LED driving power supply

Abstract

The utility model relates to the technical field of LED driving power supply integrated circuits, in particular to an LED driving power supply, which comprises an AC detection module used for isolating and detecting input signals of a rectifier bridge DB; the VBUS voltage detection module is used for detecting the output voltage of the main output unit; the dimmer input module is used for isolating and receiving a dimming control signal of a dimmer; all the signals are transmitted to the signal control module; digital signal interaction of a dimming control signal and a dimming signal is carried out between the signal control module and the dimming output module; when the AC-to-DC constant voltage module is powered off, if the voltage of the main output unit drops to a preset threshold value, a first maintaining voltage is generated, and the voltage conversion module receives the first maintaining voltage through the auxiliary output unit and generates a second maintaining voltage; the power-off delay memory function, the detection function and the dimming function are stronger in anti-interference capability, higher in accuracy and suitable for more application scenes.

Description

Technical Field

[0001] The utility model relates to the technical field of LED drive power integrated circuits, in particular to an LED drive power supply. Background Art

[0002] LED driver power supply is a voltage converter that converts power into a specific voltage and current to drive the LED to emit light. The input of a general LED driver power supply includes high-voltage industrial frequency AC (i.e., mains), low-voltage DC, high-voltage DC, low-voltage high-frequency AC (such as the output of an electronic transformer), etc. The output of the LED driver power supply is mostly a constant current source, which can change the voltage as the forward voltage drop of the LED changes. The core components of the LED power supply include switch controllers, inductors, MOS tubes, feedback resistors, input filters, output filters, etc., and according to the requirements of different occasions, there are also integrated overvoltage protection circuits, input undervoltage protection circuits, LED open circuit protection circuits, overcurrent protection circuits, signal control circuits, etc.

[0003] However, the circuit structures of existing LED driver power supplies are not perfect enough, which makes them susceptible to interference during operation, resulting in failure of some functional modules and even affecting the operation of the entire LED driver power supply. For example, the LED driver power supply uses electrolytic capacitors in the main power supply circuit to directly release electrical energy after power failure to maintain the power supply of the signal control circuit. If there is a temporary power failure, the signal control circuit will be impacted by the release of electrical energy by the electrolytic capacitor at the moment of power restoration. Or, the various detection circuits of the signal control circuit are directly connected to the detection end to obtain signals. When the voltage levels are different or the signal fluctuates at the detection end, it is easy to affect the signal control circuit. Or, the signal control circuit usually uses analog signal communication, which makes it difficult to achieve a one-to-one correspondence between the dimming signal and the output signal, and it is easy for the logic execution action and the target action to deviate when the analog signal fluctuates. Utility Model Content

[0004] In view of the above-mentioned defects, the purpose of the utility model is to provide an LED driving power supply, which has a stronger anti-interference ability and higher accuracy in power-off delay memory function, detection function and dimming function, and is suitable for more application scenarios.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] An LED driving power supply, comprising an AC to DC constant voltage module, a signal control module, a voltage conversion module, an AC detection module, a VBUS voltage detection module, a dimmer input module and a dimming output module; the AC to DC constant voltage module comprises a main output unit, a sub-output unit and a rectifier bridge DB1;

[0007] The output end of the main output unit is electrically connected to the input end of the VBUS voltage detection module, and the output end of the VBUS voltage detection module is electrically connected to the first detection end of the signal control module;

[0008] The input end of the rectifier bridge DB1 is electrically connected to the input end of the AC detection module, and the output end of the AC detection module is electrically connected to the second detection end of the signal control module;

[0009] The signal end of the dimmer input module is electrically connected to the first signal end of the signal control module; the signal end of the dimming output module is electrically connected to the second signal end of the signal control module;

[0010] The power-off maintaining terminal of the main output unit is electrically connected to the output terminal of the auxiliary output unit, the output terminal of the auxiliary output unit is electrically connected to the input terminal of the voltage conversion module, and the output terminal of the voltage conversion module is electrically connected to the power supply terminal of the signal control module and the feedback terminal of the main output unit respectively;

[0011] The AC detection module is used to isolate and detect the input signal of the rectifier bridge DB1 and transmit it to the signal control module;

[0012] The VBUS voltage detection module is used to detect the output voltage of the main output unit and transmit it to the signal control module;

[0013] The dimmer input module is used to isolate and receive the dimming control signal of the dimmer and transmit it to the signal control module;

[0014] The signal control module is used to receive the dimming control signal, generate a digital signal of the dimming control signal, and transmit it to the dimming output module;

[0015] The dimming output module is used to receive the digital signal of the dimming control signal to generate a dimming signal, and generate a digital signal of the dimming signal to feed back to the signal control module;

[0016] When the AC to DC constant voltage module is powered off, if the voltage of the main output unit drops to a preset threshold, the main output unit generates a first maintenance voltage, and the voltage conversion module receives the first maintenance voltage through the auxiliary output unit and generates a second maintenance voltage.

[0017] Furthermore, the signal control module is an MCU system, and the signal control module is connected to the dimming output module via serial communication;

[0018] The dimming output module includes a resistor R10, a capacitor C13, a resistor R34, a capacitor C14, a diode D3, a diode D4, an inductor L3, a capacitor CB2, a capacitor C15, a common mode inductor LF3, a resistor R33, a diode D11, a resistor R32, a resistor R23, a resistor R25, a resistor R16, a resistor R24, a resistor R38, a resistor R39, a resistor R40, a capacitor C4, a MOS tube Q4 and a digital dimming driver chip U2; the DIM1 terminal and the DIM2 terminal of the digital dimming driver chip U2 are both used as the signal terminal of the dimming output module, and one end and the other end of the resistor R33 are both used as the output terminal of the dimming output module;

[0019] The VCC end of the digital dimming driver chip U2 is electrically connected to one end of the capacitor C13, the other end of the capacitor C13 is grounded, the VIN end of the digital dimming driver chip U2 is electrically connected to one end of the resistor R10, the other end of the resistor R10, one end of the capacitor C14, the cathode of the diode D3, the cathode of the diode D4, one end of the capacitor CB2, one end of the capacitor C15 and the 4 pins of the common mode inductor LF3 are all connected to the VBUS power supply, the other end of the capacitor C14 and One end of the resistor R34 is electrically connected, the other end of the resistor R34, the anode of the diode D3, the anode of the diode D4, and one end of the inductor L3 are all electrically connected to the drain of the MOS tube Q4, the other end of the capacitor CB2, the other end of the capacitor C15, the other end of the inductor L3, and the pin 1 of the common-mode inductor LF3 are all grounded, the pin 3 of the common-mode inductor LF3 is electrically connected to one end of the resistor R33, and the pin 2 of the common-mode inductor LF3 is electrically connected to the other end of the resistor R33. The resistor R23 and the cathode of the diode D11 are electrically connected to the OUT terminal of the digital dimming driver chip U2, the anode of the diode D11 is electrically connected to one end of the resistor R32, the other end of the resistor R32, the other end of the resistor R23, and one end of the resistor R25 are electrically connected to the gate of the MOS tube Q4, one end of the resistor R16 and one end of the capacitor C4 are electrically connected to the ISNS terminal of the digital dimming driver chip U2, and the other end of the resistor R16 is electrically connected to the gate of the MOS tube Q4. One end of the capacitor C4, the other end of the resistor R25, one end of the resistor R38, one end of the resistor R39, and one end of the resistor R40 are all electrically connected to the gate of the MOS tube Q4, the other end of the resistor R38, the other end of the resistor R39, and the other end of the resistor R40 are all grounded, the other end of the capacitor C4, one end of the resistor R24, and the GND end of the digital dimming driver chip U2 are all grounded, and the other end of the resistor R24 ​​is electrically connected to the CFG end of the digital dimming driver chip U2.

[0020] Furthermore, the AC to DC constant voltage module also includes a front-side processing circuit, a transformer T1 and a transformer T2 for rectifying, reducing and stabilizing an external AC power supply; the output end of the front-side processing circuit is electrically connected to the primary windings of the transformer T1 and the transformer T2, respectively, and the secondary windings of the transformer T1 and the transformer T2 are electrically connected to the input ends of the main output unit and the auxiliary output unit, respectively;

[0021] The main output unit includes a resistor R12, a resistor R35, a capacitor C2, an electrolytic capacitor EC2, a diode D8 and a power-off maintenance judgment circuit; the anode of the diode D8 and the cathode of the electrolytic capacitor EC2 are used as the input end of the main output unit, the positive electrode of the electrolytic capacitor EC2 is used as the output end of the main output unit, the power-off maintenance end of the power-off maintenance judgment circuit is used as the power-off maintenance end of the main output unit, and the feedback end of the power-off maintenance judgment circuit is used as the feedback end of the main output unit;

[0022] One end of the resistor R12 and one end of the resistor R35 are electrically connected to the anode of the diode D8, the other end of the resistor R12 and the other end of the resistor R35 are electrically connected to one end of the capacitor C2, and the other end of the capacitor C2, the cathode of the diode D8, and the positive electrode of the electrolytic capacitor EC2 are electrically connected to the input end of the power-off maintenance judgment circuit;

[0023] The power-off maintenance judgment circuit is used to generate the first maintenance voltage when the voltage of the power-off maintenance judgment circuit drops to the preset threshold when the AC-to-DC constant voltage module 1 is powered off;

[0024] The auxiliary output unit includes a capacitor C16, a capacitor C17, a capacitor C18, a capacitor C21, an inductor L2, a diode D10, a resistor R27 and an electrolytic capacitor CE3; one end and the other end of the capacitor C21 are used as input ends of the auxiliary output unit, and the positive electrode of the electrolytic capacitor CE3 is used as the output end of the auxiliary output unit;

[0025] One end of the capacitor C21 is electrically connected to one end of the inductor L2, the other end of the inductor L2 is electrically connected to the anode of the diode D10, the cathode of the diode D10, one end of the capacitor C16, one end of the capacitor C17, one end of the capacitor C18, and one end of the resistor R27 are all electrically connected to the positive electrode of the electrolytic capacitor CE3, and the other end of the capacitor C21, the other end of the capacitor C16, the other end of the capacitor C17, the other end of the capacitor C18, and the other end of the resistor R27 are all electrically connected to the negative electrode of the electrolytic capacitor CE3.

[0026] Further, the power-off maintenance judgment circuit includes a resistor R2, a resistor R4, a resistor R5, a capacitor C1, a capacitor C22 and a depletion-type MOS tube Q2; one end of the resistor R4 is used as an input end of the power-off maintenance judgment circuit, the other end of the resistor R4 is used as a power-off maintenance end of the power-off maintenance judgment circuit, and the gate of the MOS tube Q2 is used as a feedback end of the power-off maintenance judgment circuit;

[0027] One end of the resistor R4 and one end of the resistor R5 are electrically connected to one end of the resistor R2, the other end of the resistor R4, the other end of the resistor R5, one end of the capacitor C1, and one end of the capacitor C22 are electrically connected to the source of the depletion-type MOS transistor Q2, the other end of the resistor R2 is electrically connected to the drain of the depletion-type MOS transistor Q2, and the other end of the capacitor C1 and the other end of the capacitor C22 are grounded;

[0028] When the depletion-type MOS transistor Q2 is turned on, the first sustaining voltage is generated.

[0029] Furthermore, it also includes a current regulating module; the output end of the current regulating module is electrically connected to the control end of the signal control module;

[0030] The current regulating module comprises a dip switch K1 and a resistor R31; one end of the resistor R31 is used as the output end of the current regulating module; one side pin of the dip switch K1 is electrically connected to the other end of the resistor R31 respectively, and the other side pin of the dip switch K1 is grounded.

[0031] Further, the dimmer input module includes a variable resistor VR2, a rectifier bridge DB2, a MOS tube Q7, a resistor R56, a resistor R57, a resistor R58, a resistor R59, a resistor R60, a resistor R61, a resistor R62, a resistor R67, a capacitor C23, a capacitor C24, a voltage regulator diode DZ1, a transistor Q5, a transistor Q6, a photocoupler U7 and a photocoupler U8; pins 3 and 2 of the rectifier bridge DB3 are used as input ends of the dimmer input module, and the emitter of the photocoupler U7 and one end of the resistor R62 are used as output ends of the dimmer input module;

[0032] Pin 4 of the rectifier bridge DB2 is grounded, pin 1 of the rectifier bridge DB2, one end of the resistor R56, and the emitter of the transistor Q6 are all electrically connected to the drain of the MOS tube Q7, the other end of the resistor R56 and the base of the transistor Q6 are all electrically connected to the emitter of the transistor Q5, one end of the resistor R57 and the collector of the transistor Q6 are all electrically connected to the base of the transistor Q5, the other end of the resistor R57 is electrically connected to one end of the resistor R58, the other end of the resistor R58 is electrically connected to one end of the resistor R59, the other end of the resistor R59 is grounded, the collector of the transistor Q5 is electrically connected to the anode of the photocoupler U7, the collector of the photocoupler U7 is connected to the 3V3 power supply, the emitter of the photocoupler U7 is electrically connected to the base of the transistor Q5, and the collector of the photocoupler U7 is electrically connected to the anode of the photocoupler U7. One end of the resistor R61 is electrically connected, and the other end of the resistor R61 is grounded. The cathode of the photoelectric coupler U7, the collector of the photoelectric coupler U8, and one end of the capacitor C24 are all electrically connected to the cathode of the voltage stabilizing diode DZ1, and the other end of the capacitor C24 is all grounded to the anode of the voltage stabilizing diode DZ1. The anode of the photoelectric coupler U8 is electrically connected to the other end of the resistor R62, and the cathode of the photoelectric coupler U8 is grounded. The emitter of the photoelectric coupler U8 and one end of the resistor R60 are all electrically connected to one end of the resistor R67, and the other end of the resistor R67 and one end of the capacitor C23 are all electrically connected to the gate of the MOS tube Q7. The other end of the resistor R60, the other end of the capacitor C23, and the source of the MOS tube Q7 are all grounded.

[0033] Further, the AC detection module includes a diode D20, a diode D6, a resistor R80, a resistor R81, a resistor R82, a resistor R88, a resistor R85, a resistor R83, a resistor R84, a voltage regulator diode DZ2, a voltage regulator diode DZ3, a capacitor C80, a capacitor C81, a transistor Q8 and a photocoupler U9; the anode of the diode D20 and the anode of the diode D6 are both used as the input end of the AC detection module, and one end of the resistor R84 is used as the output end of the AC detection module;

[0034] The cathode of the diode D20 and the cathode of the diode D6 are electrically connected to one end of the resistor R80, the other end of the resistor R80 is electrically connected to one end of the resistor R81, the other end of the resistor R81 is electrically connected to the cathode of the voltage-stabilizing diode DZ2, the anode of the voltage-stabilizing diode DZ2, one end of the resistor R82, one end of the capacitor C80, and the cathode of the voltage-stabilizing diode DZ3 are electrically connected to one end of the resistor R88, the other end of the resistor R88 is electrically connected to the base of the transistor Q8, the other end of the resistor R82, the capacitor C80, and the cathode of the voltage-stabilizing diode DZ3 are electrically connected to one end of the resistor R88. The other end, the anode of the voltage-stabilizing diode DZ3 and the emitter of the transistor Q8 are all grounded, the collector of the transistor Q8 is electrically connected to the cathode of the photoelectric coupler U9, the anode of the photoelectric coupler U9 is electrically connected to one end of the resistor R85, the other end of the resistor R85 is connected to the VDD power supply, the collector of the photoelectric coupler U9 is connected to the 3V3 power supply, the emitter of the photoelectric coupler U9, one end of the resistor R83, and one end of the capacitor C81 are all electrically connected to the other end of the resistor R84, and the other end of the resistor R83 and the other end of the capacitor C81 are all grounded.

[0035] Further, the VBUS voltage detection module includes a resistor R64, a resistor R66 and a capacitor C27; one end of the resistor R64 is used as an input end of the VBUS voltage detection module, and the other end of the resistor R64 is used as an output end of the VBUS voltage detection module;

[0036] The other end of the resistor R64 and one end of the resistor R66 are both electrically connected to one end of the capacitor C27, and the other end of the resistor R66 and the other end of the capacitor C27 are both grounded.

[0037] Furthermore, the voltage conversion module includes a capacitor C6, a capacitor C11, a capacitor C12 and a linear voltage regulator chip U3; the input end of the linear voltage regulator chip U3 is used as the input end of the voltage conversion module, and the output end of the linear voltage regulator chip U3 is used as the output end of the voltage conversion module;

[0038] One end of the capacitor C11 is electrically connected to the input end of the linear voltage regulator chip U3, one end of the capacitor C6 and one end of the capacitor C12 are electrically connected to the output end of the linear voltage regulator chip U3, and the other end of the capacitor C11, the other end of the capacitor C6, the other end of the capacitor C12 and the ground end of the linear voltage regulator chip U3 are all grounded;

[0039] The linear voltage regulator chip U3 is a 3.3V linear voltage regulator chip.

[0040] The technical solution provided by the utility model can include the following beneficial effects: the AC detection module is used to isolate and detect the input signal of the rectifier bridge DB1 and transmit it to the signal control module, so that the signal control module can read the initial input AC power information without being affected by the disturbance of the external power supply; the VBUS voltage detection module is used to detect the output voltage of the main output unit and transmit it to the signal control module, so that the signal control module can read the voltage information of the main circuit after AC conversion to DC; finally, the signal control module comprehensively judges whether the working status of the entire LED driving power supply is normal, in preparation for subsequent function expansion, such as identifying the power-on status of the AC, confirming whether to turn on the dimming function, or timely shutting down the subsequent circuit after the AC power is cut off by detecting AC and VBUS.

[0041] The dimmer input module is used to isolate the dimming control signal of the receiving dimmer and transmit it to the signal control module, so that the signal control module is not affected by the disturbance of the external dimmer when receiving the dimming control signal; the signal control module is used to receive the dimming control signal to generate a digital signal of the dimming control signal and transmit it to the dimming output module, so that the dimming output module can generate a dimming signal according to the digital signal of the dimming control signal one by one, accurately realize the dimming function, and at the same time, can feedback the digital signal of the dimming signal to the signal control module, so that the signal control module can obtain the action status of the dimming function, and finally realize the digital signal interaction between the signal control module and the dimming output module.

[0042] More importantly, when the AC-to-DC constant voltage module of the LED driver power supply is powered off, a permanent power failure occurs only when the voltage of the main output unit drops to a preset threshold. At this time, the main output unit generates a first maintenance voltage to supply the auxiliary output unit for voltage stabilization, so that the voltage conversion module can receive the first maintenance voltage and generate a second maintenance voltage to maintain the power supply of the signal control module, so that the signal control module can realize the power-off delay memory function. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram of an LED driving power supply in one embodiment of the utility model.

[0044] Figure 2 Yes Figure 1 The circuit diagram of the signal control module is shown.

[0045] Figure 3 Yes Figure 1 The circuit diagram of the dimming output module is shown.

[0046] Figure 4 Yes Figure 1 The circuit diagram of the AC to DC constant voltage module is shown.

[0047] Figure 5 Yes Figure 4The circuit diagram of the power-off maintenance judgment circuit is shown.

[0048] Figure 6 Yes Figure 1 The circuit diagram of the current regulation module is shown.

[0049] Figure 7 Yes Figure 1 The circuit diagram of the dimmer input module is shown.

[0050] Figure 8 Yes Figure 1 The circuit diagram of the AC detection module is shown.

[0051] Fig. 9 Yes Figure 1 The circuit diagram of the VBUS voltage detection module is shown.

[0052] Fig.10 Yes Figure 1 The circuit diagram of the voltage conversion module is shown.

[0053] Among them: AC to DC constant voltage module 1, signal control module 2, voltage conversion module 3, AC detection module 4, VBUS voltage detection module 5, dimmer input module 6, dimming output module 7, main output unit 11, auxiliary output unit 12, rectifier bridge DB1, resistor R10, capacitor C13, resistor R34, capacitor C14, diode D3, diode D4, inductor L3, capacitor CB2, capacitor C15, common mode inductor LF3, resistor R33, diode D11, resistor R 32, resistor R23, resistor R25, resistor R16, resistor R24, resistor R38, resistor R39, resistor R40, capacitor C4, MOS tube Q4, digital dimming driver chip U2, front side processing circuit 13, transformer T1, transformer T2, resistor R12, resistor R35, capacitor C2, electrolytic capacitor EC2, diode D8, power-off maintenance judgment circuit 111, capacitor C16, capacitor C17, capacitor C18, capacitor C21, inductor L2, diode D10 , resistor R27, electrolytic capacitor CE3, resistor R2, resistor R4, resistor R5, capacitor C1, capacitor C22, depletion type MOS tube Q2, current regulation module 8, dip switch K1, resistor R31, variable resistor VR2, rectifier bridge DB2, MOS tube Q7, resistor R56, resistor R57, resistor R58, resistor R59, resistor R60, resistor R61, resistor R62, resistor R67, capacitor C23, capacitor C24, voltage regulator diode DZ1, transistor Q5, transistor Q6, photocoupler U7, photocoupler U8, diode D20, diode D6, resistor R80, resistor R81, resistor R82, resistor R88, resistor R85, resistor R83, resistor R84, Zener diode DZ2, Zener diode DZ3, capacitor C80, capacitor C81, transistor Q8, photocoupler U9, resistor R64, resistor R66, capacitor C27, capacitor C6, capacitor C11, capacitor C12, linear voltage regulator chip U3. DETAILED DESCRIPTION

[0054] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0055] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0056] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0057] Combine the following Figures 1 to 10 , describing an LED driving power supply of an embodiment of the utility model.

[0058] An LED driving power supply includes an AC-to-DC constant voltage module 1, a signal control module 2, a voltage conversion module 3, an AC detection module 4, a VBUS voltage detection module 5, a dimmer input module 6 and a dimming output module 7; the AC-to-DC constant voltage module 1 includes a main output unit 11, a secondary output unit 12 and a rectifier bridge DB1;

[0059] The output end of the main output unit 11 is electrically connected to the input end of the VBUS voltage detection module 5, and the output end of the VBUS voltage detection module 5 is electrically connected to the first detection end of the signal control module 2;

[0060] The input end of the rectifier bridge DB1 is electrically connected to the input end of the AC detection module 4, and the output end of the AC detection module 4 is electrically connected to the second detection end of the signal control module 2;

[0061] The signal end of the dimmer input module 6 is electrically connected to the first signal end of the signal control module 2; the signal end of the dimming output module 7 is electrically connected to the second signal end of the signal control module 2;

[0062] The power-off maintaining terminal of the main output unit 11 is electrically connected to the output terminal of the auxiliary output unit 12, the output terminal of the auxiliary output unit 12 is electrically connected to the input terminal of the voltage conversion module 3, and the output terminal of the voltage conversion module 3 is electrically connected to the power supply terminal of the signal control module 2 and the feedback terminal of the main output unit 11 respectively;

[0063] The AC detection module 4 is used to isolate and detect the input signal of the rectifier bridge DB1 and transmit it to the signal control module 2;

[0064] The VBUS voltage detection module 5 is used to detect the output voltage of the main output unit 11 and transmit it to the signal control module 2;

[0065] The dimmer input module 6 is used to isolate and receive the dimming control signal of the dimmer and transmit it to the signal control module 2;

[0066] The signal control module 2 is used to receive the dimming control signal to generate a digital signal of the dimming control signal and transmit it to the dimming output module 7;

[0067] The dimming output module 7 is used to receive the digital signal of the dimming control signal to generate a dimming signal, and to feed back the generated digital signal of the dimming signal to the signal control module 2;

[0068] When the AC to DC constant voltage module 1 is powered off, if the voltage of the main output unit 11 drops to a preset threshold, the main output unit 11 generates a first maintenance voltage, and the voltage conversion module 3 receives the first maintenance voltage through the auxiliary output unit 11 and generates a second maintenance voltage.

[0069] The utility model proposes a preferred embodiment of an LED driving power supply, such as Figure 1 As shown, the AC detection module 4 is used to isolate and detect the input signal of the rectifier bridge DB1 and transmit it to the signal control module 2, so that the signal control module 2 can read the initial input AC power information without being affected by the disturbance of the external power supply; the VBUS voltage detection module 5 is used to detect the output voltage of the main output unit 11 and transmit it to the signal control module 2, so that the signal control module 2 can read the voltage information of the main circuit after AC conversion to DC; finally, the signal control module 2 comprehensively judges whether the working status of the entire LED driving power supply is normal, in preparation for subsequent function expansion, such as identifying the power-on status of the AC, confirming whether to turn on the dimming function, or timely shutting down the subsequent circuit after the AC power is cut off by detecting AC and VBUS.

[0070] The dimmer input module 6 is used to isolate the dimming control signal of the dimmer and transmit it to the signal control module 2, so that the signal control module 2 is not affected by the disturbance of the external dimmer when receiving the dimming control signal; the signal control module 2 is used to receive the dimming control signal to generate a digital signal of the dimming control signal and transmit it to the dimming output module 7, so that the dimming output module 7 can generate a dimming signal according to the digital signal of the dimming control signal one by one, accurately realize the dimming function, and at the same time, can feedback the digital signal of the dimming signal to the signal control module 2, so that the signal control module 2 can obtain the action status of the dimming function, and finally realize the digital signal interaction between the signal control module 2 and the dimming output module 7.

[0071] More importantly, when the AC to DC constant voltage module 1 of the LED driving power supply is powered off, a permanent power failure occurs only when the voltage of the main output unit 11 drops to a preset threshold. At this time, the main output unit 11 generates a first maintenance voltage to supply the auxiliary output unit 11 for voltage stabilization, so that the voltage conversion module 3 can receive the first maintenance voltage and generate a second maintenance voltage to maintain the power supply of the signal control module 2, so that the signal control module 2 can realize the power-off delay memory function.

[0072] In summary, the power-off delay memory function, detection function and dimming function of this LED driver power supply have stronger anti-interference ability and higher accuracy, and are suitable for more application scenarios.

[0073] Furthermore, the signal control module 2 is an MCU system, and the signal control module 2 is connected to the dimming output module 7 via serial communication;

[0074] The dimming output module 7 includes a resistor R10, a capacitor C13, a resistor R34, a capacitor C14, a diode D3, a diode D4, an inductor L3, a capacitor CB2, a capacitor C15, a common mode inductor LF3, a resistor R33, a diode D11, a resistor R32, a resistor R23, a resistor R25, a resistor R16, a resistor R24, a resistor R38, a resistor R39, a resistor R40, a capacitor C4, a MOS tube Q4 and a digital dimming driver chip U2; the DIM1 terminal and the DIM2 terminal of the digital dimming driver chip U2 are both used as signal terminals of the dimming output module 7, and one end and the other end of the resistor R33 are both used as output terminals of the dimming output module 7;

[0075] The VCC end of the digital dimming driver chip U2 is electrically connected to one end of the capacitor C13, and the other end of the capacitor C13 is grounded. The VIN end of the digital dimming driver chip U2 is electrically connected to one end of the resistor R10. The other end of the resistor R10, one end of the capacitor C14, the cathode of the diode D3, the cathode of the diode D4, one end of the capacitor CB2, one end of the capacitor C15, and the 4 pins of the common-mode inductor LF3 are all connected to the VBUS power supply. The other end of the capacitor C14 is electrically connected to one end of the resistor R34, the other end of the resistor R34, the anode of the diode D3, the anode of the diode D4, and one end of the inductor L3 are all electrically connected to the drain of the MOS tube Q4. The other end of the capacitor CB2, the other end of the capacitor C15, the other end of the inductor L3, and the 1 pin of the common-mode inductor LF3 are all grounded. The 3 pins of the common-mode inductor LF3 are electrically connected to one end of the resistor R33, and the 2 pins of the common-mode inductor LF3 are electrically connected to the other end of the resistor R33. The anode of the diode D11 is electrically connected to one end of the resistor R32, the other end of the resistor R32, the other end of the resistor R23, and one end of the resistor R25 are electrically connected to the gate of the MOS tube Q4, one end of the resistor R16 and one end of the capacitor C4 are electrically connected to the ISNS end of the digital dimming driver chip U2, the other end of the resistor R16, the other end of the resistor R25, one end of the resistor R38, one end of the resistor R39, and one end of the resistor R40 are electrically connected to the gate of the MOS tube Q4, the other end of the resistor R38, the other end of the resistor R39, and the other end of the resistor R40 are grounded, the other end of the capacitor C4, one end of the resistor R24, and the GND end of the digital dimming driver chip U2 are grounded, and the other end of the resistor R24 ​​is electrically connected to the CFG end of the digital dimming driver chip U2.

[0076] In this embodiment, Figure 2 and Figure 3 As shown, the signal control module 2 is a minimum MCU system composed of an MCU chip and its peripheral circuits, which realizes two-way communication with the dimming output module 7 through serial communication, and the communication instruction is a ten-bit data composed of 0 and 1, including a start bit and an end bit; the signal control module 2 can receive the dimming control signal from the dimmer input module 6, convert it into a digital signal, and control the dimming output module 7 to drive subsequent dimming with the digital signal, so that the dimming output module 7 can realize dimming by accurately corresponding to the dimming control signal through the digital signal, avoiding deviation of the dimming action.

[0077] More importantly, the dimming output module 7 builds a digital dimming circuit with the digital dimming driver chip U2 as the core. It can not only receive digital signals for dimming, but also feed back the digital signal of the dimming signal to the signal control module 2, so that the signal control module 2 can read the circuit parameters of the dimming output module 7, such as input voltage, output voltage, output current, etc., and read the operating status of the dimming output module 7, such as normal working state, open short circuit state, undervoltage state, etc.

[0078] Specifically, in the dimming output module 7, the resistor R10 is an input current limiting resistor, which is used to limit the input current of U2 and improve the surge resistance of U2. Diodes D3 and D4 are freewheeling diodes, which are used to provide a current loop for the circuit when the MOS tube Q4 is in the off state to ensure continuous output of power. Resistor R34 and capacitor C14 are absorption circuits, which are used to absorb the voltage spikes generated on the diodes D3 and D4 and adjust the switching speed. Inductor L3 is an energy storage inductor, which is used to store and release energy when the circuit is running. Capacitor CB2 is a filter capacitor, which is used to filter the ripple current at the output end. Common mode inductor LF3 is used to filter the high-frequency signal of the circuit to prevent EMC from exceeding the standard. MOS tube Q4 is used to control the opening and closing of the main circuit to achieve energy conversion output. Resistors R38, R39 and R40 are current sampling resistors. The digital dimming driver chip U2 calculates the corresponding duty cycle to control the switching time of the MOS tube Q4 through the voltage signal of the sampling resistor, thereby achieving the designed output current (dimming signal). Diode D11, resistor R32, resistor R23, and resistor R25 form a driving circuit. The digital dimming driver chip U2 adjusts the switching speed of the MOS tube Q4 through this circuit to optimize the temperature and EMC performance of the device. Resistor R26 and capacitor C4 are used to filter the current overshoot spikes of the main power circuit to prevent the control logic of the digital dimming driver chip U2 from being incorrectly controlled due to voltage spikes, resulting in abnormal power supply operation. Resistor R24 ​​is a circuit parameter setting resistor, which is used to set the communication pin output mode of the digital dimming driver chip U2. Capacitor C13 is a power supply filter capacitor, which is used to supply power to the digital dimming driver chip U2 for energy storage and filtering, and prevent the digital dimming driver chip U2 from being disturbed during operation.

[0079] It should be noted that the relationship between the temperature and EMC performance of the MOS tube Q4 is: when the switching speed of the MOS tube Q4 is fast, the temperature is low and the EMC performance is poor; when the switching speed of the MOS tube Q4 is slow, the temperature is high and the EMC performance is good. This is a performance balance process. Therefore, controlling the switching speed of the MOS tube Q4 is to control the slope of the MOS tube Q4 when it rises and falls. When the switching speed is fast, the slope of the MOS tube Q4 changes steeply, the overlapping area of ​​the Vds and Ids of the MOS tube Q4 is small, the loss is small, and the temperature is low, but when the Vds of the MOS tube Q4 is Fourier expanded, the high-order harmonic interference is large, the energy is strong, and the EMC performance will be poor; similarly, when the switching speed is slow, the slope of the MOS tube Q4 changes gently, the overlapping area of ​​the Vds and Ids of the MOS tube Q4 is large, the loss is large, and the temperature is high, but when the Vds of the MOS tube Q4 is Fourier expanded, the high-order harmonic interference is small, the energy is small, and the EMC performance will be good. In summary, the digital dimming driver chip U2 limits and adjusts the switching speed of the MOS tube Q4 through a driver circuit formed by a diode D11, a resistor R32, a resistor R23, and a resistor R25.

[0080] Furthermore, the AC to DC constant voltage module 1 further includes a front-side processing circuit 13, a transformer T1 and a transformer T2 for rectifying, reducing and stabilizing an external AC power supply; the output end of the front-side processing circuit 13 is electrically connected to the primary windings of the transformer T1 and the transformer T2, respectively, and the secondary windings of the transformer T1 and the transformer T2 are electrically connected to the input ends of the main output unit 11 and the auxiliary output unit 12, respectively;

[0081] The main output unit 11 includes a resistor R12, a resistor R35, a capacitor C2, an electrolytic capacitor EC2, a diode D8 and a power-off maintenance judgment circuit 111; the anode of the diode D8 and the cathode of the electrolytic capacitor EC2 are used as the input end of the main output unit 11, the anode of the electrolytic capacitor EC2 is used as the output end of the main output unit 11, the power-off maintenance end of the power-off maintenance judgment circuit 111 is used as the power-off maintenance end of the main output unit 11, and the feedback end of the power-off maintenance judgment circuit 111 is used as the feedback end of the main output unit 11;

[0082] One end of the resistor R12 and one end of the resistor R35 are electrically connected to the anode of the diode D8, the other end of the resistor R12 and the other end of the resistor R35 are electrically connected to one end of the capacitor C2, the other end of the capacitor C2, the cathode of the diode D8, and the positive electrode of the electrolytic capacitor EC2 are electrically connected to the input end of the power-off maintenance judgment circuit 111;

[0083] The power-off maintenance judgment circuit 111 is used to generate a first maintenance voltage when the voltage of the power-off maintenance judgment circuit 111 drops to a preset threshold when the AC-to-DC constant voltage module 1 is powered off;

[0084] The auxiliary output unit 12 includes a capacitor C16, a capacitor C17, a capacitor C18, a capacitor C21, an inductor L2, a diode D10, a resistor R27 and an electrolytic capacitor CE3; one end and the other end of the capacitor C21 are used as input ends of the auxiliary output unit 12, and the positive electrode of the electrolytic capacitor CE3 is used as an output end of the auxiliary output unit 12;

[0085] One end of capacitor 21 is electrically connected to one end of inductor L2, the other end of inductor L2 is electrically connected to the anode of diode D10, the cathode of diode D10, one end of capacitor C16, one end of capacitor C17, one end of capacitor C18, and one end of resistor R27 are all electrically connected to the positive electrode of electrolytic capacitor CE3, and the other end of capacitor 21, the other end of capacitor C16, the other end of capacitor C17, the other end of capacitor C18, and the other end of resistor R27 are all electrically connected to the negative electrode of electrolytic capacitor CE3.

[0086] In this embodiment, Figure 4 and Figure 5 As shown, the main output unit 11 and the auxiliary output unit 12 of the AC to DC constant voltage module 1 are divided by a transformer. The AC to DC constant voltage module 1 usually first uses a front-side processing circuit 13 for rectifying, reducing and stabilizing an external AC power supply to process the waveform of the AC power supply, and then obtains a constant DC voltage, which is then reduced by transformers with different windings (transformers T1 and T2) to match the subsequent main output unit 11 and negative output unit 12; wherein the main output unit 11 can directly output power after being reduced by the transformer T1, while the auxiliary output unit 12 needs further voltage conversion by the voltage conversion module 3 after being reduced by the transformer T2 to obtain the voltage matching the signal control module 2.

[0087] In the main output unit 11, when the AC to DC constant voltage module 1 is normally powered, the diode D8 is turned on, and the charging and discharging circuit composed of the resistor R12, the resistor R35 and the capacitor C2 charges the capacitor C2 and the electrolytic capacitor EC2. At the same time, the electrolytic capacitor EC2 plays a role in voltage stabilization, so that the main output unit 11 stably outputs the VBUS power supply voltage, thereby the power-off maintenance judgment circuit 111 is between the VBUS voltage and the feedback voltage of the voltage conversion module 3 (such as Figure 4 and 5 Under the maintenance of 3V3 in the power supply, the power supply is cut off to maintain the terminal (such as Figure 4 and 5 +15V in the power supply) does not output the first maintenance voltage; only when the AC to DC constant voltage module 1 is powered off, the VBUS voltage received by the power-off maintenance judgment circuit 111 begins to decrease. When it drops to a preset threshold, the power-off maintenance judgment circuit 111 outputs the first maintenance voltage to the auxiliary output unit 12, that is, for example, when the power is off from +15V to +6V, the power-off maintenance terminal outputs +6V, so that the auxiliary output unit 12 obtains the maintenance voltage, and the subsequent voltage conversion module 3 continues to convert the voltage for power supply.

[0088] In the auxiliary output unit 12, when the power is normally supplied, a series of voltage processing such as filtering and voltage stabilization is performed on the voltage received from the secondary winding of the transformer T2, and a stable voltage is output by the electrolytic capacitor CE3 to the voltage conversion module 3 for conversion; at the same time, when the power is off, the capacitor CE3 stabilizes the first maintenance voltage transmitted from the power-off maintenance end of the main output unit 11 and outputs it to the voltage conversion module 3.

[0089] Furthermore, the power-off maintenance judgment circuit 111 includes a resistor R2, a resistor R4, a resistor R5, a capacitor C1, a capacitor C22 and a depletion-type MOS transistor Q2; one end of the resistor R4 is used as an input end of the power-off maintenance judgment circuit 111, the other end of the resistor R4 is used as a power-off maintenance end of the power-off maintenance judgment circuit 111, and the gate of the MOS transistor Q2 is used as a feedback end of the power-off maintenance judgment circuit 111;

[0090] One end of the resistor R4 and one end of the resistor R5 are electrically connected to one end of the resistor R2, the other end of the resistor R4, the other end of the resistor R5, one end of the capacitor C1, and one end of the capacitor C22 are electrically connected to the source of the depletion-type MOS transistor Q2, the other end of the resistor R2 is electrically connected to the drain of the depletion-type MOS transistor Q2, and the other end of the capacitor C1 and the other end of the capacitor C22 are grounded;

[0091] When the depletion-type MOS transistor Q2 is turned on, a first sustaining voltage is generated.

[0092] In this embodiment, the preset threshold of the power-off maintenance judgment circuit 11 is actually the conduction voltage of the MOS tube Q2, that is, for example, in normal operation, the gate voltage of Q2 is 3.3V, the source voltage is 15V, the Vgs voltage is -11.7V, Q2 is in the cut-off state, and the VBUS power cannot be transmitted to the +15V (power-off maintenance end) line through Q2; when the AC power is cut off, the source +15V voltage starts to lose power, and when it drops to +6V, Q2 starts to turn on, and the +6V voltage can be output to the auxiliary output unit 12.

[0093] It should be noted that, because the control methods of depletion-type MOS tubes and enhancement-type MOS tubes are different, the Vgs (gate voltage) of the depletion-type MOS tube can be controlled by positive, zero, and negative voltages, while the enhancement-type MOS tube must make Vgs>Vgs(th) (gate threshold voltage). Therefore, the on-state voltage applied to the gate of the depletion-type MOS tube can be positive, zero, or negative voltage, while the enhancement-type MOS tube can only be a positive voltage. Therefore, the use of a depletion-type MOS tube for MOS tube Q2 can be applicable to more scenarios where different voltages drive the on-state.

[0094] Furthermore, it also includes a current regulating module 8; the output end of the current regulating module 8 is electrically connected to the control end of the signal control module 2;

[0095] The current regulating module 8 includes a dip switch K1 and a resistor R31; one end of the resistor R31 is used as the output end of the current regulating module 8; one side pin of the dip switch K1 is electrically connected to the other end of the resistor R31, and the other side pin of the dip switch K1 is grounded.

[0096] In this embodiment, Figure 6 As shown, a current regulating module 8 is also provided for the operator to manually adjust the maximum output current of the dimming signal when necessary. Therefore, the current regulating module 8 is controlled in the form of a dip switch K1, and the dip switch K1 inputs a digital signal to control the signal control module 2 to achieve current regulation, and uses the digital signal to achieve precise regulation.

[0097] Further, the dimmer input module 6 includes a variable resistor VR2, a rectifier bridge DB2, a MOS tube Q7, a resistor R56, a resistor R57, a resistor R58, a resistor R59, a resistor R60, a resistor R61, a resistor R62, a resistor R67, a capacitor C23, a capacitor C24, a voltage regulator diode DZ1, a transistor Q5, a transistor Q6, a photocoupler U7 and a photocoupler U8; pins 3 and 2 of the rectifier bridge DB3 are used as input ends of the dimmer input module 6, and the emitter of the photocoupler U7 and one end of the resistor R62 are used as output ends of the dimmer input module 6;

[0098] Pin 4 of the rectifier bridge DB2 is grounded, pin 1 of the rectifier bridge DB2, one end of the resistor R56, and the emitter of the transistor Q6 are all electrically connected to the drain of the MOS tube Q7, the other end of the resistor R56 and the base of the transistor Q6 are all electrically connected to the emitter of the transistor Q5, one end of the resistor R57 and the collector of the transistor Q6 are all electrically connected to the base of the transistor Q5, the other end of the resistor R57 is electrically connected to one end of the resistor R58, the other end of the resistor R58 is electrically connected to one end of the resistor R59, the other end of the resistor R59 is grounded, the collector of the transistor Q5 is electrically connected to the anode of the photocoupler U7, the collector of the photocoupler U7 is connected to the 3V3 power supply, the emitter of the photocoupler U7 is electrically connected to the One end of the resistor R61 is electrically connected, and the other end of the resistor R61 is grounded. The cathode of the photoelectric coupler U7, the collector of the photoelectric coupler U8, and one end of the capacitor C24 are all electrically connected to the cathode of the voltage stabilizing diode DZ1, and the other end of the capacitor C24 is all grounded to the anode of the voltage stabilizing diode DZ1. The anode of the photoelectric coupler U8 is electrically connected to the other end of the resistor R62, and the cathode of the photoelectric coupler U8 is grounded. The emitter of the photoelectric coupler U8 and one end of the resistor R60 are all electrically connected to one end of the resistor R67, and the other end of the resistor R67 and one end of the capacitor C23 are all electrically connected to the gate of the MOS tube Q7. The other end of the resistor R60, the other end of the capacitor C23, and the source of the MOS tube Q7 are all grounded.

[0099] In this embodiment, Figure 7 As shown, the dimmer input module 6 has a bidirectional signal transmission function and is controlled by the signal control module 2; when in the signal receiving state, DALI_TX is at a low level, and the dimming control signal is transmitted from DA1 / DA2 to DALI_RX; when the circuit is in the signal sending state, DALI_TX is at a high level, and the signal that the signal control module 2 needs to feedback is transmitted from DALI_TX to DA1 / DA2.

[0100] The following will analyze in detail the working process in two different states:

[0101] In the receiving state, DALI_TX is in a low level state, and the signal is transmitted from DA1 / DA2 to DALI_RX; DALI_TX is in a low level state, and the U8B side of the photocoupler U8 is cut off. When DA1 / DA2 is a high voltage, after rectification by the rectifier bridge DB2, the current flows through the constant current circuit composed of transistors Q5 and Q6, and then the current flows through the U8B side of the photocoupler U8 and the Zener diode DZ1. At this time, the U7B side of the photocoupler U7 is turned on, and DALI_RX is a high level; when DA1 / DA2 is a low voltage, the loop capacitor DB2, transistor Q5, transistor Q6, photocoupler U7, and Zener diode DZ1 have no current, and DALI_RX is a low level; so when in the receiving state, the DALI_RX signal positively follows the DA1 / DA2 signal;

[0102] In the sending state, when DALI_TX is at a high level, the U8B side of the photocoupler U8 is turned on, and the DA1 / DA2 signal passes through DB2, Q5, Q6, U7A, U8B, and Q7, so that Q7 is in the on state, and the Vds voltage of Q7 is at a low level, thereby pulling down the DA1 / DA2 signal; when DALI_TX is at a low level, the photocoupler U8 is cut off, and the DA1 / DA2 signal passes through DB2, Q5, Q6, U7A, U8B, and DZ1, so that Q7 is in the off state, and the Vds voltage of Q7 is at a high level, and the DA1 / DA2 signal is at a high level; so when in the sending state, the DALI_TX signal is opposite to the DA1 / DA2 signal.

[0103] Further, the AC detection module 4 includes a diode D20, a diode D6, a resistor R80, a resistor R81, a resistor R82, a resistor R88, a resistor R85, a resistor R83, a resistor R84, a voltage regulator diode DZ2, a voltage regulator diode DZ3, a capacitor C80, a capacitor C81, a transistor Q8 and a photocoupler U9; an anode of the diode D20 and an anode of the diode D6 are both used as input terminals of the AC detection module 4, and one end of the resistor R84 is used as an output terminal of the AC detection module 4;

[0104] The cathode of the diode D20 and the cathode of the diode D6 are electrically connected to one end of the resistor R80, the other end of the resistor R80 is electrically connected to one end of the resistor R81, the other end of the resistor R81 is electrically connected to the cathode of the Zener diode DZ2, the anode of the Zener diode DZ2, one end of the resistor R82, one end of the capacitor C80, and the cathode of the Zener diode DZ3 are electrically connected to one end of the resistor R88, the other end of the resistor R88 is electrically connected to the base of the transistor Q8, the other end of the resistor R82 and the other end of the capacitor C80 are electrically connected to the base of the transistor Q8, and the other end of the resistor R82 and the other end of the capacitor C80 are electrically connected to the cathode of the Zener diode DZ2. The end, the anode of the voltage-stabilizing diode DZ3 and the emitter of the transistor Q8 are all grounded, the collector of the transistor Q8 is electrically connected to the cathode of the photoelectric coupler U9, the anode of the photoelectric coupler U9 is electrically connected to one end of the resistor R85, the other end of the resistor R85 is connected to the VDD power supply, the collector of the photoelectric coupler U9 is connected to the 3V3 power supply, the emitter of the photoelectric coupler U9, one end of the resistor R83, one end of the capacitor C81 are all electrically connected to the other end of the resistor R84, and the other end of the resistor R83 and the other end of the capacitor C81 are all grounded.

[0105] In this embodiment, Figure 8 As shown, the AC detection module 4 uses the photoelectric coupler U9 to isolate the high and low voltages, so that the signal control module 2 is not affected by the detection end. The shaping, filtering and voltage stabilization circuits formed on the left side of the photoelectric coupler U9 collect the AC power information, which is then transmitted to the signal control module 2 for reading by the photoelectric coupling.

[0106] Further, the VBUS voltage detection module 5 includes a resistor R64, a resistor R66 and a capacitor C27; one end of the resistor R64 is used as an input end of the VBUS voltage detection module 5, and the other end of the resistor R64 is used as an output end of the VBUS voltage detection module 5;

[0107] The other end of the resistor R64 and one end of the resistor R66 are electrically connected to one end of the capacitor C27, and the other end of the resistor R66 and the other end of the capacitor C27 are grounded.

[0108] In this embodiment, Fig. 9 As shown, the VBUS voltage detection module 5 uses a voltage divider circuit to collect the VBUS voltage, that is, the main circuit voltage after the AC to DC constant voltage module 1 converts AC into DC, and transmits it to the signal control module 2 for reading.

[0109] Furthermore, the voltage conversion module 3 includes a capacitor C6, a capacitor C11, a capacitor C12 and a linear voltage regulator chip U3; the input end of the linear voltage regulator chip U3 is used as the input end of the voltage conversion module 3, and the output end of the linear voltage regulator chip U3 is used as the output end of the voltage conversion module 3;

[0110] One end of the capacitor C11 is electrically connected to the input end of the linear voltage regulator chip U3, one end of the capacitor C6 and one end of the capacitor C12 are electrically connected to the output end of the linear voltage regulator chip U3, and the other end of the capacitor C11, the other end of the capacitor C6, the other end of the capacitor C12 and the ground end of the linear voltage regulator chip U3 are all grounded;

[0111] The linear voltage regulator chip U3 is a 3.3V linear voltage regulator chip.

[0112] In this embodiment, Fig.10 As shown, the voltage conversion module 3 has the same conversion principle when it is powered normally and when it is powered off, and it converts the target voltage according to the specifications of the linear voltage regulator chip U3; and because the working voltage of the signal control module 2 is 3.3V, the linear voltage regulator chip U3 is a 3.3V linear voltage regulator chip.

[0113] Other structures and operations of an LED driving power supply according to an embodiment of the utility model are known to ordinary technicians in the field and will not be described in detail here.

[0114] In the description of this specification, the description with reference to the terms "embodiment", "example", 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 utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0115] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An LED driving power supply, characterized in that: It includes an AC to DC constant voltage module, a signal control module, a voltage conversion module, an AC detection module, a VBUS voltage detection module, a dimmer input module and a dimming output module; the AC to DC constant voltage module includes a main output unit, a sub-output unit and a rectifier bridge DB1; The output end of the main output unit is electrically connected to the input end of the VBUS voltage detection module, and the output end of the VBUS voltage detection module is electrically connected to the first detection end of the signal control module; The input end of the rectifier bridge DB1 is electrically connected to the input end of the AC detection module, and the output end of the AC detection module is electrically connected to the second detection end of the signal control module; The signal end of the dimmer input module is electrically connected to the first signal end of the signal control module; the signal end of the dimming output module is electrically connected to the second signal end of the signal control module; The power-off maintaining terminal of the main output unit is electrically connected to the output terminal of the auxiliary output unit, the output terminal of the auxiliary output unit is electrically connected to the input terminal of the voltage conversion module, and the output terminal of the voltage conversion module is electrically connected to the power supply terminal of the signal control module and the feedback terminal of the main output unit respectively; The AC detection module is used to isolate and detect the input signal of the rectifier bridge DB1 and transmit it to the signal control module; The VBUS voltage detection module is used to detect the output voltage of the main output unit and transmit it to the signal control module; The dimmer input module is used to isolate and receive the dimming control signal of the dimmer and transmit it to the signal control module; The signal control module is used to receive the dimming control signal, generate a digital signal of the dimming control signal, and transmit it to the dimming output module; The dimming output module is used to receive the digital signal of the dimming control signal to generate a dimming signal, and generate a digital signal of the dimming signal to feed back to the signal control module; When the AC to DC constant voltage module is powered off, if the voltage of the main output unit drops to a preset threshold, the main output unit generates a first maintenance voltage, and the voltage conversion module receives the first maintenance voltage through the auxiliary output unit and generates a second maintenance voltage.

2. The LED driving power supply according to claim 1, characterized in that: The signal control module is an MCU system, and the signal control module is connected to the dimming output module through serial communication; The dimming output module includes a resistor R10, a capacitor C13, a resistor R34, a capacitor C14, a diode D3, a diode D4, an inductor L3, a capacitor CB2, a capacitor C15, a common mode inductor LF3, a resistor R33, a diode D11, a resistor R32, a resistor R23, a resistor R25, a resistor R16, a resistor R24, a resistor R38, a resistor R39, a resistor R40, a capacitor C4, a MOS tube Q4 and a digital dimming driver chip U2; the DIM1 terminal and the DIM2 terminal of the digital dimming driver chip U2 are both used as the signal terminal of the dimming output module, and one end and the other end of the resistor R33 are both used as the output terminal of the dimming output module; The VCC end of the digital dimming driver chip U2 is electrically connected to one end of the capacitor C13, the other end of the capacitor C13 is grounded, the VIN end of the digital dimming driver chip U2 is electrically connected to one end of the resistor R10, the other end of the resistor R10, one end of the capacitor C14, the cathode of the diode D3, the cathode of the diode D4, one end of the capacitor CB2, one end of the capacitor C15 and the 4 pins of the common mode inductor LF3 are all connected to the VBUS power supply, the other end of the capacitor C14 and One end of the resistor R34 is electrically connected, the other end of the resistor R34, the anode of the diode D3, the anode of the diode D4, and one end of the inductor L3 are all electrically connected to the drain of the MOS tube Q4, the other end of the capacitor CB2, the other end of the capacitor C15, the other end of the inductor L3, and the pin 1 of the common-mode inductor LF3 are all grounded, the pin 3 of the common-mode inductor LF3 is electrically connected to one end of the resistor R33, and the pin 2 of the common-mode inductor LF3 is electrically connected to the other end of the resistor R33. The resistor R23 and the cathode of the diode D11 are electrically connected to the OUT terminal of the digital dimming driver chip U2, the anode of the diode D11 is electrically connected to one end of the resistor R32, the other end of the resistor R32, the other end of the resistor R23, and one end of the resistor R25 are electrically connected to the gate of the MOS tube Q4, one end of the resistor R16 and one end of the capacitor C4 are electrically connected to the ISNS terminal of the digital dimming driver chip U2, and the other end of the resistor R16 is electrically connected to the gate of the MOS tube Q4. One end of the capacitor C4, the other end of the resistor R25, one end of the resistor R38, one end of the resistor R39, and one end of the resistor R40 are all electrically connected to the gate of the MOS tube Q4, the other end of the resistor R38, the other end of the resistor R39, and the other end of the resistor R40 are all grounded, the other end of the capacitor C4, one end of the resistor R24, and the GND end of the digital dimming driver chip U2 are all grounded, and the other end of the resistor R24 ​​is electrically connected to the CFG end of the digital dimming driver chip U2.

3. The LED driving power supply according to claim 1, characterized in that: The AC to DC constant voltage module also includes a front-side processing circuit, a transformer T1 and a transformer T2 for rectifying, reducing and stabilizing an external AC power supply; the output end of the front-side processing circuit is electrically connected to the primary windings of the transformer T1 and the transformer T2, respectively, and the secondary windings of the transformer T1 and the transformer T2 are electrically connected to the input ends of the main output unit and the auxiliary output unit, respectively; The main output unit includes a resistor R12, a resistor R35, a capacitor C2, an electrolytic capacitor EC2, a diode D8 and a power-off maintenance judgment circuit; the anode of the diode D8 and the cathode of the electrolytic capacitor EC2 are used as the input end of the main output unit, the positive electrode of the electrolytic capacitor EC2 is used as the output end of the main output unit, the power-off maintenance end of the power-off maintenance judgment circuit is used as the power-off maintenance end of the main output unit, and the feedback end of the power-off maintenance judgment circuit is used as the feedback end of the main output unit; One end of the resistor R12 and one end of the resistor R35 are electrically connected to the anode of the diode D8, the other end of the resistor R12 and the other end of the resistor R35 are electrically connected to one end of the capacitor C2, and the other end of the capacitor C2, the cathode of the diode D8, and the positive electrode of the electrolytic capacitor EC2 are electrically connected to the input end of the power-off maintenance judgment circuit; The power-off maintenance judgment circuit is used to generate the first maintenance voltage when the voltage of the power-off maintenance judgment circuit drops to the preset threshold when the AC-to-DC constant voltage module 1 is powered off; The auxiliary output unit includes a capacitor C16, a capacitor C17, a capacitor C18, a capacitor C21, an inductor L2, a diode D10, a resistor R27 and an electrolytic capacitor CE3; one end and the other end of the capacitor C21 are used as input ends of the auxiliary output unit, and the positive electrode of the electrolytic capacitor CE3 is used as the output end of the auxiliary output unit; One end of the capacitor C21 is electrically connected to one end of the inductor L2, the other end of the inductor L2 is electrically connected to the anode of the diode D10, the cathode of the diode D10, one end of the capacitor C16, one end of the capacitor C17, one end of the capacitor C18, and one end of the resistor R27 are all electrically connected to the positive electrode of the electrolytic capacitor CE3, and the other end of the capacitor C21, the other end of the capacitor C16, the other end of the capacitor C17, the other end of the capacitor C18, and the other end of the resistor R27 are all electrically connected to the negative electrode of the electrolytic capacitor CE3.

4. The LED driving power supply according to claim 3, characterized in that: The power-off maintenance judgment circuit comprises a resistor R2, a resistor R4, a resistor R5, a capacitor C1, a capacitor C22 and a depletion-type MOS transistor Q2; one end of the resistor R4 is used as an input end of the power-off maintenance judgment circuit, the other end of the resistor R4 is used as a power-off maintenance end of the power-off maintenance judgment circuit, and the gate of the MOS transistor Q2 is used as a feedback end of the power-off maintenance judgment circuit; One end of the resistor R4 and one end of the resistor R5 are electrically connected to one end of the resistor R2, the other end of the resistor R4, the other end of the resistor R5, one end of the capacitor C1, and one end of the capacitor C22 are electrically connected to the source of the depletion-type MOS transistor Q2, the other end of the resistor R2 is electrically connected to the drain of the depletion-type MOS transistor Q2, and the other end of the capacitor C1 and the other end of the capacitor C22 are grounded; When the depletion-type MOS transistor Q2 is turned on, the first sustaining voltage is generated.

5. The LED driving power supply according to claim 1, characterized in that: It also includes a current regulating module; the output end of the current regulating module is electrically connected to the control end of the signal control module; The current regulating module comprises a dip switch K1 and a resistor R31; one end of the resistor R31 is used as the output end of the current regulating module; one side pin of the dip switch K1 is electrically connected to the other end of the resistor R31 respectively, and the other side pin of the dip switch K1 is grounded.

6. The LED driving power supply according to claim 1, characterized in that: The dimmer input module includes a variable resistor VR2, a rectifier bridge DB2, a MOS tube Q7, a resistor R56, a resistor R57, a resistor R58, a resistor R59, a resistor R60, a resistor R61, a resistor R62, a resistor R67, a capacitor C23, a capacitor C24, a voltage regulator diode DZ1, a transistor Q5, a transistor Q6, a photocoupler U7 and a photocoupler U8; pins 3 and 2 of the rectifier bridge DB3 are used as input ends of the dimmer input module, and the emitter of the photocoupler U7 and one end of the resistor R62 are used as output ends of the dimmer input module; Pin 4 of the rectifier bridge DB2 is grounded, pin 1 of the rectifier bridge DB2, one end of the resistor R56, and the emitter of the transistor Q6 are all electrically connected to the drain of the MOS tube Q7, the other end of the resistor R56 and the base of the transistor Q6 are all electrically connected to the emitter of the transistor Q5, one end of the resistor R57 and the collector of the transistor Q6 are all electrically connected to the base of the transistor Q5, the other end of the resistor R57 is electrically connected to one end of the resistor R58, the other end of the resistor R58 is electrically connected to one end of the resistor R59, the other end of the resistor R59 is grounded, the collector of the transistor Q5 is electrically connected to the anode of the photocoupler U7, the collector of the photocoupler U7 is connected to the 3V3 power supply, the emitter of the photocoupler U7 is electrically connected to the base of the transistor Q5, and the collector of the photocoupler U7 is electrically connected to the anode of the photocoupler U7. One end of the resistor R61 is electrically connected, and the other end of the resistor R61 is grounded. The cathode of the photoelectric coupler U7, the collector of the photoelectric coupler U8, and one end of the capacitor C24 are all electrically connected to the cathode of the voltage stabilizing diode DZ1, and the other end of the capacitor C24 is all grounded to the anode of the voltage stabilizing diode DZ1. The anode of the photoelectric coupler U8 is electrically connected to the other end of the resistor R62, and the cathode of the photoelectric coupler U8 is grounded. The emitter of the photoelectric coupler U8 and one end of the resistor R60 are all electrically connected to one end of the resistor R67, and the other end of the resistor R67 and one end of the capacitor C23 are all electrically connected to the gate of the MOS tube Q7. The other end of the resistor R60, the other end of the capacitor C23, and the source of the MOS tube Q7 are all grounded.

7. The LED driving power supply according to claim 1, characterized in that: The AC detection module includes a diode D20, a diode D6, a resistor R80, a resistor R81, a resistor R82, a resistor R88, a resistor R85, a resistor R83, a resistor R84, a voltage regulator diode DZ2, a voltage regulator diode DZ3, a capacitor C80, a capacitor C81, a transistor Q8 and a photocoupler U9; the anode of the diode D20 and the anode of the diode D6 are both used as the input end of the AC detection module, and one end of the resistor R84 is used as the output end of the AC detection module; The cathode of the diode D20 and the cathode of the diode D6 are electrically connected to one end of the resistor R80, the other end of the resistor R80 is electrically connected to one end of the resistor R81, the other end of the resistor R81 is electrically connected to the cathode of the voltage-stabilizing diode DZ2, the anode of the voltage-stabilizing diode DZ2, one end of the resistor R82, one end of the capacitor C80, and the cathode of the voltage-stabilizing diode DZ3 are electrically connected to one end of the resistor R88, the other end of the resistor R88 is electrically connected to the base of the transistor Q8, the other end of the resistor R82, the capacitor C80, and the cathode of the voltage-stabilizing diode DZ3 are electrically connected to one end of the resistor R88. The other end, the anode of the voltage-stabilizing diode DZ3 and the emitter of the transistor Q8 are all grounded, the collector of the transistor Q8 is electrically connected to the cathode of the photoelectric coupler U9, the anode of the photoelectric coupler U9 is electrically connected to one end of the resistor R85, the other end of the resistor R85 is connected to the VDD power supply, the collector of the photoelectric coupler U9 is connected to the 3V3 power supply, the emitter of the photoelectric coupler U9, one end of the resistor R83, and one end of the capacitor C81 are all electrically connected to the other end of the resistor R84, and the other end of the resistor R83 and the other end of the capacitor C81 are all grounded.

8. The LED driving power supply according to claim 1, characterized in that: The VBUS voltage detection module includes a resistor R64, a resistor R66 and a capacitor C27; one end of the resistor R64 is used as an input end of the VBUS voltage detection module, and the other end of the resistor R64 is used as an output end of the VBUS voltage detection module; The other end of the resistor R64 and one end of the resistor R66 are both electrically connected to one end of the capacitor C27, and the other end of the resistor R66 and the other end of the capacitor C27 are both grounded.

9. The LED driving power supply according to claim 1, characterized in that: The voltage conversion module includes a capacitor C6, a capacitor C11, a capacitor C12 and a linear voltage regulator chip U3; the input end of the linear voltage regulator chip U3 is used as the input end of the voltage conversion module, and the output end of the linear voltage regulator chip U3 is used as the output end of the voltage conversion module; One end of the capacitor C11 is electrically connected to the input end of the linear voltage regulator chip U3, one end of the capacitor C6 and one end of the capacitor C12 are electrically connected to the output end of the linear voltage regulator chip U3, and the other end of the capacitor C11, the other end of the capacitor C6, the other end of the capacitor C12 and the ground end of the linear voltage regulator chip U3 are all grounded; The linear voltage regulator chip U3 is a 3.3V linear voltage regulator chip.

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