of the ninth resistor R9 are connected together; the first current limiting terminal Rcs1 of the second constant current control chip U4 is connected to the first terminal of the tenth resistor R2, and the second current limiting terminal of the second constant current control chip U4, the second terminal of the tenth resistor R2, the first terminal of the eleventh resistor R3, and the first terminal of the twelfth resistor R4 are connected together; the node where the transmission terminal of the first constant current control chip U3, the first transmission terminal OUT1 of the second constant current control chip U4, and the first terminal of the first capacitor C2 are connected together is connected to a chip select circuit.

[0111] The second transmission terminal OUT2 of the second constant current control chip U4 is connected to the first terminal of the thirteenth resistor R1, and the node where the second terminal of the thirteenth resistor R1 is connected to the first terminal of the fourteenth resistor R5 is connected to the rectifying circuit 20. The second terminal of the fourteenth resistor R5, the first terminal of the fifteenth resistor R7, and the first terminal of the sixteenth resistor R6 are connected together. The second terminal of the fifteenth resistor R7, the first terminal of the second capacitor C1, and the power supply terminal VT of the first constant current control chip U3 are connected together.

[0112] The second terminals of the eighth resistor R8, the ninth resistor R9, the eleventh resistor R3, the twelfth resistor R4, the sixteenth resistor R6, the second terminal of the first capacitor C2, and the second terminal of the second capacitor C1 are grounded.

[0113] Specifically, the second constant current control chip U4 is a dual-channel chip. The input terminal and output terminal of its first channel are the second transmission terminal OUT2 and the first current limiting terminal Rcs1 respectively, and the input terminal and output terminal of its second channel are the first transmission terminal OUT1 and the second current limiting terminal Rcs2 respectively. The second channel of the second constant current control chip U4 has a discharging function. When the voltage in the circuit is at the trough, the discharging function is turned on to maintain the current.

[0114] In an alternative embodiment, the above control circuit 31 is implemented by a single-chip microcomputer U8. The single-chip microcomputer U8 has at least two PWM output terminals, and each PWM output terminal is correspondingly connected to an optocoupler.

[0115] Next, according to Figure 3 , combined with Figure 5 , the working principle of the dimming and color mixing circuit provided in this embodiment will be described:

[0116] [[ID=ZZ]] Figure 5 For Figure 3 or the schematic diagram of the input voltage corresponding to different working states of the dimming and color mixing circuit described in 4; the input voltage is represented by Vin, and the input voltage Vin refers to Figure 3 or Figure 4 the voltage at the HV point in

[0117] (1) When V1 > Vin > V0, the second channel of the second constant current control chip U4 is turned on, so that the working current of the entire circuit is greater than the minimum holding current of the thyristor inside the thyristor dimmer 10; at this time, the chip select circuit, the dimming circuit, and the light emitting module are all not conducting.

[0118] At this time, the circuit loop is: thyristor regulator - rectifier bridge BD1 - thirteenth resistor R1 - first transmission terminal OUT1 of the second constant current control chip U4 - second current limiting terminal Rcs2 of the second constant current control chip U4 - tenth resistor R2 - twelfth resistor R4 - ground. Assume the current in the circuit at this time is I1, and I1 > 0.

[0119] (2) When V2 > Vin > V1, the chip select circuit, the dimming circuit, and the light emitting module are all conducting. The enable chip U1 in the chip select circuit 1 and the enable chip U2 in the chip select circuit 2 are connected in parallel and conducting. The second diode D4 in the chip select circuit 2 is cut off, and the second diode D2 in the chip select circuit 1 is conducting.

[0120] At this time, the power supply loop of the light emitting module 1 is: thyristor dimmer 10 - rectifier circuit 20 - light emitting module 1 - current regulation circuit 1 - chip select circuit 1 - constant current control circuit 42; its second power supply loop is: thyristor dimmer 10 - rectifier circuit 20 - light emitting module 1 - current regulation circuit 1 - chip select circuit 2 - light emitting module 2 - current regulation circuit 2 - chip select circuit 1 - constant current control circuit 42. [[ID=eleven]]

[0121] More specifically, the power supply loop of the light emitting module 1 is: thyristor dimmer 10 - rectifier circuit 20 - light emitting module 1 - first switch transistor Q5 and second switch transistor Q6 of the current regulation circuit 1 - fifth resistor R11, second diode D2, transmission terminal OUT of the enable chip U2, transmission terminal OUT of the enable chip U2, chip select terminal CS of the enable chip U2, seventh resistor R12 in the chip select circuit 1 - transmission terminal OUT, current limiting terminal REXT, eighth resistor R8 of the first constant current control chip U3 - ground.

[0122] At this time, the power supply loop of the light emitting module 2 is: thyristor dimmer 10 - rectifier circuit 20 - chip select circuit 2 - light emitting module 2 - current regulation circuit 2 - chip select circuit 1 - constant current control circuit 42.

[0123] More specifically, the power supply circuit of the light-emitting module 2 is as follows: thyristor dimmer 10 - rectifier circuit 20 - the transmission terminal OUT, chip select terminal CS, and seventh resistor R16 of the enable chip U1 in the chip select circuit 2 - light-emitting module 2 - the first switching transistor Q3 and the second switching transistor Q2 in the current regulation circuit 2 - the seventh resistor R12 in the chip select circuit 1 - the transmission terminal OUT, current limiting terminal REXT, and eighth resistor R8 of the first constant current control chip U3 - ground.

[0124] At this time, the current in the circuit is I1 + I2, and I2 > 0.

[0125] (3) When V3 > Vin > V2, the chip select circuit, the dimming circuit, and the light-emitting module are all turned on. The enable chip U1 in the chip select circuit 1 and the enable chip U2 in the chip select circuit 2 are both turned off. The second diode D4 in the chip select circuit 2 is turned on, and the second diode D2 in the chip select circuit 1 is turned off. At this time, the light-emitting module 1 and the light-emitting module 2 are connected in series, and the power supply circuits of the light-emitting module 1 and the light-emitting module 2 are the same.

[0126] The power supply circuits of the light-emitting module 1 and the light-emitting module 2 are both: thyristor dimmer 10 - rectifier circuit 20 - light-emitting module 1 - current regulation circuit 1 - chip select circuit 2 - light-emitting module 2 - current regulation circuit 2 - chip select circuit 1 - constant current control circuit 42.

[0127] More specifically, the power supply circuits of the light-emitting module 1 and the light-emitting module 2 are both: thyristor dimmer 10 - rectifier circuit 20 - light-emitting module 1 - the first switching transistor Q5 and the second switching transistor Q6 in the current regulation circuit 1 - the fifth resistor R14, the second diode D4, and the third diode D6 in the chip select circuit 2 - light-emitting module 2 - the first switching transistor Q3 and the second switching transistor Q2 in the current regulation circuit 2 - the third diode D3 in the chip select circuit 1 - the first channel of the second constant current control chip U4 in the constant current control circuit 42, the transmission terminal OUT, and the current limiting terminal REXT of the first constant current control chip U3 - ground.

[0128] At this time, the working current in the circuit is I1 + I2 + I3, and I3 > 0.

[0129] The above dimming and color mixing circuit controls at least two light-emitting modules through a single circuit, and simultaneously realizes two functions of dimming and color mixing. It is compatible with thyristors and uses the constant current circuit 40 to control the current in the power supply circuit to be constant. The working efficiency of the circuit is high, and the circuit structure is simplified. It can be widely applied to DOB products.

[0130] Please refer to Figure 4, which is an example circuit schematic diagram of the dimming and color - tuning circuit provided by another embodiment of the present application. For the sake of convenience of description, only the parts related to this embodiment are shown and are described in detail as follows:

[0131] In an alternative embodiment, the above - mentioned dimming and color - tuning circuit further includes at least two ripple - removing circuits. Each ripple - removing circuit is connected to each light - emitting module. One of the ripple - removing circuits is also connected to the rectifying circuit 20, and the other ripple - removing circuit is also connected to at least one chip - select circuit. Each ripple - removing circuit is respectively used to perform ripple - removing processing on the current flowing through the light - emitting module.

[0132] Figure 4 A dimming and color - tuning circuit with two ripple - removing circuits (ripple - removing circuit 51 and ripple - removing circuit 52) is shown.

[0133] Taking the ripple - removing circuit 51 as an example, it includes diode D8, zener diodes ZD3 and ZD5, resistors, MOS transistor Q4, and electrolytic capacitors C16 and EC4. The depth of ripple - removing can be set according to the clamping voltages of zener diodes ZD3 and ZD5.

[0134] By adding the ripple - removing circuit, it is possible to eliminate stroboscopic without increasing electrolytic capacitors, avoid reducing the power factor, and thus achieve the purpose of making the dimming and color - tuning circuit compatible with thyristors, improving the power factor, and eliminating stroboscopic.

[0135] The dimming and color - tuning circuit provided in this embodiment controls at least two light - emitting modules through a single circuit, and simultaneously realizes the two functions of dimming and color - tuning. It is compatible with thyristors, uses a ripple - removing circuit to remove the stroboscopic caused by thyristors, does not require electrolytic capacitors, keeps the power factor above 0.9, and has high electrical utilization efficiency.

[0136] In an alternative embodiment, the above - mentioned dimming and color - tuning circuit further includes a power - supply circuit 60. The power - supply circuit 60 is connected to the rectifying circuit 20 and is used to output a power - supply signal to the control circuit 31 to supply power to the single - chip microcomputer U8.

[0137] In an alternative embodiment, the above - mentioned color - tuning circuit 30 further includes a control component 34.

[0138] The control component 34 is connected to the control circuit 31.

[0139] The control component 34 outputs a corresponding dimming instruction to the control circuit 31 according to the user's operation instruction.

[0140] Specifically, the control component 34 is implemented by a touch screen, a button panel, a DIP switch, or a knob. By the user outputting an operation instruction, a corresponding dimming instruction is generated. Figure 4 It shows that the control component 34 is implemented by the DIP switch SW1.

[0141] The above-mentioned control component 34 has multiple selectable gears for users to select color temperature. The operation is simple and convenient, and the user experience is high.

[0142] The second aspect of the present application provides a lighting fixture. The lighting fixture includes at least two light-emitting modules 100 and the above-mentioned dimming and color temperature adjusting circuit, and the dimming and color temperature adjusting circuit is used to control the light-emitting modules 100 to emit light.

[0143] In summary, the present application provides a dimming and color temperature adjusting circuit and a lighting fixture. At least two light-emitting modules are controlled by a single circuit, and the two functions of dimming and color temperature adjustment are realized simultaneously. It is compatible with thyristors, and a constant current circuit is used to control the current in the power supply circuit to be constant. The working efficiency of the circuit is high, and the circuit structure is simplified. It can be widely applied to DOB products.

[0144] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; 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, and should all be included in the protection scope of the present application.

Claims

1. A dimming and color - tuning circuit is used to control at least two light - emitting modules to emit light, and is characterized in that, The dimming and color - temperature - adjusting circuit includes: A thyristor dimmer for accessing an alternating - current signal and performing voltage - regulation processing on the alternating - current signal; A rectification circuit connected to the thyristor dimmer, for rectifying the alternating - current signal after voltage - regulation processing and outputting a direct - current signal to supply power to each of the light - emitting modules; wherein, the rectification circuit is implemented by a rectifier bridge; A color - temperature - adjusting circuit connected to each of the light - emitting modules, for accessing a dimming instruction and correspondingly adjusting the current ratio flowing through each of the light - emitting modules according to the dimming instruction; and A constant - current circuit connected to the rectification circuit, the color - temperature - adjusting circuit and each of the light - emitting modules, for performing constant - current control on the power - supply loop of each of the light - emitting modules; The color - temperature - adjusting circuit includes: A control circuit for accessing the dimming instruction and correspondingly outputting at least two color - temperature - adjusting signals according to the dimming instruction; An isolation circuit connected to the control circuit, for performing opto - isolation and transmitting the color - temperature - adjusting signals; and At least two current - adjusting circuits connected to the constant - current circuit and the isolation circuit, one current - adjusting circuit corresponding to one light - emitting module, and the current - adjusting circuit is used for receiving the corresponding color - temperature - adjusting signal and adjusting the current of the corresponding light - emitting module according to the received color - temperature - adjusting signal; The constant - current circuit includes: At least two chip - select circuits, one of the chip - select circuits is connected to at least one of the current - adjusting circuits, and the other chip - select circuit is connected to the light - emitting module, and each chip - select circuit is used for switching the power - supply loop of each of the light - emitting modules; and A constant - current control circuit connected to the rectification circuit and each of the chip - select circuits, for performing constant - current control on the power - supply loop of each of the light - emitting modules.

2. The dimming and color - adjusting circuit according to claim 1, wherein, The isolation circuit includes: At least two opto - couplers; The light - emitter of each opto - coupler is connected to the control circuit, and the light - receiver of each opto - coupler is correspondingly connected to one current - adjusting circuit.

3. The dimming and color - adjusting circuit according to claim 1, wherein It further includes: A control component connected to the control circuit, for outputting the corresponding dimming instruction to the control circuit according to the user's operation instruction.

4. The dimming and color - tuning circuit according to claim 1, wherein, The current - adjusting circuit includes: A first resistor, a second resistor, a third resistor, a fourth resistor, a first switching tube, a second switching tube and a first diode; The first end of the first resistor is connected to one of the light - emitting modules, the node where the second end of the first resistor, the first end of the second resistor and the controlled end of the first switching tube are commonly connected is connected to the isolation circuit, the node where the input end of the first switching tube and the cathode of the first diode are commonly connected is connected to one of the light - emitting modules, and the anode of the first diode, the first end of the third resistor, the first end of the fourth resistor and the controlled end of the second switching tube are commonly connected; the second end of the third resistor and the input end of the second switching tube are both connected to one of the light - emitting modules; The node where the second end of the second resistor, the second end of the fourth resistor, the output end of the first switching tube and the output end of the second switching tube are commonly connected is connected to the constant - current circuit.

5. The dimming and color mixing circuit according to claim 1, characterized in that The chip - select circuit includes: An enabling chip, a fifth resistor, a sixth resistor, a seventh resistor, a second diode, and a third diode; The first end of the fifth resistor is connected to at least one of the current adjustment circuits. The second end of the fifth resistor is commonly connected to the anode of the second diode. The cathode of the second diode is connected to the transmission end or the chip select end of the enabling chip. The chip select end of the enabling chip, the first end of the sixth resistor, the first end of the seventh resistor, and the anode of the third diode are commonly connected. The second end of the sixth resistor, the second end of the seventh resistor, and the cathode of the third diode are commonly connected.

6. The dimming and color - adjusting circuit according to claim 1, wherein, The constant current control circuit includes: A first constant current control chip, a second constant current control chip, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a first capacitor, and a second capacitor; The current limiting end of the first constant current control chip, the first end of the eighth resistor, and the first end of the ninth resistor are commonly connected. The first current limiting end of the second constant current control chip is commonly connected to the first end of the tenth resistor. The second current limiting end of the second constant current control chip, the second end of the tenth resistor, the first end of the eleventh resistor, and the first end of the twelfth resistor are commonly connected. The node where the transmission end of the first constant current control chip, the first transmission end of the second constant current control chip, and the first end of the first capacitor are commonly connected is connected to one of the chip select circuits. The second transmission end of the second constant current control chip is commonly connected to the first end of the thirteenth resistor. The node where the second end of the thirteenth resistor is commonly connected to the first end of the fourteenth resistor is connected to the rectification circuit. The second end of the fourteenth resistor, the first end of the fifteenth resistor, and the first end of the sixteenth resistor are commonly connected. The second end of the fifteenth resistor, the first end of the second capacitor, and the power supply end of the first constant current control chip are commonly connected; The second ends of the eighth resistor, the ninth resistor, the eleventh resistor, the twelfth resistor, the sixteenth resistor, the second end of the first capacitor, and the second end of the second capacitor are grounded.

7. The dimming and color mixing circuit according to claim 1, wherein It further includes: At least two ripple removal circuits, all connected to each of the light emitting modules. One of the ripple removal circuits is further connected to the rectification circuit, and the other ripple removal circuit is further connected to at least one of the chip select circuits. Each of the ripple removal circuits is respectively used for performing ripple removal processing on the current flowing through the light emitting module.

8. A lighting fixture, characterized in that, It includes: At least two light emitting modules; And The dimming and color mixing circuit according to any one of claims 1 to 7, and the dimming and color mixing circuit is used to control the light emitting module to emit light.

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