Dimming and color temperature adjusting circuit and lamp

Abstract

The embodiment of the utility model discloses a dimming and color temperature adjusting circuit and a lamp. The dimming and color temperature adjusting circuit comprises a control module, a first dimming module and a second dimming module, the control module is connected with the first dimming module and the second dimming module, and the first dimming module and the second dimming module are connected with the power input circuit; the control module outputs a corresponding first adjusting signal and a corresponding second adjusting signal after the delay time of the input PWM signal is removed; the first dimming module converts the first adjusting signal into a direct-current voltage signal and adjusts the current between the positive power supply voltage and the first negative power supply voltage in the power supply input circuit according to the direct-current voltage signal; and the second dimming module converts the second adjusting signal into another DC voltage signal, and adjusts the current between the power supply positive voltage and the second power supply negative voltage in the power supply input circuit according to the another DC voltage signal. And the PWM signal is converted into the DC voltage signal, so that rapid switching can be realized, a dimming low end does not flicker, and stepless dimming is realized.

Description

Technical Field

[0001] The utility model relates to the field of electronic technology, in particular to a light-adjusting and color-temperature-adjusting circuit and a lamp. Background Art

[0002] When common LED power modules power lamps, they use PWM (pulse width modulation) dimming or resistor dimming, and the dimming voltage range is 0~10v dimming. This dimming method based on PWM signals will cause flickering at the low end of the dimming when the high and low levels of the pulse are switched. If matched with an external intelligent dimming module for inputting PWM signals, the external input PWM signal will cause interference, timing confusion and flickering, affecting the dimming effect. Utility Model Content

[0003] In view of the above technical problems, the embodiments of the present invention provide a dimming and color temperature adjusting circuit and a lamp to solve the flickering problem of the existing PWM dimming.

[0004] The embodiment of the utility model provides a dimming and color temperature adjusting circuit, which is connected to a power input circuit, and includes a control module, a first dimming module and a second dimming module; the control module is connected to the first dimming module and the second dimming module, and the first dimming module and the second dimming module are connected to the power input circuit;

[0005] The control module removes the delay time from the input PWM signal and outputs the corresponding first adjustment signal and second adjustment signal;

[0006] The first dimming module converts the first adjustment signal into a DC voltage signal, and adjusts the current between the positive power supply voltage and the first negative power supply voltage in the power input circuit according to the DC voltage signal;

[0007] The second dimming module converts the second adjustment signal into another DC voltage signal, and adjusts the current between the positive power supply voltage and the second negative power supply voltage in the power input circuit according to the other DC voltage signal.

[0008] Optionally, in the dimming and color temperature adjusting circuit, in the power input circuit, the first pin of the output interface outputs the positive power supply voltage LED+, which is connected to the positive poles of the first dimming module, the second dimming module and two LED light strings; the second pin outputs the first negative power supply voltage LED1-, which is connected to the negative pole of the first dimming module and an LED light string; the third pin outputs the second negative power supply voltage LED2-, which is connected to the negative pole of the second dimming module and another LED light string.

[0009] Optionally, in the dimming and color temperature adjusting circuit, the control module includes a single chip microcomputer, an input interface, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor and a second capacitor;

[0010] The VCC pin of the single-chip microcomputer is connected to the power input circuit, the OUT2 pin of the single-chip microcomputer is connected to the second dimming module, the GND pin of the single-chip microcomputer is connected to one end of the second capacitor, one end of the first resistor and the GND pin of the input interface ON2; the OUT1 pin of the single-chip microcomputer is connected to the first dimming module, the CCT pin of the single-chip microcomputer is connected to the other end of the second capacitor and one end of the second resistor, the other end of the second resistor is connected to the other end of the first resistor and one end of the third resistor, the other end of the third resistor is connected to one end of the seventh resistor and the 12V+ pin of the input interface, the other end of the seventh resistor is connected to the 12V+ pin of the input interface, the DIM pin of the single-chip microcomputer is connected to one end of the first capacitor and one end of the fourth resistor, the other end of the fourth resistor is connected to one end of the fifth resistor and one end of the sixth resistor, the other end of the first capacitor is connected to the other end of the sixth resistor and ground, the other end of the fifth resistor is connected to the DIM pin of the input interface and one end of the eighth resistor, and the other end of the eighth resistor is connected to the power input circuit.

[0011] Optionally, in the dimming and color temperature adjusting circuit, the first dimming module includes a first dimming chip, a first diode, a second diode, a first inductor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor and an eighth capacitor;

[0012] The LPF pin of the first dimming chip is grounded through the sixth capacitor, the HPWM pin of the first dimming chip is connected to the cathode of the first diode, one end of the thirteenth resistor and one end of the seventh capacitor; the anode of the first diode is connected to one end of the ninth resistor and OUT1 of the single-chip computer, the other end of the ninth resistor is connected to one end of the third capacitor and one end of the tenth resistor, the other end of the tenth resistor is connected to one end of the eleventh resistor and one end of the fourth capacitor; the other end of the eleventh resistor is connected to one end of the fifth capacitor, one end of the twelfth resistor and the ADIM pin of the first dimming chip; the GND pin of the first dimming chip, the third capacitor The other end of the fourth capacitor, the other end of the fifth capacitor and the other end of the twelfth resistor are all grounded; the ZVS pin of the first dimming chip is connected to one end of the fourteenth resistor and one end of the fifteenth resistor; the other end of the fourteenth resistor is connected to the other end of the thirteenth resistor, the other end of the seventh capacitor and ground; the other end of the fifteenth resistor is connected to one end of the eighth capacitor; the other end of the eighth capacitor is connected to the D pin of the first dimming chip, one end of the first inductor and the positive electrode of the second diode; the cathode of the second diode is connected to the first pin of the output interface, and the CS pin and VIN pin of the first dimming chip are both connected to the power input circuit.

[0013] Optionally, in the dimming and color temperature adjusting circuit, the first dimming module further includes a sixteenth resistor, a seventeenth resistor and a ninth capacitor;

[0014] One end of the sixteenth resistor is connected to one end of the ninth capacitor, the other end of the sixteenth resistor is connected to one end of the seventeenth resistor and the positive electrode of the second diode, the other end of the ninth capacitor is connected to the negative electrode of the second diode, and the other end of the seventeenth resistor is connected to the D pin of the first dimming chip and one end of the first inductor.

[0015] Optionally, in the dimming and color temperature adjusting circuit, the first dimming module also includes an eighteenth resistor and a tenth capacitor, one end of the eighteenth resistor is connected to one end of the tenth capacitor and the VIN pin of the first dimming chip, the other end of the eighteenth resistor is connected to the power input circuit, and the other end of the tenth capacitor is grounded.

[0016] Optionally, in the dimming and color temperature adjusting circuit, the second dimming module includes a second dimming chip, a third diode, a fourth diode, a second inductor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor and a sixteenth capacitor;

[0017] The LPF pin of the second dimming chip is grounded through the fourteenth capacitor, the HPWM pin of the second dimming chip is connected to the cathode of the third diode, one end of the twenty-third resistor and one end of the fifteenth capacitor; the anode of the third diode is connected to one end of the nineteenth resistor and OUT2 of the single-chip computer, the other end of the nineteenth resistor is connected to one end of the eleventh capacitor and one end of the twentieth resistor, the other end of the twentieth resistor is connected to one end of the twenty-first resistor and one end of the twelfth capacitor; the other end of the twenty-first resistor is connected to one end of the thirteenth capacitor, one end of the twenty-second resistor and the ADIM pin of the second dimming chip; the GND pin, the eleventh resistor and the ADIM pin of the second dimming chip are connected to the GND pin, the eleventh resistor and the ADIM pin of the second dimming chip. The other end of the capacitor, the other end of the twelfth capacitor, the other end of the thirteenth capacitor and the other end of the twenty-second resistor are all grounded; the ZVS pin of the second dimming chip is connected to one end of the twenty-fourth resistor and one end of the twenty-fifth resistor; the other end of the twenty-fourth resistor is connected to the other end of the twenty-third resistor, the other end of the fifteenth capacitor and ground; the other end of the twenty-fifth resistor is connected to one end of the sixteenth capacitor; the other end of the sixteenth capacitor is connected to the D pin of the second dimming chip, one end of the second inductor and the positive electrode of the fourth diode; the negative electrode of the fourth diode is connected to the first pin of the output interface, and the CS pin and VIN pin of the second dimming chip are both connected to the power input circuit.

[0018] Optionally, in the dimming and color temperature adjusting circuit, the second dimming module also includes a twenty-sixth resistor, a twenty-seventh resistor and a seventeenth capacitor; one end of the twenty-sixth resistor is connected to one end of the seventeenth capacitor, the other end of the twenty-sixth resistor is connected to one end of the twenty-seventh resistor and the positive electrode of the fourth diode, the other end of the seventeenth capacitor is connected to the negative electrode of the fourth diode, and the other end of the twenty-seventh resistor is connected to the D pin of the second dimming chip and one end of the second inductor.

[0019] Optionally, in the dimming and color temperature adjusting circuit, the second dimming module also includes a twenty-eighth resistor and an eighteenth capacitor, one end of the twenty-eighth resistor is connected to one end of the eighteenth capacitor and the VIN pin of the second dimming chip, the other end of the twenty-eighth resistor is connected to the power input circuit, and the other end of the eighteenth capacitor is grounded.

[0020] The second aspect of the embodiment of the utility model provides a lamp, comprising a main board and at least two LED light strings, wherein the main board is provided with a power input circuit, wherein the main board is also provided with the dimming and color temperature adjusting circuit;

[0021] The dimming and color temperature adjusting circuit is connected to a power input circuit, and the power input circuit is connected to an LED light string;

[0022] The power input circuit performs rectification and filtering on the mains electricity to achieve constant voltage and current and then outputs the supply voltage;

[0023] The dimming and color temperature adjusting circuit converts an externally input PWM signal into a corresponding DC voltage signal and then outputs two supply currents to adjust the brightness and color temperature of two LED light strings respectively.

[0024] In the technical solution provided by the embodiment of the utility model, the dimming and color temperature adjustment circuit includes a control module, a first dimming module and a second dimming module; the control module is connected to the first dimming module and the second dimming module, and the first dimming module and the second dimming module are connected to the power input circuit; the control module outputs the corresponding first adjustment signal and the second adjustment signal after removing the delay time from the input PWM signal; the first dimming module converts the first adjustment signal into a DC voltage signal, and adjusts the current between the positive power supply voltage and the first negative power supply voltage in the power input circuit according to the DC voltage signal; the second dimming module converts the second adjustment signal into another DC voltage signal, and adjusts the current between the positive power supply voltage and the second negative power supply voltage in the power input circuit according to the other DC voltage signal. The conversion of the PWM signal into a DC voltage signal can achieve fast switching, and there will be no flickering at the low end of the dimming, so as to achieve stepless dimming. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural block diagram of the lamp in the embodiment of the utility model.

[0026] Figure 2 Schematic diagram of the circuit of the control module in the embodiment of the utility model.

[0027] Figure 3 Schematic diagram of the circuit of the first dimming module in the embodiment of the utility model.

[0028] Figure 4 Schematic diagram of the circuit of the second dimming module in the embodiment of the utility model. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The embodiments in the utility model and all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0030] See also Figure 1 The lamp provided by the embodiment of the utility model includes a mainboard arranged inside the lamp and at least two LED light strings, the mainboard is provided with an existing power input circuit and a dimming and color temperature adjustment circuit 10 provided by the embodiment; the dimming and color temperature adjustment circuit 10 is connected to the power input circuit, and the power input circuit is connected to the LED light strings. The power input circuit rectifies and filters the mains (connected to the mains through an interface) to constant voltage and constant current, and then outputs a supply voltage (this embodiment includes a positive power supply LED+, a first negative power supply LED1-, and a second negative power supply LED2-), and the dimming and color temperature adjustment circuit 10 converts the external input PWM signal into a DC voltage signal of a corresponding voltage value, and then outputs two supply currents to adjust the brightness and color temperature of the two LED light strings respectively.

[0031] By converting the PWM signal into a DC voltage signal, fast switching can be achieved, and the low end of the dimming (i.e. the negative pole of the LED light string) will not flicker, thus achieving stepless dimming. There is no delay when matching the intelligent dimming module, which can effectively avoid the problems of dimming flickering and timing confusion during the use of the intelligent module.

[0032] In specific implementation, there are several negative power supply voltages for several LED light strings, and one positive power supply voltage is shared. One power input circuit and one dimming and color temperature adjustment circuit control two LED light strings. If there are multiple LED light strings, the number of power input circuits and dimming and color temperature adjustment circuits can be increased accordingly.

[0033] The power input circuit is a prior art circuit, which processes the mains power and outputs a first voltage of 5V+ and a second voltage of 12V+ to supply power, and also outputs a first current setting signal CS1 and a second current setting signal CS2 for controlling the maximum output current to set the maximum output current. Figure 1As shown, the first pin of the output interface CON1 outputs the positive power supply voltage LED+, which is connected to the positive poles of the first dimming module, the second dimming module and the two LED light strings; the second pin outputs the first negative power supply voltage LED1-, which is connected to the negative poles of the first dimming module and one LED light string; the third pin outputs the second negative power supply voltage LED2-, which is connected to the negative pole of the second dimming module and another LED light string. Here, the main adjustment is made to the output power supply current, and the internal interface CON1 is used to output different power supply currents to adjust the brightness and color temperature of the two LED light strings. The larger the power supply current, the brighter the brightness. Similarly, the smaller the power supply current, the smaller the brightness. If the power supply currents of the two LED light strings are different, the brightness combination will present different color temperatures (such as cold light, warm light, warm white light, etc.).

[0034] In this embodiment, the dimming and color temperature adjustment circuit 10 includes a control module 110, a first dimming module 120 and a second dimming module 130; the control module 110 is connected to the first dimming module 120 and the second dimming module 130, the first dimming module 120 is connected to the first and second pins of the output interface CON1, and the second dimming module 130 is connected to the first and third pins of the output interface CON1. ​​The control module 110 removes the delay time from the input PWM signal and outputs the corresponding first adjustment signal PWM1 and second adjustment signal PWM2; the first dimming module converts the first adjustment signal PWM1 into a DC voltage signal, and adjusts the current between the positive power supply voltage LED+ and the first negative power supply voltage LED1- according to the DC voltage signal; the second dimming module converts the second adjustment signal PWM2 into another DC voltage signal, and adjusts the current between the positive power supply voltage LED+ and the second negative power supply voltage LED12- according to the other DC voltage signal. The magnitude of the two currents determines the brightness of the two LED light strings. If the magnitudes of the two currents are the same and increase or decrease, the two LED light strings will become brighter or darker at one color temperature; if the current values ​​of the two LED light strings are different, they will be combined into corresponding color temperatures.

[0035] Please also read Figure 2The control module 110 includes a single-chip microcomputer U1, an input interface CON2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first capacitor C1 and a second capacitor C2; the VCC pin of the single-chip microcomputer U1 is connected to the power input circuit (inputting a first voltage 5V+), the OUT2 pin of the single-chip microcomputer U1 is connected to the second dimming module 130, and the GND pin of the single-chip microcomputer U1 is connected to one end of the second capacitor C2, one end of the first resistor R1 and the GND pin of the input interface CON2; the OUT1 pin of the single-chip microcomputer U1 is connected to the first dimming module 120, and the CCT pin of the single-chip microcomputer U1 is connected to the other end of the second capacitor C2 and One end of the second resistor R2 and the other end of the second resistor R2 are connected to the other end of the first resistor R1 and one end of the third resistor R3, the other end of the third resistor R3 is connected to one end of the seventh resistor R7 and the 12V+ pin of the input interface, the other end of the seventh resistor R7 is connected to the 12V+ pin of the input interface, the DIM pin of the microcontroller U1 is connected to one end of the first capacitor C1 and one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to one end of the fifth resistor R5 and one end of the sixth resistor R6, the other end of the first capacitor C1 is connected to the other end of the sixth resistor and ground, the other end of the fifth resistor is connected to the DIM pin of the input interface and one end of the eighth resistor, and the other end of the eighth resistor R8 is connected to the power input circuit (input second voltage 12V+).

[0036] Among them, the single-chip microcomputer U1 preferably has a model of YFE51F; it can also be replaced by other models during specific implementation, such as YF8A053E, YF8B061E, AGT-001 or YF61E. The input interface CON2 is externally connected to an existing dimming module for providing a PWM signal, such as a Tuya smart dimming module. The PWM signal includes a color temperature adjustment signal for adjusting the color temperature input from the CCT pin of the input interface CON2, and a brightness adjustment signal for adjusting the brightness input from the DIM pin. The single-chip microcomputer U1 outputs the corresponding first adjustment signal PWM1 to the first dimming module 120 according to the color temperature adjustment signal and the brightness adjustment signal, and outputs the second adjustment signal PWM2 to the second dimming module 130. The single-chip microcomputer U1 can remove the delay time of the PWM signal, so it can execute quickly and respond quickly. The circuit composed of R1~R8, C1 and C2 can filter and remove the interference and noise caused by the external signal input, so that the single-chip microcomputer can detect accurate signals. When there is no PWM signal input, the voltage on the CCT pin of the microcontroller is discharged to the ground through C2, and pulled down to the ground through R2 and R1; the DIM pin of the microcontroller is pulled up to a high level by the second voltage 12V+ through R4, R5, and R8, and the microcontroller has no output here.

[0037] Please also read Figure 3The first dimming module 120 includes a first dimming chip U2, a first diode D1, a second diode D2, a first inductor T1, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8; the LPF pin of the first dimming chip U2 is grounded through the sixth capacitor C6, and the HPWM pin of the first dimming chip U2 is connected to the cathode of the first diode D1, one end of the thirteenth resistor R13 and one end of the seventh capacitor C7; the anode of the first diode D1 is connected to one end of the ninth resistor and OUT1 of the single-chip computer U1, the other end of the ninth resistor R9 is connected to one end of the third capacitor C3 and one end of the tenth resistor R10, and the other end of the tenth resistor R10 is connected to one end of the eleventh resistor R11 and one end of the fourth capacitor C4; The other end of the resistor is connected to one end of the fifth capacitor C5, one end of the twelfth resistor R12 and the ADIM pin of the first dimming chip U2; the GND pin of the first dimming chip U1, the other end of the third capacitor, the other end of the fourth capacitor, the other end of the fifth capacitor and the other end of the twelfth resistor are all grounded; the ZVS pin of the first dimming chip U2 is connected to one end of the fourteenth resistor R14 and one end of the fifteenth resistor R15; the other end of the fourteenth resistor R14 is connected to the other end of the thirteenth resistor R13, the other end of the seventh capacitor C7 and ground; the other end of the fifteenth resistor is connected to one end of the eighth capacitor C8; the other end of the eighth capacitor is connected to the D pin of the first dimming chip U2, one end of the first inductor T1 and the positive electrode of the second diode D2; the negative electrode of the second diode D2 is connected to the first pin of the output interface CON1, and the CS pin and VIN pin of the first dimming chip U2 are both connected to the power input circuit (the CS pin inputs the first current setting signal CS1, and the VIN pin inputs the second voltage 12V+).

[0038] Among them, the model of the first dimming chip U2 is preferably DIO8280, and can be replaced by other models during specific implementation, such as IW380, BP1386 or RT8406. After the first adjustment signal PWM1 is input, it is integrated and divided by the circuit composed of R9~R12 and C3~C5 to be converted into a DC voltage signal and input into the ADIM pin, and supplied to the first dimming chip U2 to realize analog dimming, so that there will be no jitter and flicker during the dimming process. The other path of the first adjustment signal PWM1 is rectified by the first diode D1, and then converted into a 5V enable signal by R13 and C7 to control whether the first dimming chip U2 works; if the first adjustment signal PWM1 is input, a 5V enable signal can be output, and the first dimming chip U2 works; if there is no first adjustment signal PWM1 input, the electric energy on C7 is discharged to the ground through R13, and becomes a 0V enable signal, and the first dimming chip U2 stops working; so that the first dimming chip U2 can be quickly shut down, the dimming is smooth, and the flashing light and poor dimming linearity when adjusting the color temperature are effectively avoided.

[0039] The second voltage 12V+ is input to the VIN pin to power the first dimming chip U2. The first current setting signal CS1 is used to set the maximum output current, that is, the upper limit of the power supply current when it is working; when adjusting the brightness and color temperature, the power supply current is increased or decreased according to the percentage of the maximum output current. The first dimming chip U2 adjusts the current between the positive power supply voltage LED+ and the first negative power supply voltage LED1- according to the first adjustment signal PWM1. The first inductor T1 is used for energy storage, and the second diode D2 is used for unidirectional conduction to prevent the positive power supply voltage LED+ from flowing back to T1, affecting the accuracy of dimming and color temperature adjustment. R14, R15, C6 and C8 are used to set the working parameters of the first dimming chip U2.

[0040] Preferably, the first dimming module 120 also includes a sixteenth resistor R16, a seventeenth resistor R17 and a ninth capacitor C9; one end of the sixteenth resistor R16 is connected to one end of the ninth capacitor C9, the other end of the sixteenth resistor R16 is connected to one end of the seventeenth resistor R17 and the positive electrode of the second diode D2, the other end of the ninth capacitor C9 is connected to the negative electrode of the second diode D2, and the other end of the seventeenth resistor R17 is connected to the D pin of the first dimming chip U2 and one end of the first inductor T1.

[0041] The sixteenth resistor R16, the seventeenth resistor R17, the ninth capacitor C9 and the second diode form a circuit to perform electrostatic protection to avoid burning the first dimming chip U2.

[0042] Preferably, the first dimming module 120 also includes an eighteenth resistor R18 and a tenth capacitor C10, one end of the eighteenth resistor R18 is connected to one end of the tenth capacitor C10 and the VIN pin of the first dimming chip U2, the other end of the eighteenth resistor R18 is connected to the power input circuit (input second voltage 12V+), and the other end of the tenth capacitor C10 is grounded.

[0043] The R18 is used for current limiting to protect the first dimming chip U2, and the R18 and C10 form an RC filter circuit to filter the input second voltage 12V+, so that the first dimming chip U2 can work more stably.

[0044] Please also read Figure 4 The second dimming module 130 has the same structure as the first dimming module 120, including a second dimming chip U3, a third diode D3, a fourth diode D4, a second inductor T2, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15 and a sixteenth capacitor C 16; the LPF pin of the second dimming chip U3 is grounded through the fourteenth capacitor C14, the HPWM pin of the second dimming chip U3 is connected to the cathode of the third diode D3, one end of the twenty-third resistor R23 and one end of the fifteenth capacitor C15; the anode of the third diode D3 is connected to one end of the nineteenth resistor R19 and OUT2 of the single-chip computer U1, the other end of the nineteenth resistor R19 is connected to one end of the eleventh capacitor C11 and one end of the twentieth resistor R20, the other end of the twentieth resistor R20 is connected to one end of the twenty-first resistor R21 and the tenth one end of the second capacitor C12; the other end of the twenty-first resistor R21 is connected to one end of the thirteenth capacitor C13, one end of the twenty-second resistor R22 and the ADIM pin of the second dimming chip U3; the GND pin of the second dimming chip U3, the other end of the eleventh capacitor, the other end of the twelfth capacitor, the other end of the thirteenth capacitor and the other end of the twenty-second resistor R22 are all grounded; the ZVS pin of the second dimming chip U3 is connected to one end of the twenty-fourth resistor R24 ​​and one end of the twenty-fifth resistor R25; the other end of the twenty-fourth resistor R24 ​​is connected to the twenty-three The other end of the resistor R23, the other end of the fifteenth capacitor C15 and the ground; the other end of the twenty-fifth resistor R25 is connected to one end of the sixteenth capacitor C16; the other end of the sixteenth capacitor C16 is connected to the D pin of the second dimming chip U3, one end of the second inductor T2 and the positive electrode of the fourth diode D4; the cathode of the fourth diode D4 is connected to the first pin of the output interface CON1, and the CS pin and VIN pin of the second dimming chip U3 are both connected to the power input circuit (the CS pin inputs the second current setting signal CS2, and the VIN pin inputs the second voltage 12V+).

[0045] The model of the second dimming chip U3 is preferably DIO8280, and can be replaced by other models during implementation, such as IW380, BP1386 or RT8406. After the second adjustment signal PWM2 is input, it is integrated and divided by the circuit composed of R19-R22 and C11-C13 to be converted into a DC voltage signal and input to the ADIM pin, which is supplied to the second dimming chip U3 to realize analog dimming, and no jitter or flicker will occur during the dimming process. The other path of the second adjustment signal PWM2 is rectified by the third diode D3, and then converted into an enable signal of 0V or 5V by R23 and C15 to control whether the second dimming chip U3 works; when the second adjustment signal PWM2 is input, a 5V enable signal is output, and the second dimming chip U3 works; when there is no second adjustment signal PWM2 input, the electric energy on C15 is discharged to the ground through R23, and becomes a 0V enable signal, and the second dimming chip U3 stops working; thereby, the second dimming chip U3 can be quickly shut down and the dimming is smooth, which effectively avoids flashing lights and poor dimming linearity when adjusting the color temperature.

[0046] The second voltage 12V+ is input to the VIN pin to power the second dimming chip U3. The second current setting signal CS2 is used to set the maximum output current, that is, the upper limit of the power supply current when it is working; when adjusting the brightness and color temperature, the power supply current is increased or decreased according to the percentage of the maximum output current. The second dimming chip U3 adjusts the current between the positive power supply voltage LED+ and the second negative power supply voltage LED2- according to the second adjustment signal PWM2. The second inductor T2 is used for energy storage, and the fourth diode D4 is used for unidirectional conduction to prevent the positive power supply voltage LED+ from flowing back to T2, affecting the accuracy of dimming and color temperature adjustment. R24, R25, C14 and C16 are used to set the working parameters of the second dimming chip U3.

[0047] Preferably, the second dimming module 130 also includes a twenty-sixth resistor R26, a twenty-seventh resistor R27 and a seventeenth capacitor C17; one end of the twenty-sixth resistor R26 is connected to one end of the seventeenth capacitor C17, the other end of the twenty-sixth resistor R26 is connected to one end of the twenty-seventh resistor R27 and the positive electrode of the fourth diode D4, the other end of the seventeenth capacitor C17 is connected to the negative electrode of the fourth diode D4, and the other end of the twenty-seventh resistor R27 is connected to the D pin of the second dimming chip U3 and one end of the second inductor T2.

[0048] The twenty-sixth resistor R26, the twenty-seventh resistor R27, the seventeenth capacitor C17 and the fourth diode form a circuit for electrostatic protection to avoid burning the second dimming chip U3.

[0049] Preferably, the second dimming module 130 also includes a twenty-eighth resistor R28 and an eighteenth capacitor C18, one end of the twenty-eighth resistor R28 is connected to one end of the eighteenth capacitor C18 and the VIN pin of the second dimming chip U3, the other end of the twenty-eighth resistor R28 is connected to the power input circuit (input second voltage 12V+), and the other end of the eighteenth capacitor C18 is grounded.

[0050] Among them, the R28 is used for current limiting to protect the second dimming chip U3, and R28 and C18 form an RC filter circuit to filter the input second voltage 12V+, so that the second dimming chip U3 works more stably.

[0051] Please continue reading Figures 1 to 4 The working principle of the dimming and color temperature adjustment circuit is as follows:

[0052] After removing the delay time of the external input PWM signal, the single-chip computer U1 outputs the corresponding first adjustment signal PWM1 and the second adjustment signal PWM2. On the one hand, the first dimming chip U2 converts the first adjustment signal PWM1 into a 5V enable signal through rectification and filtering, and the first dimming chip U2 works; on the other hand, the first adjustment signal PWM1 is converted into a DC voltage signal through integration and voltage division and input into the ADIM pin, which is supplied to the first dimming chip U2 to realize analog dimming and adjust the current between the positive power supply voltage LED+ and the first negative power supply voltage LED1-. The working principle of the second adjustment signal PWM2 and the second dimming chip U3 is the same as that of the first dimming chip U2.

[0053] Based on the PWM signal, the color temperature adjustment signal is input from the CCT pin of the input interface CON2, and the brightness adjustment signal is input from the DIM pin; by setting the periodic pulses of the two adjustment signals, different first adjustment signals PWM1 and second adjustment signals PWM2 can be obtained, and the current between the positive power supply voltage LED+ and the first negative power supply voltage LED1-, and the current between the positive power supply voltage LED+ and the second negative power supply voltage LED2- of corresponding magnitudes are output. The magnitude of these two currents determines the brightness of the two LED light strings. If the current values ​​of the two LED light strings are different, they are combined into corresponding color temperatures.

[0054] In summary, the dimming and color temperature adjustment circuit and lamp provided by the utility model can quickly perform dimming operations by removing the delay time of the PWM signal through the single-chip microcomputer; the dimming method is analog dimming, that is, converting two pulse-like adjustment signals into a 0-5V DC voltage signal as the basis for adjustment, and no longer using the existing PWM dimming with limited levels, thereby avoiding the problem of step sense and flickering caused by insufficient dimming levels in PWM dimming.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dimming and color temperature adjusting circuit, connected to a power input circuit, characterized in that: It includes a control module, a first dimming module and a second dimming module; the control module is connected to the first dimming module and the second dimming module, and the first dimming module and the second dimming module are connected to a power input circuit; The control module removes the delay time from the input PWM signal and outputs the corresponding first adjustment signal and second adjustment signal; The first dimming module converts the first adjustment signal into a DC voltage signal, and adjusts the current between the positive power supply voltage and the first negative power supply voltage in the power input circuit according to the DC voltage signal; The second dimming module converts the second adjustment signal into another DC voltage signal, and adjusts the current between the positive power supply voltage and the second negative power supply voltage in the power input circuit according to the other DC voltage signal.

2. The dimming and color temperature adjusting circuit according to claim 1, characterized in that: In the power input circuit, the first pin of the output interface outputs a positive power supply voltage LED+, which is connected to the positive poles of the first dimming module, the second dimming module and two LED light strings; the second pin outputs a first negative power supply voltage LED1-, which is connected to the negative pole of the first dimming module and one LED light string; the third pin outputs a second negative power supply voltage LED2-, which is connected to the negative pole of the second dimming module and another LED light string.

3. The dimming and color temperature adjusting circuit according to claim 2, characterized in that: The control module includes a single chip microcomputer, an input interface, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor and a second capacitor; The VCC pin of the single-chip microcomputer is connected to the power input circuit, the OUT2 pin of the single-chip microcomputer is connected to the second dimming module, and the GND pin of the single-chip microcomputer is connected to one end of the second capacitor, one end of the first resistor and the GND pin of the input interface ON2; The OUT1 pin of the single-chip microcomputer is connected to the first dimming module, the CCT pin of the single-chip microcomputer is connected to the other end of the second capacitor and one end of the second resistor, the other end of the second resistor is connected to the other end of the first resistor and one end of the third resistor, the other end of the third resistor is connected to one end of the seventh resistor and the 12V+ pin of the input interface, the other end of the seventh resistor is connected to the 12V+ pin of the input interface, the DIM pin of the single-chip microcomputer is connected to one end of the first capacitor and one end of the fourth resistor, the other end of the fourth resistor is connected to one end of the fifth resistor and one end of the sixth resistor, the other end of the first capacitor is connected to the other end of the sixth resistor and ground, the other end of the fifth resistor is connected to the DIM pin of the input interface and one end of the eighth resistor, and the other end of the eighth resistor is connected to the power input circuit.

4. The dimming and color temperature adjusting circuit according to claim 3, characterized in that: The first dimming module includes a first dimming chip, a first diode, a second diode, a first inductor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor and an eighth capacitor; The LPF pin of the first dimming chip is grounded through the sixth capacitor, the HPWM pin of the first dimming chip is connected to the cathode of the first diode, one end of the thirteenth resistor and one end of the seventh capacitor; the anode of the first diode is connected to one end of the ninth resistor and OUT1 of the single-chip computer, the other end of the ninth resistor is connected to one end of the third capacitor and one end of the tenth resistor, the other end of the tenth resistor is connected to one end of the eleventh resistor and one end of the fourth capacitor; the other end of the eleventh resistor is connected to one end of the fifth capacitor, one end of the twelfth resistor and the ADIM pin of the first dimming chip; the GND pin of the first dimming chip, the third capacitor The other end of the fourth capacitor, the other end of the fifth capacitor and the other end of the twelfth resistor are all grounded; the ZVS pin of the first dimming chip is connected to one end of the fourteenth resistor and one end of the fifteenth resistor; the other end of the fourteenth resistor is connected to the other end of the thirteenth resistor, the other end of the seventh capacitor and ground; the other end of the fifteenth resistor is connected to one end of the eighth capacitor; the other end of the eighth capacitor is connected to the D pin of the first dimming chip, one end of the first inductor and the positive electrode of the second diode; the cathode of the second diode is connected to the first pin of the output interface, and the CS pin and VIN pin of the first dimming chip are both connected to the power input circuit.

5. The dimming and color temperature adjusting circuit according to claim 4, characterized in that: The first dimming module further includes a sixteenth resistor, a seventeenth resistor and a ninth capacitor; One end of the sixteenth resistor is connected to one end of the ninth capacitor, the other end of the sixteenth resistor is connected to one end of the seventeenth resistor and the positive electrode of the second diode, the other end of the ninth capacitor is connected to the negative electrode of the second diode, and the other end of the seventeenth resistor is connected to the D pin of the first dimming chip and one end of the first inductor.

6. The dimming and color temperature adjusting circuit according to claim 4, characterized in that: The first dimming module also includes an eighteenth resistor and a tenth capacitor, one end of the eighteenth resistor is connected to one end of the tenth capacitor and the VIN pin of the first dimming chip, the other end of the eighteenth resistor is connected to the power input circuit, and the other end of the tenth capacitor is grounded.

7. The dimming and color temperature adjusting circuit according to claim 3, characterized in that: The second dimming module includes a second dimming chip, a third diode, a fourth diode, a second inductor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor and a sixteenth capacitor; The LPF pin of the second dimming chip is grounded through the fourteenth capacitor, the HPWM pin of the second dimming chip is connected to the cathode of the third diode, one end of the twenty-third resistor and one end of the fifteenth capacitor; the anode of the third diode is connected to one end of the nineteenth resistor and OUT2 of the single-chip computer, the other end of the nineteenth resistor is connected to one end of the eleventh capacitor and one end of the twentieth resistor, the other end of the twentieth resistor is connected to one end of the twenty-first resistor and one end of the twelfth capacitor; the other end of the twenty-first resistor is connected to one end of the thirteenth capacitor, one end of the twenty-second resistor and the ADIM pin of the second dimming chip; the GND pin, the eleventh resistor and the ADIM pin of the second dimming chip are connected to the GND pin, the eleventh resistor and the ADIM pin of the second dimming chip. The other end of the capacitor, the other end of the twelfth capacitor, the other end of the thirteenth capacitor and the other end of the twenty-second resistor are all grounded; the ZVS pin of the second dimming chip is connected to one end of the twenty-fourth resistor and one end of the twenty-fifth resistor; the other end of the twenty-fourth resistor is connected to the other end of the twenty-third resistor, the other end of the fifteenth capacitor and ground; the other end of the twenty-fifth resistor is connected to one end of the sixteenth capacitor; the other end of the sixteenth capacitor is connected to the D pin of the second dimming chip, one end of the second inductor and the positive electrode of the fourth diode; the negative electrode of the fourth diode is connected to the first pin of the output interface, and the CS pin and VIN pin of the second dimming chip are both connected to the power input circuit.

8. The dimming and color temperature adjusting circuit according to claim 7, characterized in that: The second dimming module also includes a twenty-sixth resistor, a twenty-seventh resistor and a seventeenth capacitor; one end of the twenty-sixth resistor is connected to one end of the seventeenth capacitor, the other end of the twenty-sixth resistor is connected to one end of the twenty-seventh resistor and the positive electrode of the fourth diode, the other end of the seventeenth capacitor is connected to the negative electrode of the fourth diode, and the other end of the twenty-seventh resistor is connected to the D pin of the second dimming chip and one end of the second inductor.

9. The dimming and color temperature adjusting circuit according to claim 7, characterized in that: The second dimming module also includes a twenty-eighth resistor and an eighteenth capacitor, one end of the twenty-eighth resistor is connected to one end of the eighteenth capacitor and the VIN pin of the second dimming chip, the other end of the twenty-eighth resistor is connected to the power input circuit, and the other end of the eighteenth capacitor is grounded.

10. A lamp, comprising a main board and at least two LED light strings, wherein the main board is provided with a power input circuit, characterized in that: The main board is also provided with a dimming and color temperature adjusting circuit as described in any one of claims 1 to 9; The dimming and color temperature adjusting circuit is connected to a power input circuit, and the power input circuit is connected to an LED light string; The power input circuit performs rectification and filtering on the mains electricity to achieve constant voltage and current and then outputs the supply voltage; The dimming and color temperature adjusting circuit converts an externally input PWM signal into a corresponding DC voltage signal and then outputs two supply currents to adjust the brightness and color temperature of two LED light strings respectively.

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