Dual-path output LED lighting circuit

Abstract

The utility model discloses a dual-path output LED lighting circuit, which comprises an LED 1 conduction circuit, a boost switch circuit, a boost circuit, an MCU, an LED 1 and an LED 2. The input end of the LED1 conduction circuit is connected with the MCU, the output end of the LED1 conduction circuit is connected with the negative electrode of the LED1, the positive electrode of the LED1 is connected with the VCC-in, the input end of the boost switch circuit is connected with the VCC-in and the MCU, the output end of the boost switch circuit is connected with the boost circuit, and the output end of the boost circuit is connected with the LED2. According to the utility model, the conduction circuit is used as a switch of the LED1, the switching circuit is used as a switch of the boost circuit, and the boost circuit provides high voltage for the LED2, so that dual-path output of the LED1 and the LED2 is realized; according to the utility model, the output of two different circuits is suitable for old system reconstruction.

Description

Technical Field

[0001] This utility model relates to LED lighting, specifically a dual-output LED lighting circuit. Background Technology

[0002] Decorative lights are often installed on streetlights before holidays. However, the main power supply for streetlights is 3V, while many decorative lights are powered by 12V. Therefore, a 12V output needs to be added to the existing 3V output system. Currently, a boost circuit is added to the original circuit system to output 12V. However, in use, it has been found that directly boosting the voltage output from the photovoltaic panel or battery to 12V often results in unstable power supply, causing the decorative lights to flicker and even affecting the power supply to the original streetlights. Utility Model Content

[0003] To address the shortcomings of the existing technology, this utility model provides a dual-output LED lighting circuit. The circuit provides a conduction circuit to ensure the stable output of the original LED1, and the circuit provides a switching circuit to ensure the stable operation of the boost circuit. Thus, the boost circuit outputs a stable voltage to the second LED, ensuring stable operation and solving the flickering problem.

[0004] To achieve the above technical objectives, this utility model adopts the following technical solution: a dual-output LED lighting circuit, including an LED1 conduction circuit, a boost switch circuit, a boost circuit, an MCU, LED1, and LED2; the input terminal of the LED1 conduction circuit is connected to the MCU, the output terminal of the LED1 conduction circuit is connected to the negative terminal of LED1, the positive terminal of LED1 is connected to VCC-in, the input terminal of the boost switch circuit is connected to VCC-in and the MCU, the output terminal of the boost switch circuit is connected to the boost circuit, and the output terminal of the boost circuit is connected to LED2;

[0005] The LED1 conduction circuit includes field-effect transistors M4 and M5. The drains of M4 and M5 are connected to the negative terminal of LED1. The gates of M4 and M5 are connected together and divided into two paths. The first path is connected to pins 9 and 10 of the MCU through resistor R18, and the second path is grounded through resistor R17. The sources of M4 and M5 are connected together and connected to resistors R19, R20, R21, and R22. Resistors R19, R20, R21, and R22 are connected in parallel and then grounded. The sources of M4 and M5 are also connected to resistor R16. One path of resistor R16 is grounded through capacitor C13, and the other path is connected to pin 11 of the MCU.

[0006] The boost switching circuit includes a MOSFET M6, a resistor R25, a capacitor C14, a transistor Q2, a resistor R23, and a resistor R24. The gate of the MOSFET M6, the cathode of the resistor R25, and the cathode of the capacitor C14 are all connected to the collector of the transistor Q2. The source of the MOSFET M6, the anode of the resistor R25, and the anode of the capacitor C14 are all connected to VCC-in. The emitter of the transistor Q2 is grounded, and the base of the transistor Q2 is connected to the resistors R23 and R24 respectively. The resistor R23 is connected to pin 14 of the MCU, and the resistor R24 ​​is grounded. The drain of the MOSFET M6 is connected to the boost circuit.

[0007] The boost circuit includes a boost chip U3. Pins 1 and 3 of the boost chip U3 are connected to the drain of MOSFET M6, capacitors C15 and C16, and inductor L2. Capacitors C15 and C16 are grounded. Inductor L2 is connected to the drain of MOSFET M7. The gate of MOSFET M7 is connected to pin 2 of the boost chip U3. The source of MOSFET M7 is grounded. The drain of MOSFET M7 is also connected to diode D4. Diode D4 is connected to resistor R26, capacitor E2, and LED2. Resistor R26 is connected to pin 7 of the boost chip U3 and resistor R27. Resistor R27 is grounded. Capacitor E2 is grounded. Pin 8 of the boost chip U3 is connected to resistor R28 and LED2. Resistor R28 is grounded. Pin 6 of the boost chip U3 is connected to capacitor C17, which is grounded.

[0008] The VCC-in is 3V.

[0009] The MCU is U2, model SOP-16.

[0010] The boost chip U3 is model HM1539.

[0011] In summary, this utility model achieves the following technical effects:

[0012] This utility model sets a conduction circuit as the switch for LED1 and a switching circuit as the switch for the boost circuit. The boost circuit provides high voltage to LED2, realizing dual-channel output of LED1 and LED2.

[0013] This utility model features dual outputs with different circuits, making it suitable for upgrading older systems. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a dual-output LED lighting circuit provided in an embodiment of the present invention. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to the accompanying drawings.

[0016] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

[0017] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0019] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0020] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] Example:

[0022] Figure 1 This is a schematic diagram of a dual-output LED lighting circuit, including an LED1 conduction circuit 1, a boost switch circuit 2, a boost circuit 3, an MCU, LED1, and LED2. The input terminal of the LED1 conduction circuit 1 is connected to the MCU, the output terminal of the LED1 conduction circuit 1 is connected to the negative terminal of LED1, and the positive terminal of LED1 is connected to VCC-in. The input terminal of the boost switch circuit 2 is connected to VCC-in and the MCU, the output terminal of the boost switch circuit 2 is connected to the boost circuit 3, and the output terminal of the boost circuit 3 is connected to LED2.

[0023] This invention utilizes LED1 conduction circuit 1 to control the conduction state of LED1, achieving constant current control and ensuring stable output for LED1. A boost switch circuit 2 is set as the switch for boost circuit 3, ensuring stable operation of the boost circuit and thus stable output for LED2. This invention uses LED1 as one output and LED2 as the second output, achieving stable dual-channel output at different voltages. In retrofitting older systems, it can effectively match LEDs with different voltages and currents.

[0024] The LED1 conduction circuit 1 includes field-effect transistors M4 and M5. The drains of field-effect transistors M4 and M5 are connected to the negative terminal of LED1. The gates of field-effect transistors M4 and M5 are connected together and divided into two paths. The first path is connected to pins 9 and 10 of the MCU through resistor R18, and the second path is grounded through resistor R17. The sources of field-effect transistors M4 and M5 are connected together and connected to resistors R19, R20, R21, and R22. Resistors R19, R20, R21, and R22 are connected in parallel and then grounded. The sources of field-effect transistors M4 and M5 are also connected to resistor R16. One path of resistor R16 is grounded through capacitor C13, and the other path is connected to pin 11 of the MCU.

[0025] M4 and M5 are N-channel field-effect transistors (FETs) that control the conduction state of LED1. By adjusting the duty cycle of the gates of M4 and M5, the driving current of LED1 is controlled, thereby adjusting the brightness of LED1. This embodiment uses two FETs to improve the stability of LED control and prevent driving disturbances.

[0026] R18 is the driving resistor for the gates of M4 and M5, and R17 is the pull-down resistor for the gates of M4 and M5, ensuring that M4 and M5 are in the off state even under uncertain signal conditions, i.e., the LED1 light source board is in a stable off state. In this embodiment, R19, R20, R21, and R22 are sampling resistors for the LED discharge current, R16 is the protection resistor for the MCU to sample the LED discharge current, and C13 serves as a sampling filter.

[0027] The boost switching circuit 2 includes a MOSFET M6, a resistor R25, a capacitor C14, a transistor Q2, a resistor R23, and a resistor R24. The gate of the MOSFET M6, the cathode of the resistor R25, and the cathode of the capacitor C14 are all connected to the collector of the transistor Q2. The source of the MOSFET M6, the anode of the resistor R25, and the anode of the capacitor C14 are all connected to VCC-in. The emitter of the transistor Q2 is grounded, and the base of the transistor Q2 is connected to the resistors R23 and R24 respectively. The resistor R23 is connected to pin 14 of the MCU, and the resistor R24 ​​is grounded. The drain of the MOSFET M6 is connected to the boost circuit 3.

[0028] Pins 12, 13, and 14 of the MCU (U2) are connected together, outputting a high level to R23. R23 conducts, driving Q2, which in turn conducts, and then drives M6, enabling the entire boost circuit 3 to operate and output high voltage to power LED2. C14 is a filter capacitor, and R23 and R24 are voltage divider resistors.

[0029] The boost circuit 3 includes a boost chip U3. Pins 1 and 3 of the boost chip U3 are connected to the drain of MOSFET M6, capacitors C15 and C16, and inductor L2. Capacitors C15 and C16 are grounded. Inductor L2 is connected to the drain of MOSFET M7. The gate of MOSFET M7 is connected to pin 2 of the boost chip U3. The source of MOSFET M7 is grounded. The drain of MOSFET M7 is also connected to diode D4. Diode D4 is connected to resistor R26, capacitor E2, and LED2. Resistor R26 is connected to pin 7 of the boost chip U3 and resistor R27. Resistor R27 is grounded. Capacitor E2 is grounded. Pin 8 of the boost chip U3 is connected to resistor R28 and LED2. Resistor R28 is grounded. Pin 6 of the boost chip U3 is connected to capacitor C17, which is grounded.

[0030] L2 is an energy storage inductor, M7 is a switching transistor, D4 is a reverse protection diode, and the output voltage supplied to LED2 is adjusted by regulating the ratio of the resistance values ​​of R26 and R27. E2 is an energy storage capacitor, R28 is a current-limiting resistor, pin 8 of U3 samples the current of LED2, and pins 1 and 3 of U3 together output a constant voltage current to LED2 as a constant voltage power supply. U3 uses model HM1539.

[0031] The MCU is U2, and it uses the SOP-16 model.

[0032] It also includes a power supply circuit (not shown), which outputs a wide voltage of 3V from the photovoltaic panel or lithium battery as VCC-in. One path of VCC-in directly powers LED1, and the other path is boosted to 12V through a boost circuit to power LED2. Stable power supply is achieved by using the conduction circuit and the boost circuit, realizing different outputs of wide voltage 3V and 12V.

[0033] This invention sets a conduction circuit as the switch for LED1 and a switching circuit as the switch for the boost circuit. The boost circuit provides high voltage to LED2, thereby achieving dual-channel output of LED1 and LED2.

[0034] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall fall within the scope of the technical solution of the present utility model.

Claims

1. A dual-output LED lighting circuit, characterized in that: The system includes an LED1 conduction circuit (1), a boost switch circuit (2), a boost circuit (3), an MCU, LED1, and LED2. The input terminal of the LED1 conduction circuit (1) is connected to the MCU, the output terminal of the LED1 conduction circuit (1) is connected to the negative terminal of LED1, and the positive terminal of LED1 is connected to VCC-in. The input terminal of the boost switch circuit (2) is connected to VCC-in and the MCU, the output terminal of the boost switch circuit (2) is connected to the boost circuit (3), and the output terminal of the boost circuit (3) is connected to LED2. The LED1 conduction circuit (1) includes field-effect transistors M4 and M5. The drains of field-effect transistors M4 and M5 are connected to the negative terminal of LED1. The gates of field-effect transistors M4 and M5 are connected together and divided into two paths. The first path is connected to pins 9 and 10 of the MCU through resistor R18, and the second path is grounded through resistor R17. The sources of field-effect transistors M4 and M5 are connected together and connected to resistors R19, R20, R21, and R22. Resistors R19, R20, R21, and R22 are connected in parallel and then grounded. The sources of field-effect transistors M4 and M5 are also connected to resistor R16. One path of resistor R16 is grounded through capacitor C13, and the other path is connected to pin 11 of the MCU. The boost switching circuit (2) includes a MOSFET M6, a resistor R25, a capacitor C14, a transistor Q2, a resistor R23, and a resistor R24; the gate of the MOSFET M6, the cathode of the resistor R25, and the cathode of the capacitor C14 are all connected to the collector of the transistor Q2; the source of the MOSFET M6, the anode of the resistor R25, and the anode of the capacitor C14 are all connected to VCC-in; the emitter of the transistor Q2 is grounded, and the base of the transistor Q2 is connected to the resistors R23 and R24 respectively. The resistor R23 is connected to pin 14 of the MCU, and the resistor R24 ​​is grounded; the drain of the MOSFET M6 is connected to the boost circuit (3).

2. The dual-output LED lighting circuit according to claim 1, characterized in that: The boost circuit (3) includes a boost chip U3. Pins 1 and 3 of the boost chip U3 are connected to the drain of MOSFET M6, capacitor C15, capacitor C16, and inductor L2. Capacitor C15 is grounded, capacitor C16 is grounded, inductor L2 is connected to the drain of MOSFET M7, the gate of MOSFET M7 is connected to pin 2 of the boost chip U3, the source of MOSFET M7 is grounded, and the drain of MOSFET M7 is also connected to diode D4. Diode D4 is connected to resistor R26, capacitor E2, and LED2. Resistor R26 is connected to pin 7 of the boost chip U3 and resistor R27. Resistor R27 is grounded, capacitor E2 is grounded, pin 8 of the boost chip U3 is connected to resistor R28 and LED2. Resistor R28 is grounded, and pin 6 of the boost chip U3 is connected to capacitor C17. Capacitor C17 is grounded.

3. The dual-output LED lighting circuit according to claim 1, characterized in that: The VCC-in is 3V.

4. The dual-output LED lighting circuit according to claim 1, characterized in that: The MCU is U2, model SOP-16.

5. A dual-output LED lighting circuit according to claim 2, characterized in that: The boost chip U3 is model HM1539.

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