Driver for lighting device and lighting device

Abstract

The utility model relates to a driver for a lighting device and the lighting device, and the driver comprises a flyback constant voltage module which comprises a primary side and a secondary side and provides flyback output voltage at the secondary side according to a power signal of the primary side; the constant-current step-down module is used for receiving the flyback output voltage and providing a load output voltage of a power consumption load of the lighting device by reducing the flyback output voltage; the detection module is connected between the constant-current voltage reduction module and the flyback constant-voltage module, generates a detection signal representing the difference between the flyback output voltage and the load output voltage in an inductance mode and feeds back the detection signal to the flyback constant-voltage module; the flyback constant voltage module receives a feedback voltage reference signal representing the output current of the power consumption load from the primary side and adjusts the flyback output voltage according to the detection signal and the feedback voltage reference signal. According to the lighting device driver, the structure is simple, the cost is low, the standby power loss is reduced, and the overall efficiency of a load power supply of the lighting device is improved.

Description

Technical Field

[0001] The utility model relates to a driver for a lighting device and a lighting device. Background Art

[0002] In the field of drivers for medium and low power lighting devices, in order to obtain low cost, flyback modules and buck modules are usually adopted. In order to output a full range of non-flickering signals, the flyback output voltage is set to be higher than the driver output voltage. Further, when the output voltage is high, the overall efficiency of the driver is high. However, as the output voltage decreases, the difference between the flyback output voltage and the driver output voltage becomes larger, which results in increasing system losses. In the prior art, in order to solve the above problems, the buck circuit is changed, a floating ground voltage is provided, and an optocoupler device is added. When the floating ground voltage exceeds the threshold, the optocoupler outputs a high level, otherwise it outputs a low level. When the percentage of the high and low levels is constant, the average value of the floating ground voltage will reach a specific value, so that the flyback output voltage changes with the change of the driver output voltage. However, this solution increases the complexity and manufacturing cost of the system. Summary of the Utility Model

[0003] In view of this, an embodiment of the present utility model provides a new driver for a lighting device and a lighting device including the driver. The driver for the lighting device according to the present utility model has a simple structure and low cost, can reduce standby power loss, and improve the overall efficiency of the load power supply of the lighting device.

[0004] According to a preferred embodiment of the present utility model, there is provided a driver for a lighting device, the driver including: a flyback constant voltage module, including a primary side and a secondary side, and configured to provide a flyback output voltage at the secondary side according to a power signal at the primary side; a constant current buck module, configured to receive the flyback output voltage and provide a load output voltage for a power-consuming load of the lighting device by reducing the flyback output voltage; and a detection module, connected between the constant current buck module and the flyback constant voltage module, and configured to generate a detection signal characterizing the difference between the flyback output voltage and the load output voltage in an inductive manner and feedback the detection signal to the flyback constant voltage module, wherein the flyback constant voltage module is further configured to receive a feedback voltage reference signal characterizing the output current for the power-consuming load from the primary side, and adjust the flyback output voltage according to the detection signal and the feedback voltage reference signal. Thus, by reducing the difference between the output voltages of the two conversion stages, especially the driver can effectively reduce the difference between the flyback output voltage and the load output voltage at any time, reduce system losses, and improve the overall efficiency of the system.

[0005] According to an exemplary embodiment of the present utility model, the constant current buck module includes an inductor connected between the flyback constant voltage module and the power-consuming load, and the detection module includes a winding connected to the inductor in an inductive coupling manner, and the winding converts the voltage on the inductor into a detection signal. The present utility model provides a simple detection and adjustment method, making it simple to detect the difference between the flyback output voltage and the load output voltage that affects the system loss and efficiency. With fewer components, the manufacturing cost of the driver is reduced.

[0006] According to an exemplary embodiment of the present utility model, the flyback constant voltage module further includes a first feedback terminal, and the detection module further includes a first capacitor. Wherein, the first terminal of the first capacitor is connected to the winding, and the second terminal of the first capacitor is connected to the first feedback terminal. Wherein, the detection signal is determined by the voltage of the first capacitor. Furthermore, the driver adopts a simple circuit structure and fewer electrical components, achieving an efficient detection and feedback effect.

[0007] According to an exemplary embodiment of the present utility model, the flyback constant voltage module further includes a constant bias voltage source and a voltage dividing circuit. Wherein, the voltage dividing circuit divides the voltage of the constant bias voltage source. Wherein, the flyback constant voltage module is further configured to determine a feedback voltage reference signal according to the divided output voltage of the voltage dividing circuit and the voltage on the branch of the voltage dividing circuit, such that the flyback output voltage is greater than the load output voltage. The driver according to this embodiment adopts a detection mechanism and structure with a simple structure, effectively determining the driver output current that affects the change of the flyback output voltage.

[0008] According to an exemplary embodiment of the present utility model, the flyback constant voltage module further includes a second feedback terminal and a first transistor, and the voltage dividing circuit includes a first resistor and a second resistor. Wherein, the first terminal of the first resistor is connected to the rectifier bridge on the primary side, the second terminal of the first resistor is connected to the source electrode of the first transistor and connected to the second feedback terminal, and the first terminal of the second resistor is connected to the constant bias voltage source, and the second terminal of the second resistor is connected to the node between the first resistor and the second feedback terminal. This enables the driver to effectively utilize the original circuit module to implement additional functions, realize the characterization of the output current and the determination of the basis for adjusting the flyback output voltage, and achieve the detection effect expected in this embodiment, reduce the addition of additional electrical components, and suppress the overall manufacturing cost of the driver.

[0009] According to an exemplary embodiment of the present utility model, the flyback constant voltage module further includes a third resistor and a second capacitor. Among them, the first terminal of the third resistor is connected to the second terminal of the first resistor, and the second terminal of the third resistor is connected to the second feedback terminal and grounded via the second capacitor. This effectively improves the quality of the feedback signal fed to the controller of the flyback constant voltage module, makes the signal smooth, and improves the reliability and stability of the adjustment process of the driver.

[0010] According to an exemplary embodiment of the present utility model, the flyback constant voltage module includes a microcontroller and an operational amplifier. Among them, a detection signal and a feedback voltage reference signal are provided to the input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the input terminal of the microcontroller, and the output terminal of the microcontroller is connected to the gate of the first transistor. This effectively reduces the manufacturing cost of the driver and uses low-cost controller components.

[0011] According to an exemplary embodiment of the present utility model, the constant current buck module further includes a second transistor, a diode, and a third capacitor. The first terminal of the inductor is connected to the node between the source of the second transistor and the negative electrode of the diode, the second terminal of the inductor is connected to the node between the power-consuming load and the third capacitor, and the diode and the third capacitor are respectively connected in parallel with the power-consuming load. The driver according to this embodiment uses a small number of electrical components, effectively controlling the manufacturing cost and the circuit structure complexity of the driver.

[0012] According to a preferred embodiment of the present utility model, there is also provided a lighting device, which includes a driver according to the above description. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The preferred embodiments of the present utility model will be described in detail below with reference to the drawings, so that those of ordinary skill in the art can more clearly understand the above and other features and advantages of the present utility model. In the drawings:

[0014] Figure 1 A block diagram of a driver according to an exemplary embodiment of the present utility model is shown.

[0015] Figure 2 A circuit schematic diagram of a driver according to an exemplary embodiment of the present utility model is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the objectives, technical solutions, and advantages of the present utility model clearer, the following embodiments are given to further elaborate on the present utility model in detail.

[0017] Figure 1 A block diagram of a driver according to an exemplary embodiment of the present utility model is shown. As Figure 1As shown, in this embodiment, the driver for the lighting device includes a flyback constant voltage module 10, a constant current buck module 20, and a detection module 30. The flyback constant voltage module 10 includes a primary side and a secondary side, and is configured to provide a flyback output voltage on the secondary side according to the power supply signal on the primary side. The constant current buck module 20 is configured to receive the flyback output voltage and provide a load output voltage for the power-consuming load Ro of the lighting device by reducing the flyback output voltage. The detection module 30 is connected between the constant current buck module 20 and the flyback constant voltage module 10. The detection module 30 is configured to generate a detection signal characterizing the difference between the flyback output voltage and the load output voltage in an inductive manner and feedback the detection signal to the flyback constant voltage module 10. In Figure 1 the embodiment, the flyback constant voltage module 10 is further configured to receive a feedback voltage reference signal characterizing the output current for the power-consuming load Ro from the primary side, and adjust the flyback output voltage according to the feedback voltage reference signal and the detection signal from the detection module 30. If the buck output voltage or the load output voltage decreases, the flyback output voltage decreases, and the waveform of the flyback output voltage will vary depending on the output current of the buck module.

[0018] Figure 2 shows a circuit schematic diagram of the driver according to an exemplary embodiment of the present invention. As Figure 2 shown, in this embodiment, the constant current buck module 20 includes an inductor L connected between the flyback constant voltage module 10 and the power-consuming load Ro, and the detection module 30 includes a winding connected to the inductor L in a manner of inductive coupling with the inductor L. The winding transforms the voltage on the inductor L into a detection signal. In Figure 2 it, the flyback constant voltage module 10 further includes a first feedback terminal, and the detection module 30 further includes a first capacitor C1. The first terminal of the first capacitor C1 is connected to the winding, and the second terminal of the first capacitor C1 is connected to the first feedback terminal. For example, the detection signal fed back to the flyback constant voltage module 10 is determined by the voltage on the first capacitor C1. An auxiliary winding coupled to the inductor L is adopted on the secondary side. This winding can carry information about the difference between the flyback output voltage Vfb and the load output voltage Vo. This information is used as one of the information for adjusting the flyback output voltage Vfb for the first feedback terminal of the controller of the flyback constant voltage module. Another piece of information fed back to the controller of the flyback constant voltage module 10 is the current signal passing through the primary side representing the output current Io of the constant current buck module 20, that is, the feedback voltage reference signal.

[0019] As Figure 2As shown, the flyback constant voltage module 10 further includes a constant bias voltage source Vbias and a voltage dividing circuit. The constant bias voltage source Vbias is, for example, a constant voltage of 3.3V. The voltage dividing circuit divides the voltage of the constant bias voltage source Vbias. The flyback constant voltage module 10 is further configured to determine a feedback voltage reference signal based on the voltage divided output voltage of the voltage dividing circuit and the voltage on the branch of the voltage dividing circuit, such that the flyback output voltage Vfb is greater than the load output voltage Vo. For example, the sum of the voltage divided output voltage and the branch voltage is used as the feedback voltage reference signal.

[0020] The flyback constant voltage module 10 further includes a second feedback terminal and a first transistor Q1, and the voltage dividing circuit includes a first resistor R1 and a second resistor R2. The first terminal of the first resistor R1 is connected to the rectifier bridge on the primary side, and the second terminal of the first resistor R1 is connected to the source of the first transistor Q1 and to the second feedback terminal. The first terminal of the second resistor R2 is connected to the constant bias voltage source, and the second terminal of the second resistor R2 is connected to the node between the first resistor R1 and the second feedback terminal. The flyback constant voltage module 10 further includes a third resistor R3 and a second capacitor C2. The first terminal of the third resistor R3 is connected to the second terminal of the first resistor R1, and the second terminal of the third resistor R3 is connected to the second feedback terminal and grounded via the second capacitor C2.

[0021] The flyback constant voltage module 10 further includes a microcontroller 11 and an operational amplifier 12. The detection signal and the feedback voltage reference signal are provided to the two input terminals of the operational amplifier 12 that serve as the first feedback terminal and the second feedback terminal. The output terminal of the operational amplifier 12 is connected to the input terminal of the microcontroller 11, and the output terminal of the microcontroller 11 is connected to the gate of the first transistor Q1. The constant current buck module 20 includes a corresponding microcontroller 21 and an operational amplifier 22. The constant current buck module 20 further includes a second transistor Q2, a diode D, and a third capacitor C3. The first terminal of the inductor L is connected to the node between the source of the second transistor Q2 and the cathode of the diode D. The second terminal of the inductor L is connected to the node between the power-consuming load Ro and the third capacitor C3, and the diode D and the third capacitor C3 are respectively connected in parallel with the power-consuming load Ro.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0024] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A driver for a lighting device, characterized in that: The driver comprises: A flyback constant voltage module (10), comprising a primary side and a secondary side, and configured to provide a flyback output voltage (Vfb) on the secondary side according to a power supply signal on the primary side; A constant current step-down module (20) is configured to receive the flyback output voltage (Vfb) and provide a load output voltage (Vo) for a power consumption load (Ro) of the lighting device by reducing the flyback output voltage (Vfb); and A detection module (30) is connected between the constant current buck module (20) and the flyback constant voltage module (10), and is configured to generate a detection signal representing the difference between the flyback output voltage (Vfb) and the load output voltage (Vo) in an inductive manner, and to feed back the detection signal to the flyback constant voltage module (10). The flyback constant voltage module (10) is further configured to receive a feedback voltage reference signal representing an output current (Io) for the power consuming load (Ro) from the primary side, and to adjust the flyback output voltage (Vfb) according to the detection signal and the feedback voltage reference signal.

2. The driver according to claim 1, characterized in that: The constant current step-down module (20) comprises an inductor (L) connected between the flyback constant voltage module (10) and the power consumption load (Ro), and the detection module (30) comprises a winding connected to the inductor (L) in an inductively coupled manner, the winding converting the voltage on the inductor (L) into the detection signal.

3. The driver according to claim 2, characterized in that: The flyback constant voltage module (10) further comprises a first feedback terminal, and the detection module (30) further comprises a first capacitor (C1), wherein a first terminal of the first capacitor (C1) is connected to the winding, and a second terminal of the first capacitor (C1) is connected to the first feedback terminal, wherein the detection signal is determined by the voltage of the first capacitor (C1).

4. The driver according to claim 3, characterized in that: The flyback constant voltage module (10) further comprises a constant bias voltage source and a voltage divider circuit, wherein the voltage divider circuit divides the voltage of the constant bias voltage source, wherein the flyback constant voltage module (10) is further configured to determine the feedback voltage reference signal according to the voltage divider output voltage of the voltage divider circuit and the voltage on the branch of the voltage divider circuit, so that the flyback output voltage (Vfb) is greater than the load output voltage (Vo).

5. The driver according to claim 4, characterized in that: The flyback constant voltage module (10) further comprises a second feedback terminal and a first transistor (Q1), and the voltage divider circuit comprises a first resistor (R1) and a second resistor (R2), wherein a first terminal of the first resistor (R1) is connected to a rectifier bridge on the primary side, a second terminal of the first resistor (R1) is connected to a source of the first transistor (Q1) and to the second feedback terminal, and a first terminal of the second resistor (R2) is connected to the constant bias voltage source, and a second terminal of the second resistor (R2) is connected to a node between the first resistor (R1) and the second feedback terminal.

6. The driver according to claim 5, characterized in that: The flyback constant voltage module (10) further comprises a third resistor (R3) and a second capacitor (C2), wherein a first terminal of the third resistor (R3) is connected to a second terminal of the first resistor (R1), and a second terminal of the third resistor (R3) is connected to the second feedback terminal and is grounded via the second capacitor (C2).

7. The driver according to claim 5, characterized in that: The flyback constant voltage module (10) further comprises a microcontroller (11) and an operational amplifier (12), wherein the detection signal and the feedback voltage reference signal are provided to the input end of the operational amplifier (12), the output end of the operational amplifier (12) is connected to the input end of the microcontroller (11), and the output end of the microcontroller (11) is connected to the gate of the first transistor (Q1).

8. The driver according to claim 2, characterized in that: The constant current step-down module (20) further comprises a second transistor (Q2), a diode (D) and a third capacitor (C3); a first terminal of the inductor (L) is connected to a node between a source of the second transistor (Q2) and a negative electrode of the diode (D); a second terminal of the inductor (L) is connected to a node between the power-consuming load (Ro) and the third capacitor (C3); and the diode (D) and the third capacitor (C3) are respectively connected in parallel with the power-consuming load (Ro).

9. A lighting device, characterized in that: The lighting device comprises a driver according to any one of claims 1-8.

Images