Voltage-tracking two-stage driver circuit and lighting apparatus

Abstract

The present application relates to the technical field of lighting driver circuits. Provided are a voltage-tracking two-stage driver circuit and a lighting apparatus. The circuit comprises: a rectifier module; a voltage increase module, which is connected to an output end of the rectifier module; a voltage adjustment module, which is connected to an output end of the voltage increase module; a first voltage measurement module, which is connected to an input end of the voltage increase module; a second voltage measurement module, which is connected to the output end of the voltage increase module; and a feedback control module, which is respectively connected to the first voltage measurement module, the second voltage measurement module and a controlled end of the voltage increase module. A feedback signal is generated on the basis of a voltage difference between an input voltage and an output voltage of a voltage increase module, such that the output voltage of the voltage increase module varies with the input voltage, so as to ensure the normal operation of the voltage increase module and also reduce the output voltage of the voltage increase module to the greatest possible extent, thereby facilitating a reduction in a switching loss and an improvement in the efficiency.

Description

Voltage tracking secondary driving circuit and lighting device

[0001] Cross Reference to Related Applications

[0002] This application claims priority to Chinese Patent Application No. 2024207119260, filed on April 8, 2024, entitled “A Voltage Tracking Secondary Driving Circuit and Lighting Device,” and Chinese Patent Application No. 2024104177875, filed on April 8, 2024, entitled “A Voltage Tracking Secondary Driving Circuit and Lighting Device,” which are incorporated by reference herein in their entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of lighting driving circuit, in particular to a voltage tracking secondary driving circuit and lighting device. BACKGROUND

[0004] With the improvement of living standards, LED lighting is increasingly applied in many scenarios. In the LED lighting driving circuit, the secondary topology architecture of the boost circuit and the voltage regulation circuit is widely used. The boost circuit in the front stage boosts the voltage, and the voltage regulation circuit in the rear stage adjusts the output voltage of the boost circuit to a voltage range suitable for the operation of the lighting device.

[0005] Since the output voltage of the boost circuit cannot be too low, there is a minimum voltage difference between the input voltage and the output voltage for normal operation, that is, the output voltage of the boost circuit needs to exceed the minimum voltage difference threshold of the input voltage. In the traditional technology, considering the fluctuation of the power grid, the alternating current voltage provided by the power grid is 220V±20%, that is, the maximum error of the alternating current fluctuation is 264V, and the peak voltage of 264V alternating current is 264x√2=373V. In addition to the minimum voltage difference threshold, the output voltage of the boost circuit is usually set to 400V DC to ensure that the boost circuit can work normally.

[0006] However, the switching loss of the switch tube also increases as the voltage increases. In the case where the output voltage of the boost circuit is set to a high value, the switch tubes in the boost circuit and the voltage regulation circuit have high switching loss, which increases the energy loss and is not conducive to improving the efficiency. SUMMARY

[0007] The present application provides a voltage tracking secondary driving circuit and lighting device to solve the defects of large energy loss and low efficiency of the secondary driving circuit in the traditional technology.

[0008] The present application provides a voltage tracking secondary driving circuit, comprising:

[0009] a rectifier module, an input end of the rectifier module being configured to be connected with commercial power;

[0010] a boost module, an output end of the rectifier module being connected with the boost module;

[0011] a voltage regulating module, an output end of the boost module being connected with the voltage regulating module;

[0012] a first voltage detection module, an input end of the boost module being connected with the first voltage detection module;

[0013] a second voltage detection module, an output end of the boost module being connected with the second voltage detection module;

[0014] a feedback control module, the feedback control module being connected with the first voltage detection module, the second voltage detection module and a controlled end of the boost module respectively, the feedback control module being configured to generate a feedback signal according to a voltage difference between a first voltage detected by the first voltage detection module and a second voltage detected by the second voltage detection module, the feedback signal being configured to adjust an output voltage of the boost module.

[0015] According to the voltage tracking secondary drive circuit provided by the application, the feedback control module comprises a first control unit and a filter unit, the first control unit is connected with the first voltage detection module, the second voltage detection module and an input end of the filter unit respectively, an output end of the filter unit is connected with the controlled end of the boost module, and the first control unit is configured to generate a pulse width modulation signal according to the voltage difference between the first voltage of the first voltage detection module and the second voltage of the second voltage detection module.

[0016] According to the voltage tracking secondary drive circuit provided by the application, the boost module comprises a power factor correction boost circuit and a second control unit, an input end of the power factor correction boost circuit is connected with the output end of the rectifier module and the first voltage detection module respectively, an output end of the power factor correction boost circuit is connected with the voltage regulating module and the second voltage detection module respectively, and the second control unit is connected with a controlled end of the power factor correction boost circuit.

[0017] According to the voltage tracking secondary drive circuit provided by the application, the power factor correction boost circuit comprises a boost inductor, a switch tube, a first diode and a filter capacitor E, one end of the boost inductor is connected with the rectifier module and the first voltage detection module respectively, the other end of the boost inductor is connected with one end of the switch tube and an anode of the first diode respectively, a cathode of the first diode is connected with the voltage regulating module and one end of the filter capacitor E respectively, 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 with a controlled end of the switch tube.

[0018] According to the voltage tracking secondary drive circuit provided in the application, the boost module further comprises a current detection unit, the current detection unit is connected with the power factor correction boost circuit, the second control unit is connected with the current detection unit, and the second control unit controls the switch tube to be turned on or turned off according to the detection current of the current detection unit being zero.

[0019] According to the voltage tracking secondary drive circuit provided in the application, the current detection unit comprises a coupling inductor and a current limiting resistor, one end of the coupling inductor is coupled with the boost inductor, and the other end of the coupling inductor is connected with the second control unit through the current limiting resistor.

[0020] According to the voltage tracking secondary drive circuit provided in the application, the filter unit comprises a first resistor, a second resistor, a third resistor, a first capacitor and a second capacitor, one end of the first resistor is connected with the first control unit, the other end of the first resistor is connected with one end of the second resistor and one end of the first capacitor respectively, the other end of the second resistor is connected with one end of the third resistor and one end of the second capacitor respectively, the other end of the third resistor is connected with 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.

[0021] According to the voltage tracking secondary drive circuit provided in the application, the first voltage detection module comprises a second diode, a third capacitor, a fourth resistor and a fifth resistor, the anode of the second diode is connected with the input end of the boost module, the cathode of the second diode is connected with one end of the third capacitor and one end of the fourth resistor respectively, the other end of the fourth resistor is connected with one end of the fifth resistor and the feedback control module respectively, and the other end of the third capacitor and the other end of the fifth resistor are grounded.

[0022] According to the voltage tracking secondary drive circuit provided in the application, the second voltage detection module comprises a sixth resistor and a seventh resistor, one end of the sixth resistor is connected with the output end of the boost module, the other end of the sixth resistor is connected with the feedback control module and one end of the seventh resistor respectively, and the other end of the seventh resistor is grounded.

[0023] The application further provides a lighting device, comprising the voltage tracking secondary drive circuit, and further comprising a lighting member, wherein the output end of the voltage tracking secondary drive circuit is connected with the lighting member.

[0024] The application provides a voltage tracking two-stage driving circuit and a lighting device, which have at least the following beneficial effects: a rectification module rectifies an input commercial power and outputs the rectified commercial power to a front-stage boost module; the boost module converts the rectified input electrical signal into high-voltage direct current through voltage boosting; then the boost module outputs the high-voltage direct current to a rear-stage voltage regulation module; the voltage regulation module adjusts the high-voltage direct current to a suitable voltage range to form a driving electrical signal and outputs the driving electrical signal to a load, thereby realizing a driving function. Meanwhile, a first voltage detection module detects an input voltage of the boost module, i.e., a first voltage is transmitted to a feedback control module; a second voltage detection module detects an output voltage of the boost module, i.e., a second voltage is transmitted to the feedback control module; 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, i.e., the size of the second voltage, under the action of the feedback signal, and the voltage difference between the first voltage and the second voltage can be maintained in a suitable range. In this way, the feedback signal is generated according to the voltage difference between the input voltage and the output voltage of the boost module, so that the output voltage of the boost module changes with the input voltage, the voltage tracking effect is achieved, the output voltage of the boost module is minimized while ensuring the normal operation of the boost module, and the switching loss is reduced and the efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0026] FIG. 1 is a structural block diagram of a voltage tracking two-stage driving circuit according to an embodiment of the application;

[0027] FIG. 2 is a circuit diagram of one of the embodiments of the voltage tracking two-stage driving circuit according to the application;

[0028] FIG. 3 is a circuit diagram of another embodiment of the voltage tracking two-stage driving circuit according to the application.

[0029] Reference signs: rectification module 100; boost module 200; power factor correction and 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; filter unit 620. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0031] The voltage tracking secondary drive circuit of the present application is described below in combination with FIG. 1-FIG. 3, which comprises:

[0032] a rectifier module 100, an input end of the rectifier module 100 being configured to be connected with commercial power;

[0033] a boost module 200, connected with an output end of the rectifier module 100;

[0034] a voltage regulating module 300, connected with an output end of the boost module 200;

[0035] a first voltage detection module 400, connected with an input end of the boost module 200;

[0036] a second voltage detection module 500, connected with an output end of the boost module 200;

[0037] a feedback control module 600, connected with the first voltage detection module 400, the second voltage detection module 500 and a controlled end of the boost module 200 respectively, the feedback control module 600 being configured to generate a feedback signal according to a voltage difference between a first voltage detected by the first voltage detection module 400 and a second voltage detected by the second voltage detection module 500, the feedback signal being configured to adjust an output voltage of the boost module 200.

[0038] The rectifier module 100 rectifies the input commercial power and outputs to the boost module 200 in front stage, the boost module 200 converts the rectified input electrical signal into high-voltage direct current, then the boost module 200 outputs the high-voltage direct current to the voltage regulating module 300 in rear stage, the voltage regulating module 300 adjusts the high-voltage direct current to a suitable voltage range to form a drive electrical signal and outputs to a load, realizing the drive function. At the same time, the first voltage detection module 400 detects the input voltage of the boost module 200, i.e. the first voltage is transmitted to the feedback control module 600, the second voltage detection module 500 detects the output voltage of the boost module 200, i.e. 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, i.e. the size of the second voltage, under the action of the feedback signal, thereby being able to maintain the voltage difference between the first voltage and the second voltage in a suitable range.

[0039] Compared with the scheme of fixing the output voltage as 400V, the 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 changes with the input voltage, achieving the effect of voltage tracking, while ensuring the normal operation of the boost module 200, minimizing the output voltage of the boost module 200, which is beneficial to reduce the switching loss and improve the efficiency. In areas with lower mains voltage, such as areas with mains voltage of 120V and 110V, the effect of reducing switching loss and improving efficiency is more obvious and effective.

[0040] Referring to FIGS. 2 and 3, the rear-stage voltage regulating module 300 can be an embodiment including an isolated flyback voltage regulating circuit, a non-isolated flyback voltage regulating circuit, a Buck voltage regulating circuit, etc., to realize the function of adjusting the output voltage of the boost module 200 to meet the demand of the rated working voltage of the lighting element.

[0041] It can be understood that the boost module 200 and the voltage regulating module 300 include a switching tube, which can be integrated in a chip. As shown in FIG. 2, in some embodiments of the application, when the voltage regulating module 300 adopts a flyback voltage regulating circuit, a flyback control chip with a model of BP3337D internally integrated with a switching tube can be selected. The rectifier module 100 can be an embodiment including a rectifier bridge chip or a rectifier bridge circuit formed by four diodes to realize the rectification of the input mains.

[0042] Referring to FIGS. 2 and 3, in some embodiments of the voltage tracking two-stage driving circuit of the application, the feedback control module 600 includes a first control unit 610 and a filter unit 620, the first control unit 610 is connected with the first voltage detection module 400, the second voltage detection module 500 and the input end of the filter unit 620 respectively, the output end of the filter unit 620 is connected with the controlled end of the boost module 200, and the first control unit 610 is configured 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.

[0043] The first control unit 610 generates a pulse width modulation (PWM) signal corresponding to the 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 voltage of the feedback DC signal is used by the boost module 200 to adjust the output voltage, so that the voltage difference between the input and output voltages of the boost module 200 is maintained within a set range. In this way, the input and output voltage difference of the boost module 200 is adjusted by the PWM signal. Since the duty cycle of the PWM signal can be accurately controlled, a more accurate feedback DC signal can be formed. At the same time, the PWM signal is filtered to form a corresponding feedback DC signal, which simplifies the circuit structure without requiring a device or circuit to directly generate a feedback DC signal corresponding to the voltage difference between the first voltage and the second voltage.

[0044] After the PWM signal is filtered, a DC signal with an average voltage is formed. Therefore, the duty cycle of the PWM signal has a linear relationship with the voltage of the feedback DC signal. To facilitate understanding, an example is given: assuming that the high level of the PWM signal is 3.3V and the low level is 0V, then the voltage V of the feedback DC signal is fb D*3.3, where D is the duty cycle. When the duty cycle D = 100%, V fb = 3.3V, and when D = 0%, V fb = 0V. Based on the linear relationship between the duty cycle and the voltage of the feedback DC signal, stepless voltage regulation between 0V and 3V can be achieved, and a more accurate feedback DC signal V fb is transmitted to the controlled end of the boost module 200.

[0045] The first control unit 610 can be an embodiment including a single-chip microcomputer, an embedded chip, or the like. In an embodiment including a single-chip microcomputer, the single-chip microcomputer can be selected from a type having an ADC sampling function and a PWM signal output function.

[0046] In some embodiments of the present application, the feedback control module 600 can also be a subtraction operation circuit formed by an integrated operational amplifier. The first voltage detection module 400 is connected to the first input end of the subtraction operation circuit, the second voltage detection module 500 is connected to the second input end of the subtraction operation circuit, the output end of the subtraction operation circuit is connected to the controlled end of the boost module 200, and the output voltage value of the subtraction operation circuit is determined by the difference between the voltage of the first input end and the voltage of the second input end. In this embodiment, a feedback DC signal corresponding to the voltage difference between the first voltage and the second voltage can be directly generated.

[0047] Referring to FIG. 2 and FIG. 3, in some embodiments of the voltage tracking two-stage driving circuit, the boost module 200 comprises 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 connected with the output end of the rectifier module 100 and the first voltage detection module 400 respectively, the output end of the power factor correction boost circuit 210 is connected with the voltage regulating module 300 and the second voltage detection module 500 respectively, and the second control unit 220 is connected with the controlled end of the power factor correction boost circuit 210.

[0048] Under the control of the second control unit 220, the power factor correction (PFC) boost circuit reduces the phase difference between voltage and current while boosting the voltage to improve the power factor, and 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 keeping the voltage difference between the input voltage and the output voltage of the PFC boost circuit within a set range.

[0049] The second control unit 220 can be an embodiment comprising a PFC control chip, a single-chip microcomputer and the like, which can 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 comprised by the second control unit 220 can be PFC IC BP2628, MP44018, MP44014, ST6562A and the like.

[0050] Referring to FIG. 2 and FIG. 3, in some embodiments of the voltage tracking two-stage driving circuit, the power factor correction boost circuit 210 comprises a boost inductor, a switching tube Q1, a first diode D2 and a filter capacitor EC1, one end of the boost inductor is connected with the rectifier module 100 and the first voltage detection module 400 respectively, the other end of the boost inductor is connected with one end of the switching tube Q1 and the anode of the first diode D2 respectively, the cathode of the first diode D2 is connected with the voltage regulating module 300 and one end of the filter capacitor EC1 respectively, the other end of the switching tube Q1 and the other end of the filter capacitor EC1 are grounded, and the second control unit 220 is connected with the controlled end of the switching tube Q1.

[0051] The boost inductor, the switching tube Q1, the first diode D2 and the filter capacitor EC1 form a Boost circuit, and the second control unit 220 controls the switching tube Q1 to be turned on and turned off, so that the boost inductor and the filter capacitor EC1 are charged and discharged, realizing the function of voltage boosting and achieving the effect of power factor correction.

[0052] In some embodiments of the application, the power factor correction boost circuit 210 can also be a boost circuit including an active PFC boost circuit, such as a full-bridge PFC circuit, a flyback PFC circuit, etc. The switch tube Q1 can be an embodiment of a MOS tube, an IGBT tube, etc.

[0053] Referring to FIGS. 2 and 3, in some embodiments of the voltage tracking two-stage drive circuit of the application, the boost module 200 further includes a current detection unit 230, the current detection unit 230 being connected with the power factor correction boost circuit 210, the second control unit 220 being connected with the current detection unit 230, and the second control unit 220 being controlled to turn on or off the switch tube Q1 when the current detected by the current detection unit 230 is zero.

[0054] 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 between the on and off states when the current is zero, which is beneficial to further reduce the switching loss of the switch tube Q1 and improve the efficiency.

[0055] Referring to FIGS. 2 and 3, in some embodiments of the voltage tracking two-stage drive circuit of the application, the current detection unit 230 includes a coupling inductor and a current limiting resistor R11, the coupling inductor being coupled with the boost inductor, one end of the coupling inductor being connected with the second control unit 220 through the current limiting resistor R11, and the other end of the coupling inductor being grounded.

[0056] The coupling inductor is coupled with the boost inductor, the current change of the coupling inductor is consistent with the current change of the boost inductor, the current of the coupling inductor forms a voltage signal through the current limiting resistor R11 and transmits to the second control unit 220, and the current detection function of the boost inductor is realized. The current limiting resistor R11 is configured to limit the current size to avoid excessive current, which is beneficial to protect the second control unit 220.

[0057] In some embodiments of the application, the current detection unit 230 can also be a current detection circuit formed by a resistor.

[0058] Referring to FIG. 2 and FIG. 3, in some embodiments of the voltage tracking secondary drive circuit, the filter 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 connected to one end of the second resistor R6 and one end of the first capacitor C2, respectively. The other end of the second resistor R6 is connected to one end of the third resistor R7 and one end of the second capacitor C3, respectively. The other end of the third resistor R7 is connected to the controlled end of the boost module 200. The other end of the first capacitor C2 and the other end of the second capacitor C3 are grounded.

[0059] 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, thereby protecting the controlled end of the boost module 200 and the feedback end of the second control unit 220.

[0060] In some embodiments of the present application, the filter unit 620 can also include only a first-stage filter circuit or more than two stages of filter circuits, depending on the filtering accuracy requirement of converting the PWM signal into the feedback DC signal.

[0061] Referring to FIG. 2 and FIG. 3, in some embodiments of the voltage tracking secondary drive circuit, 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 connected to one end of the third capacitor C1 and one end of the fourth resistor R3, respectively. The other end of the fourth resistor R3 is connected to one end of the fifth resistor R4 and the feedback control module 600, respectively. The other end of the third capacitor C1 and the other end of the fifth resistor R4 are grounded.

[0062] The first voltage detection module 400 detects the input voltage of the voltage boosting module 200. Since the rectifier module 100 rectifies the mains to form a half-wave signal with fluctuations, the third capacitor C1 is arranged to filter the input voltage to form a more stable voltage, and then the fourth resistor R3 and the fifth resistor R4 form a voltage dividing circuit to divide the input voltage to convert to a suitable voltage range, and the first voltage is transmitted to the first control unit 610, so as to achieve the function of detecting the input voltage of the voltage boosting module 200. The circuit structure is simple and easy to implement. At the same time, in order to avoid the reverse output of the electric energy stored in the third capacitor C1 to the voltage boosting module 200, the second diode D1 is arranged to limit the flow direction of the current, which is beneficial to protect the voltage boosting module 200 and improve the reliability.

[0063] Referring to FIGS. 2 and 3, in some embodiments of the voltage tracking two-stage driving circuit provided in 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 with the output end of the voltage boosting module 200, and the other end of the sixth resistor R8 is connected with the feedback control module 600 and one end of the seventh resistor R9, respectively. The other end of the seventh resistor R9 is grounded.

[0064] The voltage boosting module 200 outputs a direct current, and the sixth resistor R8 and the seventh resistor R9 form a voltage dividing circuit to divide the output voltage of the voltage boosting module 200 to convert to a suitable voltage range, and the second voltage is transmitted to the second control unit 220, so as to achieve the function of detecting the output voltage of the voltage boosting module 200. The circuit structure is simple and easy to implement.

[0065] The lighting device provided in the present application is described below. The lighting device described below can be correspondingly referred to the voltage tracking two-stage driving circuit described above.

[0066] The present application also provides a lighting device, which includes the voltage tracking two-stage driving circuit described above, and further includes a lighting member. The output end of the voltage regulating module 300 is connected with the lighting member.

[0067] The rectifier module 100 rectifies the input mains to output to the front-stage voltage boosting module 200. The voltage boosting module 200 boosts and converts the rectified input signal to high-voltage direct current. Then, the voltage boosting module 200 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 to form a driving signal output to the lighting member, so as to drive the lighting member to perform lighting work.

[0068] Meanwhile, the first voltage detection module 400 detects the input voltage of the voltage boosting module 200, i.e., the first voltage, and transmits the first voltage to the feedback control module 600, and the second voltage detection module 500 detects the output voltage of the voltage boosting module 200, i.e., the second voltage, and transmits the second voltage to the feedback control module 600, and 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 voltage boosting module 200 adjusts the size of the output voltage, i.e., the second voltage, under the action of the feedback signal, and thus the voltage difference between the first voltage and the second voltage can be maintained within a suitable range.

[0069] In this way, by generating a feedback signal according to the voltage difference between the input voltage and the output voltage of the voltage boosting module 200, the output voltage of the voltage boosting module 200 follows the change of the input voltage, achieving the effect of voltage tracking, while ensuring the normal operation of the voltage boosting module 200, and minimizing the size of the output voltage of the voltage boosting module 200, which is conducive to reducing switching loss and improving efficiency.

[0070] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0071] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 the description of the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0072] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A voltage tracking secondary drive circuit, comprising: A rectifier module, wherein an input end of the rectifier module is configured 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 is 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. The feedback control module is configured to generate a feedback signal based on 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. The feedback signal is configured to adjust the output voltage of the boost module.

2. A voltage tracking secondary drive circuit according to claim 1, wherein: 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. The first control unit is configured to generate a pulse width modulation signal according to the voltage difference between the first voltage of the first voltage detection module and the second voltage of the second voltage detection module.

3. A voltage tracking secondary drive circuit according to claim 1, wherein: 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 secondary drive circuit according to claim 3, wherein: The power factor correction boost circuit includes a boost inductor, a switching 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 switching 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 switching tube and the other end of the filter capacitor are grounded, and the second control unit is connected to the controlled end of the switching tube.

5. A voltage tracking secondary drive circuit according to claim 4, wherein: 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 secondary drive circuit according to claim 5, wherein: The current detection unit includes a coupled inductor and a current limiting resistor. The coupled inductor is coupled to the boost inductor. One end of the coupled inductor is connected to the second control unit through the current limiting resistor, and the other end of the coupled inductor is grounded.

7. A voltage tracking secondary drive circuit according to claim 2, wherein: 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 secondary drive circuit according to claim 1, wherein: 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 secondary drive circuit according to claim 1, wherein: 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 connected to the feedback control module and one end of the seventh resistor respectively, and the other end of the seventh resistor is grounded.

10. Lighting devices, including: 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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