A current distribution control circuit

Abstract

The application provides a current distribution control circuit, which comprises an EMI and rectifier circuit, an auxiliary power supply circuit, a current distribution control circuit, a control circuit, a constant-current dimming control circuit and a constant-voltage output control circuit; an input end of the EMI and rectifier circuit is connected with an input power supply; output ends of the EMI and rectifier circuit are connected with the auxiliary power supply circuit, the constant-current dimming control circuit and the constant-voltage output control circuit; an output end of the auxiliary power supply circuit is connected with the control circuit and provides a power supply for the control circuit; and output ends of the control circuit are connected with the current distribution control circuit, the constant-current dimming control circuit and the constant-voltage output control circuit. The scheme can reduce the current flowing through the LED load in an instant and effectively improve the light efficiency of the LED.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of LED driving color temperature switching control circuit, especially to a current distribution control circuit. BACKGROUND

[0002] The existing LED driving color temperature switching control circuit mainly adopts PWM+MOS chopper scheme, and also adopts dial+resistor scheme. But both of the two schemes have disadvantages, ① the PWM+MOS chopper scheme has a larger current peak value than the analog scheme when conducting, which leads to the light source working under the condition of large current and affecting the light efficiency; ② the dial+resistor scheme can only be applied to non-intelligent products, and the user needs to manually adjust when needing to switch the color temperature, which has poor user experience. SUMMARY

[0003] In view of the above problems, we propose a current distribution control scheme, which can be connected to the output end of constant current driving or the output end of constant voltage driving, for distributing the current of two LED loads. In order to achieve the above purpose, the present application adopts the following technical scheme: a current distribution control circuit, comprising: an EMI and rectifier circuit, an auxiliary power supply circuit, a current distribution control circuit, a control circuit, a constant current dimming control circuit and a constant voltage output control circuit; the input end of the EMI and rectifier circuit is connected to the input power supply, and the output end of the EMI and rectifier circuit is connected to the auxiliary power supply circuit, the constant current dimming control circuit and the constant voltage output control circuit; the output end of the auxiliary power supply circuit is connected to the control circuit, and the control circuit is provided with a power supply; the output end of the control circuit is connected to the current distribution control circuit, the constant current dimming control circuit and the constant voltage output control circuit; the output end of the constant current dimming control circuit and the constant voltage output control circuit is connected to the current distribution control circuit respectively; the control circuit judges the conduction and cut-off of the constant current dimming control circuit and the constant voltage output control circuit, when judging that the constant current dimming control circuit is conducted and the constant voltage output control circuit is cut off, the control circuit outputs a dimming signal to the constant current dimming control circuit, and outputs a current distribution control signal to the current distribution control circuit; when judging that the constant current dimming control circuit is cut off and the constant voltage output control circuit is conducted, the control circuit outputs a current distribution signal to the current distribution control circuit.

[0004] Through the above technical means, it can be connected to the output end of constant current driving or the output end of constant voltage driving, for distributing the current of two LED loads, and the control of the scheme is analog output, which can reduce the instantaneous current flowing through the LED load and effectively improve the light efficiency of the LED.

[0005] Specifically, the EMI and rectifier circuit comprises: a capacitor CX1, a voltage-dependent resistor VR1, a fuse F1, a common-mode inductor L1, an inductor L2, a resistor R1, a capacitor CX2, and a rectifier diode composed of diodes D1, D2, D3, and D4; the live wire is connected to one end of the capacitor CX1, one end of the voltage-dependent resistor VR1, and one end of the common-mode inductor L1 through the fuse F1; the neutral wire is connected to the other end of the capacitor CX1, the other end of the voltage-dependent resistor VR1, and the third end of the common-mode inductor L1; the rectifier diode is connected to the capacitor CX2, the inductor L2, the resistor R1, the fourth end of the common-mode inductor L1, and the auxiliary power supply circuit; one end of the resistor R1 is connected to one end of the inductor L2, one end of the capacitor CX2, and the second end of the common-mode inductor L1, and the other end of the resistor R1 is connected to the rectifier diode, the other end of the capacitor CX2, the fourth end of the common-mode inductor L1, the other end of the inductor L2, and the auxiliary power supply circuit.

[0006] Specifically, the auxiliary power supply circuit comprises: a fuse FR1, an inductor coil LF1, a capacitor CF1, a chip U1, a capacitor C4, a polarity capacitor C2, a polarity capacitor C3, an inductor LF2, and a resistor R2; one end of the capacitor CX2 close to the neutral wire is connected to one end of the capacitor CF1 and the first end of the chip U1; one end of the resistor R1 close to the rectifier diode is connected to the other end of the capacitor CF1 and one end of the inductor coil LF1 through the fuse FR1; the other end of the inductor coil LF1 is connected to the seventh end of the chip U1; the sixth end of the chip U1 is connected to the positive electrode of the polarity capacitor C2, and the negative electrode of the polarity capacitor is grounded; the second end of the chip U1 is connected to the negative electrode of the polarity capacitor C3 and one end of the resistor R2; the third end of the chip U1 is connected to the positive electrode of the polarity capacitor C3, the other end of the resistor R2, and one end of the inductor LF2; the fourth end of the chip U1 is connected to one end of the capacitor C4, and the other end of the capacitor C4 is connected to the other end of the inductor LF2 and the fifth end of the chip U1.

[0007] The auxiliary power supply circuit provides a stable 3.3V voltage for the control circuit, ensuring the stable operation of the control circuit.

[0008] Specifically, the constant current dimming control circuit comprises: a capacitor CB1, a capacitor CY1, a resistor RT1, a resistor RT2, a capacitor C1, a diode D5, an inductor coil T1, a chip U2, a resistor R01, a resistor R02, a resistor R03, a resistor RS1, a resistor RS2, a resistor RS3, a resistor RC2, a capacitor CR1, a diode D6, a diode D7, a resistor ER1, a resistor ER2, a diode DF1, a diode DF2, a resistor RF1, a resistor RF12, a polarity capacitor EC1, a resistor RF13, a resistor RF4, a resistor RF5, and a voltage stabilizer Q4; one end of the rectifier diode connected to one end of the capacitor CY1, a positive electrode of the diode D5, one end of the resistor RT1, one end of the inductor coil T1, one end of the chip U2, two ends of the capacitor CB1, one end of the capacitor C1, one end of the resistor R01, one end of the resistor RS1, one end of the resistor RS2, one end of the resistor RS3, one end of the resistor RF4, one end of the resistor RF13, a negative electrode of the polarity capacitor EC1, and a first end of the voltage stabilizer Q4; the other end of the capacitor CY1 is connected to a negative electrode of the diode D5, one end of the resistor RC2, a negative electrode of the diode D6, a negative electrode of the diode D7, one end of the resistor ER1, and a positive electrode of the polarity capacitor EC1; the other end of the inductor coil T1 is connected to one end of the capacitor CR1, a positive electrode of the diode D6, a positive electrode of the diode D7, and a 5 end of the chip U2; the other end of the capacitor CR1 is connected to the other end of the resistor RC2; one end of the resistor RT2 is connected to the other end of the resistor RT1, and the other end of the resistor RT2 is connected to the other end of the capacitor C1 and an 8 end of the chip U2; a 3 end of the chip U2 is connected to the other end of the resistor R01 and one end of the resistor R02, the other end of the resistor R02 is connected to the resistor R03, a 4 end of the chip U2 is connected to the other end of the resistor RS1, the other end of the resistor RS2, and the other end of the resistor RS3 respectively, a 2 end of the chip U2 is connected to one end of the resistor RF1, a 7 end of the chip U2 is configured to receive a dimming signal; one end of the resistor ER2 is connected to the other end of the resistor ER1, the other end of the resistor ER2 is connected to a positive electrode of the diode DF1, a positive electrode of the diode DF2, and one end of the resistor RF12; a second end of the voltage stabilizer Q4 is connected to the other end of the resistor RF4 and one end of the resistor RF5, a third end of the voltage stabilizer Q4 is connected to the other end of the resistor RF1, the other end of the resistor RF5, the other end of the resistor RF12, and the other end of the resistor RF13.

[0009] Specifically, the constant voltage output control circuit comprises: a capacitor CB1, a capacitor CY1, a resistor RT1, a resistor RT2, a capacitor C1, a diode D5, an inductor T1, a chip U3, a resistor R01, a resistor R02, a resistor R03, a resistor RS1, a resistor RS2, a resistor RS3, a resistor RC2, a capacitor CR1, a diode D6, a diode D7, a resistor ER1, a resistor ER2, a diode DF1, a diode DF2, a resistor RF12, a polarity capacitor EC1, a resistor RF13, a resistor RF4, a resistor RF5, a voltage stabilizer Q4, a resistor RV1, a resistor RV2, a resistor RF3, a resistor RF1, a capacitor RC1, a diode DV1 and a transistor Q3; one end of the capacitor CY1, the anode of the diode D5, one end of the resistor RT1, one end of the inductor T1, the 1 end and the 6 end of the chip U3, both ends of the capacitor CB1, one end of the capacitor C1, one end of the resistor R01, one end of the resistor RS1, one end of the resistor RS2, one end of the resistor RS3, one end of the resistor RF4, one end of the resistor RF13, the negative pole of the polarity capacitor EC1, the first end of the voltage stabilizer Q4 and one end of the resistor RV1 are connected; the other end of the capacitor CY1 is connected to the cathode of the diode D5, one end of the resistor RC2, the negative pole of the diode D6, the negative pole of the diode D7, one end of the resistor ER1 and the positive pole of the polarity capacitor EC1; the other end of the inductor T1 is connected to one end of the capacitor CR1, the anode of the diode D6, the anode of the diode D7 and the 5 end of the chip U3; the other end of the capacitor CR1 is connected to the other end of the resistor RC2; one end of the resistor RT2 is connected to the other end of the resistor RT1, and the other end of the resistor RT2 is connected to the other end of the capacitor C1 and the 8 end of the chip U3; the 3 end of the chip U3 is connected to the other end of the resistor R01 and one end of the resistor R02, the other end of the resistor R02 is connected to the resistor R03, the 4 end of the chip U3 is connected to the other end of the resistor RS1, the other end of the resistor RS2 and the other end of the resistor RS3 respectively, and the 2 end of the chip U3 is connected to one end of the resistor RF1, the negative pole of the diode DV1, one end of the capacitor RC1, one end of the resistor RF3, one end of the resistor RF5, one end of the resistor RF12, one end of the resistor RF13 and the third end of the voltage stabilizer Q4; the emitter of the transistor Q3 is connected to the other end of the capacitor RF3 and grounded, the collector of the transistor Q3 is connected to the other end of the resistor RF3, and the base of the transistor Q3 is configured to receive an IO signal; one end of the resistor ER2 is connected to the other end of the resistor ER1, and the other end of the resistor ER2 is connected to the anode of the diode DF1, the anode of the diode DF2 and the other end of the resistor RF12; the second end of the voltage stabilizer Q4 is connected to the other end of the resistor RF5 and the other end of the resistor RF4.

[0010] Specifically, the current distribution control circuit comprises: a chip U4, a chip U5, a resistor PR1, a capacitor PC1, a resistor PR2, a capacitor PC2, a MOS tube Q1, a light emitting diode LED1, a light emitting diode LED2, a resistor RS5, a resistor RS6, a resistor RS7, a resistor RS8 and a MOS tube Q2; the 1 end of the chip U4 is connected with the 2 end of the chip U4, the 1 and 2 ends of the chip U5, the constant current dimming control circuit and the constant voltage output control circuit; the 3 end of the chip U4 is connected with one end of the capacitor PC1 and one end of the resistor PR1, the other end of the capacitor PC1 is connected with the other end of the resistor PR1 and grounded, and the 3 end of the chip U4 is configured to receive a current distribution signal; the 5 end of the chip U4 is connected with the gate of the MOS tube Q1; the 6 end of the chip U4 is connected with one end of the resistor RS5, one end of the resistor RS6 and the source of the MOS tube Q1, and the drain of the MOS tube Q1 is connected with the light emitting diode LED1; the 3 end of the chip U5 is connected with one end of the capacitor PC2 and one end of the resistor PR2, the other end of the capacitor PC2 is connected with the other end of the resistor PR2 and grounded, and the 3 end of the chip U5 is configured to receive a current distribution signal; the 5 end of the chip U5 is connected with the gate of the MOS tube Q2; the 6 end of the chip U5 is connected with one end of the resistor RS7, one end of the resistor RS8 and the source of the MOS tube Q2, and the drain of the MOS tube Q2 is connected with the light emitting diode LED2.

[0011] Through the above technical means, the current distribution control circuit can output different currents to the two groups of LED light sources, so that they have different brightness and realize color temperature switching.

[0012] Specifically, the control circuit comprises: a chip P1; the chip P1 is provided with three signal output ports for outputting IO signals, current distribution control signals and dimming signals.

[0013] Specifically, it further comprises a voltage-dependent resistor VR2; the EMI and rectifier circuit is connected with the resistor RT1 and the capacitor C1 through the voltage-dependent resistor VR2.

[0014] Specifically, the dimming signal is a PWM3 signal, and the current distribution signal comprises: a PWM1 signal and a PWM2 signal; when the constant current dimming control circuit is turned on and the constant voltage output control circuit is turned off, the chip P1 outputs the PWM3 signal to the constant current dimming control circuit and outputs the PWM1 signal and the PWM2 signal to the current distribution control circuit, wherein the duty ratio of the PWM3 signal is equal to the sum of the duty ratios of the PWM1 signal and the PWM2 signal.

[0015] Specifically, when the constant current dimming control circuit is turned off and the constant voltage output control circuit is turned on, the chip P1 does not output the PWM3 signal but outputs the IO signal to the constant voltage output control circuit.

[0016] The beneficial effects of the present application are as follows:

[0017] The existing CCT control is chopping output, although the effective value of the output power and the analog output are the same, but the current peak value of the analog output is lower and has no switching loss, and has lower LED heat loss. Optimizing the CCT control mode from the chopping mode to the analog scheme can improve the light efficiency of the whole machine product (the light efficiency of the 200W light projector can be improved by 10%).

[0018] The scheme can design the current distribution control circuit as an independent control module product, which is connected to the output end of the constant voltage power supply in use, without the need to redesign the driving circuit, so as to upgrade the conventional lighting product to a dimming and color adjusting product. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain principles of the present application. Other embodiments and many of the intended advantages of the present application will be readily appreciated as the same becomes better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

[0020] Figure 1 is a circuit diagram of an EMI and rectifier circuit of a current distribution control circuit according to an embodiment of the present application;

[0021] Figure 2 is a circuit diagram of an auxiliary power supply circuit of a current distribution control circuit according to an embodiment of the present application;

[0022] Figure 3 is a circuit diagram of a constant current dimming control circuit of a current distribution control circuit according to an embodiment of the present application;

[0023] Figure 4 is a circuit diagram of a constant voltage output control circuit of a current distribution control circuit according to an embodiment of the present application;

[0024] Figure 5 is a circuit diagram of a control circuit of a current distribution control circuit according to an embodiment of the present application;

[0025] Figure 6 is a circuit diagram of a current distribution control circuit of a current distribution control circuit according to an embodiment of the present application;

[0026] Figure 7 is a work flow diagram of a control circuit of a current distribution control circuit according to an embodiment of the present application;

[0027] Figure 8 is a current waveform diagram of a current distribution control circuit according to an embodiment of the present application;

[0028] Figure 9 is a current waveform diagram using the chopping output method;

[0029] Figure 10 is a schematic diagram when a current distribution control circuit according to an embodiment of the present application selects a constant voltage mode;

[0030] Figure 11 is a schematic diagram when a current distribution control circuit according to an embodiment of the present application selects a constant current mode. DETAILED DESCRIPTION

[0031] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration illustrative embodiments in which the application can be practiced. For purposes of explanation and illustration, directional terms are used with reference to the orientation of the described figures. However, it is to be understood that the embodiments can be practiced in other orientations than those presented in the figures. The directional terms used herein refer to the orientation of the figure under discussion. Because components of embodiments can be positioned in a number of orientations, the directional terminology is used for purposes of illustration and description and is in no way limiting. It is to be understood that other embodiments can be utilized and structural or logical changes can be made without departing from the scope of the present application. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present application is defined by the appended claims.

[0032] Figure 10 is a schematic diagram when a current distribution control circuit according to an embodiment of the present application selects a constant voltage mode, Figure 11 is a schematic diagram when a current distribution control circuit according to an embodiment of the present application selects a constant current mode, in combination with Figure 10 , Figure 11 It can be known that a current distribution control circuit comprises an EMI and rectifier circuit, an auxiliary power supply circuit, a current distribution control circuit, a control circuit, a constant current dimming control circuit and a constant voltage output control circuit. An input end of the EMI and rectifier circuit is connected to an input power supply. Output ends of the EMI and rectifier circuit are connected to the auxiliary power supply circuit, the constant current dimming control circuit and the constant voltage output control circuit. An output end of the auxiliary power supply circuit is connected to the control circuit and provides a power supply for the control circuit. Output ends of the control circuit are connected to the current distribution control circuit, the constant current dimming control circuit and the constant voltage output control circuit. Output ends of the constant current dimming control circuit and the constant voltage output control circuit are respectively connected to the current distribution control circuit. The control circuit judges the conduction and the cut-off of the constant current dimming control circuit and the constant voltage output control circuit. When the constant current dimming control circuit is judged to be conducted and the constant voltage output control circuit is judged to be cut off, the control circuit outputs a dimming signal to the constant current dimming control circuit and outputs a current distribution control signal to the current distribution control circuit. When the constant current dimming control circuit is judged to be cut off and the constant voltage output control circuit is judged to be conducted, the control circuit outputs a current distribution signal to the current distribution control circuit.

[0033] Using the above-mentioned technical means, it can be connected to the output terminal of a constant current drive or a constant voltage drive to distribute the current of two LED loads. Furthermore, the control of this scheme is an analog output, which can reduce the instantaneous current flowing through the LED load and effectively improve the luminous efficacy of the LED.

[0034] Figure 1 This is a circuit diagram of an EMI and rectifier circuit for a current distribution control circuit according to an embodiment of this application, as shown below. Figure 1 As shown, the EMI and rectifier circuit includes: capacitor CX1, varistor VR1, fuse F1, common-mode inductor L1, inductor L2, resistor R1, capacitor CX2, and a rectifier diode composed of diodes D1, D2, D3, and D4; the live wire is connected to one end of capacitor CX1, one end of varistor VR1, and one end of common-mode inductor L1 through fuse F1; the neutral wire is connected to the other end of capacitor CX1, the other end of varistor VR1, and three ends of common-mode inductor L1; the rectifier diode is connected to one end of capacitor CX2, inductor L2, resistor R1, four ends of common-mode inductor L1, and the auxiliary power supply circuit; one end of resistor R1 is connected to one end of inductor L2, one end of capacitor CX2, and two ends of common-mode inductor L1, and the other end of resistor R1 is connected to the rectifier diode, the other end of capacitor CX2, four ends of common-mode inductor L1, the other end of inductor L2, and the auxiliary power supply circuit.

[0035] Figure 2 This is a circuit diagram of an auxiliary power supply circuit for a current distribution control circuit according to an embodiment of this application, such as... Figure 2 As shown, the auxiliary power supply circuit includes: fuse FR1, inductor LF1, capacitor CF1, chip U1, capacitor C4, polarized capacitor C2, polarized capacitor C3, inductor LF2, and resistor R2; the end of capacitor CF2 near the neutral wire is connected to one end of capacitor CF1 and one end of chip U1; the end of resistor R1 near the rectifier diode is connected through fuse FR1 to the other end of capacitor CF1 and one end of inductor LF1; the other end of inductor LF1 is connected to terminal 7 of chip U1; terminal 6 of chip U1 is connected to the positive terminal of polarized capacitor C2, and the negative terminal of polarized capacitor is grounded; terminal 2 of chip U1 is connected to the negative terminal of polarized capacitor C3 and one end of resistor R2; terminal 3 of chip U1 is connected to the positive terminal of polarized capacitor C3, the other end of resistor R2, and one end of inductor LF2; terminal 4 of chip U1 is connected to one end of capacitor C4, and the other end of capacitor C4 is connected to the other end of inductor LF2 and terminal 5 of chip U1.

[0036] The auxiliary power supply circuit provides a stable 3.3V voltage to the control circuit, ensuring its stable operation.

[0037] Figure 3 This is a circuit diagram of a constant current dimming control circuit according to an embodiment of the present application, such as...Figure 3 As shown, the constant current dimming control circuit comprises: a capacitor CB1, a capacitor CY1, a resistor RT1, a resistor RT2, a capacitor C1, a diode D5, an inductor coil T1, a chip U2, a resistor R01, a resistor R02, a resistor R03, a resistor RS1, a resistor RS2, a resistor RS3, a resistor RC2, a capacitor CR1, a diode D6, a diode D7, a resistor ER1, a resistor ER2, a diode DF1, a diode DF2, a resistor RF1, a resistor RF12, a polarity capacitor EC1, a resistor RF13, a resistor RF4, a resistor RF5, and a voltage stabilizer Q4; one end of the rectifier diode connected to the capacitor CY1, the positive electrode of the diode D5, one end of the resistor RT1, one end of the inductor coil T1, the 1 end and the 6 end of the chip U2, both ends of the capacitor CB1, one end of the capacitor C1, one end of the resistor R01, one end of the resistor RS1, one end of the resistor RS2, one end of the resistor RS3, one end of the resistor RF4, one end of the resistor RF13, the negative electrode of the polarity capacitor EC1, and the first end of the voltage stabilizer Q4; the other end of the capacitor CY1 is connected to the negative electrode of the diode D5, one end of the resistor RC2, the negative electrode of the diode D6, the negative electrode of the diode D7, one end of the resistor ER1, and the positive electrode of the polarity capacitor EC1; the other end of the inductor coil T1 is connected to one end of the capacitor CR1, the positive electrode of the diode D6, the positive electrode of the diode D7, and the 5 end of the chip U2; the other end of the capacitor CR1 is connected to the other end of the resistor RC2; one end of the resistor RT2 is connected to the other end of the resistor RT1, and the other end of the resistor RT2 is connected to the other end of the capacitor C1 and the 8 end of the chip U2; the 3 end of the chip U2 is connected to the other end of the resistor R01 and one end of the resistor R02, the other end of the resistor R02 is connected to the resistor R03, the 4 end of the chip U2 is connected to the other end of the resistor RS1, the other end of the resistor RS2, and the other end of the resistor RS3 respectively, the 2 end of the chip U2 is connected to one end of the resistor RF1, and the 7 end of the chip U2 is configured to receive a dimming signal; one end of the resistor ER2 is connected to the other end of the resistor ER1, and the other end of the resistor ER2 is connected to the positive electrode of the diode DF1, the positive electrode of the diode DF2, and one end of the resistor RF12; the second end of the voltage stabilizer Q4 is connected to the other end of the resistor RF4 and one end of the resistor RF5, and the third end of the voltage stabilizer Q4 is connected to the other end of the resistor RF1, the other end of the resistor RF5, the other end of the resistor RF12, and the other end of the resistor RF13.

[0038] Figure 4 is a constant voltage output control circuit of a current distribution control circuit according to an embodiment of the present application, like Figure 4As shown, the constant voltage output control circuit includes: a capacitor CB1, a capacitor CY1, a resistor RT1, a resistor RT2, a capacitor C1, a diode D5, an inductor coil T1, a chip U3, a resistor R01, a resistor R02, a resistor R03, a resistor RS1, a resistor RS2, a resistor RS3, a resistor RC2, a capacitor CR1, a diode D6, a diode D7, a resistor ER1, a resistor ER2, a diode DF1, a diode DF2, a resistor RF12, a polarity capacitor EC1, a resistor RF13, a resistor RF4, a resistor RF5, a voltage stabilizer Q4, a resistor RV1, a resistor RV2, a resistor RF3, a resistor RF1, a capacitor RC1, a diode DV1 and a triode Q3; one end of the rectifier diode connected to the capacitor CY1, the positive electrode of the diode D5, one end of the resistor RT1, one end of the inductor coil T1, the 1 end and the 6 end of the chip U3, both ends of the capacitor CB1, one end of the capacitor C1, one end of the resistor R01, one end of the resistor RS1, one end of the resistor RS2, one end of the resistor RS3, one end of the resistor RF4, one end of the resistor RF13, the negative electrode of the polarity capacitor EC1, the first end of the voltage stabilizer Q4 and one end of the resistor RV1; the other end of the capacitor CY1 is connected to the negative electrode of the diode D5, one end of the resistor RC2, the negative electrode of the diode D6, the negative electrode of the diode D7, one end of the resistor ER1 and the positive electrode of the polarity capacitor EC1; the other end of the inductor coil T1 is connected to one end of the capacitor CR1, the positive electrode of the diode D6, the positive electrode of the diode D7 and the 5 end of the chip U3; the other end of the capacitor CR1 is connected to the other end of the resistor RC2; one end of the resistor RT2 is connected to the other end of the resistor RT1, and the other end of the resistor RT2 is connected to the other end of the capacitor C1 and the 8 end of the chip U3; the 3 end of the chip U3 is connected to the other end of the resistor R01 and one end of the resistor R02, the other end of the resistor R02 is connected to the resistor R03, the 4 end of the chip U3 is connected to the other end of the resistor RS1, the other end of the resistor RS2, the other end of the resistor RS3 respectively, the 2 end of the chip U3 is connected to one end of the resistor RF1, the negative electrode of the diode DV1, one end of the capacitor RC1, one end of the resistor RF3, one end of the resistor RF5, one end of the resistor RF12, one end of the resistor RF13 and the third end of the voltage stabilizer Q4; the emitter of the triode Q3 is connected to the other end of the capacitor RF3 and grounded, the collector of the triode Q3 is connected to the other end of the resistor RF3, and the base of the triode Q3 is configured to receive an IO signal; one end of the resistor ER2 is connected to the other end of the resistor ER1, and the other end of the resistor ER2 is connected to the positive electrode of the diode DF1, the positive electrode of the diode DF2 and the other end of the resistor RF12; the second end of the voltage stabilizer Q4 is connected to the other end of the resistor RF5 and the other end of the resistor RF4.

[0039] Figure 6 is a current distribution control circuit of a current distribution control circuit according to an embodiment of the present application, as Figure 6As shown, the current distribution control circuit comprises: chip U4, chip U5, resistor PR1, capacitor PC1, resistor PR2, capacitor PC2, MOS tube Q1, light emitting diode LED1, light emitting diode LED2, resistor RS5, resistor RS6, resistor RS7, resistor RS8 and MOS tube Q2; the 1 end of chip U4 is connected with the 2 end of chip U4, the 1 and 2 ends of chip U5, the constant current dimming control circuit and the constant voltage output control circuit; the 3 end of chip U4 is connected with one end of capacitor PC1 and one end of resistor PR1, the other end of capacitor PC1 is connected with the other end of resistor PR1 and grounded, and the 3 end of chip U4 is configured to receive a current distribution signal; the 5 end of chip U4 is connected with the gate of MOS tube Q1; the 6 end of chip U4 is connected with one end of resistor RS5, one end of resistor RS6 and the source of MOS tube Q1, and the drain of MOS tube Q1 is connected with light emitting diode LED1; the 3 end of chip U5 is connected with one end of capacitor PC2 and one end of resistor PR2, the other end of capacitor PC2 is connected with the other end of resistor PR2 and grounded, and the 3 end of chip U5 is configured to receive a current distribution signal; the 5 end of chip U5 is connected with the gate of MOS tube Q2; the 6 end of chip U5 is connected with one end of resistor RS7, one end of resistor RS8 and the source of MOS tube Q2, and the drain of MOS tube Q2 is connected with light emitting diode LED2.

[0040] Through the above technical means, the current distribution control circuit can output different currents to the two groups of LED light sources, so that they have different brightness and realize color temperature switching.

[0041] Figure 5 is a circuit diagram of a control circuit of a current distribution control circuit according to an embodiment of the application, as shown in the figure, Figure 5 As shown, the control circuit comprises: chip P1; chip P1 is provided with three signal output ports for outputting IO signal, current distribution control signal and dimming signal.

[0042] Specifically, it further comprises a pressure sensitive resistor VR2; the EMI and rectifier circuit is connected with resistor RT1 and capacitor C1 through the pressure sensitive resistor VR2.

[0043] Figure 7 is a working flow chart of a control circuit of a current distribution control circuit according to an embodiment of the application, as shown in the figure, Figure 7 As shown, the dimming signal is PWM3 signal, the current distribution signal comprises: PWM1 signal and PWM2 signal; when the constant current dimming control circuit is turned on and the constant voltage output control circuit is turned off, chip P1 outputs PWM3 to the constant current dimming control circuit, and outputs PWM1 signal and PWM2 signal to the current distribution control circuit, wherein the duty ratio of PWM3 signal is equal to the sum of the duty ratios of PWM1 signal and PWM2 signal.

[0044] Specifically, when the constant current dimming control circuit is off and the constant voltage output control circuit is on, the chip P1 does not output the PWM3 signal but outputs the IO signal to the constant voltage output control circuit.

[0045] Embodiment:

[0046] Figure 8 is a current waveform diagram of a current distribution control circuit according to an embodiment of the present application, Figure 9 is a current waveform diagram of a current distribution control circuit according to an embodiment of the present application, Figure 8 and Figure 9 It can be seen from the diagram that Irms1 = ILED1, Irms2 = ILED2, and Irms = ILED1 + ILED2. It can be known from the characteristics of the LED light source that the greater the current flowing through the LED, the lower the light efficiency of the LED.

[0047] When the chopping control output current is adopted, the waveform diagram of the chopping output at each moment is compared:

[0048] Taking the PWM3 as an example, at the moment of t0-t1, Iout = 0; at the moment of t1-t2, Iout = the current peak value, at this moment, the LED works under the condition of the maximum current Iout, and the output light efficiency is the lowest. The present scheme adopts the analog output mode Figure 8 ), and the actual output is the analog current ILED1. The continuous constant output current can make the LED output higher light efficiency, thereby improving the overall light efficiency.

[0049] Further, in combination with Figure 11 and Figure 7 The working logic of each circuit in the constant current dimming circuit is as follows: PWM1 is the front-stage constant current dimming control signal, PWM1 / PWM2 is the rear-stage distribution current signal, the current distribution control circuit outputs the corresponding current according to the PWM3 signal, at the moment of PWM3 = X%, PWM1 + PWM2 = X%, and the output current Iout of the constant current dimming control circuit is equal to the sum of Iled1 + Iled2. The color temperature control is realized by the proportional control of Iled1 and Iled2. The low standby power consumption is realized by turning off PWM1, PWM2 and PWM3 in standby mode. At the same time, the output end makes voltage feedback VFB1 / VFB2, and the output voltage signal is fed back to the FB pin of the front-stage IC, so as to realize the real-time adjustment of the output voltage and realize high efficiency.

[0050] In combination with Figure 10 and Figure 7The working logic of each circuit in the constant voltage circuit is as follows: PWM1 / PWM2 is a current signal allocated by a rear stage, and the module current allocation control circuit outputs corresponding current according to the PWM1 / PWM2 signal. The color temperature is realized by controlling the proportion of Iled1 and Iled2; the standby is realized by turning off PWM1 and PWM2, and the low standby power consumption is realized by increasing the IO pin to pull down the FB signal; meanwhile, the output end is made of voltage feedback VFB1 / VFB2, the output voltage signal is fed back to the FB pin of the front stage IC, and the output voltage is adjusted in real time to realize high efficiency.

[0051] Obviously, those skilled in the art can make various modifications and changes to the embodiments of the present application without departing from the spirit and scope of the present application. In this way, if these modifications and changes are within the scope of the claims of the present application and their equivalents, the present application also aims to cover these modifications and changes. The word "comprises" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are described in mutually different dependent claims does not mean that the combination of these measures cannot be used to advantage. Any reference signs in the claims should not be considered as limiting the scope.

Claims

1. A current distribution control circuit, characterized in that, include: EMI and rectifier circuit, auxiliary power supply circuit, current distribution control circuit, control circuit, constant current dimming control circuit and constant voltage output control circuit; The input terminal of the EMI and rectifier circuit is connected to the input power supply, and the output terminal of the EMI and rectifier circuit is connected to the auxiliary power supply circuit, the constant current dimming control circuit, and the constant voltage output control circuit; the output terminal of the auxiliary power supply circuit is connected to the control circuit and provides power to the control circuit; the output terminal of the control circuit is connected to the current distribution control circuit, the constant current dimming control circuit, and the constant voltage output control circuit; the output terminals of the constant current dimming control circuit and the constant voltage output control circuit are respectively connected to the current distribution control circuit. The control circuit determines whether the constant current dimming control circuit and the constant voltage output control circuit are on or off. When the constant current dimming control circuit is on and the constant voltage output control circuit is off, the control circuit outputs a dimming signal to the constant current dimming control circuit and a current distribution control signal to the current distribution control circuit. When the constant current dimming control circuit is off and the constant voltage output control circuit is on, the control circuit outputs a current distribution signal to the current distribution control circuit. The current distribution control circuit includes: chip U4, chip U5, resistor PR1, capacitor PC1, resistor PR2, capacitor PC2, MOSFET Q1, LED1, LED2, resistor RS5, resistor RS6, resistor RS7, resistor RS8, and MOSFET Q2. Terminal 1 of chip U4 is connected to terminal 2 of chip U4, terminals 1 and 2 of chip U5, the constant current dimming control circuit, and the constant voltage output control circuit. Terminal 3 of chip U4 is connected to one end of capacitor PC1 and one end of resistor PR1. The other end of capacitor PC1 is connected to the other end of resistor PR1 and grounded. Terminal 3 of chip U4 is configured to receive the current distribution signal. Terminal 5 of chip U4 is connected to the gate of MOSFET Q1. Terminal 6 of chip U4 is connected to one end of resistor RS5, one end of resistor RS6, and the source of MOSFET Q1. The drain of MOSFET Q1 is connected to LED1. Terminal 3 of chip U5 is connected to one end of capacitor PC2 and one end of resistor PR2. The other end of capacitor PC2 is connected to the other end of resistor PR2 and grounded. Terminal 3 of chip U5 is configured to receive the current distribution signal. Terminal 5 of chip U5 is connected to the gate of MOSFET Q2. Terminal 6 of chip U5 is connected to one end of resistor RS7, one end of resistor RS8, and the source of MOSFET Q2. The drain of MOSFET Q2 is connected to LED2.

2. The current distribution control circuit according to claim 1, characterized in that, The EMI and rectifier circuit includes: capacitor CX1, varistor VR1, fuse F1, common-mode inductor L1, inductor L2, resistor R1, capacitor CX2, and a rectifier diode composed of diodes D1, D2, D3, and D4; the live wire is connected to one end of capacitor CX1, one end of varistor VR1, and one end of common-mode inductor L1 through fuse F1; the neutral wire is connected to the other end of capacitor CX1, the other end of varistor VR1, and one end of common-mode inductor L1; the rectifier diode is connected to capacitor CX2, inductor L2, resistor R1, one end of common-mode inductor L1, and the auxiliary power supply circuit; one end of resistor R1 is connected to one end of inductor L2, one end of capacitor CX2, and one end of common-mode inductor L1, and the other end of resistor R1 is connected to the rectifier diode, the other end of capacitor CX2, one end of common-mode inductor L1, the other end of inductor L2, and the auxiliary power supply circuit.

3. The current distribution control circuit according to claim 2, characterized in that, The auxiliary power supply circuit includes: fuse FR1, inductor LF1, capacitor CF1, chip U1, capacitor C4, polarized capacitor C2, polarized capacitor C3, inductor LF2, and resistor R2; the end of capacitor CF2 near the neutral wire is connected to one end of capacitor CF1 and one end of chip U1; the end of resistor R1 near the rectifier diode is connected to the other end of capacitor CF1 and one end of inductor LF1 through fuse FR1; the other end of inductor LF1 is connected to... Terminal 7 of chip U1 is connected to the positive terminal of polarized capacitor C2, and the negative terminal of polarized capacitor C2 is grounded. Terminal 2 of chip U1 is connected to the negative terminal of polarized capacitor C3 and one end of resistor R2. Terminal 3 of chip U1 is connected to the positive terminal of polarized capacitor C3, the other end of resistor R2, and one end of inductor LF2. Terminal 4 of chip U1 is connected to one end of capacitor C4, and the other end of capacitor C4 is connected to the other end of inductor LF2 and terminal 5 of chip U1.

4. The current distribution control circuit according to claim 2, characterized in that, The constant current dimming control circuit includes: capacitor CB1, capacitor CY1, resistor RT1, resistor RT2, capacitor C1, diode D5, inductor T1, chip U2, resistor R01, resistor R02, resistor R03, resistor RS1, resistor RS2, resistor RS3, resistor RC2, capacitor CR1, diode D6, diode D7, resistor ER1, resistor ER2, diode DF1, diode DF2, resistor RF1, resistor RF12, polarized capacitor EC1, resistor RF13, resistor RF4, resistor RF5, and voltage regulator Q4; the rectifier diode is connected to one end of capacitor CY1, the positive terminal of diode D5, and the resistor... One end of RT1, one end of the inductor T1, terminals 1 and 6 of the chip U2, both ends of the capacitor CB1, one end of the capacitor C1, one end of the resistor R01, one end of the resistor RS1, one end of the resistor RS2, one end of the resistor RS3, one end of the resistor RF4, one end of the resistor RF13, the negative terminal of the polarized capacitor EC1, and the first terminal of the voltage regulator Q4; the other end of the capacitor CY1 is connected to the negative terminal of the diode D5, one end of the resistor RC2, the negative terminal of the diode D6, the negative terminal of the diode D7, one end of the resistor ER1, and the positive terminal of the polarized capacitor EC1; the inductor The other end of coil T1 is connected to one end of capacitor CR1, the positive terminal of diode D6, the positive terminal of diode D7, and terminal 5 of chip U2; the other end of capacitor CR1 is connected to the other end of resistor RC2; one end of resistor RT2 is connected to the other end of resistor RT1, and the other end of resistor RT2 is connected to the other end of capacitor C1 and terminal 8 of chip U2; terminal 3 of chip U2 is connected to the other end of resistor R01 and one end of resistor R02, the other end of resistor R02 is connected to resistor R03, and terminal 4 of chip U2 is connected to the other ends of resistor RS1 and resistor RS2 respectively. The other end of resistor RS3, pin 2 of chip U2 is connected to one end of resistor RF1, and pin 7 of chip U2 is configured to receive the dimming signal; one end of resistor ER2 is connected to the other end of resistor ER1, and the other end of resistor ER2 is connected to the positive terminal of diode DF1, the positive terminal of diode DF2, and one end of resistor RF12; the second end of voltage regulator Q4 is connected to the other end of resistor RF4 and one end of resistor RF5, and the third end of voltage regulator Q4 is connected to the other end of resistor RF1, the other end of resistor RF5, the other end of resistor RF12, and the other end of resistor RF13.

5. A current distribution control circuit according to claim 2, characterized in that, The constant voltage output control circuit includes: capacitor CB1, capacitor CY1, resistor RT1, resistor RT2, capacitor C1, diode D5, inductor T1, chip U3, resistor R01, resistor R02, resistor R03, resistor RS1, resistor RS2, resistor RS3, resistor RC2, capacitor CR1, diode D6, diode D7, resistor ER1, resistor ER2, diode DF1, diode DF2, resistor RF12, polarized capacitor EC1, resistor RF13, resistor RF4, resistor RF5, voltage regulator Q4, resistor RV1, resistor RV2, resistor RF3, resistor RF1, capacitor RC1, diode DV1, and transistor Q3; the rectifier diode is connected to one end of capacitor CY1. The following terminals are connected to the following: the positive terminal of diode D5, one end of resistor RT1, one end of inductor T1, terminals 1 and 6 of chip U3, both ends of capacitor CB1, one end of capacitor C1, one end of resistor R01, one end of resistor RS1, one end of resistor RS2, one end of resistor RS3, one end of resistor RF4, one end of resistor RF13, the negative terminal of polarized capacitor EC1, the first terminal of voltage regulator Q4, and one end of resistor RV1; the other end of capacitor CY1 is connected to the negative terminal of diode D5, one end of resistor RC2, the negative terminal of diode D6, the negative terminal of diode D7, one end of resistor ER1, and the positive terminal of polarized capacitor EC1. The inductor T1 is connected to one end of the capacitor CR1, the positive terminal of the diode D6, the positive terminal of the diode D7, and terminal 5 of the chip U3; the other end of the capacitor CR1 is connected to the other end of the resistor RC2; one end of the resistor RT2 is connected to the other end of the resistor RT1, and the other end of the resistor RT2 is connected to the other end of the capacitor C1 and terminal 8 of the chip U3; terminal 3 of the chip U3 is connected to the other end of the resistor R01 and one end of the resistor R02, the other end of the resistor R02 is connected to the resistor R03, and terminal 4 of the chip U3 is connected to the other ends of the resistors RS1, RS2, and RS3 respectively. Two terminals of chip U3 are connected to one terminal of resistor RF1, the cathode of diode DV1, one terminal of capacitor RC1, one terminal of resistor RF3, one terminal of resistor RF5, one terminal of resistor RF12, one terminal of resistor RF13, and the third terminal of voltage regulator Q4; the emitter of transistor Q3 is connected to the other terminal of capacitor RF3 and grounded, the collector of transistor Q3 is connected to the other terminal of resistor RF3, and the base of transistor Q3 is configured to receive I / O signals; one terminal of resistor ER2 is connected to the other terminal of resistor ER1, and the other terminal of resistor ER2 is connected to the anode of diode DF1, the anode of diode DF2, and the other terminal of resistor RF12;The second terminal of the voltage regulator Q4 is connected to the other terminal of the resistor RF5 and the other terminal of the resistor RF4.

6. The current distribution control circuit according to claim 1, characterized in that, The control circuit includes a chip P1; the chip P1 is provided with three signal output ports for outputting I / O signals, current distribution control signals and dimming signals.

7. A current distribution control circuit according to any one of claims 4 or 5, characterized in that, It also includes a varistor VR2; the EMI and rectifier circuit is connected to the resistor RT1 and the capacitor C1 through the varistor VR2.

8. A current distribution control circuit according to claim 6, characterized in that, The dimming signal is a PWM3 signal, and the current distribution signal includes a PWM1 signal and a PWM2 signal. When the constant current dimming control circuit is turned on and the constant voltage output control circuit is turned off, the chip P1 outputs the PWM3 signal to the constant current dimming control circuit and the PWM1 signal and the PWM2 signal to the current distribution control circuit, wherein the duty cycle of the PWM3 signal is equal to the sum of the duty cycles of the PWM1 signal and the PWM2 signal.

9. A current distribution control circuit according to claim 8, characterized in that, When the constant current dimming control circuit is turned off and the constant voltage output control circuit is turned on, the chip P1 does not output the PWM3 signal but outputs an IO signal to the constant voltage output control circuit.

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