Composite control circuit capable of deep dimming

Abstract

The utility model relates to a composite control circuit capable of deep dimming, which comprises a constant current control chip circuit, a voltage sampling circuit, a push-pull circuit of which one end is electrically connected with the constant current control chip circuit and the other end is electrically connected with a switching circuit, and a choking coil of which one end is electrically connected with the switching circuit and the other end is electrically connected with an output circuit, one end of the current sampling circuit is electrically connected with the switching circuit, the other end of the current sampling circuit is electrically connected with the filter circuit, and the other end of the filter circuit is electrically connected with the current feedback end. One end of the first dimming circuit is electrically connected with a first signal pin of the single chip microcomputer, and the other end of the first dimming circuit is electrically connected with a brightness signal input end of the constant-current control chip circuit; one end of the second dimming circuit is electrically connected with a current feedback end, and the other end of the second dimming circuit is electrically connected with a second signal pin of the single chip microcomputer. According to the scheme, the second dimming circuit creatively changes the current feedback end signal of the constant current control chip, so that the constant current control chip is further adjusted to achieve lower brightness, and the whole-course stroboflash-free dimming is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of lamps and lanterns products especially, relates to a compound control circuit of depth dimming. BACKGROUND

[0002] With the popularization and market acceptance of intelligent lighting product application, the demand of intelligent lighting product individualization and customization is more and more obvious. With the improvement of the cognition of the public to LED dimming, the problem of the delicate degree of LED lamp dimming, dimming depth and no flicker is proposed.

[0003] However, the existing dimming scheme on the market still has technical defects: such as dimming is not smooth, dimming depth is insufficient (for example: brightness can only be adjusted in the range of 100% to 5%, and the brightness cannot be further reduced from 5% to 0.1%), and cannot meet the problem of full-range no flicker. It seriously affects the experience of users and cannot meet the expectations of the public for intelligent LED lamps.

[0004] In order to overcome the above shortcomings, the present scheme provides a compound control circuit capable of deep dimming. INVENTION CONTENTS

[0005] The purpose of the utility model is to solve the problem of the existing dimming scheme, such as dimming is not smooth, dimming depth is insufficient, and cannot meet the problem of full-range no flicker. The specific solution is as follows:

[0006] A compound control circuit capable of deep dimming, comprising: a constant current control chip circuit, one end of which is electrically connected with a first power supply end, and the other end is electrically connected with a voltage sampling end of the constant current control chip circuit; a voltage sampling circuit electrically connected with the voltage sampling end of the constant current control chip circuit; a push-pull circuit electrically connected with one end of the constant current control chip circuit and the other end of the switch circuit; a choke coil electrically connected with one end of the switch circuit and the other end of the output circuit; a current sampling circuit electrically connected with one end of the switch circuit and the other end of the filter circuit; and the other end of the filter circuit is electrically connected with a current feedback end of the constant current control chip circuit. Further comprising a first dimming circuit electrically connected with one end of a first signal pin of a single-chip microcomputer and the other end of a brightness signal input end of the constant current control chip circuit; and a second dimming circuit electrically connected with one end of the current feedback end and the other end of a second signal pin of the single-chip microcomputer. The constant current control chip circuit and the push-pull circuit are electrically connected with a second power supply end, the single-chip microcomputer and the second dimming circuit are electrically connected with a third power supply end, and the switch circuit and the output circuit are electrically connected with the first power supply end.

[0007] Further, the constant current control chip circuit comprises: a constant current control chip U3, a 2-pin of the constant current control chip U3 is a voltage sampling end, a 7-pin of the constant current control chip U3 is electrically connected with a second power supply end Vcc and one end of a capacitor C20, a 5-pin of the constant current control chip U3 and the other end of the capacitor C20 are grounded, a 1-pin of the constant current control chip U3 is a brightness signal input end, a 3-pin of the constant current control chip U3 is a current feedback end, an 8-pin of the constant current control chip U3 is electrically connected with a 4-pin of the constant current control chip U3 and one end of a capacitor C28 through a resistor R38, the other end of the capacitor C28 is grounded, and a 6-pin of the constant current control chip U3 is electrically connected with one end of a resistor R37.

[0008] Further, the voltage sampling circuit comprises: a resistor R30 having one end electrically connected with the first power supply end 60V, the other end of the resistor R30 is electrically connected with one end of a resistor R31, the other end of the resistor R31 is electrically connected with the 2-pin of the constant current control chip U3 and one end of a resistor R32 at the same time, and the other end of the resistor R32 is grounded.

[0009] Further, the push-pull circuit comprises: bases of triodes Q5 and Q6 which are electrically connected with the other end of the resistor R37 at the same time, emitters of the triodes Q5 and Q6 which are electrically connected with one end of a resistor R40 at the same time, a collector of the triode Q5 which is electrically connected with the second power supply end Vcc through a resistor R39, and a collector of the triode Q6 which is grounded.

[0010] Further, the switch circuit comprises: a gate of a MOS tube Q7 which is electrically connected with the other end of the resistor R40, a drain of the MOS tube Q7 which is electrically connected with a positive electrode of a freewheeling diode D11 and one end of a choke coil L5 at the same time, and a negative electrode of the freewheeling diode D11 which is electrically connected with the first power supply end 60V.

[0011] Further, the output circuit comprises: one end of a capacitor C22 and a first coil of a common mode inductor L6 which are electrically connected with the first power supply end 60V at the same time, the other end of the capacitor C22 and a second coil of the common mode inductor L6 which are electrically connected with the other end of the choke coil L5 at the same time, the other end of the first coil of the common mode inductor L6 which is electrically connected with one end of a resistor R42 and a 2-pin of an LED socket at the same time, and the other end of the second coil of the common mode inductor L6 which is electrically connected with the other end of the resistor R42 and a 1-pin of the LED socket at the same time.

[0012] Further, the current sampling circuit comprises: one end of resistors R45, R46 and R47 which are electrically connected with a source of the MOS tube Q7 at the same time, and the other end of the resistors R45, R46 and R47 which are grounded at the same time. The filter circuit comprises: one end of a resistor R48 which is electrically connected with one end of the resistors R45, R46 and R47, and the other end of the resistor R48 which is electrically connected with one end of a capacitor C23 and a 3-pin of the constant current control chip U3 at the same time, and the other end of the capacitor C23 which is grounded.

[0013] Further, the single-chip microcomputer comprises a single-chip microcomputer chip U4, a 4-pin of the single-chip microcomputer chip U4 is a first signal pin PWM1, a 2-pin of the single-chip microcomputer chip U4 is a second signal pin PWM2, a 9-pin of the single-chip microcomputer chip U4 is electrically connected with a third power supply end 5V and one end of a capacitor C25 at the same time, a 7-pin of the single-chip microcomputer chip U4 and the other end of the capacitor C25 are grounded at the same time.

[0014] Further, the first light adjusting circuit comprises one end of a resistor R50 electrically connected with the 4-pin of the single-chip microcomputer chip U4, the other end of the resistor R50 is electrically connected with a capacitor C24 and one end of a resistor R51 at the same time, the other end of the resistor R51 is electrically connected with a 1-pin of a constant current control chip U3 and one end of a resistor R52 at the same time, the capacitor C24 and the other end of the resistor R52 are grounded at the same time.

[0015] Further, the second light adjusting circuit comprises one end of a resistor R55 electrically connected with the 2-pin of the single-chip microcomputer chip U4, the other end of the resistor R55 is electrically connected with a capacitor C27 and one end of a resistor R56 at the same time, the other end of the resistor R56 is electrically connected with a positive input 3-pin of an operational amplifier chip U5A, a negative input 2-pin of the operational amplifier chip U5A is electrically connected with an output 1-pin of the operational amplifier chip U5A, a 5-pin of the operational amplifier chip U5A is electrically connected with the third power supply end 5V, the other end of the capacitor C27 and a 4-pin of the operational amplifier chip U5A are grounded at the same time, the output 1-pin of the operational amplifier chip U5A is electrically connected with a positive electrode of an isolation diode D113, a negative electrode of the isolation diode D113 is electrically connected with one end of a resistor R57, the other end of the resistor R57 is electrically connected with a 3-pin of the constant current control chip U3.

[0016] In conclusion, the technical scheme of the utility model has the following beneficial effects:

[0017] The first light adjusting circuit and the second light adjusting circuit are provided, and the depth control problem of light adjusting from 5% to 0.1% is solved. The integral circuit is arranged in the first light adjusting circuit and the second light adjusting circuit, so that the light adjusting is smooth and continuous, and the frequency flicker phenomenon is avoided. The filter circuit, the choke coil and the common mode inductor are added, so that the high frequency interference in the circuit is further eliminated, and the light is more stable and flicker-free. When the light is adjusted from 100% to 5%, the light is adjusted by the first light adjusting circuit, and when the light is adjusted from 5% to 0.1%, the first light adjusting circuit is kept at 5% analog level, and the second light adjusting circuit continues to adjust the light to achieve the depth light adjusting from 5% to 0.1%. The second light adjusting circuit changes the current feedback signal of the constant current control chip (that is, the current feedback amplitude is increased to further reduce the light output), so that the constant current control chip is further adjusted to a lower light. The second light adjusting signal intervenes in the current detection signal of the constant current control chip, and does not affect the frequency flicker-free light of the constant current control chip kept at 5% analog level by the first light adjusting signal, so that the lower light adjusting and the frequency flicker-free light adjusting are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0019] Fig. 1 The block diagram of the composite control circuit capable of deep light adjusting of the present application;

[0020] Fig. 2 The circuit diagram of the composite control circuit capable of deep light adjusting of the present application, which does not include the second light adjusting circuit and the single-chip microcomputer part;

[0021] Fig. 3 The circuit diagram of the second light adjusting circuit of the present application;

[0022] Fig. 4 The circuit diagram of the single-chip microcomputer of the present application. DETAILED DESCRIPTION

[0023] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0024] As shown in the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application. Figs. 1 to 4 A composite control circuit capable of deep dimming, comprising: a constant current control chip circuit, a voltage sampling circuit electrically connected to one end of the constant current control chip circuit and the voltage sampling end of the constant current control chip circuit, a push-pull circuit electrically connected to one end of the constant current control chip circuit and the other end of the switch circuit, a choke coil electrically connected to one end of the switch circuit and the other end of the output circuit, a current sampling circuit electrically connected to one end of the switch circuit and the other end of the filter circuit, and the other end of the filter circuit electrically connected to the current feedback end of the constant current control chip circuit. Further comprising a first dimming circuit electrically connected to one end of the first signal pin of the single-chip microcomputer and the brightness signal input end of the constant current control chip circuit, and a second dimming circuit electrically connected to one end of the current feedback end and the second signal pin of the single-chip microcomputer. The constant current control chip circuit and the push-pull circuit are electrically connected to the second power supply end (for example, the second power supply end adopts Vcc=12V voltage), the single-chip microcomputer and the second dimming circuit are electrically connected to the third power supply end (for example, the third power supply end adopts 5V voltage), and the switch circuit and the output circuit are electrically connected to the first power supply end. The output circuit is electrically connected to the LED lamp circuit (not shown in the drawings).

[0025] Specifically, the constant current control chip circuit comprises: a constant current control chip U3, the 2-pin of the constant current control chip U3 is the voltage sampling end, the 7-pin of the constant current control chip U3 is electrically connected to the second power supply end Vcc and one end of the capacitor C20, the 5-pin of the constant current control chip U3 and the other end of the capacitor C20 are grounded, the 1-pin of the constant current control chip U3 is the brightness signal input end, the 3-pin of the constant current control chip U3 is the current feedback end, the 8-pin of the constant current control chip U3 is electrically connected to the 4-pin of the constant current control chip U3 and one end of the capacitor C28 through the resistor R38, the other end of the capacitor C28 is grounded, and the 6-pin (brightness control pin) of the constant current control chip U3 is electrically connected to one end of the resistor R37. The resistor R38 and the capacitor C28 form an RC circuit, and by setting the parameters thereof, the switching frequency and the maximum output duty cycle of the 6-pin of the constant current control chip U3 can be set.

[0026] The model of the constant current control chip U3 is HVLED002 or AAC243. The constant current control chip U3 belongs to the prior art, and will not be described in detail here.

[0027] Specifically, the voltage sampling circuit comprises a resistor R30 having one end electrically connected to the first power supply end 60V, the other end of the resistor R30 electrically connected to one end of a resistor R31, the other end of the resistor R31 electrically connected to the 2th pin of the constant current control chip U3 and one end of a resistor R32, the other end of the resistor R32 grounded.

[0028] Specifically, the push-pull circuit comprises the bases of transistors Q5 and Q6 electrically connected to the other end of a resistor R37, the emitters of the transistors Q5 and Q6 electrically connected to one end of a resistor R40, the collector of the transistor Q5 electrically connected to the second power supply end Vcc through a resistor R39, and the collector of the transistor Q6 grounded. The transistor Q5 is an NPN transistor, which can be of the S8050 type. The transistor Q6 is a PNP transistor, which can be of the S8550 type.

[0029] Specifically, the switch circuit comprises the gate of a MOS transistor Q7 electrically connected to the other end of the resistor R40, the drain of the MOS transistor Q7 electrically connected to the anode of a freewheeling diode D11 and one end of a choke coil L5, and the cathode of the freewheeling diode D11 electrically connected to the first power supply end 60V. The MOS transistor Q7 is an N-channel MOS transistor, which is preferably of the FIR15N10 type.

[0030] Specifically, the output circuit comprises one end of a capacitor C22 and one end of a common-mode inductor L6 electrically connected to the first power supply end 60V, the other end of the capacitor C22 and one end of a second coil of the common-mode inductor L6 electrically connected to the other end of the choke coil L5, the other end of the first coil of the common-mode inductor L6 electrically connected to one end of a resistor R42 and the 2th pin of an LED socket, and the other end of the second coil of the common-mode inductor L6 electrically connected to the other end of the resistor R42 and the 1th pin of the LED socket.

[0031] Specifically, the current sampling circuit comprises one end of resistors R45, R46 and R47 electrically connected to the source of the MOS transistor Q7, and the other ends of the resistors R45, R46 and R47 grounded.

[0032] Specifically, the filter circuit comprises one end of a resistor R48 electrically connected to one end of the resistors R45, R46 and R47, the other end of the resistor R48 electrically connected to one end of a capacitor C23 and the 3th pin of the constant current control chip U3, and the other end of the capacitor C23 grounded.

[0033] Specifically, the single-chip microcomputer includes a single-chip microcomputer chip U4, a 4-pin of the single-chip microcomputer chip U4 is a first signal pin PWM1, a 2-pin of the single-chip microcomputer chip U4 is a second signal pin PWM2, a 9-pin of the single-chip microcomputer chip U4 is electrically connected with a third power supply end 5V and one end of a capacitor C25, a 7-pin of the single-chip microcomputer chip U4 and the other end of the capacitor C25 are grounded. The model of the single-chip microcomputer chip U4 is preferably STM8S103F3P6, and can also be replaced by NDA102FC1 or HC89S003F4P6NND. Since the single-chip microcomputer chip U4 is prior art, it is not described in detail here. PWM is the abbreviation of Pulse width modulation, which means pulse width modulation. The first signal pin PWM1 and the second signal pin PWM2 both emit pulse width modulation waveforms, which are prior art.

[0034] Specifically, the first light adjusting circuit includes one end of a resistor R50 electrically connected with the 4-pin (i.e. PWM1) of the single-chip microcomputer chip U4, the other end of the resistor R50 is electrically connected with a capacitor C24 and one end of a resistor R51, the other end of the resistor R51 is electrically connected with a 1-pin of a constant current control chip U3 and one end of a resistor R52, the capacitor C24 and the other end of the resistor R52 are grounded.

[0035] Specifically, the second light adjusting circuit includes one end of a resistor R55 electrically connected with the 2-pin (i.e. PWM2) of the single-chip microcomputer chip U4, the other end of the resistor R55 is electrically connected with a capacitor C27 and one end of a resistor R56, the other end of the resistor R56 is electrically connected with a positive input 3-pin of an operational amplifier chip U5A, a negative input 2-pin of the operational amplifier chip U5A is electrically connected with an output 1-pin of the operational amplifier chip U5A, a 5-pin of the operational amplifier chip U5A is electrically connected with the third power supply end 5V, the other end of the capacitor C27 and a 4-pin of the operational amplifier chip U5A are grounded, the output 1-pin of the operational amplifier chip U5A is electrically connected with a positive electrode of an isolation diode D113, a negative electrode of the isolation diode D113 is electrically connected with one end of a resistor R57, the other end of the resistor R57 is electrically connected with a 3-pin (i.e. current feedback end, corresponding to DIM-L in the figure) of the constant current control chip U3. The model of the operational amplifier chip U5A is LM2904 or LM358.

[0036] The light adjusting principle of the scheme is briefly described as follows:

[0037] After the circuit is normally powered on, the 4th pin of the single-chip microcomputer chip U4 outputs PWM1 high level, the 2nd pin of the U4 outputs PWM2 low level, after the constant current control chip circuit receives the PWM1 and PWM2 signals, through the push-pull circuit, the switching circuit, the choke coil and the output circuit, the LED lamp product reaches the maximum brightness. The dimming is divided into two stages: (1) the first dimming stage from 100% to 5%: PWM2 outputs low level, PWM1 is adjusted from 100% to 5% (decreasing amplitude signal) to dim down, and the output circuit is adjusted from 100% brightness to 5% brightness. Specifically, the PWM1 signal becomes a direct current level signal through the integration circuit composed of the resistor R50 and the capacitor C24, and then the direct current level signal provides a suitable first dimming signal for the 1st pin of the constant current control chip U3 through the voltage dividing circuit composed of the resistors R51 and R52. (2) the second dimming stage from 5% to 0.1%: PWM1 is in the 5% brightness state and does not change, PWM2 is adjusted from 0% to 5% (increasing amplitude signal) to adjust up (the purpose of further reducing the brightness output is achieved by artificially increasing the current feedback amplitude), and the output circuit is adjusted from 5% brightness to 0.1% brightness. Specifically, the PWM2 signal becomes a direct current level signal through the integration circuit composed of the resistor R55 and the capacitor C27, the direct current level signal is provided to the positive input 3rd pin of the operational amplifier chip U5A, the negative input 2nd pin of the operational amplifier chip U5A is directly connected to the output 1st pin of the operational amplifier chip U5A, and the direct current level signal is output by the operational amplifier chip by using the voltage follower principle and the high resistance state of the operational amplifier chip. After the isolation diode D113 (the diode reverse blocking characteristic does not affect the sampling current signal of the constant current control chip U3, that is, the current feedback signal), the resistor R57 provides the 3rd pin (current feedback end) of the constant current control chip U3 with the second dimming signal level through the voltage dividing circuit composed of the resistor R57, the resistor R48 and the resistors R45 / R46 / R47. After the constant current control chip U3 receives the level, the brightness of the LED lamp product is further adjusted to 0.1% in the direction.

[0038] The working principle of the push-pull circuit and the switching circuit of the present scheme is as follows:

[0039] The push-pull circuit is set to solve the problem that the 8-pin output of the constant current control chip U3 is weak and cannot normally switch the MOS tube Q7. The push-pull circuit takes power from the external power supply (i.e. Vcc) to provide sufficient energy for the normal switching of the MOS tube. (1) When the 6-pin output of the constant current control chip U3 is high, the voltage is transmitted to the base of the transistor Q5 and provides a bias current, the transistor Q5 is turned on, and the Vcc voltage is transmitted to the gate of the MOS tube Q7 through the current limiting resistor R40 to drive the MOS tube to turn on. (2) When the 6-pin output of the constant current control chip U3 is low, the base of the transistor Q5 is low, the Q5 is not turned on, and the Vcc cannot continue to supply power to the MOS tube Q7, so the MOS tube Q7 will enter the cut-off state. The MOS tube Q7 has a parasitic capacitor, which causes the gate voltage of the MOS tube to slowly decrease. At this time, because the transistor Q6 is a PNP tube, the emitter voltage of Q6 is higher than the base voltage, Q6 is turned on, and the voltage at the gate of the MOS tube Q7 is quickly released through Q6. Thus, the MOS tube Q7 is quickly turned off.

[0040] In summary, the technical scheme of the utility model has the following beneficial effects:

[0041] The first light adjusting circuit and the second light adjusting circuit are used in the scheme, and the control depth problem of light adjusting from 5% to 0.1% is solved. The integral circuit is arranged in the first light adjusting circuit and the second light adjusting circuit, so that the light adjusting is smooth and continuous, and no frequency flicker phenomenon occurs. The filter circuit, the choke coil and the common mode inductor are added, so that the high frequency interference in the circuit is further eliminated, and the light is more stable and has no flicker. When the light is adjusted from 100% to 5%, the light is adjusted by the first light adjusting circuit, when the light is adjusted from 5% to 0.1%, the first light adjusting circuit is kept at 5% analog level, and the second light adjusting circuit continues to adjust the light to achieve the purpose of depth light adjusting from 5% to 0.1%. The second light adjusting circuit of the scheme changes the current feedback end signal of the constant current control chip (i.e. the current feedback amplitude is increased by the second light adjusting circuit to further reduce the light output purpose), so that the constant current control chip is further adjusted to a lower light. The second light adjusting signal interferes with the current detection signal of the constant current control chip, and does not affect the frequency flicker-free light in the first light adjusting signal keeping 5% analog level, so that the lower light adjusting brightness and the full-range frequency flicker-free light adjusting are achieved.

[0042] The above-mentioned embodiments do not constitute a limitation on the protection scope of the technical scheme. Any modification, equivalent replacement and improvement within the spirit and principles of the above-mentioned embodiments shall be included in the protection scope of the technical scheme.

Claims

1. A compound control circuit for deep dimming, characterized by, The application relates to a constant current control chip circuit, a voltage sampling circuit, a push-pull circuit, a choke coil, a current sampling circuit, a first dimming circuit, a second dimming circuit and a single-chip microcomputer. The constant current control chip circuit comprises a constant current control chip U3, the 2-pin of the constant current control chip U3 is a voltage sampling end, the 7-pin of the constant current control chip U3 is electrically connected with a second power supply end Vcc and one end of a capacitor C20, the 5-pin of the constant current control chip U3 and the other end of the capacitor C20 are grounded, the 1-pin of the constant current control chip U3 is a brightness signal input end, the 3-pin of the constant current control chip U3 is a current feedback end, the 8-pin of the constant current control chip U3 is electrically connected with the 4-pin of the constant current control chip U3 and one end of a capacitor C28 through a resistor R38, the other end of the capacitor C28 is grounded, and the 6-pin of the constant current control chip U3 is electrically connected with one end of a resistor R37.

2. The compound control circuit according to claim 1, wherein, The voltage sampling circuit comprises a resistor R30, one end of the resistor R30 is electrically connected with the first power supply end 60V, the other end of the resistor R30 is electrically connected with one end of a resistor R31, the other end of the resistor R31 is electrically connected with the 2-pin of the constant current control chip U3 and one end of a resistor R32 at the same time, and the other end of the resistor R32 is grounded.

3. The compound control circuit according to claim 2, wherein, The push-pull circuit comprises bases of triodes Q5 and Q6 which are electrically connected with the other end of the resistor R37 at the same time, emitters of the triodes Q5 and Q6 which are electrically connected with one end of a resistor R40 at the same time, a collector of the triode Q5 which is electrically connected with the second power supply end Vcc through a resistor R39, and a collector of the triode Q6 which is grounded.

4. The compound control circuit according to claim 3, wherein, The switch circuit comprises a gate of a MOS tube Q7 which is electrically connected with the other end of the resistor R40, a drain of the MOS tube Q7 which is electrically connected with a positive electrode of a freewheeling diode D11 and one end of a choke coil L5 at the same time, and a negative electrode of the freewheeling diode D11 which is electrically connected with the first power supply end 60V.

5. The compound control circuit according to claim 4, wherein, ​ 6. The compound control circuit for deep dimming according to claim 5, wherein, The output circuit comprises one end of a capacitor C22 and one end of a first coil of a common-mode inductor L6 which are electrically connected with a first power supply end 60V at the same time, the other end of the capacitor C22 and one end of a second coil of the common-mode inductor L6 which are electrically connected with the other end of the choke coil L5 at the same time, the other end of the first coil of the common-mode inductor L6 which is electrically connected with one end of a resistor R42 and a 2-pin of an LED socket at the same time, and the other end of the second coil of the common-mode inductor L6 which is electrically connected with the other end of the resistor R42 and a 1-pin of the LED socket at the same time.

7. The compound control circuit for deep dimming according to claim 6, wherein: The current sampling circuit comprises one end of resistors R45, R46 and R47 which are electrically connected with a source electrode of a MOS transistor Q7, and the other end of the resistors R45, R46 and R47 which are grounded at the same time; and the filter circuit comprises one end of a resistor R48 which is electrically connected with one end of the resistors R45, R46 and R47, and the other end of the resistor R48 which is electrically connected with one end of a capacitor C23 and a 3-pin of a constant current control chip U3 at the same time, and the other end of the capacitor C23 which is grounded.

8. The compound control circuit for deep dimming according to claim 7, wherein: The single-chip microcomputer comprises a single-chip microcomputer chip U4, a 4-pin of the single-chip microcomputer chip U4 is a first signal pin PWM1, a 2-pin of the single-chip microcomputer chip U4 is a second signal pin PWM2, a 9-pin of the single-chip microcomputer chip U4 is electrically connected with a third power supply end 5V and one end of a capacitor C25 at the same time, and a 7-pin of the single-chip microcomputer chip U4 and the other end of the capacitor C25 are grounded at the same time.

9. The compound control circuit for deep dimming according to claim 8, wherein: The first light adjusting circuit comprises one end of a resistor R50 which is electrically connected with the 4-pin of the single-chip microcomputer chip U4, and the other end of the resistor R50 which is electrically connected with one end of a capacitor C24 and one end of a resistor R51 at the same time, and the other end of the resistor R51 which is electrically connected with one end of a resistor R52 and a 1-pin of the constant current control chip U3 at the same time, and the other end of the capacitor C24 and the resistor R52 which are grounded at the same time.

10. The compound control circuit for deep dimming according to claim 9, wherein: The second light adjusting circuit comprises one end of a resistor R55 which is electrically connected with the 2-pin of the single-chip microcomputer chip U4, and the other end of the resistor R55 which is electrically connected with one end of a capacitor C27 and one end of a resistor R56 at the same time, and the other end of the resistor R56 which is electrically connected with a positive input 3-pin of an operational amplifier chip U5A, and a negative input 2-pin of the operational amplifier chip U5A which is electrically connected with an output 1-pin of the operational amplifier chip U5A, and a 5-pin of the operational amplifier chip U5A which is electrically connected with the third power supply end 5V, and the other end of the capacitor C27 which is grounded at the same time with a 4-pin of the operational amplifier chip U5A, and the output 1-pin of the operational amplifier chip U5A which is electrically connected with a positive electrode of an isolation diode D113, and one end of a resistor R57 which is electrically connected with a negative electrode of the isolation diode D113, and the other end of the resistor R57 which is electrically connected with the 3-pin of the constant current control chip U3.

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