Lighting power supply circuit, electric equipment and range hood

Abstract

The invention relates to a lighting power supply circuit, electric equipment and a range hood. The lighting power supply circuit comprises a power conversion circuit, a control circuit and a voltage division conversion circuit, and the power conversion circuit is connected with a lighting circuit and a load and used for supplying power to the lighting circuit and the load. The control circuit is connected with the load for determining the state of the load. The partial voltage conversion circuit is connected with the control circuit and the power conversion circuit. When the load is in an operation state, the control circuit controls the voltage division conversion circuit to be in a first voltage division state, so that the power supply conversion circuit outputs a first power supply voltage; and under the condition that the load is in the running stopping state, the control circuit controls the voltage division conversion circuit to output a second voltage division signal, so that the voltage division conversion circuit is in a second voltage division state, and the second power supply voltage is greater than the first power supply voltage. The lighting power supply circuit gives consideration to cooperative power supply of lighting and load, and solves the problem that a traditional power supply cannot improve the brightness demand.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a lighting power supply circuit, electrical equipment, and range hood. Background Technology

[0002] With the continuous development of technology, people have placed higher demands on the ease of use of electrical appliances. For example, adding lighting to electrical appliances can improve the user experience; such as equipping range hoods with cool light lamps, which can make the kitchen environment brighter and thus provide convenience for users.

[0003] Currently, the power supplies that power cold fluorescent lamps often also power other loads (such as motors). The voltage provided by these power supplies is usually a constant value, which makes the brightness of the cold fluorescent lamps constant and cannot meet users' requirements for higher lighting brightness, thus limiting the ease of use of electrical equipment. Summary of the Invention

[0004] Therefore, it is necessary to provide a lighting power supply circuit, electrical equipment, and range hood that can improve lighting brightness.

[0005] A lighting power supply circuit, comprising:

[0006] A power conversion circuit is used to connect a lighting circuit and a load, and to supply power to the lighting circuit and the load.

[0007] A control circuit, connected to the load, is used to determine the state of the load;

[0008] A voltage divider conversion circuit is connected to the control circuit and the power conversion circuit. When the load is in operation, the control circuit controls the voltage divider conversion circuit to be in a first voltage divider state so that the power conversion circuit outputs a first power supply voltage. When the load is not in operation, the control circuit controls the voltage divider conversion circuit to be in a second voltage divider state so that the power conversion circuit outputs a second power supply voltage, which is greater than the first power supply voltage.

[0009] In one embodiment, the voltage divider conversion circuit includes a switching unit and a first resistor; a first end of the first resistor is connected to the power conversion circuit, a second end of the first resistor is grounded via the switching unit, and the control terminal of the switching unit is connected to the control circuit.

[0010] In one embodiment, the switching unit includes a first switching transistor, the control electrode of the first switching transistor is connected to the control circuit, the first terminal of the first switching transistor is connected to the second terminal of the first resistor, and the second terminal of the first switching transistor is grounded.

[0011] In one embodiment, the power conversion circuit includes:

[0012] A switching power supply unit is connected to the lighting circuit and the load;

[0013] A feedback control unit is connected to the switching power supply unit and the voltage divider conversion circuit. When the voltage divider conversion circuit is in a first voltage divider state, the feedback control unit outputs a first feedback signal to the switching power supply unit, causing the switching power supply unit to output a first power supply voltage. When the voltage divider conversion circuit is in a second voltage divider state, the feedback control unit outputs a second feedback signal to the switching power supply unit, causing the switching power supply unit to output a second power supply voltage.

[0014] In one embodiment, the switching power supply unit includes:

[0015] A transformer, wherein the first end of the primary winding of the transformer is used to connect to an external power source;

[0016] The second switch has its first terminal connected to the second end of the primary winding, its second terminal grounded, and its control terminal connected to the feedback control unit.

[0017] A rectifier output unit, the input terminal of which is connected to the secondary winding of the transformer, and the output terminal of which is connected to the lighting circuit, the load, and the feedback control unit.

[0018] In one embodiment, the rectifier output unit includes a diode and a first capacitor; the anode of the diode serves as the input terminal of the rectifier output unit and is connected to the first terminal of the secondary winding; the cathode of the diode is connected to the first terminal of the first capacitor, and the common terminal connecting the diode and the first capacitor serves as the output terminal of the rectifier output unit; the second terminal of the first capacitor and the second terminal of the secondary winding are grounded.

[0019] In one embodiment, the feedback control unit includes an adjustable voltage regulator chip, a power control chip, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and an optocoupler;

[0020] The first end of the second resistor is connected to the output terminal of the rectifier output unit, the second end of the second resistor is connected to the first end of the third resistor and the voltage divider circuit, and the second end of the third resistor is grounded; the reference terminal of the adjustable voltage regulator chip is connected to the second end of the second resistor, and the anode of the adjustable voltage regulator chip is grounded; the first end of the fourth resistor is connected to the output terminal of the rectifier output unit, the second end of the fourth resistor is connected to the first end of the fifth resistor and the anode of the optocoupler, and the second end of the fifth resistor is connected to the cathode of the optocoupler and the cathode of the adjustable voltage regulator chip; the collector of the optocoupler is connected to the power control chip via the sixth resistor, the emitter of the optocoupler is grounded, and the power control chip is also connected to the control electrode of the second switching transistor.

[0021] An electrical device includes: a lighting circuit, a load control circuit, a load, and a lighting power supply circuit according to the above; the power conversion circuit is connected to the lighting circuit and the load control circuit respectively, the load control circuit is connected to the control circuit and the load, and the control circuit is used to control the load to run or stop running through the load control circuit.

[0022] In one embodiment, the load control circuit includes a third switch, a fourth switch, a seventh resistor, an eighth resistor, and a ninth resistor;

[0023] The control circuit is connected to the control electrode of the third switch via the seventh resistor. The first electrode of the third switch is connected to the first terminal of the ninth resistor and the control electrode of the fourth switch via the eighth resistor. The second electrode of the third switch is grounded. The second terminal of the ninth resistor and the second electrode of the fourth switch are connected to the power conversion circuit. The second electrode of the fourth switch is connected to the load.

[0024] In one embodiment, the electrical device further includes a lighting control circuit connected to the lighting circuit; the control terminal of the lighting control circuit is connected to the control circuit, and the control circuit is also used to control the lighting circuit through the lighting control circuit.

[0025] In one embodiment, the lighting control circuit includes a fifth switch, a sixth switch, a tenth resistor, an eleventh resistor, and a twelfth resistor; the control circuit is connected to the control terminal of the fifth switch via the tenth resistor, the first terminal of the fifth switch is connected to the first terminal of the twelfth resistor and the control terminal of the sixth switch via the eleventh resistor, and the second terminal of the fifth switch is grounded; the second terminal of the twelfth resistor and the second terminal of the sixth switch are connected to the power conversion circuit, and the second terminal of the sixth switch is connected to the lighting circuit.

[0026] A range hood includes the electrical equipment described above.

[0027] The aforementioned lighting power supply circuit, electrical equipment, and range hood include: a power conversion circuit, a control circuit, and a voltage divider conversion circuit. The power conversion circuit connects the lighting circuit and the load, providing power to both. The control circuit connects to the load and determines its state. The voltage divider conversion circuit connects the control circuit and the power conversion circuit. When the load is running, the control circuit controls the voltage divider conversion circuit to a first voltage divider state, causing the power conversion circuit to output a first power supply voltage. When the load is not running, the control circuit controls the voltage divider conversion circuit to output a second voltage divider signal, causing the voltage divider conversion circuit to operate in a second voltage divider state, where the second power supply voltage is greater than the first power supply voltage. Therefore, when the load (such as a motor) is running, the power conversion circuit provides a lower first power supply voltage, which meets the high drive current requirements of the load while maintaining a certain brightness in the lighting circuit. When the load is not running, the power conversion circuit outputs a higher second power supply voltage, increasing the brightness of the lighting circuit to enhance the ambient lighting effect. This achieves voltage switching of the lighting circuit based on the load state, balancing the coordinated power supply of lighting and the load, and solving the problem that traditional power supplies cannot meet brightness requirements. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A schematic diagram of a lighting power supply circuit according to one embodiment;

[0030] Figure 2 A schematic diagram of the circuit structure of a lighting power supply circuit according to one embodiment;

[0031] Figure 3 This is a schematic diagram of a module of an electrical device according to one embodiment;

[0032] Figure 4 This is a schematic diagram of the circuit structure of a load control circuit according to one embodiment;

[0033] Figure 5 This is a schematic diagram of a module of an electrical device according to another embodiment;

[0034] Figure 6 This is a schematic diagram of the circuit structure of a lighting control circuit according to one embodiment;

[0035] Figure 7This is a schematic diagram of a DC-DC conversion module according to one embodiment. Detailed Implementation

[0036] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0038] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a third resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a third resistor. Both the third resistor and the second resistor are resistors, but they are not the same resistor.

[0039] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0040] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0041] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0042] In one exemplary embodiment, a lighting power supply circuit is provided, which can be applied to electrical equipment. The electrical equipment includes a lighting circuit that illuminates when powered, increasing the brightness of the surrounding environment and facilitating user operation. The electrical equipment also includes a load, such as a motor, fan, etc. To simplify the circuit structure and reduce costs, the power supply terminals of both the load and the lighting circuit are typically connected to the lighting power supply circuit, enabling a shared lighting power supply circuit and reducing redundant configuration of power modules.

[0043] In some embodiments, such as Figure 1 As shown, the lighting power supply circuit includes a power conversion circuit 100, a voltage divider conversion circuit 200, and a control circuit 300. The power conversion circuit 100 is used to connect the lighting circuit and the load, and to supply power to the lighting circuit and the load.

[0044] The control circuit 300 is connected to the load and is used to determine the state of the load. The control circuit 300 can be an existing control circuit within the electrical equipment or a separate control circuit independent of the original control circuit in the electrical equipment. The type of load can be set according to the specific situation of the electrical equipment used in the lighting power supply circuit. As an example, the electrical equipment is a range hood, which includes a lighting circuit, a lighting power supply circuit, a controller, an oil fume purification device connected to the controller, and an air conditioning unit. The air conditioning unit includes a push rod motor module connected to the controller and a cooling / heating module. When the range hood is turned on, the controller controls the push rod motor in the push rod motor module to operate. The push rod motor opens the air outlet through a mechanical transmission mechanism to output cooling or heating energy to the kitchen, creating a more comfortable environment for the user. In this embodiment, the push rod motor can act as a load, connected to the power conversion circuit 100 along with the lighting circuit. The control circuit 300 can reuse the controller in the range hood or be a separate control circuit connected to the controller. For ease of understanding, the following explanations will use the example of an electrical device used in a range hood with a push rod motor as the load.

[0045] The load status includes an operating state and a stopped state. The control circuit 300 determines the load status in multiple ways; in some embodiments, it also controls the load status. For example, when a user issues an on command via the range hood's control panel, the control circuit 300 sends a drive signal to the push rod motor, causing it to enter the operating state and open the air vent. Thus, the control circuit 300 can clearly determine the load's current operating status. In other embodiments, the control circuit 300 can monitor the load's current or voltage parameters in real time to determine the load status. For example, when the push rod motor is operating normally, its operating current is within a specific range. The control circuit 300 continuously monitors the current value through a built-in current detection module. When the current value fluctuates within this normal range, the control circuit 300 determines that the load is in the operating state; conversely, when the current value suddenly drops to zero or is far below the normal operating range, the control circuit 300 determines that the load is in the stopped state.

[0046] The voltage divider conversion circuit 200 is connected to the control circuit 300 and the power conversion circuit 100. When the load is running, the control circuit 300 controls the voltage divider conversion circuit 200 to be in the first voltage divider state so that the power conversion circuit 100 outputs the first power supply voltage. When the load is not running, the control circuit 300 controls the voltage divider conversion circuit 200 to be in the second voltage divider state so that the power conversion circuit 100 outputs the second power supply voltage, which is greater than the first power supply voltage.

[0047] Specifically, when the control circuit 300 determines that the push rod motor is in operation, it immediately sends a control signal to the voltage divider conversion circuit 200, causing the voltage divider conversion circuit 200 to enter the first voltage divider state. In the first voltage divider state, the power conversion circuit 100 outputs a first power supply voltage. This first power supply voltage can meet the power requirements of the push rod motor during operation, while providing a stable lighting voltage for the lighting circuit, ensuring that the lighting circuit lights up normally and providing a good operating environment for the user.

[0048] When the control circuit 300 determines that the push rod motor is in a stopped state (for example, after the air outlet is opened, the cooling and heating outputs are stable, and the control circuit 300 controls the push rod motor to stop), it sends a control signal to the voltage divider conversion circuit 200 again, causing the voltage divider conversion circuit 200 to switch to the second voltage divider state. In the second voltage divider state, the second power supply voltage output by the power conversion circuit 100 is greater than the first power supply voltage. The higher second power supply voltage can provide more sufficient power to the lighting circuit, increasing the lighting brightness and making it more convenient for users.

[0049] When the load is not running, the power conversion circuit 100 is in a light-load state. At this time, increasing the power supply voltage output to the lighting circuit can improve energy utilization efficiency. This solves the problem that existing power supplies cannot increase lighting brightness without increasing the load capacity of the power conversion circuit 100.

[0050] The aforementioned lighting power supply circuit includes a power conversion circuit 100, a voltage divider conversion circuit 200, and a control circuit 300. The power conversion circuit 100 connects to the lighting circuit and the load, providing power to both. The control circuit 300 connects to the load and determines its state. The voltage divider conversion circuit 200 connects to both the control circuit 300 and the power conversion circuit 100. When the load is running, the control circuit 300 controls the voltage divider conversion circuit 200 to operate in a first voltage divider state, causing the power conversion circuit 100 to output a first power supply voltage. When the load is not running, the control circuit 300 controls the voltage divider conversion circuit 200 to operate in a second voltage divider state, causing the power conversion circuit 100 to output a second power supply voltage, which is higher than the first power supply voltage. Therefore, when the load (such as a motor) is running, the power conversion circuit 100 provides a lower first power supply voltage, which meets the high drive current requirements of the load while maintaining a certain brightness in the lighting circuit. When the load is not running, the power conversion circuit 100 outputs a higher second power supply voltage, increasing the brightness of the lighting circuit to enhance the ambient lighting effect. This enables the lighting circuit to switch power supply voltage based on load status, taking into account the coordinated power supply of lighting and load, and solving the problem that traditional power supplies cannot meet the brightness requirements.

[0051] In some embodiments, such as Figure 2 As shown, the voltage divider conversion circuit 200 includes a switching unit 210 and a first resistor R1. The first end of the first resistor R1 is connected to the power conversion circuit 100, and the second end of the first resistor R1 is grounded through the switching unit 210. The control terminal of the switching unit 210 is connected to the control circuit 300.

[0052] When the load is confirmed to be running, the control circuit 300 outputs a shutdown control signal to the control terminal of the control switch unit 210, causing the control switch unit 210 to be in the off state. At this time, the first resistor R1 is not connected to the power conversion circuit 100, that is, it is in the first voltage division state that does not affect the voltage division of the power conversion circuit 100, and the power conversion circuit 100 outputs the first power supply voltage.

[0053] When the control circuit 300 determines that the load is in a stopped state, it sends a turn-on control signal to the control terminal of the switching unit 210 to turn it on. At this time, the first resistor R1 forms a circuit with the switching unit 210 and is connected to the power conversion circuit 100, that is, it is in the second voltage division state that affects the voltage division of the power conversion circuit 100, and the power conversion circuit 100 outputs the second power supply voltage.

[0054] In this embodiment, the switching unit 210 has a fast response speed and can quickly switch between on and off states under the control of the control circuit 300, controlling the first resistor R1 to be connected to the power conversion circuit 100, thereby making the output voltage regulation process of the power conversion circuit 100 fast and stable. Moreover, the voltage divider conversion circuit 200 is composed of the switching unit 210 and the first resistor R1, and the circuit structure is simple.

[0055] In some embodiments, the switching unit 210 includes a first switching transistor Q1. The control electrode of the first switching transistor Q1 is connected to the control circuit 300, the first electrode of the first switching transistor Q1 is connected to the second terminal of the first resistor R1, and the second electrode of the first switching transistor Q1 is grounded.

[0056] The type of the first switching transistor Q1 can be set according to specific circumstances. The first terminal, second terminal, and control terminal of the first switching transistor Q1 need to be determined according to the type of the first switching transistor Q1. As an example, the first switching transistor Q1 is a bipolar transistor, with the base as the control terminal, the collector as the first terminal, and the emitter as the second terminal.

[0057] In this embodiment, the control circuit 300 can accurately output the level of the control signal IO-POWER according to the actual state of the load, so that the first switching transistor Q1 can switch quickly between the on and off states, thereby effectively controlling whether the first resistor R1 is connected to the power conversion circuit 100, so as to accurately adjust the output voltage of the power conversion circuit 100.

[0058] The topology of the power conversion circuit 100 can be configured according to specific circumstances. In some embodiments, the power conversion circuit 100 includes a switching power supply unit 110 and a feedback control unit 120. The switching power supply unit 110 connects to the lighting circuit and the load, and supplies power to the lighting circuit and the load.

[0059] The feedback control unit 120 is connected to both the switching power supply unit 110 and the voltage divider / conversion circuit 200. When the voltage divider / conversion circuit 200 is in the first voltage divider state, the feedback control unit 120 outputs a first feedback signal to the switching power supply unit 110, causing the switching power supply unit 110 to output a first power supply voltage. When the voltage divider / conversion circuit 200 is in the second voltage divider state, the feedback control unit 120 outputs a second feedback signal to the switching power supply unit 110, causing the switching power supply unit 110 to output a second power supply voltage.

[0060] In this embodiment, the feedback control unit 120 can output a corresponding feedback signal according to the actual connection state of the first resistor R1, enabling the switching power supply unit 110 to dynamically adjust the output voltage. When the load is running, the switching power supply unit 110 provides a lower first power supply voltage, which can meet the high drive current requirements of the load while maintaining a certain brightness of the lighting circuit. When the load stops running, the switching power supply unit 110 outputs a higher second power supply voltage, increasing the brightness of the lighting circuit to enhance the ambient lighting effect.

[0061] In some embodiments, the switching power supply unit 110 includes a transformer T, a second switching transistor Q2, and a rectifier output unit 111. A first end of the primary winding of the transformer T is connected to an external power source. The first terminal of the second switching transistor Q2 is connected to the second end of the primary winding, the second terminal of the second switching transistor Q2 is grounded, and the control terminal of the second switching transistor Q2 is connected to a feedback control unit 120. The input terminal of the rectifier output unit 111 is connected to the secondary winding of the transformer T, and the output terminal of the rectifier output unit 111 is connected to a lighting circuit, a load, and the feedback control unit 120.

[0062] In this embodiment, the second switch Q2, under the control of the feedback control unit 120, realizes the switching control of the primary winding current of the transformer T. Through rapid switching action, the input external power supply can be converted into a high-frequency pulse voltage, resulting in high power conversion efficiency and low energy loss. The rectifier output unit 111 converts the AC voltage output from the secondary winding of the transformer T into a DC voltage, providing a stable power supply voltage for the lighting circuit and load.

[0063] The output terminal of the rectifier output unit 111 is connected to the feedback control unit 120, forming a closed-loop feedback control system. The feedback control unit 120 can dynamically adjust the switching frequency and duty cycle of the second switching transistor Q2 according to the voltage output of the rectifier output unit 111, thereby precisely controlling the output power supply voltage.

[0064] Specifically, when the load is running, the control circuit 300 controls the first switch Q1 to turn off, and the first resistor R1 is not connected to the feedback control unit 120. At this time, the feedback control unit 120 adjusts the output voltage according to the actual needs of the load, ensuring that the load can obtain a suitable power supply under normal operating conditions, thereby improving the load's working efficiency and performance. When the load stops running, the control circuit 300 controls the first switch Q1 to turn on, and the first resistor R1 is connected to the feedback control unit 120. By changing the parameters of the feedback loop, the feedback control unit 120 can adjust the operating state of the second switch Q2 in a timely manner, increasing the output voltage and thus improving the brightness of the lighting circuit.

[0065] In some embodiments, the rectifier output unit 111 includes a diode D1 and a first capacitor C1. The anode of the diode D1 serves as the input terminal of the rectifier output unit 111 and is connected to the first terminal of the secondary winding. The cathode of the diode D1 is connected to the first terminal of the first capacitor C1, and the common terminal connecting the diode D1 and the first capacitor C1 serves as the output terminal of the rectifier output unit 111. The second terminal of the first capacitor C1 and the second terminal of the secondary winding are grounded.

[0066] In this embodiment, the rectifier output unit 111 uses a diode D1 and a first capacitor C1 to form a half-wave rectifier filter circuit. Utilizing the unidirectional conductivity of diode D1, the AC voltage output from the secondary winding of transformer T is converted into a unidirectional pulsating DC voltage. During the positive half-cycle of the AC voltage, diode D1 conducts, and current flows through diode D1 to charge the first capacitor C1, simultaneously supplying power to the load and lighting circuit. During the negative half-cycle of the AC voltage, diode D1 is cut off, and the first capacitor C1 discharges to the load, maintaining the power supply voltage to the load and lighting circuit.

[0067] The first capacitor C1 acts as a filter element, smoothing the output voltage. It can store charge during the conduction period of diode D1 and release charge during the cutoff period of diode D1, thereby reducing the fluctuation of the output voltage and making the output voltage more stable. This, in turn, makes the operation of the downstream load and lighting circuit more stable and reliable.

[0068] In some embodiments, the first end of the primary winding of transformer T is connected to an external power source through a second capacitor C2, thereby improving the power quality supplied to the first end of the primary winding by utilizing the filtering effect of the second capacitor C2.

[0069] In some embodiments, the feedback control unit 120 includes an adjustable voltage regulator chip U1, a power control chip U2, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and an optocoupler U3.

[0070] The first end of the second resistor R2 is connected to the output terminal of the rectifier output unit 111. The second end of the second resistor R2 is connected to the first end of the third resistor R3 and the voltage divider circuit 200. The second end of the third resistor R3 is grounded. The reference terminal of the adjustable voltage regulator chip U1 is connected to the second end of the second resistor R2. The anode of the adjustable voltage regulator chip U1 is grounded. The first end of the fourth resistor R4 is connected to the output terminal of the rectifier output unit 111. The second end of the fourth resistor R4 is connected to the first end of the fifth resistor R5 and the anode of the optocoupler U3. The second end of the fifth resistor R5 is connected to the cathode of the optocoupler U3 and the cathode of the adjustable voltage regulator chip U1. The collector of the optocoupler U3 is connected to the power control chip U2 via the sixth resistor R6. The emitter of the optocoupler U3 is grounded. The power control chip U2 is also connected to the control electrode of the second switching transistor Q2.

[0071] Among them, the adjustable voltage regulator chip U1 can be a TL431 device.

[0072] In this embodiment, when the load is running, the control circuit 300 controls the first switch Q1 to turn off, and the first resistor R1 is not connected to the feedback control unit 120. At this time, the feedback resistor in the feedback control unit 120 is the resistance value of the third resistor R3. This feedback resistance value is fed back to the power control chip U2 through the adjustable voltage regulator chip U1 and the optocoupler U3. The power control chip U2 adjusts the switching state of the second switch Q2 so that the rectifier output unit 111 outputs the first power supply voltage.

[0073] When the load stops running, the control circuit 300 controls the first switch Q1 to turn on, and the first resistor R1 is connected to the feedback control unit 120. At this time, the feedback resistor in the feedback control unit 120 is the parallel resistance value of the first resistor R1 and the third resistor R3 connected in parallel. This feedback resistance value is lower than that of the third resistor R3. After being fed back to the power control chip U2 through the adjustable voltage regulator chip U1 and the optocoupler U3, the power control chip U2 adjusts the switching state of the second switch Q2 so that the rectifier output unit 111 outputs the second power supply voltage.

[0074] In this embodiment, the switching power supply unit 110 is determined to be in a light load state based on the operating state of the load, so as to control whether the first resistor R1 is connected to the feedback control unit 120, thereby enabling the power control chip U2 to accurately adjust the output voltage of the switching power supply unit 110, taking into account the coordinated power supply of lighting and load.

[0075] To better understand the above embodiments, a detailed explanation is provided below with reference to a specific embodiment. Please refer to... Figures 1-2 In one embodiment, the lighting power supply circuit includes a power conversion circuit 100, a voltage divider circuit 200, and a control circuit 300. The power conversion circuit 100 connects the lighting circuit and the load, supplying power to both. The control circuit 300 connects to the load and determines the load's state. The voltage divider circuit 200 connects the control circuit 300 and the power conversion circuit 100.

[0076] The power conversion circuit 100 is a flyback topology, specifically including a switching power supply unit 110 and a feedback control unit 120. The switching power supply unit 110 includes a transformer T, a second switching transistor Q2, and a rectifier output unit 111. The rectifier output unit 111 includes a diode D1 and a first capacitor C1. The feedback control unit 120 includes an adjustable voltage regulator chip U1, a power control chip U2, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and an optocoupler U3.

[0077] The voltage divider conversion circuit 200 includes a switching unit 210 and a first resistor R1. The switching unit 210 includes a first switching transistor Q1.

[0078] In one specific application scenario, this lighting power supply circuit is used in a range hood. The range hood has an air conditioning function, and the lighting circuit includes a cool light.

[0079] During the range hood's operation, the push rod motor and LED lights need to be activated. The control circuit 300 controls the power conversion circuit 100 to enter its maximum load state, and the output signal IO-POWER is low, with the first switching transistor Q1 in the off state. The reference voltage of the TL431 device U1 is 2.54V. At this time, the power supply voltage V-POWER output by the power conversion circuit 100 is 2.54V / (R3 / (R2+R3)), which is set as the first power supply voltage. The selection of the second resistor R2 and the third resistor R3 must ensure that the first power supply voltage meets the rated power supply requirements of the push rod motor.

[0080] When the power conversion circuit 100 outputs the first power supply voltage, the push rod motor and the cold light operate normally, and the cold light displays its first brightness. After the range hood completes its startup and enters the stable operation stage, the push rod motor has fully opened the air outlet. At this point, the push rod motor can stop operating and does not require power. After removing the load demand on the motor, the power conversion circuit 100 enters a light-load state.

[0081] Under light load conditions, the load driving capacity of the power conversion circuit 100 has a portion that cannot be effectively utilized. The control circuit 300 converts the output signal IO-POWER to a high level, and the first switching transistor Q1 is in the conducting state. At this time, the feedback resistance of the power conversion circuit 100 is the resistance value of the third resistor R3 and the first resistor R1 connected in parallel. The parallel resistance value R0 = (R1*R3) / (R1+R3). The parallel resistance value R0 is less than the resistance value of the third resistor R3, so the feedback resistance value becomes smaller, thereby realizing the adjustment of the feedback resistance of the power conversion circuit 100.

[0082] Since the reference voltage of the TL431 device U1 is 2.54V, the output voltage V-POWER of the power conversion circuit 100 is 2.54V / (R0 / (R2+R0)), which is set as the second power supply voltage. Because the parallel resistance R0 is less than the resistance of the third resistor R3, the feedback voltage signal fed back to the power control chip U2 decreases, thus making the second power supply voltage higher than the first power supply voltage. Under the influence of the second power supply voltage, the supply voltage of the cold light lamp increases, the current of its internal LED (Light Emitting Diode) beads increases, and the brightness of the LED beads increases, realizing the function of boosting the brightness of the cold light lamp.

[0083] When the range hood enters the off operation phase, the push rod motor, display, and other loads need to be operated. The power conversion circuit 100 needs to enter the maximum load state. At this time, the control circuit 300 sets the output signal IO-POWER to a low level, the first switching transistor Q1 is in the off state, the first resistor R1 is no longer connected in parallel with the third resistor R3, the resistance value of the feedback resistor is adjusted from R0 to R3, and the resistance value of the feedback resistor increases. Under the reference voltage of 2.54V of the reference TL431 device U1, the output voltage V-POWER of the power conversion circuit 100 is 2.54V / (R3 / (R2+R3)). The output voltage is adjusted to the first power supply voltage, which meets the rated power supply requirements of the push rod motor, so that the push rod motor can operate normally.

[0084] This lighting power supply circuit eliminates the need for an additional power conversion circuit 100 with load capacity, achieving load power distribution through control circuit 300. During load operation, a lower output voltage ensures high current to drive loads requiring rated voltage and the operation of cold fluorescent lamps. After the load operation is complete, the power conversion circuit 100 enters a light load state. The control circuit 300 adjusts the feedback signal by adjusting the ratio of the feedback resistors, thereby increasing the output voltage of the power conversion circuit 100. This results in a higher voltage supplying power to the cold fluorescent lamps, increasing the current of the lamp beads and improving lighting brightness. Simultaneously, it effectively utilizes the idle load capacity of the power conversion circuit 100 during different operating stages, resulting in high utilization efficiency.

[0085] In one exemplary embodiment, such as Figure 3 As shown, an electrical device is provided, including a lighting circuit, a load control circuit, a load, and a lighting power supply circuit. The lighting power supply circuit can be configured with reference to the lighting power supply circuits in the above embodiments.

[0086] The power conversion circuit 100 in the lighting power supply circuit is connected to both the lighting circuit and the load control circuit. The load control circuit is connected to the control circuit 300 and the load. The control circuit 300 is used to control the load to start or stop operating through the load control circuit.

[0087] The load control circuit receives the power voltage output from the power conversion circuit 100 and flexibly supplies it to the load according to actual conditions. Simultaneously, it communicates with the control circuit 300, receiving signals from the control circuit 300 and precisely controlling the operation or shutdown of the load based on these signals. This allows for more flexible and precise load control, meeting the flexible control needs of different application scenarios.

[0088] In some embodiments, such as Figure 4As shown, the load control circuit includes a third switch Q3, a fourth switch Q4, a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9. The control circuit 300 is connected to the control terminal of the third switch Q3 via the seventh resistor R7. The first terminal of the third switch Q3 is connected to the first terminal of the ninth resistor R9 and the control terminal of the fourth switch Q4 via the eighth resistor R8. The second terminal of the third switch Q3 is grounded. The second terminal of the ninth resistor R9 and the second terminal of the fourth switch Q4 are connected to the power conversion circuit 100. The second terminal of the fourth switch Q4 is connected to the load.

[0089] When the load needs to be controlled to run, the MOTOR signal output by the control circuit 300 is high. At this time, the third switch Q3 is turned on, which in turn turns on the fourth switch Q4, providing the power supply voltage V-POWER output by the power conversion circuit 100 to the load. The load starts running after receiving the power supply voltage V-POWER. When the load needs to be controlled to stop running, the MOTOR signal output by the control circuit 300 is low. At this time, the third switch Q3 is turned off, which in turn turns off the fourth switch Q4, stopping the power supply to the load, and the load stops running.

[0090] In this embodiment, the load can be a push rod motor or other device, such as the display screen of an electrical appliance. The third switch Q3 amplifies the signal and performs drive conversion. When the control circuit 300 outputs a high-level signal, the third switch Q3 turns on, and its collector current increases. This increased current provides sufficient drive current for the fourth switch Q4, ensuring that the fourth switch Q4 can reliably turn on, thereby ensuring that the load can obtain a stable power supply voltage V-POWER to start operation. This improves the stability of the electrical appliance's operation.

[0091] In some embodiments, such as Figure 5 As shown, the electrical equipment also includes a lighting control circuit connected to the lighting circuit. The control terminal of the lighting control circuit is connected to the control circuit 300, and the control circuit 300 is also used to control the lighting circuit through the lighting control circuit.

[0092] The lighting control circuit receives the power voltage output from the power conversion circuit 100 and flexibly supplies it to the lighting circuit according to actual conditions. Simultaneously, it communicates with the control circuit 300, receiving LED signals from the control circuit 300 and precisely controlling the lighting circuit to illuminate or de-illuminate based on these signals. This allows for more flexible and precise control of the lighting circuit, improving its ease of use.

[0093] In some embodiments, such as Figure 6As shown, the lighting control circuit includes a fifth switch Q5, a sixth switch Q6, a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12. The control circuit 300 is connected to the control terminal of the fifth switch Q5 via the tenth resistor R10. The first terminal of the fifth switch Q5 is connected to the first terminal of the twelfth resistor R12 and the control terminal of the sixth switch Q6 via the eleventh resistor R11. The second terminal of the fifth switch Q5 is grounded. The second terminal of the twelfth resistor R12 and the second terminal of the sixth switch Q6 are connected to the power conversion circuit 100. The second terminal of the sixth switch Q6 is connected to the lighting circuit.

[0094] The structure of the lighting circuit can be configured according to specific circumstances. For example, the lighting circuit includes multiple light-emitting diodes (LEDs) D2 and a thirteenth resistor R13. The LEDs D2 are connected in parallel, and the common anode terminal of each LED D2 is used to connect to the second terminal of the sixth switching transistor Q6. The cathode of each LED D2 is grounded through the thirteenth resistor R13. The number of LEDs D2 needs to be set according to actual requirements.

[0095] When the lighting circuit needs to be controlled to emit light, the LED signal output by the control circuit 300 is at a high level. At this time, the fifth switch Q5 is turned on, which in turn turns on the sixth switch Q6, providing the power supply voltage V-POWER output by the power conversion circuit 100 to each LED D2 in the lighting circuit, causing each LED D2 to emit light. When it is necessary to control each LED D2 to stop emitting light, the LED signal output by the control circuit 300 is at a low level. At this time, the fifth switch Q5 is turned off, which in turn turns off the sixth switch Q6, stopping the power supply to each LED D2, and causing each LED D2 to turn off.

[0096] It is understandable that, in practical applications, the power supply voltage V-POWER output by the power conversion circuit 100 is also used to provide the control power VCC to the main control chip in the control circuit 300. For details, please refer to... Figure 7 The electrical equipment also includes a DC-DC conversion module, which converts the power supply voltage V-POWER output by the power conversion circuit 100 into the control power supply VCC to power the main control chip in the control circuit 300. Because the DC-DC conversion module has a wide input voltage range and can maintain a stable output voltage, the control power supply VCC is unaffected by fluctuations in the input power supply voltage V-POWER, resulting in higher power supply reliability.

[0097] In one exemplary embodiment, a range hood is provided, including an electrical appliance, which can be configured with reference to the embodiments described above.

[0098] In some embodiments, the range hood further includes an air conditioning unit. The air conditioning unit includes a push rod motor module connected to the control circuit and a cooling / heating module. When the range hood is turned on, the control circuit controls the push rod motor in the push rod motor module to operate. The push rod motor opens the air outlet through a mechanical transmission mechanism to output cooling or heating energy to the kitchen, creating a more comfortable environment for the user.

[0099] Once the air conditioning unit reaches its operating temperature, the push rod motor stops running. At this time, the power conversion circuit outputs a second power supply voltage with a larger amplitude, making the lighting circuit in the range hood brighter and easier for users to use.

[0100] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0101] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A lighting power supply circuit, characterized in that, include: A power conversion circuit is used to connect a lighting circuit and a load, and to supply power to the lighting circuit and the load. A control circuit, connected to the load, is used to determine the state of the load; A voltage divider conversion circuit is connected to the control circuit and the power conversion circuit. When the load is in operation, the control circuit controls the voltage divider conversion circuit to be in a first voltage divider state so that the power conversion circuit outputs a first power supply voltage. When the load is not in operation, the control circuit controls the voltage divider conversion circuit to be in a second voltage divider state so that the power conversion circuit outputs a second power supply voltage. The second power supply voltage is greater than the first power supply voltage.

2. The lighting power supply circuit according to claim 1, characterized in that, The voltage divider conversion circuit includes a switching unit and a first resistor; the first end of the first resistor is connected to the power conversion circuit, the second end of the first resistor is grounded through the switching unit, and the control terminal of the switching unit is connected to the control circuit.

3. The lighting power supply circuit according to claim 2, characterized in that, The switching unit includes a first switching transistor, the control electrode of the first switching transistor is connected to the control circuit, the first electrode of the first switching transistor is connected to the second terminal of the first resistor, and the second electrode of the first switching transistor is grounded.

4. The lighting power supply circuit according to claim 1, characterized in that, The power conversion circuit includes: A switching power supply unit is connected to the lighting circuit and the load; A feedback control unit is connected to the switching power supply unit and the voltage divider conversion circuit. When the voltage divider conversion circuit is in a first voltage divider state, the feedback control unit outputs a first feedback signal to the switching power supply unit, causing the switching power supply unit to output a first power supply voltage. When the voltage divider conversion circuit is in a second voltage divider state, the feedback control unit outputs a second feedback signal to the switching power supply unit, causing the switching power supply unit to output a second power supply voltage.

5. The lighting power supply circuit according to claim 4, characterized in that, The switching power supply unit includes: A transformer, wherein the first end of the primary winding of the transformer is used to connect to an external power source; The second switch has its first terminal connected to the second end of the primary winding, its second terminal grounded, and its control terminal connected to the feedback control unit. A rectifier output unit, the input terminal of which is connected to the secondary winding of the transformer, and the output terminal of which is connected to the lighting circuit, the load, and the feedback control unit.

6. The lighting power supply circuit according to claim 5, characterized in that, The rectifier output unit includes a diode and a first capacitor; the anode of the diode serves as the input terminal of the rectifier output unit and is connected to the first terminal of the secondary winding; the cathode of the diode is connected to the first terminal of the first capacitor, and the common terminal connecting the diode and the first capacitor serves as the output terminal of the rectifier output unit; the second terminal of the first capacitor and the second terminal of the secondary winding are grounded.

7. The lighting power supply circuit according to claim 5, characterized in that, The feedback control unit includes an adjustable voltage regulator chip, a power control chip, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and an optocoupler; The first end of the second resistor is connected to the output terminal of the rectifier output unit, the second end of the second resistor is connected to the first end of the third resistor and the voltage divider circuit, and the second end of the third resistor is grounded; the reference terminal of the adjustable voltage regulator chip is connected to the second end of the second resistor, and the anode of the adjustable voltage regulator chip is grounded; the first end of the fourth resistor is connected to the output terminal of the rectifier output unit, the second end of the fourth resistor is connected to the first end of the fifth resistor and the anode of the optocoupler, and the second end of the fifth resistor is connected to the cathode of the optocoupler and the cathode of the adjustable voltage regulator chip; the collector of the optocoupler is connected to the power control chip via the sixth resistor, the emitter of the optocoupler is grounded, and the power control chip is also connected to the control electrode of the second switching transistor.

8. An electrical appliance, characterized in that, include: Lighting circuit, load control circuit, load, and lighting power supply circuit according to any one of claims 1-7; The power conversion circuit is connected to the lighting circuit and the load control circuit respectively. The load control circuit is connected to the control circuit and the load. The control circuit is used to control the load to run or stop running.

9. The electrical equipment according to claim 8, characterized in that, The load control circuit includes a third switch, a fourth switch, a seventh resistor, an eighth resistor, and a ninth resistor; The control circuit is connected to the control electrode of the third switch via the seventh resistor. The first electrode of the third switch is connected to the first terminal of the ninth resistor and the control electrode of the fourth switch via the eighth resistor. The second electrode of the third switch is grounded. The second terminal of the ninth resistor and the second electrode of the fourth switch are connected to the power conversion circuit. The second electrode of the fourth switch is connected to the load.

10. The electrical equipment according to claim 8, characterized in that, It also includes a lighting control circuit connected to the lighting circuit; the control terminal of the lighting control circuit is connected to the control circuit, and the control circuit is also used to control the lighting circuit through the lighting control circuit.

11. The electrical equipment according to claim 10, characterized in that, The lighting control circuit includes a fifth switch, a sixth switch, a tenth resistor, an eleventh resistor, and a twelfth resistor. The control circuit is connected to the control terminal of the fifth switch via the tenth resistor. The first terminal of the fifth switch is connected to the first terminal of the twelfth resistor and the control terminal of the sixth switch via the eleventh resistor. The second terminal of the fifth switch is grounded. The second terminal of the twelfth resistor and the second terminal of the sixth switch are connected to the power conversion circuit. The second terminal of the sixth switch is connected to the lighting circuit.

12. A range hood, characterized in that, The electrical equipment included in any one of claims 8-11.

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