Voltage tracking secondary drive circuit and lighting device

Abstract

The utility model provides a voltage tracking secondary drive circuit and a lighting device, and relates to the technical field of lighting drive circuits. The boosting module is connected with the output end of the rectifying module; the voltage regulating module is connected with the output end of the boosting module; the first voltage detection module is connected with the input end of the boosting module; the second voltage detection module is connected with the output end of the boosting module; and the feedback control module is respectively connected with the first voltage detection module, the second voltage detection module and the controlled end of the boosting module. The feedback signal is generated according to the voltage difference between the input voltage and the output voltage of the boosting module, so that the output voltage of the boosting module changes along with the input voltage, normal work of the boosting module is guaranteed, the output voltage of the boosting module is reduced as much as possible, switching loss is reduced, and efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lighting drive circuits, and in particular to a voltage tracking secondary drive circuit and a lighting device. Background Art

[0002] With the improvement of living standards, LED lighting is increasingly used in many scenarios. In LED lighting drive circuits, a two-stage topology architecture of boost circuit and voltage regulator circuit is widely used. The boost circuit part of the front stage boosts the voltage, and the voltage regulator circuit part of the rear stage adjusts the boost output voltage to a voltage range suitable for the operation of the lighting device.

[0003] Since the output voltage of the boost circuit cannot be too low, normal operation requires a minimum voltage difference between the input voltage and the output voltage, that is, the output voltage of the boost circuit needs to exceed the minimum voltage difference threshold of the input voltage. In the prior art, considering the fluctuation of the mains power grid, the AC voltage provided by the grid is 220V±20%, that is, the maximum AC fluctuation error is 264V, and the peak voltage of 264V AC is 264×√2=373V. In addition to the minimum voltage difference threshold, the output voltage of the boost circuit is usually set at 400V DC to ensure that the boost circuit can work normally.

[0004] However, the switching loss of the switch tube will increase as the voltage increases. When the output voltage of the boost circuit is set at a higher value, the switch tubes in the boost circuit and the voltage regulation circuit will have higher switching losses, resulting in increased energy loss, which is not conducive to improving efficiency. Utility Model Content

[0005] The utility model provides a voltage tracking secondary driving circuit and a lighting device, which are used to solve the defects of large power loss and low efficiency of the secondary driving circuit in the prior art.

[0006] The utility model provides a voltage tracking secondary drive circuit, comprising:

[0007] A rectifier module, the input end of which is used to be connected to the mains;

[0008] A boost module connected to the output end of the rectifier module;

[0009] A voltage regulating module connected to the output end of the boost module;

[0010] A first voltage detection module connected to the input end of the boost module;

[0011] A second voltage detection module connected to the output end of the boost module;

[0012] A feedback control module is respectively connected to the first voltage detection module, the second voltage detection module and the controlled end of the boost module, and the feedback control module is used to generate a feedback signal according to the voltage difference between the first voltage detected by the first voltage detection module and the second voltage detected by the second voltage detection module, and the feedback signal is used to adjust the output voltage of the boost module.

[0013] According to a voltage tracking secondary drive circuit provided by the utility model, the feedback control module includes a first control unit and a filtering unit, the first control unit is respectively connected to the first voltage detection module, the second voltage detection module and the input end of the filtering unit, and the output end of the filtering unit is connected to the controlled end of the boost module.

[0014] According to a voltage tracking secondary drive circuit provided by the utility model, the boost module includes a power factor correction boost circuit and a second control unit, the input end of the power factor correction boost circuit is respectively connected to the output end of the rectifier module and the first voltage detection module, the output end of the power factor correction boost circuit is respectively connected to the voltage regulation module and the second voltage detection module, and the second control unit is connected to the controlled end of the power factor correction boost circuit.

[0015] According to a voltage tracking secondary drive circuit provided by the utility model, the power factor correction boost circuit includes a boost inductor, a switch tube, a first diode and a filter capacitor E, one end of the boost inductor is respectively connected to the rectifier module and the first voltage detection module, the other end of the boost inductor is respectively connected to one end of the switch tube and the anode of the first diode, the cathode of the first diode is respectively connected to the voltage regulation module and one end of the filter capacitor E, the other end of the switch tube and the other end of the filter capacitor E are grounded, and the second control unit is connected to the controlled end of the switch tube.

[0016] According to a voltage tracking secondary drive circuit provided by the utility model, the boost module also includes a current detection unit, the current detection unit is connected to the power factor correction boost circuit, the second control unit is connected to the current detection unit, and the second control unit controls the switch tube to be turned on or off when the detection current of the current detection unit is zero.

[0017] According to a voltage tracking secondary drive circuit provided by the utility model, the current detection unit includes a coupling inductor and a current limiting resistor, the coupling inductor is coupled with the boost inductor, one end of the coupling inductor is connected to the second control unit through the current limiting resistor, and the other end of the coupling inductor is grounded.

[0018] According to a voltage tracking secondary drive circuit provided by the utility model, the filtering unit includes a first resistor, a second resistor, a third resistor, a first capacitor and a second capacitor, one end of the first resistor is connected to the first control unit, the other end of the first resistor is respectively connected to one end of the second resistor and one end of the first capacitor, the other end of the second resistor is respectively connected to one end of the third resistor and one end of the second capacitor, the other end of the third resistor is connected to the controlled end of the boost module, and the other end of the first capacitor and the other end of the second capacitor are grounded.

[0019] According to a voltage tracking secondary drive circuit provided by the utility model, the first voltage detection module includes a second diode, a third capacitor, a fourth resistor and a fifth resistor, the anode of the second diode is connected to the input end of the boost module, the cathode of the second diode is respectively connected to one end of the third capacitor and one end of the fourth resistor, the other end of the fourth resistor is respectively connected to one end of the fifth resistor and the feedback control module, and the other end of the third capacitor and the other end of the fifth resistor are grounded.

[0020] According to a voltage tracking secondary drive circuit provided by the utility model, the second voltage detection module includes a sixth resistor and a seventh resistor, one end of the sixth resistor is connected to the output end of the boost module, the other end of the sixth resistor is respectively connected to the feedback control module and one end of the seventh resistor, and the other end of the seventh resistor is grounded.

[0021] The utility model also provides a lighting device, comprising: the above-mentioned voltage tracking secondary driving circuit, and also comprising a lighting component, and the output end of the voltage regulating module is connected to the lighting component.

[0022] The utility model provides a voltage tracking secondary drive circuit and lighting device, which have at least the following beneficial effects: the rectifier module rectifies the input AC power and outputs it to the boost module of the front stage, the boost module boosts the input electrical signal after rectification and converts it into high-voltage direct current, and then the boost module outputs the high-voltage direct current to the voltage regulating module of the rear stage, the voltage regulating module adjusts the high-voltage direct current to a suitable voltage range and then forms a driving electrical signal and outputs it to the load, thereby realizing the driving function. At the same time, the first voltage detection module detects the input voltage of the boost module, that is, the first voltage is transmitted to the feedback control module, the second voltage detection module detects the output voltage of the boost module, that is, the second voltage is transmitted to the feedback control module, and the feedback control module generates a corresponding feedback signal according to the voltage difference between the first voltage and the second voltage, so that the boost module adjusts the output voltage, that is, the size of the second voltage, under the action of the feedback signal, thereby maintaining the voltage difference between the first voltage and the second voltage within a suitable range. In this way, by generating a feedback signal according to the voltage difference between the input voltage and the output voltage of the boost module, the output voltage of the boost module follows the input voltage changes to achieve the effect of voltage tracking. While ensuring the normal operation of the boost module, the output voltage of the boost module is minimized as much as possible, which is conducive to reducing switching losses and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a structural block diagram of a voltage tracking secondary drive circuit provided by the utility model;

[0025] Figure 2 This is a circuit diagram of one embodiment of a voltage tracking secondary drive circuit provided by the utility model;

[0026] Figure 3 The utility model provides a circuit diagram of another embodiment of a voltage tracking secondary drive circuit.

[0027] Reference numerals:

[0028] Rectification module 100; boost module 200; power factor correction boost circuit 210; second control unit 220; current detection unit 230; voltage regulation module 300; first voltage detection module 400; second voltage detection module 500; feedback control module 600; first control unit 610; filtering unit 620. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] Combine the following Figure 1-Figure 3 A voltage tracking secondary drive circuit of the present application is described, comprising:

[0031] A rectifier module 100, wherein the input end of the rectifier module 100 is used to be connected to the mains;

[0032] A boost module 200 connected to the output end of the rectifier module 100;

[0033] A voltage regulating module 300 connected to the output end of the boost module 200;

[0034] A first voltage detection module 400 connected to an input end of the boost module 200;

[0035] A second voltage detection module 500, connected to the output end of the boost module 200;

[0036] The feedback control module 600 is respectively connected to the first voltage detection module 400, the second voltage detection module 500 and the controlled end of the boost module 200. The feedback control module 600 is used to generate a feedback signal according to the voltage difference between the first voltage detected by the first voltage detection module 400 and the second voltage detected by the second voltage detection module 500. The feedback signal is used to adjust the output voltage of the boost module 200.

[0037] The rectifier module 100 rectifies the input AC power and outputs it to the boost module 200 of the front stage. The boost module 200 boosts the rectified input electrical signal and converts it into high-voltage direct current. Then the boost module 200 outputs the high-voltage direct current to the voltage regulating module 300 of the rear stage. The voltage regulating module 300 adjusts the high-voltage direct current to a suitable voltage range and then forms a driving electrical signal to output to the load to achieve the driving function. At the same time, the first voltage detection module 400 detects the input voltage of the boost module 200, that is, the first voltage is transmitted to the feedback control module 600, and the second voltage detection module 500 detects the output voltage of the boost module 200, that is, the second voltage is transmitted to the feedback control module 600. The feedback control module 600 generates a corresponding feedback signal according to the voltage difference between the first voltage and the second voltage, so that the boost module 200 adjusts the output voltage, that is, the size of the second voltage, under the action of the feedback signal, so that the voltage difference between the first voltage and the second voltage can be maintained within a suitable range.

[0038] Compared with the solution with a fixed output voltage of 400V, the present application generates a feedback signal according to the voltage difference between the input voltage and the output voltage of the boost module 200, so that the output voltage of the boost module 200 follows the input voltage change, achieving the effect of voltage tracking. While ensuring the normal operation of the boost module 200, the output voltage of the boost module 200 is minimized, which is conducive to reducing switching losses and improving efficiency. In areas with lower mains voltage, such as areas with 120V or 110V AC mains, the effect of reducing switch tube losses and improving efficiency is more obvious and effective.

[0039] refer to Figure 2 and Figure 3 The subsequent voltage regulating module 300 may be an implementation of a circuit including an isolated flyback voltage regulating circuit, a non-isolated flyback voltage regulating circuit, a buck voltage regulating circuit, etc., to achieve the function of adjusting the output voltage of the boost module 200 so that the final driving voltage meets the rated operating voltage requirement of the lighting component.

[0040] It is understandable that the boost module 200 and the voltage regulating module 300 include switch tubes, which may be integrated in the chip. Figure 2 In some embodiments of the present application, when the voltage regulating module 300 adopts a flyback voltage regulating circuit, the flyback control chip in the flyback voltage regulating circuit can be a chip with a model number of BP3337D and an internally integrated switch tube. The rectifier module 100 can be an implementation method including a rectifier bridge chip or a rectifier bridge circuit formed by four diodes to realize rectification of the input mains power.

[0041] refer to Figure 2 and Figure 3In some embodiments of a voltage tracking secondary drive circuit of the present application, the feedback control module 600 includes a first control unit 610 and a filtering unit 620, the first control unit 610 is respectively connected to the first voltage detection module 400, the second voltage detection module 500 and the input end of the filtering unit 620, the output end of the filtering unit 620 is connected to the controlled end of the boost module 200, and the first control unit 610 is used to generate a pulse width modulation signal according to the voltage difference between the first voltage of the first voltage detection module 400 and the second voltage of the second voltage detection module 500.

[0042] The first control unit 610 generates a pulse width modulation (PWM) signal of a corresponding duty cycle according to the voltage difference between the first voltage and the second voltage. After the PWM signal is filtered by the filtering unit 620, a stable feedback DC signal is formed, and the voltage of the feedback DC signal corresponds to the duty cycle of the PWM signal. The boost module 200 adjusts the output voltage according to the voltage of the feedback DC signal, so that the output voltage of the boost module 200 and the voltage difference between the output voltage are maintained within a set range. In this way, the feedback adjustment of the input and output voltage difference of the boost module 200 is realized through the PWM signal. Since the PWM signal can accurately control the duty cycle, it is conducive to forming a more accurate feedback DC signal. At the same time, the method of filtering the PWM signal to form a corresponding feedback DC signal is conducive to simplifying the circuit structure because it does not require a device or circuit to directly generate a feedback DC signal of a corresponding voltage according to the voltage difference between the first voltage and the second voltage.

[0043] After filtering, the PWM signal forms a DC with an average voltage. Therefore, the duty cycle of the PWM signal has a linear relationship with the voltage of the feedback DC signal. For ease of understanding, let's take an example: assuming that the high level of the PWM signal is 3.3V and the low level is 0V, the voltage of the feedback DC signal V fb =D×3.3, where D is the duty cycle. When the duty cycle D=100%, V fb =3.3V, D = 0% when V fb =0V, based on the linear relationship between duty cycle and feedback DC signal voltage, it can achieve stepless voltage regulation between 0V and 3V, and more accurately form the feedback DC signal V fb Transmitted to the controlled end of the boost module 200.

[0044] The first control unit 610 may be implemented as a single-chip microcomputer, an embedded chip, or the like. In the embodiment including a single-chip microcomputer, the single-chip microcomputer may be a model having an ADC sampling function and a PWM signal output function.

[0045] In some embodiments of the present application, the feedback control module 600 may also include a subtraction circuit formed by an integrated operational amplifier, the first voltage detection module 400 is connected to the first input terminal of the subtraction circuit, the second voltage detection module 500 is connected to the second input terminal of the subtraction circuit, the output terminal of the subtraction circuit is connected to the controlled terminal of the boost module 200, and the output voltage value of the subtraction circuit is determined by the difference between the voltage at the first input terminal and the voltage at the second input terminal. In this embodiment, a feedback DC signal of a corresponding voltage magnitude can be directly generated according to the voltage difference between the first voltage and the second voltage.

[0046] refer to Figure 2 and Figure 3 In some embodiments of a voltage tracking secondary drive circuit of the present application, the boost module 200 includes a power factor correction boost circuit 210 and a second control unit 220, the input end of the power factor correction boost circuit 210 is respectively connected to the output end of the rectifier module 100 and the first voltage detection module 400, the output end of the power factor correction boost circuit 210 is respectively connected to the voltage regulation module 300 and the second voltage detection module 500, and the second control unit 220 is connected to the controlled end of the power factor correction boost circuit 210.

[0047] Under the control of the second control unit 220, the power factor correction (PFC) boost circuit reduces the phase difference between the voltage and the current to improve the power factor while boosting the voltage. The second control unit 220 controls the output voltage of the PFC boost circuit according to the feedback DC signal generated by the feedback control module 600, so as to achieve the effect of making the voltage difference between the input voltage and the output voltage of the PFC boost circuit within a set range.

[0048] The second control unit 220 may be an implementation including a PFC control chip, a single-chip microcomputer and other devices, and may control the output voltage of the PFC boost circuit according to the feedback signal of the feedback control module 600. In some embodiments of the present application, the PFC control chip included in the second control unit 220 may be a chip model such as PFC IC BP2628, MP44018, MP44014, ST6562A, etc.

[0049] refer to Figure 2 and Figure 3In some embodiments of a voltage tracking secondary drive circuit of the present application, the power factor correction boost circuit 210 includes a boost inductor, a switch tube Q1, a first diode D2 and a filter capacitor EC1, one end of the boost inductor is respectively connected to the rectifier module 100 and the first voltage detection module 400, the other end of the boost inductor is respectively connected to one end of the switch tube Q1 and the anode of the first diode D2, the cathode of the first diode D2 is respectively connected to the voltage regulation module 300 and one end of the filter capacitor EC1, the other end of the switch tube Q1 and the other end of the filter capacitor EC1 are grounded, and the second control unit 220 is connected to the controlled end of the switch tube Q1.

[0050] The boost inductor, the switch tube Q1, the first diode D2 and the filter capacitor EC1 form a Boost circuit. The second control unit 220 controls the switch tube Q1 to be turned on and off, so that the boost inductor and the filter capacitor EC1 are charged and discharged, thereby realizing the boost function and achieving the effect of power factor correction.

[0051] In some embodiments of the present application, the power factor correction boost circuit 210 may also include an active PFC boost circuit, such as a full-bridge PFC circuit, a flyback PFC circuit, etc. The switch tube Q1 may be implemented as a MOS tube, an IGBT tube, or other device.

[0052] refer to Figure 2 and Figure 3 In some embodiments of a voltage tracking secondary drive circuit of the present application, the boost module 200 also includes a current detection unit 230, the current detection unit 230 is connected to the power factor correction boost circuit 210, the second control unit 220 is connected to the current detection unit 230, and the second control unit 220 controls the switch tube Q1 to be turned on or off when the detection current of the current detection unit 230 is zero.

[0053] The current of the PFC boost circuit is detected by the current detection unit 230 so as to control the switch tube Q1 to switch on or off when the current is zero, which is beneficial to further reduce the switching loss of the switch tube Q1 and improve the efficiency.

[0054] refer to Figure 2 and Figure 3 In some embodiments of a voltage tracking secondary drive circuit of the present application, the current detection unit 230 includes a coupled inductor and a current limiting resistor R11, the coupled inductor is coupled with the boost inductor, one end of the coupled inductor is connected to the second control unit 220 through the current limiting resistor R11, and the other end of the coupled inductor is grounded.

[0055] By coupling the coupled inductor with the boost inductor, the current change of the coupled inductor is consistent with the current change of the boost inductor, and the current of the coupled inductor forms a voltage signal through the current limiting resistor R11 and is transmitted to the second control unit 220, thereby realizing the current detection function of the boost inductor. The current limiting resistor R11 is used to limit the current size to avoid excessive current, which is beneficial to protecting the second control unit 220.

[0056] In some embodiments of the present application, the current detection unit 230 may also be a current detection circuit formed by a resistor.

[0057] refer to Figure 2 and Figure 3 In some embodiments of a voltage tracking secondary drive circuit of the present application, the filtering unit 620 includes a first resistor R5, a second resistor R6, a third resistor R7, a first capacitor C2 and a second capacitor C3, one end of the first resistor R5 is connected to the first control unit 610, the other end of the first resistor R5 is respectively connected to one end of the second resistor R6 and one end of the first capacitor C2, the other end of the second resistor R6 is respectively connected to one end of the third resistor R7 and one end of the second capacitor C3, the other end of the third resistor R7 is connected to the controlled end of the boost module 200, and the other end of the first capacitor C2 and the other end of the second capacitor C3 are grounded.

[0058] The first resistor R5 and the first capacitor C2 form a first-stage RC filter circuit, and the second resistor R6 and the second capacitor C3 form a second-stage RC filter circuit. The PWM signal generated by the first control unit 610 is filtered by the two-stage RC filter circuit to ensure that the PWM signal is converted into a feedback DC signal. The third resistor R7 can limit the current generated by the feedback DC signal to protect the controlled end of the boost module 200 and the feedback end pin of the second control unit 220.

[0059] In some embodiments of the present application, the filtering unit 620 may include only one stage of filtering circuit, or may include more than two stages of filtering circuit, depending on the filtering accuracy requirement for converting the PWM signal into the feedback DC signal.

[0060] refer to Figure 2 and Figure 3In some embodiments of a voltage tracking secondary drive circuit of the present application, the first voltage detection module 400 includes a second diode D1, a third capacitor C1, a fourth resistor R3 and a fifth resistor R4, the anode of the second diode D1 is connected to the input end of the boost module 200, the cathode of the second diode D1 is respectively connected to one end of the third capacitor C1 and one end of the fourth resistor R3, the other end of the fourth resistor R3 is respectively connected to one end of the fifth resistor R4 and the feedback control module 600, and the other end of the third capacitor C1 and the other end of the fifth resistor R4 are grounded.

[0061] The first voltage detection module 400 detects the input voltage of the boost module 200. Since the rectifier module 100 rectifies the mains power, it is usually a half-wave signal with fluctuations. By providing a third capacitor C1, the input voltage is filtered to form a more stable voltage, and then the input voltage is divided by the voltage divider circuit formed by the fourth resistor R3 and the fifth resistor R4 to convert it into a voltage range of a suitable size, forming a first voltage to be transmitted to the first control unit 610, so as to achieve the function of input voltage detection of the boost module 200. The circuit structure is simple and easy to implement. At the same time, in order to prevent the electric energy stored in the third capacitor C1 from being outputted to the boost module 200 in reverse, the second diode D1 is used to limit the flow direction of the current, which is conducive to protecting the boost module 200 and improving reliability.

[0062] refer to Figure 2 and Figure 3 In some embodiments of a voltage tracking secondary drive circuit of the present application, the second voltage detection module 500 includes a sixth resistor R8 and a seventh resistor R9, one end of the sixth resistor R8 is connected to the output end of the boost module 200, the other end of the sixth resistor R8 is respectively connected to the feedback control module 600 and one end of the seventh resistor R9, and the other end of the seventh resistor R9 is grounded.

[0063] The output of the boost module 200 is direct current. The output voltage of the boost module 200 is divided by a voltage divider circuit formed by the sixth resistor R8 and the seventh resistor R9 to convert it into a voltage range of a suitable size, forming a second voltage to be transmitted to the second control unit 220, thereby achieving the function of detecting the output voltage of the boost module 200. The circuit structure is simple and easy to implement.

[0064] The lighting device provided in the present application is described below. The lighting device described below and the voltage tracking secondary drive circuit described above can be referenced to each other.

[0065] The present application also provides a lighting device, including: the above-mentioned voltage tracking secondary drive circuit, and also including a lighting component, and the output end of the voltage regulation module 300 is connected to the lighting component.

[0066] The rectifier module 100 rectifies the input AC power and outputs it to the front-stage boost module 200. The boost module 200 boosts and converts the rectified input electrical signal into high-voltage direct current. The boost module 200 then outputs the high-voltage direct current to the rear-stage voltage regulating module 300. The voltage regulating module 300 adjusts the high-voltage direct current to a suitable voltage range and forms a driving electrical signal to output to the lighting component to drive the lighting component to perform lighting work.

[0067] At the same time, the first voltage detection module 400 detects the input voltage of the boost module 200, that is, the first voltage is transmitted to the feedback control module 600, and the second voltage detection module 500 detects the output voltage of the boost module 200, that is, the second voltage is transmitted to the feedback control module 600. The feedback control module 600 generates a corresponding feedback signal according to the voltage difference between the first voltage and the second voltage, so that the boost module 200 adjusts the output voltage, that is, the size of the second voltage, under the action of the feedback signal, so as to maintain the voltage difference between the first voltage and the second voltage within an appropriate range.

[0068] In this way, by generating a feedback signal according to the voltage difference between the input voltage and the output voltage of the boost module 200, the output voltage of the boost module 200 follows the input voltage change, thereby achieving a voltage tracking effect. While ensuring the normal operation of the boost module 200, the output voltage of the boost module 200 is minimized as much as possible, which is beneficial to reducing switching losses and improving efficiency.

[0069] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0070] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. 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 application.

Claims

1. A voltage tracking secondary drive circuit, characterized in that: include: A rectifier module, the input end of which is used to be connected to the mains; A boost module connected to the output end of the rectifier module; A voltage regulating module connected to the output end of the boost module; A first voltage detection module connected to the input end of the boost module; A second voltage detection module connected to the output end of the boost module; A feedback control module is respectively connected to the first voltage detection module, the second voltage detection module and the controlled end of the boost module, and the feedback control module is used to generate a feedback signal according to the voltage difference between the first voltage detected by the first voltage detection module and the second voltage detected by the second voltage detection module, and the feedback signal is used to adjust the output voltage of the boost module.

2. A voltage tracking secondary drive circuit according to claim 1, characterized in that: The feedback control module includes a first control unit and a filtering unit. The first control unit is respectively connected to the first voltage detection module, the second voltage detection module and the input end of the filtering unit. The output end of the filtering unit is connected to the controlled end of the boost module.

3. A voltage tracking two-stage drive circuit according to claim 1, characterized in that: The boost module includes a power factor correction boost circuit and a second control unit, the input end of the power factor correction boost circuit is respectively connected to the output end of the rectifier module and the first voltage detection module, the output end of the power factor correction boost circuit is respectively connected to the voltage regulation module and the second voltage detection module, and the second control unit is connected to the controlled end of the power factor correction boost circuit.

4. A voltage tracking two-stage drive circuit according to claim 3, characterized in that: The power factor correction boost circuit includes a boost inductor, a switch tube, a first diode and a filter capacitor. One end of the boost inductor is respectively connected to the rectifier module and the first voltage detection module, the other end of the boost inductor is respectively connected to one end of the switch tube and the anode of the first diode, the cathode of the first diode is respectively connected to the voltage regulation module and one end of the filter capacitor, the other end of the switch tube and the other end of the filter capacitor are grounded, and the second control unit is connected to the controlled end of the switch tube.

5. A voltage tracking two-stage drive circuit according to claim 4, characterized in that: The boost module also includes a current detection unit, which is connected to the power factor correction boost circuit. The second control unit is connected to the current detection unit, and the second control unit controls the switch tube to be turned on or off when the detection current of the current detection unit is zero.

6. A voltage tracking two-stage drive circuit according to claim 5, characterized in that: The current detection unit includes a coupling inductor and a current limiting resistor. The coupling inductor is coupled to the boost inductor. One end of the coupling inductor is connected to the second control unit through the current limiting resistor, and the other end of the coupling inductor is grounded.

7. A voltage tracking two-stage drive circuit according to claim 2, characterized in that: The filtering unit includes a first resistor, a second resistor, a third resistor, a first capacitor and a second capacitor, one end of the first resistor is connected to the first control unit, the other end of the first resistor is respectively connected to one end of the second resistor and one end of the first capacitor, the other end of the second resistor is respectively connected to one end of the third resistor and one end of the second capacitor, the other end of the third resistor is connected to the controlled end of the boost module, and the other end of the first capacitor and the other end of the second capacitor are grounded.

8. The voltage tracking two-stage driving circuit according to claim 1, characterized in that: The first voltage detection module includes a second diode, a third capacitor, a fourth resistor and a fifth resistor, the anode of the second diode is connected to the input end of the boost module, the cathode of the second diode is respectively connected to one end of the third capacitor and one end of the fourth resistor, the other end of the fourth resistor is respectively connected to one end of the fifth resistor and the feedback control module, and the other end of the third capacitor and the other end of the fifth resistor are grounded.

9. The voltage tracking two-stage driving circuit according to claim 1, characterized in that: The second voltage detection module includes a sixth resistor and a seventh resistor, one end of the sixth resistor is connected to the output end of the boost module, the other end of the sixth resistor is respectively connected to the feedback control module and one end of the seventh resistor, and the other end of the seventh resistor is grounded.

10. A lighting device, characterized in that: include: The voltage tracking secondary drive circuit according to any one of claims 1 to 9 further comprises a lighting component, and the output end of the voltage regulating module is connected to the lighting component.

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