Light source driving circuit, light source driving device and lamp

Abstract

The invention discloses a light source driving circuit, a light source driving device and a lamp. The light source driving circuit comprises an input matching module, a voltage rectifying module, an input filtering module, a ballast matching module, a mode control module, a voltage regulating module and a feedback module. The ballast matching module can be controlled through the mode control module according to the type of the connected power supply. Under the condition that the light source driving circuit is connected to the ballast, the ballast matching module can bypass the input filtering module which affects power supply of the ballast, and the mode control module can release electric energy on the direct current bus through the ballast matching module, so that large current provided by the ballast is prevented from damaging related circuits. Meanwhile, voltage regulation is carried out through the voltage regulation module, so that the device can adapt to alternating current power supplies and ballasts with different voltages, and required output voltage is obtained. And finally, the compatibility of the AC power supply with the quick-start ballast, the ECG and the CCG is realized.

Description

Technical Field

[0001] The present application belongs to the technical field of lamps, and in particular, relates to a light source driving circuit, a light source driving device and a lamp. Background Art

[0002] At present, there are several types of mainstream driving circuits for lamps (such as LED lamps) on the market, such as a typical circuit that directly lights up the LED lamp after being successfully started by an electronic ballast (ECG) or a fast-start ballast, or a circuit that is compatible with a capacitive ballast (CCG) and alternating current (AC).

[0003] Since the fast start ballast is a ballast with a large inductance, it is usually difficult to be compatible with alternating current (AC). Summary of the invention

[0004] The purpose of the present application is to provide a light source driving circuit, a light source driving device and a lamp, aiming to solve the compatibility problem of traditional lamp tube driving circuits.

[0005] A first aspect of an embodiment of the present application provides a light source driving circuit, which is connected to a light-emitting module and includes: an input matching module, wherein the input end of the input matching module is used to connect to an AC power supply or a ballast, and the input matching module is used to match the impedance of the input end of the input matching module based on the voltage of the input end of the input matching module, and output a first electrical signal; a voltage rectification module, wherein the input end of the voltage rectification module is connected to the output end of the input matching module, and is used to rectify the first electrical signal and output a second electrical signal; an input filtering module, wherein the output end of the voltage rectification module is connected to a DC bus through the input filtering module, and the input filtering module is used to filter the electrical energy provided by the AC power supply; and a ballast matching module, wherein the ballast matching module is respectively connected to the output end of the voltage rectification module and the DC bus, and the ballast matching module is used to filter the electrical energy provided by the AC power supply. the input filter module is bypassed; a mode control module, the mode control module is connected to the input matching module and the ballast matching module respectively, and the mode control module is used to control the ballast matching module to release the electric energy on the DC bus when the ballast is powered; a voltage regulating module, the voltage regulating module is connected between the DC bus and the output end of the light source driving circuit, and is used to perform voltage regulation on the second electric signal and output a third current signal; the mode control module is also used to control the voltage regulating module to boost the voltage when the AC power supply is powered and the voltage on the DC bus is lower than the first preset threshold value or when the ballast is powered; a feedback module, the feedback module is connected to the output end of the light source driving circuit and the voltage regulating module respectively, and the feedback module is used to control the working parameters of the voltage regulating module based on the voltage of the third current signal.

[0006] In one embodiment, the input matching module also includes an overcurrent protection unit and an electromagnetic interference suppression unit. The overcurrent protection unit is arranged at the input end of the input matching module for overcurrent protection, and the electromagnetic interference suppression unit is arranged at the output end of the input matching module for reducing the electromagnetic interference generated by the first electrical signal.

[0007] In one embodiment, the input filter module includes a π-shaped filter circuit.

[0008] In one embodiment, the mode control module includes a coupling power supply unit and a main control unit; the coupling power supply unit is respectively connected to the output end of the input matching module and the comparison voltage input end of the main control unit, the comparison voltage input end of the main control unit is connected to the DC bus through a voltage divider sampling circuit, and the output end of the main control unit is connected to the ballast matching module, the coupling power supply unit is used to output a first comparison voltage based on the first electrical signal when the ballast is powered, and the main control unit is used to control the ballast matching module to release the electric energy on the DC bus when the first comparison voltage is received or when the first comparison voltage is not received and the voltage on the DC bus is lower than a first preset threshold, and control the voltage regulation module to boost the voltage.

[0009] In one embodiment, the ballast matching module includes an ECG matching unit and a quick-start ballast matching unit; the ECG matching unit is connected in parallel with the input filter module, and the quick-start ballast matching unit is connected between the first bus of the DC bus and the second bus of the DC bus; the ECG matching unit is used to be turned on when the ballast is powered, and the quick-start ballast matching unit is used to release the electrical energy on the DC bus under the control of the mode control module.

[0010] In one embodiment, the voltage regulation module includes a buck-boost unit and a pulse modulation unit; the buck-boost unit is connected between the DC bus and the output end of the light source driving circuit, and the pulse modulation unit is respectively connected to the buck-boost unit and the feedback module, and the pulse modulation unit is used to generate a pulse width modulation signal to control the buck-boost unit to perform voltage regulation on the second electrical signal.

[0011] In one embodiment, the voltage regulating module is further configured to perform overcurrent protection based on a first overcurrent threshold when the AC power supply is used, and to perform overcurrent protection based on a second overcurrent threshold when the ballast is used.

[0012] In one embodiment, the feedback module includes a first feedback unit and a second feedback unit; the first feedback unit is respectively connected to the output end of the light source driving circuit and the voltage regulating module, the first feedback unit is used to sample the voltage of the output end of the light source driving circuit and output a first feedback signal, the voltage of the first feedback signal is in direct proportion to the voltage of the output end of the light source driving circuit, the voltage regulating module is used to control the voltage of the third current signal by comparing the first feedback signal with a reference signal; the second feedback unit is respectively connected to the output end of the light source driving circuit and the voltage regulating module, the second feedback unit is used to sample the voltage of the output end of the light source driving circuit, and output a second feedback signal when the voltage of the output end of the light source driving circuit is less than a second preset threshold, and the voltage regulating module is used to boost the voltage when receiving the second feedback signal.

[0013] A second aspect of the embodiments of the present application provides a light source driving device connected to a light emitting module, wherein the light source driving device includes the light source driving circuit as described above.

[0014] A third aspect of the embodiments of the present application provides a lamp, comprising a light emitting module and the light source driving circuit as described above, wherein the light source driving circuit is connected to the light emitting module.

[0015] Compared with the prior art, the embodiments of the present application have the following beneficial effects: the ballast matching module can be controlled by the mode control module according to the type of power supply connected. When the light source driving circuit is connected to the ballast, the ballast matching module can bypass the input filter module that affects the power supply of the ballast, and the mode control module can release the electric energy on the DC bus through the ballast matching module to avoid the large current provided by the ballast from damaging the related circuits. At the same time, by adjusting the voltage through the voltage regulating module, it is possible to adapt to AC power supplies and ballasts with different voltages to obtain the required output voltage. Ultimately, the compatibility of the AC power supply with the quick-start ballast, ECG and CCG is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a light source driving circuit provided in an embodiment of the present application;

[0017] Figure 2 Another schematic diagram of a light source driving circuit provided by an embodiment of the present application;

[0018] Figure 3 A circuit diagram of an input matching module, a voltage rectification module, an input filtering module, and a ballast matching module provided in an embodiment of the present application;

[0019] Figure 4 A circuit diagram of a mode control module provided in one embodiment of the present application;

[0020] Figure 5 A circuit diagram of a voltage regulating module provided in an embodiment of the present application;

[0021] Figure 6 A circuit diagram of a feedback module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0024] In addition, 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 the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0025] Figure 1 A schematic diagram of a light source driving circuit provided in an embodiment of the present application is shown. For ease of description, only the part related to the present embodiment is shown, which is described in detail as follows:

[0026] The light source driving circuit 10 is connected to the light emitting module and can be used to drive the light emitting module to work. The light emitting module can be specifically an LED lamp group.

[0027] The light source driving circuit 10 includes an input matching module 100 , a voltage rectifying module 200 , an input filtering module 300 , a ballast matching module 500 , a mode control module 600 , a voltage regulating module 700 and a feedback module 800 .

[0028] The input end of the input matching module 100 is used to connect to an AC power source or a ballast. The input matching module 100 is used to match the impedance of the input end of the input matching module 100 based on the voltage of the input end of the input matching module 100 and output a first electrical signal.

[0029] The input end of the voltage rectifying module 200 is connected to the output end of the input matching module 100 , and is used to rectify the first electrical signal and output a second electrical signal.

[0030] The output end of the voltage rectification module 200 is connected to the DC bus 400 through the input filtering module 300 , and the input filtering module 300 is used to filter the electric energy provided by the AC power supply.

[0031] The ballast matching module 500 is connected to the output end of the voltage rectifier module 200 and the DC bus 400 respectively. The ballast matching module 500 is used to bypass the input filter module 300 when the ballast is powered.

[0032] The mode control module 600 is connected to the input matching module 100 and the ballast matching module 500 respectively. The mode control module 600 is used to control the ballast matching module 500 to release the electric energy on the DC bus 400 when the ballast is powered.

[0033] The voltage regulating module 700 is connected between the DC bus 400 and the output end of the light source driving circuit 10, and is used to regulate the voltage of the second electrical signal and output a third current signal. The mode control module 600 is also used to control the voltage regulating module 700 to boost the voltage when the AC power supply is supplied and the voltage on the DC bus 400 is lower than the first preset threshold value or when the ballast is supplied.

[0034] The feedback module 800 is connected to the output end of the light source driving circuit 10 and the voltage regulating module 700 respectively. The feedback module 800 is used to control the working parameters of the voltage regulating module 700 based on the voltage of the third current signal.

[0035] The ballast matching module 500 can be controlled by the mode control module 600 according to the type of power supply connected. When the light source driving circuit 10 is connected to the ballast, the ballast matching module 500 can bypass the input filter module 300 that affects the power supply of the ballast, and the mode control module 600 can release the power on the DC bus 400 through the ballast matching module 500 to prevent the large current provided by the ballast from damaging the related circuits. At the same time, by adjusting the voltage through the voltage regulating module 700, it can adapt to AC power supplies and ballasts with different voltages to obtain the required output voltage.

[0036] It is understandable that, due to the different parameters of the power provided by the AC power supply and the ballast, only input matching cannot make the conventional circuit compatible with both inputs at the same time. In the case where the AC power supply provides power, the power provided by the AC power supply can be provided to the DC bus 400 through the input filter module 300 after being rectified by the voltage rectifier module 200. The power provided by the ballast needs to be transmitted to the DC bus 400 through the ballast matching module 500.

[0037] In one embodiment, if Figure 2As shown, the input matching module 100 includes a first input matching unit 110 and a second input matching unit 120 , and the input end of the first input matching unit 110 and the input end of the second input matching unit 120 are both used to connect to an AC power source or a ballast.

[0038] The first input matching unit 110 and the second input matching unit 120 may be configured according to actual requirements, and the first input matching unit 110 and the second input matching unit 120 may be configured with different circuits, respectively.

[0039] It should be noted that each input matching unit has two ports, and one AC power source may only require one input matching unit, while one ballast needs to be connected to two input matching units at the same time.

[0040] In one embodiment, the input matching module 100 also includes an overcurrent protection unit and an electromagnetic interference suppression unit. The overcurrent protection unit is arranged at the input end of the input matching module 100 for overcurrent protection, and the electromagnetic interference suppression unit is arranged at the output end of the input matching module 100 for reducing the electromagnetic interference generated by the first electrical signal.

[0041] The overcurrent protection unit may include a fuse.

[0042] For example, Figure 3 As shown, in one embodiment, the electromagnetic interference suppression unit includes a common mode inductor LF1, the overcurrent protection unit includes a first fuse F3, a second fuse F1 and a third fuse F2, the first input matching unit 110 specifically includes a first thermistor PTC1 and a first input capacitor CM1, the first end of the common mode inductor LF1, the first end of the first thermistor PTC1 and the first end of the first input capacitor CM1 are all connected to the first port AC-3 through the first fuse F3, and the second end of the common mode inductor LF1, the second end of the first thermistor PTC1 and the second end of the first input capacitor CM1 are all connected to the second port AC-4. The third end of the common mode inductor LF1 and the fourth end of the common mode inductor LF1 are both connected to the voltage rectifier module 200.

[0043] The second input matching unit 120 specifically includes a second thermistor PTC2 and a second input capacitor CM2, wherein the first end of the second thermistor PTC2 and the first end of the second input capacitor CM2 are connected to the third port AC-2 via the second fuse F1, and the second end of the second thermistor PTC2 and the second end of the second input capacitor CM2 are connected to the fourth port AC-1 via the third fuse F2.

[0044] The electromagnetic interference suppression unit specifically also includes a first filter capacitor CX1, a second filter capacitor CX2 and a third filter capacitor CX3. The first filter capacitor CX1 is connected between the first end of the common-mode inductor LF1 and the second end of the common-mode inductor LF1, and the second filter capacitor CX2 and the third filter capacitor CX3 are both connected between the third end of the common-mode inductor LF1 and the fourth end of the common-mode inductor LF1.

[0045] It should be noted that the temperature of the thermistor will increase with the increase of input current, and the impedance of the thermistor will increase accordingly to adapt to different inputs. At the same time, when the ballast is powered, the increase in the impedance of the thermistor will also cause the ballast to recognize the abnormality and stop supplying power.

[0046] In some embodiments, Figure 3 As shown, the voltage rectifier module 200 includes a first full-bridge rectifier circuit DB1 and a second full-bridge rectifier circuit DB2, the output end of the first input matching unit 110 is connected to the input end of the first full-bridge rectifier circuit DB1, the output end of the second input matching unit 120 is connected to the input end of the second full-bridge rectifier circuit DB2, the positive output end of the first full-bridge rectifier circuit DB1 is connected to the positive output end of the second full-bridge rectifier circuit DB2, and the negative output end of the first full-bridge rectifier circuit DB1 is connected to the negative output end of the second full-bridge rectifier circuit DB2.

[0047] In one embodiment, the input filter module 300 may include a π-shaped filter circuit.

[0048] For example, Figure 3 As shown, the input filter module 300 specifically includes a fourth filter capacitor C6-1, a fifth filter capacitor C6-20, a first filter inductor L1 and a temperature fuse TH1. The temperature fuse TH1 can be a 125°C fuse, that is, when the temperature of the temperature fuse TH1 reaches 125°C, the temperature fuse TH1 will be disconnected.

[0049] The first end of the first filter inductor L1 is connected to the positive output end of the voltage rectifier module 200, the second end of the first filter inductor L1 is connected to the first bus VBUS of the DC bus 400 through the temperature fuse TH1, and the fourth filter capacitor C6-1 and the fifth filter capacitor C6-20 are connected between the first bus VBUS of the DC bus 400 and the second bus of the DC bus 400.

[0050] The second busbar is also grounded.

[0051] In one embodiment, if Figure 3 , Figure 4 As shown, the mode control module 600 includes a coupled power supply unit 610 and a main control unit 620 .

[0052] The coupling power supply unit 610 is respectively connected to the output end of the input matching module 100 and the comparison voltage input end of the main control unit 620. The comparison voltage input end of the main control unit 620 is connected to the DC bus 400 through a voltage divider sampling circuit. The output end of the main control unit 620 is connected to the ballast matching module 500. The coupling power supply unit 610 is used to output a first comparison voltage U2-VDD based on a first electrical signal when the ballast is powered. The main control unit 620 is used to control the ballast matching module 500 to release the electrical energy on the DC bus 400 when the first comparison voltage U2-VDD is received or when the first comparison voltage U2-VDD is not received and the voltage on the DC bus 400 is lower than a first preset threshold, and control the voltage regulation module 700 to boost the voltage.

[0053] It can be understood that, only when a ballast is connected, the coupling power supply unit 610 can provide the first comparison voltage U2-VDD to enable the main control unit 620 to start working, so that the ballast matching module 500 bypasses the input filter module 300, thereby completing the mode switching, and the ballast matching module 500 processes the electric energy provided by the ballast to achieve the compatibility of the light source driving circuit 10 with the ballast.

[0054] For example, Figure 3 As shown, the coupling power supply unit 610 specifically includes a first power supply capacitor C3, a second power supply capacitor C5, a third power supply capacitor C4, a first power supply diode D9, a second power supply diode D10 and a first power supply resistor R43.

[0055] The first end of the first power supply capacitor C3 is connected to the third end of the common mode inductor LF1, the second end of the first power supply capacitor C3 is connected to the cathode of the first power supply diode D9, the anode of the first power supply diode D9 is grounded, the anode of the second power supply diode D10 is connected to the second end of the first power supply capacitor C3, the cathode of the second power supply diode D10 is connected to the mode control module 600, the first end of the second power supply capacitor C5, the first end of the third power supply capacitor C4 and the first end of the first power supply resistor R43 are all connected to the cathode of the second power supply diode D10, the second end of the second power supply capacitor C5, the second end of the third power supply capacitor C4 and the second end of the first power supply resistor R43 are all grounded. The cathode of the second power supply diode D10 is used to output the first comparison voltage U2-VDD.

[0056] It should be noted that only when the ballast is powered, can the high-frequency AC current of 25-70KHZ be coupled out as the first comparison voltage U2-VDD through the coupling power supply unit 610. When the main control unit 620 receives the first comparison voltage U2-VDD, the main control unit 620 determines whether a ballast is connected based on the first comparison voltage U2-VDD.

[0057] For example, Figure 4 As shown, the main control unit 620 specifically includes a first control chip IC2, and the voltage-dividing sampling circuit includes a first voltage-dividing resistor R55, a second voltage-dividing resistor R37, a third voltage-dividing resistor R36, a first sampling capacitor C16, a first sampling diode DZ7, and a second sampling diode D17. The PIN2 pin of the first control chip IC2 is the comparison voltage input terminal, and the PIN3 pin of the first control chip IC2 is connected to the ballast matching module 500 and the voltage regulating module 700. The anode of the first sampling diode DZ7, the first end of the first sampling capacitor C16, A first end of the first voltage-dividing resistor R55 is connected to the second bus, a cathode of the first sampling diode DZ7, a second end of the first sampling capacitor C16, a second end of the first voltage-dividing resistor R55, a first end of the second voltage-dividing resistor R37, and a cathode of the second sampling diode D17 are connected to the PIN3 pin of the first control chip IC2, a first end of the second voltage-dividing resistor R37 is connected to the first bus VBUS through a third voltage-dividing resistor R36, and an anode of the second sampling diode D17 is connected to the coupling power supply unit 610 to access the first comparison voltage U2-VDD.

[0058] Therefore, when the coupling power supply unit 610 does not output the first comparison voltage U2-VDD, the main control unit 620 can determine that no ballast currently provides power. At this time, the light source driving circuit 10 can default to being provided by the AC power supply, and the PIN3 pin of the first control chip IC2 outputs a low level. When the coupling power supply unit 610 outputs the first comparison voltage U2-VDD, the main control unit 620 can determine that the ballast currently provides power. Therefore, the first control chip IC2 can send a high-level control signal to the ballast matching module 500 and the voltage regulating module 700 through the PIN3 pin to control the ballast matching module 500 to release the power on the DC bus 400 and control the voltage regulating module 700 to boost the voltage.

[0059] In one embodiment, if Figure 3 , Figure 4 As shown, the ballast matching module 500 includes an ECG matching unit 510 and a fast-start ballast matching unit 520 .

[0060] The ECG matching unit 510 is connected in parallel with the input filter module 300 , and the fast-start ballast matching unit 520 is connected between the first bus VBUS of the DC bus 400 and the second bus of the DC bus 400 .

[0061] The ECG matching unit 510 can be turned on when the ballast is powered, thereby bypassing the input filter module 300. The fast-start ballast matching unit 520 is used to release the power on the DC bus 400 under the control of the mode control module 600.

[0062] It should be noted that when the high-frequency signal and high current provided by the ECG ballast flow through the first filter inductor L1 in the input filter module 300, high-frequency resonance will be generated, and the resulting loss will affect the power supply efficiency. Therefore, the ECG matching unit 510 can reduce the power loss when the ballast is used for power supply.

[0063] For example, Figure 3 , Figure 4 As shown, the ECG matching unit 510 specifically includes a first control capacitor C23, a first control resistor R45, a second control resistor R46 and a first control switch Q10, wherein the first end of the first control switch Q10 is connected to the positive output end of the voltage rectifier module 200, the second end of the first control switch Q10 is connected to the first bus VBUS, the control end of the first control switch Q10 is connected to the first bus VBUS through the first control resistor R45 and the second control resistor R46, and the control end of the first control switch Q10 is also connected to the positive output end of the voltage rectifier module 200 through the first control capacitor C23. Specifically, the first control switch Q10 can be a thyristor.

[0064] When the ballast is powered, the first control switch Q10 can be triggered to turn on through the first control capacitor C23.

[0065] For example, Figure 3 , Figure 4 As shown, the quick-start ballast matching unit 520 specifically includes a second control capacitor C7, a first control diode D11, a second control switch Q8, a third control resistor R2 and a fourth control resistor R1. The first end of the second control switch Q8 is connected to the mode control module 600 through the third control resistor R2. Specifically, the first end of the second control switch Q8 is connected to the PIN3 pin of the first control chip IC2 through the third control resistor R2, the first end of the second control switch Q8 is connected to the second bus through the fourth control resistor R1, the second end of the second control switch Q8 is connected to the second bus through the first control diode D11, and is connected to the first bus VBUS through the second control capacitor C7, and the control end of the second control switch Q8 is connected to the second bus. Among them, the second control switch Q8 can specifically be a thyristor.

[0066] It should be noted that, when the PIN3 pin of the first control chip IC2 outputs a low level, the second control switch Q8 is in an off state, and the electric energy on the first bus VBUS cannot be transmitted to the second bus through the first control diode D11. In the case of a high-level control signal, the second control switch Q8 is in an on state, and the electric energy on the first bus VBUS can be transmitted to the second bus through the second control capacitor C7, the second control switch Q8 and the fourth control resistor R1 in sequence.

[0067] In one embodiment, if Figures 3 to 6 As shown, the voltage regulation module 700 includes a buck-boost unit and a pulse modulation unit.

[0068] The buck-boost unit is connected between the DC bus 400 and the output end of the light source driving circuit 10. The pulse modulation unit is connected to the buck-boost unit and the feedback module 800 respectively. The pulse modulation unit is used to generate a pulse width modulation signal to control the buck-boost unit to perform voltage regulation on the second electrical signal.

[0069] The buck-boost unit may include a BCUK / BOOST converter. The BCUK / BOOST converter may adjust the voltage of the second electrical signal according to the pulse width modulation signal.

[0070] In some embodiments, the voltage regulating module 700 is also configured to perform overcurrent protection based on a first overcurrent threshold when powered by an AC power supply, and to perform overcurrent protection based on a second overcurrent threshold when powered by a ballast, wherein the first overcurrent threshold and the second overcurrent threshold can be set according to actual needs.

[0071] For example, Figures 3 to 6 As shown, the buck-boost unit may specifically include a transformer T1, a transformer switch Q5, a transformer capacitor C30, a zero-crossing feedback resistor R50, a fourth voltage-dividing resistor R28, a fifth voltage-dividing resistor R81, a sixth voltage-dividing resistor R82 and a seventh voltage-dividing resistor R83, and the pulse modulation unit includes a second control chip IC1.

[0072] The first end of the transformer T1 is connected to the first bus VBUS, the second end of the transformer T1 is grounded, the third end of the transformer T1 is connected to the first end of the transformer switch Q5, and the fourth end of the transformer T1 is connected to the PIN5 pin of the second control chip IC1 through the zero-crossing feedback resistor R50.

[0073] The PIN7 pin of the second control chip IC1 is connected to the controlled end of the voltage-changing switch Q5, the first end of the fourth voltage-dividing resistor R28 is connected to the controlled end of the voltage-changing switch Q5, the second end of the fourth voltage-dividing resistor R28 is respectively connected to the first ends of the fifth voltage-dividing resistor R81, the sixth voltage-dividing resistor R82 and the seventh voltage-dividing resistor R83 and the PIN4 pin of the second control chip IC1, and the second ends of the fifth voltage-dividing resistor R81, the sixth voltage-dividing resistor R82 and the seventh voltage-dividing resistor R83 are grounded. The second end of the voltage-changing switch Q5 is connected to the second end of the fourth voltage-dividing resistor R28. The two ends of the voltage-changing capacitor C30 are respectively connected to the first end of the voltage-changing switch Q5 and the second end of the voltage-changing switch Q5.

[0074] It should be noted that the PIN7 pin of the second control chip IC1 is used to output a pulse width modulation signal, and voltage regulation is achieved by controlling the on and off of the transformer switch Q5. It can be understood that the duty cycle of the pulse width modulation signal is positively correlated with the voltage of the third current signal.

[0075] The transformer T1 can provide a feedback voltage to the PIN5 pin of the second control chip IC1 according to the third current signal. The second control chip IC1 can also adjust the pulse width modulation signal accordingly according to the voltage of the PIN5 pin of the second control chip IC1 to keep the voltage of the third current signal stable.

[0076] The second control chip IC1 can also perform overcurrent protection according to the voltage of the PIN4 pin of the second control chip IC1.

[0077] In one embodiment, the pulse modulation unit further includes a third control chip IC3, the third control chip IC3, a switch Q11, an eighth voltage-dividing resistor R84, a ninth voltage-dividing resistor R85, and a tenth voltage-dividing resistor R86, the first end of the switch Q11 is connected to the second end of the fourth voltage-dividing resistor R28, the control end of the switch Q11 is connected to the PIN3 pin of the third control chip IC3, the first end of the eighth voltage-dividing resistor R84, the first end of the ninth voltage-dividing resistor R85, and the first end of the tenth voltage-dividing resistor R86 are all connected to the second end of the switch Q11. The PIN2 pin of the third control chip IC3 is also connected to the PIN3 pin of the first control chip IC2.

[0078] The third control chip IC3 is used to control the switching switch Q11 to turn on when the ballast is powered (when receiving the high-level control signal output by the first control chip IC2), so as to connect the eighth voltage-dividing resistor R84, the ninth voltage-dividing resistor R85 and the tenth voltage-dividing resistor R86 in parallel with the fifth voltage-dividing resistor R81, the sixth voltage-dividing resistor R82 and the seventh voltage-dividing resistor R83, so as to adjust the first overcurrent threshold to the second overcurrent threshold. It can be understood that after the control switching switch Q11 is turned on so that the eighth voltage-dividing resistor R84, the ninth voltage-dividing resistor R85 and the tenth voltage-dividing resistor R86 are connected in parallel with the fifth voltage-dividing resistor R81, the sixth voltage-dividing resistor R82 and the seventh voltage-dividing resistor R83, the voltage of the PIN4 pin of the second control chip IC1 will change accordingly, thereby reducing the overcurrent protection point of the third control chip IC3, and adjusting the first overcurrent threshold to the second overcurrent threshold. After the control switching switch Q11 is turned off, the overcurrent protection point of the third control chip IC3 is increased, and the second overcurrent threshold is adjusted to the first overcurrent threshold.

[0079] In one embodiment, if Figures 3 to 6 As shown, the feedback module 800 includes a first feedback unit 810 and a second feedback unit 820 .

[0080] The first feedback unit 810 is connected to the output end of the light source driving circuit 10 and the voltage regulating module 700 respectively. The first feedback unit 810 is used to sample the voltage at the output end of the light source driving circuit 10 and output a first feedback signal. The voltage regulating module 700 is used to compare the first feedback signal with the reference signal to control the voltage of the third current signal.

[0081] The second feedback unit 820 is connected to the output end of the light source driving circuit 10 and the voltage regulating module 700 respectively. The second feedback unit 820 is used to sample the voltage at the output end of the light source driving circuit 10, and output a second feedback signal when the voltage at the output end of the light source driving circuit 10 is less than a second preset threshold. The voltage regulating module 700 is used to boost the voltage when receiving the second feedback signal.

[0082] Exemplarily, the first feedback unit 810 can collect the voltage of the third current signal at a certain ratio through the first optocoupler U1 to obtain a sampling voltage (first feedback signal), and feed back the sampling voltage to the PIN1 pin of the second control chip IC1 and the PIN2 pin of the second control chip IC1. The second control chip IC1 adjusts the duty cycle of the pulse width modulation signal according to the voltage of the PIN1 pin of the second control chip IC1 and the PIN2 pin of the second control chip IC1.

[0083] The second feedback unit 820 can collect the voltage of the third current signal (that is, the voltage difference between the output ends of the light source driving circuit 10) at a certain ratio through the second optocoupler U2, and output a second feedback signal to the PIN1 pin of the second control chip IC1 and the PIN2 pin of the second control chip IC1 when the voltage at the output end of the light source driving circuit 10 is less than the second preset threshold value, so that the voltages of the PIN1 pin of the second control chip IC1 and the PIN2 pin of the second control chip IC1 are all pulled down, so that the second control chip IC1 is boosted with a pulse width modulation signal with a maximum duty cycle.

[0084] It should be noted that, when the voltage at the output end of the light source driving circuit 10 is less than the second preset threshold, it means that the ballast is currently supplying power, so the voltage regulating module 700 is required to boost the voltage.

[0085] The embodiment of the present application further provides a light source driving device, which is connected to the light emitting module. The light source driving device includes a light source driving circuit 10 as described in any one of the above embodiments.

[0086] An embodiment of the present application further provides a lamp, which includes a light emitting module and a light source driving circuit 10 as in any one of the above embodiments, wherein the light source driving circuit 10 is connected to the light emitting module.

[0087] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0088] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0089] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such 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, and should all be included in the protection scope of the present application.

Claims

1. A light source driving circuit connected to a light emitting module, characterized in that: include: An input matching module, wherein the input end of the input matching module is used to connect to an AC power source or a ballast, and the input matching module is used to match the impedance of the input end of the input matching module based on the voltage of the input end of the input matching module, and output a first electrical signal; a voltage rectification module, the input end of the voltage rectification module being connected to the output end of the input matching module, and being used for rectifying the first electrical signal and outputting a second electrical signal; An input filter module, the output end of the voltage rectifier module is connected to the DC bus through the input filter module, and the input filter module is used to filter the electric energy provided by the AC power supply; A ballast matching module, the ballast matching module is connected to the output end of the voltage rectifier module and the DC bus respectively, and the ballast matching module is used to bypass the input filter module when the ballast is powered; A mode control module, the mode control module is connected to the input matching module and the ballast matching module respectively, and the mode control module is used to control the ballast matching module to release the electric energy on the DC bus when the ballast is powered; a voltage regulating module, the voltage regulating module being connected between the DC bus and the output end of the light source driving circuit, and being used for regulating the voltage of the second electrical signal and outputting a third current signal; the mode control module being further used for controlling the voltage regulating module to boost the voltage when the AC power supply is powered and the voltage on the DC bus is lower than a first preset threshold value or when the ballast is powered; A feedback module is connected to the output end of the light source driving circuit and the voltage regulating module respectively, and is used to control the working parameters of the voltage regulating module based on the voltage of the third current signal.

2. The light source driving circuit according to claim 1, characterized in that: The input matching module also includes an overcurrent protection unit and an electromagnetic interference suppression unit. The overcurrent protection unit is arranged at the input end of the input matching module for overcurrent protection, and the electromagnetic interference suppression unit is arranged at the output end of the input matching module for reducing the electromagnetic interference generated by the first electrical signal.

3. The light source driving circuit according to claim 1, characterized in that: The input filter module includes a π-shaped filter circuit.

4. The light source driving circuit according to any one of claims 1 to 3, characterized in that: The mode control module includes a coupled power supply unit and a main control unit; The coupling power supply unit is respectively connected to the output end of the input matching module and the comparison voltage input end of the main control unit. The comparison voltage input end of the main control unit is connected to the DC bus through a voltage divider sampling circuit. The output end of the main control unit is connected to the ballast matching module. The coupling power supply unit is used to output a first comparison voltage based on the first electrical signal when the ballast is powered. The main control unit is used to control the ballast matching module to release the electric energy on the DC bus when the first comparison voltage is received or when the first comparison voltage is not received and the voltage on the DC bus is lower than a first preset threshold, and control the voltage regulation module to boost the voltage.

5. The light source driving circuit according to any one of claims 1 to 3, characterized in that: The ballast matching module includes an ECG matching unit and a fast-start ballast matching unit; The ECG matching unit is connected in parallel with the input filter module, and the fast-start ballast matching unit is connected between the first busbar of the DC bus and the second busbar of the DC bus; The ECG matching unit is used to be turned on when the ballast is powered, and the quick-start ballast matching unit is used to release the electrical energy on the DC bus under the control of the mode control module.

6. The light source driving circuit according to any one of claims 1 to 3, characterized in that: The voltage regulation module includes a buck-boost unit and a pulse modulation unit; The buck-boost unit is connected between the DC bus and the output end of the light source driving circuit, the pulse modulation unit is connected to the buck-boost unit and the feedback module respectively, and the pulse modulation unit is used to generate a pulse width modulation signal to control the buck-boost unit to perform voltage regulation on the second electrical signal.

7. The light source driving circuit according to any one of claims 1 to 3, characterized in that: The voltage regulating module is further configured to perform overcurrent protection based on a first overcurrent threshold when the AC power supply is used, and to perform overcurrent protection based on a second overcurrent threshold when the ballast is used.

8. The light source driving circuit according to any one of claims 1 to 3, characterized in that: The feedback module includes a first feedback unit and a second feedback unit; The first feedback unit is connected to the output end of the light source driving circuit and the voltage regulating module respectively, the first feedback unit is used to sample the voltage of the output end of the light source driving circuit and output a first feedback signal, the voltage of the first feedback signal is in direct proportion to the voltage of the output end of the light source driving circuit, and the voltage regulating module is used to control the voltage of the third current signal according to the comparison between the first feedback signal and the reference signal; The second feedback unit is connected to the output end of the light source driving circuit and the voltage regulating module respectively. The second feedback unit is used to sample the voltage at the output end of the light source driving circuit and output a second feedback signal when the voltage at the output end of the light source driving circuit is less than a second preset threshold. The voltage regulating module is used to boost the voltage when receiving the second feedback signal.

9. A light source driving device, connected to a light emitting module, characterized in that: The light source driving circuit comprises the light source driving circuit as claimed in any one of claims 1 to 8.

10. A lamp, characterized in that: It comprises a light emitting module and a light source driving circuit as claimed in any one of claims 1 to 8, wherein the light source driving circuit is connected to the light emitting module.

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