LED power supply capable of eliminating afterglow
By combining DC/DC conversion modules, switching modules, energy consumption modules, and driving modules, and utilizing constant current source circuits to optimize the energy consumption process, the problems of long afterglow elimination time and low efficiency in LED power supplies are solved, achieving fast and effective afterglow elimination.
Patent Information
- Application Number
- CN202521847930.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-29
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2035-08-29
AI Technical Summary
Existing LED power supplies are inefficient and ineffective at eliminating afterglow, affecting LED brightness and conversion efficiency.
The system employs a combination of DC/DC converter module, switch module, energy consumption module and drive module. The controller controls the energy consumption module to quickly dissipate leakage current when the dimming signal turns off the light and eliminates afterglow after the path is blocked. The constant current source circuit optimizes the energy consumption process.
Eliminating afterglow in a very short time avoids losses affecting the conversion efficiency of the LED power supply and improves the normal operation of the LED power supply.
Smart Images
Figure CN223528248U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to drive power supply technical field, especially a LED power supply of elimination afterglow. BACKGROUND
[0002] The afterglow problem is the problem that the LED power supply often faces, and the afterglow formation principle is as shown in the figure, when the DC / DC conversion module P2 is pulled down by the dimming signal PWM1 and enters the light-off state, the L input end is rectified through the rectifier P1, the DC / DC conversion module P2, the load P3 (LED) and the load parasitic capacitor P4 to the PE ground end, forming a path (for example PE→CP1→Cout→L) with negative voltage from the L input end to the PE ground end, this voltage will be added to the output capacitor Cout of the DC / DC conversion module P2 and the load parasitic capacitor P4, resulting in a leakage current, so that the load P3 on the path produces afterglow. When the load P3 has multiple parallel branches (the load parasitic capacitor P4 also has multiple parallel branches), each branch has a parallel voltage (for example PE→CP2→LED2→LED3→L, PE→CP3→LED3→L), which also produces afterglow. Figure 1
[0003] Therefore, according to the above-mentioned afterglow formation principle, the existing LED power supply usually has a diode connected in series between the positive and negative poles of the DC / DC conversion module P2 and the load P3, respectively, to cut off the path and achieve the purpose of eliminating afterglow. However, in normal operation of the LED power supply, the output current also needs to flow through the diode to reach the load P3, which will cause loss and affect the conversion efficiency, and may cause insufficient brightness of the LED. In addition, although the diode can prevent the leakage current from charging the capacitor Cout, there is still a residual voltage on the capacitor Cout that is higher than the LED turn-on voltage, and the LED afterglow will still exist for a period of time, and the afterglow elimination effect is not good. UTILITY MODEL CONTENTS
[0004] In view of the above-mentioned defects, the purpose of the utility model is to provide a LED power supply capable of eliminating afterglow, solving the problems of long afterglow elimination time and affecting the conversion efficiency of the LED power supply.
[0005] To achieve this purpose, the utility model adopts the following technical solutions:
[0006] The application discloses an LED power supply capable of eliminating afterglow, which comprises a DC / DC conversion module, a controller, a switch module, an energy consumption module and a driving module; the DC / DC conversion module is provided with an output capacitor Cout; the switch module is coupled to the input side negative electrode of the output capacitor Cout; the energy consumption module is connected in parallel to the output side of the output capacitor Cout; the controller is electrically connected with the energy consumption module through the driving module; and the DC / DC conversion module and the switch module are electrically connected with the controller.
[0007] Further, the energy consumption module comprises a switch tube and at least one resistor R1; the positive electrode of the switch tube is electrically connected with the output side positive electrode of the output capacitor Cout; the negative electrode of the switch tube is electrically connected with the output side negative electrode of the output capacitor Cout after being connected in series with one or more resistors R1; and the control end of the switch tube is electrically connected with the driving module.
[0008] Further, the switch tube is a triode Q1, the emitter of the triode Q1 is used as the positive electrode of the switch tube, the collector of the triode Q1 is used as the negative electrode of the switch tube, and the base of the triode Q1 is used as the control end of the switch tube.
[0009] The driving module comprises a resistor R3, a resistor R4, a resistor R5 and a triode Q2; the base of the triode Q1 is electrically connected with the collector of the triode Q2 after being connected in series with the resistor R3 and the resistor R4 in sequence; the base of the triode Q2 is electrically connected with the controller after being connected in series with the resistor R5; and the emitter of the triode Q2 is electrically connected with the output side negative electrode of the output capacitor Cout.
[0010] Further, the driving module is a constant current source circuit.
[0011] Further, the switch tube is a MOS tube Q4, the drain of the MOS tube Q4 is used as the positive electrode of the switch tube, the source of the MOS tube Q4 is used as the negative electrode of the switch tube, and the gate of the MOS tube Q4 is used as the control end of the switch tube.
[0012] Further, the driving module comprises a resistor R9, a resistor R10, a resistor R11, a resistor R12, an operational amplifier U3B and a capacitor C2; one end of the resistor R9 and one end of the resistor R10 are electrically connected with the gate of the MOS tube Q4, the other end of the resistor R9 is electrically connected with the output end of the operational amplifier U3B, the other end of the resistor R10 and the negative input end of the operational amplifier U3B are electrically connected with the source of the MOS tube Q4, the positive input end of the operational amplifier U3B is electrically connected with one end of the resistor R11, the other end of the resistor R11 and one end of the capacitor C2 are electrically connected with one end of the resistor R12, the other end of the capacitor C2 is electrically connected with the output negative pole of the output capacitor Cout, and the other end of the resistor R12 is electrically connected with the controller.
[0013] Further, the switch module comprises a MOS tube Q3, a resistor R6 and a resistor R7; the source and the drain of the MOS tube Q3 are connected in series with the input negative pole of the output capacitor Cout; the gate of the MOS tube Q3 is connected with the controller after being connected in series with the resistor R7; and the resistor R6 is connected in parallel between the source and the gate of the MOS tube Q3.
[0014] Further, the DC / DC conversion module is further provided with a diode D5 and a DC / DC conversion chip U1; the diode D5 is coupled to the input positive pole of the output capacitor Cout, the anode of the diode D5 is electrically connected with the DC / DC conversion chip U1, and the cathode of the diode D5 is electrically connected with the output capacitor Cout.
[0015] The technical scheme provided by the utility model can have the following beneficial effects: the switch module is kept on when the LED power supply is working normally, when the controller (for example, MCU) sends a PWM3 signal to turn off the light by the DC / DC conversion module, the energy consumption module is kept on for a preset energy consumption time (which can be preset according to actual conditions), the energy consumption module consumes the leakage current quickly in this period of time, and because the energy consumption module is connected in parallel, it does not affect the conversion efficiency when the LED power supply is working normally; after the energy consumption module eliminates the reverse leakage current, the controller sends a PWM2 signal to disconnect the input negative pole of the output capacitor Cout by the switch module, thereby blocking the path (otherwise, the residual voltage of the output capacitor Cout will still supply power to the LED); therefore, under the condition that the leakage current is consumed and the path is blocked, the afterglow can be eliminated in a very short time, and the effect is better without affecting the conversion efficiency of the LED power supply. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 It is a circuit diagram of the prior LED power supply.
[0017] Figure 2 is a circuit diagram of the LED power supply capable of eliminating afterglow of the embodiment 1 of the utility model.
[0018] Figure 3 is a circuit diagram of the LED power supply capable of eliminating afterglow of the embodiment 2 of the utility model.
[0019] Wherein: DC / DC conversion module 1, switch module 2, energy consumption module 3, drive module 4, output capacitor Cout, resistance R1, triode Q1, resistance R3, resistance R4, resistance R5, triode Q2, MOS tube Q4, resistance R9, resistance R10, resistance R11, resistance R12, operational amplifier U3B, capacitor C2, MOS tube Q3, resistance R6, resistance R7, diode D5, DC / DC conversion chip U1. DETAILED DESCRIPTION
[0020] The embodiments of the utility model are described in detail below, the examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the utility model and cannot be understood as limiting the utility model.
[0021] In the description of the embodiments of the utility model, the terms "first", "second" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the utility model, the meaning of "multiple" is two or more than two, unless otherwise specifically limited.
[0022] In the description of the embodiments of the utility model, it should be noted that, unless otherwise specifically specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication or interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the embodiments of the utility model can be understood according to the specific circumstances.
[0023] The utility model embodiment capable of eliminating afterglow of LED power supply is described below in combination with Figures 2 to 3
[0024] The application discloses an LED power supply capable of eliminating afterglow, which comprises a DC / DC conversion module 1 and a controller, and further comprises a switch module 2, a power consumption module 3 and a driving module 4; the switch module 2 is coupled to the input side negative pole of an output capacitor Cout of the DC / DC conversion module 1, the power consumption module 3 is connected in parallel to the output side of the output capacitor Cout, the controller is electrically connected with the power consumption module 3 through the driving module 4, and the DC / DC conversion module 1 and the switch module 2 are electrically connected with the controller.
[0025] The application discloses an LED power supply capable of eliminating afterglow, which comprises a DC / DC conversion module 1 and a controller, and further comprises a switch module 2, a power consumption module 3 and a driving module 4; the switch module 2 is coupled to the input side negative pole of an output capacitor Cout of the DC / DC conversion module 1, the power consumption module 3 is connected in parallel to the output side of the output capacitor Cout, the controller is electrically connected with the power consumption module 3 through the driving module 4, and the DC / DC conversion module 1 and the switch module 2 are electrically connected with the controller. Figure 2 Or 3, the switch module 2 is kept on during normal working of the LED power supply, when the controller adjusts the light signal PWM1 received by the DC / DC conversion module 1 to turn off the light, the controller (for example, MCU) first sends a PWM3 signal, the power consumption module 3 is kept on to a preset power consumption time (which can be preset according to actual conditions) through the driving module 4, the power consumption module 3 consumes the leakage current quickly in the time, and based on the parallel connection, the conversion efficiency is not affected by the loss during normal working of the LED power supply; after the power consumption module 3 eliminates the reverse flowing leakage current, the controller sends a PWM2 signal, the input side negative pole of the output capacitor Cout is disconnected through the switch module 2, and the path is blocked (otherwise, the residual voltage of the output capacitor Cout can still supply power to the LED); therefore, under the condition that the leakage current is consumed and the path is blocked, the afterglow can be eliminated in a very short time, the effect is better, and the conversion efficiency of the normal working of the LED power supply is not affected.
[0026] Further, the switch module 2 comprises a MOS tube Q3, a resistor R6 and a resistor R7; the source and the drain of the MOS tube Q3 are connected in series to the input side negative pole of the output capacitor Cout; the gate of the MOS tube Q3 is connected with the controller after being connected in series with the resistor R7; and the resistor R6 is connected in parallel between the source and the gate of the MOS tube Q3.
[0027] In the embodiment, the switch module 2 is preferably composed of the MOS tube Q3 and the peripheral circuit thereof, when the MOS tube Q3 is cut off, the equivalent capacitor CQ3 of the MOS tube Q3 can be connected in series to the output capacitor Cout and the load parasitic capacitor CP1 on the loop from the L input end to the PE ground end, based on the fact that the equivalent capacitor CQ3 has a small capacitance and a large equivalent impedance, the voltage on the output capacitor Cout and the load parasitic capacitor CP1 is much smaller, and the corresponding leakage current is also small, and the preset power consumption time is further shortened.
[0028] Further, the DC / DC conversion module 1 is further provided with a diode D5 and a DC / DC conversion chip U1; the diode D5 is coupled to the input side positive pole of the output capacitor Cout, the anode of the diode D5 is electrically connected with the DC / DC conversion chip U1, and the cathode of the diode D5 is electrically connected with the output capacitor Cout.
[0029] In this embodiment, if the DC / DC conversion module 1 is a boost architecture, the diode D5 functions as a rectifier; if the DC / DC conversion module 1 is a buck architecture, the diode functions as a reverse connection prevention (input to the output end), both of which are necessary measures to protect the safety of the DC / DC conversion module 1.
[0030] It should be noted that the diode D5 is not the diode used to block the leakage current in the background technology, and the diode in the background technology needs to be additionally provided on the output side of the output capacitor Cout.
[0031] Embodiment 1
[0032] The energy consumption module 3 includes a switch tube and at least one resistor R1; the positive electrode of the switch tube and the output side positive electrode of the output capacitor Cout are electrically connected; the negative electrode of the switch tube and one or more resistors R1 are connected in series and then electrically connected with the output side negative electrode of the output capacitor Cout; the control end of the switch tube is electrically connected with the driving module 4.
[0033] In this embodiment, as shown in Figure 2 The consumption of the leakage current by the energy consumption module 3 is mainly achieved by discharging through the equivalent resistance loss of one or more resistors R1, that is, when the switch tube is turned on, the resistor R1 is connected in series and then connected in parallel on the output capacitor Cout, and since the resistance value of the resistor R1 is very small and the capacitance is large, the discharging speed is very fast, and the output capacitor Cout can discharge the energy in a short time.
[0034] Further, the switch tube is a triode Q1, the emitter of the triode Q1 is used as the positive electrode of the switch tube, the collector of the triode Q1 is used as the negative electrode of the switch tube, and the base of the triode Q1 is used as the control end of the switch tube.
[0035] The driving module 4 includes a resistor R3, a resistor R4, a resistor R5, and a triode Q2; the base of the triode Q1 is connected in series with the resistor R3 and the resistor R4 in sequence and then electrically connected with the collector of the triode Q2; the base of the triode Q2 is connected in series with the resistor R5 and then electrically connected with the controller; the emitter of the triode Q2 is electrically connected with the output side negative electrode of the output capacitor Cout.
[0036] In this embodiment, in order to accelerate the switching speed of the energy consumption module 3, the switch tube and the driving module 4 are both preferably driven by the triode and the controller.
[0037] Embodiment 2
[0038] The driving module 4 is a constant current source circuit.
[0039] Considering that the energy consumption module 3 mainly discharges and consumes energy by using a resistor, even if the resistor is small, the current consumed by the resistor decreases as the voltage decreases, that is, during the discharging process, the process of the voltage dropping consumes less and less current and consumes less and less power, which may cause the leakage current to be not completely eliminated within the preset energy consumption time.
[0040] In this embodiment, in order to solve this problem, as shown in the figure, the driving module 4 is changed to a constant current source circuit, which can make the instantaneous discharge power consumption of the energy consumption module 3 larger, and maintain the same consumption current at different output voltage values, further shorten the preset energy consumption time, and discharge the voltage of the output capacitor Cout to far below the voltage point at which the LED lamp is turned on, thereby eliminating the possibility of afterglow and providing users with a better experience. More importantly, for different LEDs, the output of the constant current source circuit can be changed by the controller to adapt to the leakage current generated by different loads, thereby improving the adaptability of the product. Figure 3 Further, the switch tube is a MOS tube Q4, the drain of the MOS tube Q4 is used as the positive electrode of the switch tube, the source of the MOS tube Q4 is used as the negative electrode of the switch tube, and the gate of the MOS tube Q4 is used as the control end of the switch tube.
[0041] In this embodiment, based on the driving module 4 being a constant current source circuit, the switch tube needs to withstand greater discharge power, and at this time the switch tube is preferably a MOS tube Q4.
[0042] Further, the driving module 4 includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, an operational amplifier U3B, and a capacitor C2; one end of the resistor R9 and one end of the resistor R10 are electrically connected to the gate of the MOS tube Q4, the other end of the resistor R9 and the output end of the operational amplifier U3B are electrically connected, the other end of the resistor R10 and the negative input end of the operational amplifier U3B are electrically connected to the source of the MOS tube Q4, the positive input end of the operational amplifier U3B and one end of the resistor R11 are electrically connected, the other end of the resistor R11 and one end of the resistor R12 and one end of the capacitor C2 are electrically connected, the other end of the capacitor C2 and the output side negative electrode of the output capacitor Cout are electrically connected, and the other end of the resistor R12 is electrically connected to the controller.
[0043]
[0044] In this embodiment, based on the MOS tube Q4 to be driven on or off, the constant current source circuit of the driving module 4 is preferably composed of resistance R9, resistance R10, resistance R11, resistance R12, operational amplifier U3B and capacitor C2, and the principle is that the PWM3 signal is a signal from low level to a certain duty cycle, which forms a fixed voltage reference value after passing through the RCR filter network (resistance R11, resistance R12 and capacitor C2), which can be marked as Vref, and due to the virtual short characteristic of the operational amplifier, the voltage of the negative input end of the operational amplifier U3B is also Vref, so the constant output current of the driving module 4 is I=Vref / R1 (based on resistance R1 which can be one or more, R1 is the total resistance of resistance R1), so that the MOS tube Q4 works in the saturation region.
[0045] Other configurations and operations of the LED power supply capable of eliminating afterglow according to the embodiments of the present application are known to those skilled in the art, and will not be described in detail herein.
[0046] In the description of the present specification, the description referring to the terms "embodiment", "example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description 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.
[0047] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.
Claims
1. An LED power supply capable of eliminating afterglow, characterized by: The application relates to a DC / DC conversion module, a controller, a switch module, an energy consumption module and a driving module; the DC / DC conversion module is provided with an output capacitor Cout; the switch module is coupled to the input side negative electrode of the output capacitor Cout; the energy consumption module is connected in parallel to the output side of the output capacitor Cout; the controller is electrically connected with the energy consumption module through the driving module; and the DC / DC conversion module and the switch module are electrically connected with the controller.
2. The LED power supply capable of eliminating the afterglow according to claim 1, characterized in that: The energy consumption module comprises a switch tube and at least one resistor R1; the positive electrode of the switch tube is electrically connected with the output side positive electrode of the output capacitor Cout; the negative electrode of the switch tube is electrically connected with the output side negative electrode of the output capacitor Cout after being connected in series with one or more resistors R1; and the control end of the switch tube is electrically connected with the driving module.
3. The LED power supply capable of eliminating the residual light according to claim 2, characterized in that: The switch tube is a triode Q1, the emitter of the triode Q1 is used as the positive electrode of the switch tube, the collector of the triode Q1 is used as the negative electrode of the switch tube, and the base of the triode Q1 is used as the control end of the switch tube. The driving module comprises a resistor R3, a resistor R4, a resistor R5 and a triode Q2; the base of the triode Q1 is electrically connected with the collector of the triode Q2 after being connected in series with the resistor R3 and the resistor R4 in sequence; the base of the triode Q2 is electrically connected with the controller after being connected in series with the resistor R5; and the emitter of the triode Q2 is electrically connected with the output side negative electrode of the output capacitor Cout.
4. The LED power supply capable of eliminating the residual light according to claim 2, characterized in that: The driving module is a constant current source circuit.
5. The LED power supply capable of eliminating the residual light according to claim 4, characterized in that: The switch tube is a MOS tube Q4, the drain of the MOS tube Q4 is used as the positive electrode of the switch tube, the source of the MOS tube Q4 is used as the negative electrode of the switch tube, and the gate of the MOS tube Q4 is used as the control end of the switch tube.
6. The LED power supply capable of eliminating the residual light according to claim 5, characterized in that: The driving module comprises a resistor R9, a resistor R10, a resistor R11, a resistor R12, an operational amplifier U3B and a capacitor C2; one end of the resistor R9 and one end of the resistor R10 are electrically connected with the gate of the MOS tube Q4, the other end of the resistor R9 is electrically connected with the output end of the operational amplifier U3B, the other end of the resistor R10 and the negative input end of the operational amplifier U3B are electrically connected with the source of the MOS tube Q4, the positive input end of the operational amplifier U3B is electrically connected with one end of the resistor R11, the other end of the resistor R11 and one end of the capacitor C2 are electrically connected with one end of the resistor R12, the other end of the capacitor C2 is electrically connected with the output side negative electrode of the output capacitor Cout, and the other end of the resistor R12 is electrically connected with the controller.
7. The LED power supply capable of eliminating the residual light according to claim 1, characterized in that: The switch module comprises a MOS tube Q3, a resistor R6 and a resistor R7; the source and the drain of the MOS tube Q3 are connected in series to the input side negative electrode of the output capacitor Cout; the gate of the MOS tube Q3 is electrically connected with the controller after being connected in series with the resistor R7; and the resistor R6 is connected in parallel between the source and the gate of the MOS tube Q3.
8. The LED power supply without residual light according to claim 1, characterized in that: The DC / DC conversion module is also provided with a diode D5 and a DC / DC conversion chip U1; the diode D5 is coupled to the input side positive pole of the output capacitor Cout, the anode of the diode D5 is electrically connected with the DC / DC conversion chip U1, and the cathode of the diode D5 is electrically connected with the output capacitor Cout.