Lighting control system

Abstract

To provide a lighting control system that can automatically turn on or off light-emitting diodes in response to changes in ambient light intensity.SOLUTION: A lighting control system includes a switching power supply 10 and a control circuit 20. The control circuit includes a photosensor 21 and a resistor 22 connected in series, one end of which is connected to a DC voltage V and the other end of which is grounded. The junction between the photosensor and the resistor is connected to the PWMD pin or LD pin of the switching power supply. The photosensor is configured to sense the ambient light intensity, and the control circuit outputs a control voltage, which is transmitted to the switching power supply via the PWMD pin or LD pin to turn the LED light source on or off.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to a lighting control system, and more particularly to a lighting control system that includes a switching power supply for supplying power and that can automatically turn on or off light emitting diodes in response to changes in ambient light intensity. [Background technology]

[0002] 2. Description of Related Art Light-emitting diodes (LEDs) have many advantages, such as light weight, small size, high luminous efficiency, and long service life. As the next generation light source, LEDs have been widely adopted in various lighting applications.

[0003] Currently, most LED lamps on the market are powered by mains power or rechargeable batteries via USB connection, and their lighting is mainly controlled manually by the user. If the light is left on due to carelessness or forgetfulness, not only does it waste energy, but it also generates heat over a long period of time, which can lead to lamp deterioration and a shortened lifespan. To solve this drawback, motion sensor lamps have been introduced. These lamps are equipped with sensors that control the lighting and automatically turn on the light when it is needed, thereby saving energy consumption and extending the lamp's lifespan.

[0004] One type of motion sensor lamp known in the art primarily employs infrared emission and reception technology to achieve lighting control. These lamps primarily employ passive infrared (PIR) sensors to detect the presence of moving objects emitting infrared light within a predetermined sensing range, thereby determining whether a human or animal is entering or exiting the sensing area. The light immediately turns on upon human or animal detection and automatically turns off after a certain period of time without motion, thereby saving energy and extending the lamp's lifespan.

[0005] Another type of motion sensor lamp is equipped with a brightness sensor module for lighting management. The lamp turns on or off based on the ambient light intensity measured by the brightness sensor module. This type of lamp can be configured to automatically turn on at night and turn off during the day, providing both convenience and energy savings. However, there is still a need in the related industry to develop more useful and ideal lighting control systems to meet consumer demands. Summary of the Invention [Problem to be solved by the invention]

[0006] In response to the above market needs, the present invention provides a lighting control system that includes a switching power supply to provide power and can automatically turn on or off light emitting diodes in response to changes in ambient light intensity. [Means for solving the problem]

[0007] In one aspect, a lighting control system provided herein includes a switching power supply including an input terminal for connecting to a power source and an output terminal for connecting to a light emitting diode (LED) light source, the switching power supply further including a pulse width modulation dimming (PWMD) pin; and a control circuit including a photosensor and a resistor connected in series, one end of the control circuit being connected to a DC voltage and the other end being grounded, the PWMD pin being connected to a junction between the photosensor and the resistor, the photosensor being configured to sense ambient light intensity, and a control voltage that varies according to ambient light intensity being transmitted to the switching power supply via the PWMD pin, thereby turning on or off the LED light source.

[0008] The present invention utilizes a photosensor to sense the ambient light intensity and automatically turn on or off the LED light source accordingly. Furthermore, the control circuit disclosed herein can be directly connected to the switching power supply without modifying the existing circuit layout of the switching power supply. This configuration enables automatic on-off control of the LED light source, achieves energy savings, and greatly simplifies installation, thereby increasing user enthusiasm.

[0009] In a preferred embodiment, the resistor is connected in series with the DC voltage, and the photosensor is connected in series between the resistor and ground.

[0010] In a preferred embodiment, the photosensor is connected in series with the DC voltage, the resistor is connected in series between the photosensor and ground, and the PWMD pin is connected to the junction between the photosensor and the resistor through an inverter.

[0011] In another aspect, a lighting control system provided herein includes a switching power supply including an input terminal for connecting to a power source and an output terminal for connecting to a light emitting diode (LED) light source, the switching power supply further including a linear dimming (LD) pin; and a control circuit including a photosensor and a resistor connected in series, one end of the control circuit being connected to a DC voltage and the other end being grounded, the LD pin being connected to a junction between the photosensor and the resistor, the photosensor being configured to sense ambient light intensity, and a control voltage that varies according to ambient light intensity being transmitted to the switching power supply via the LD pin, thereby turning on or off the LED light source.

[0012] In a preferred embodiment, the resistor is connected in series with the DC voltage, the photosensor is connected in series between the resistor and ground, and the LD pin is connected to the junction between the photosensor and the resistor via a diode.

[0013] In a preferred embodiment, the diode has a forward bias voltage. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic configuration diagram showing a lighting control system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic configuration diagram showing a lighting control system according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a schematic configuration diagram showing a lighting control system according to a third embodiment of the present invention. [Figure 4] FIG. 4 is a schematic configuration diagram showing a lighting control system according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments taken in conjunction with the accompanying drawings.

[0016] 1 is a schematic diagram showing the configuration of a lighting control system according to a first embodiment of the present invention. The lighting control system includes a switching power supply 10 and a control circuit 20.

[0017] Switching power supply 10 includes an input terminal 11 for connecting to a power source and an output terminal 12 for connecting to a light emitting diode (LED) light source 30. Switching power supply 10 further includes a pulse width modulation dimming (PWMD) pin 13 and a linear dimming (LD) pin 14. LED light source 30 includes at least one LED 31.

[0018] The control circuit 20 includes a photosensor 21 and a resistor 22 connected in series. One end of the control circuit 20 is connected to a DC voltage V, and the other end 23 is grounded. The PWMD pin 13 is connected to the junction between the photosensor 21 and the resistor 22. According to the first embodiment shown in FIG. 1 , the resistor 22 is connected in series to the DC voltage V, and the photosensor 21 is connected in series between the resistor 22 and ground 23. The photosensor 21 is configured to sense ambient light intensity. When the ambient light intensity increases, the electrical resistance of the photosensor 21 decreases. Alternatively, when the ambient light intensity decreases, the electrical resistance of the photosensor 21 increases. As a result, a control voltage that varies depending on the ambient light intensity is transmitted to the switching power supply 10 via the PWMD pin 13, thereby turning on or off the LED light source 30. The photosensor 21 can be selected from a photoresistor, photodiode, phototransistor, solar panel, or other electronic component whose electrical resistance varies depending on light intensity.

[0019] During use, the input terminal 11 is first connected to a power source, and the photosensor 21 senses the ambient light intensity. When the ambient light intensity is high, the resistance of the photosensor 21 decreases, and the photosensor 21 and resistor 22 convert the DC voltage V into a low control voltage. This low control voltage is transmitted to the switching power supply 10 via the PWMD pin 13, turning off the LED light source 30. Alternatively, when the ambient light intensity is low, the resistance of the photosensor 21 increases, outputting a high control voltage at the PWMD pin 13, thereby turning on the LED light source 30. Therefore, by simply connecting the control circuit 20 to the PWMD pin 13 built into the switching power supply 10, the present invention can function as an automatic switch that outputs a control voltage based on the ambient light intensity detected by the photosensor 21, thereby turning the LED light source 30 on or off without disconnecting from the power source. Again, the control circuit 20 is used to sense the ambient light intensity, thereby automatically turning the LED light source 30 on or off in response to changes in the ambient light intensity.

[0020] Conventionally, the built-in PWMD pin 13 of the switching power supply 10 is configured to receive a PWM digital signal to rapidly turn the LED light source 30 on and off multiple times to achieve dimming. In contrast, in this specification, the PWMD pin 13 is primarily used as a switch, and the control circuit 20 serves to sense the ambient light intensity. When the ambient light intensity increases, the control circuit 20 outputs a low control voltage to the PWMD pin 13, turning the LED light source 30 off. Alternatively, when the ambient light intensity decreases, the control circuit 20 outputs a high control voltage to the PWMD pin 13, turning the LED light source 30 on. This circuit layout eliminates the need for manual switching and achieves automatic on-off control of the LED light source 30. Essentially, in this specification, the PWMD pin is used as a switch that receives an analog signal from the control circuit to turn the LED light source on or off, thereby performing a function entirely different from the dimming function for which it was originally designed.

[0021] 2, a photosensor 21 is connected in series with a DC voltage V, and a resistor 22 is connected in series between the photosensor 21 and ground 23. A PWMD pin 13 is connected to the junction between the photosensor 21 and the resistor 22 via an inverter 24. Similar to that disclosed in the first embodiment, the photosensor 21 is used here to sense the ambient light intensity, and a control voltage that varies according to the ambient light intensity is transmitted to the switching power supply 10 via the PWMD pin 13, thereby turning the LED light source 30 on or off.

[0022] In a third embodiment shown in FIG. 3 , the control circuit 20 may alternatively be connected to the linear dimming (LD) pin 14. As shown, a resistor 22 is connected in series with a DC voltage V, and a photosensor 21 is connected in series between the resistor 22 and ground 23. The photosensor 21 is used here to sense ambient light intensity, and a control voltage that varies depending on the ambient light intensity is transmitted to the switching power supply 10 via the LD pin 14, thereby turning the LED light source 30 on or off. The photosensor 21 is configured so that its electrical resistance changes depending on changes in ambient light intensity. When the photosensor 21 detects low ambient light intensity, the control circuit 20 outputs a high control voltage to the LD pin 14, thereby automatically turning on the LED light source 30. Alternatively, when the photosensor 21 detects high ambient light intensity, the control circuit 20 outputs a low control voltage to the LD pin 14, thereby automatically turning off the LED light source 30. Therefore, by simply connecting the control circuit 20 to the LD pin 14 already present on the switching power supply 10, the control circuit 20 can output a control voltage based on the ambient light intensity sensed by the photosensor 21, thereby functioning as an automatic switch to turn the LED light source 30 on or off without disconnecting it from the power supply.

[0023] In a fourth embodiment shown in FIG. 4, the LD pin 14 is connected to the junction between the photosensor 21 and the resistor 22 through a diode 25. The diode 25 has a forward bias voltage that acts as a threshold voltage, ensuring that the control voltage is transmitted to the switching power supply 10 via the LD pin 14 only if it is greater than the forward bias voltage of the diode 25. This arrangement improves the flickering problem of the LED light source 30 caused by the control voltage being too low in dark environments. Furthermore, when the ambient light increases, the forward bias voltage of the diode 25 causes the control voltage to rapidly drop to zero, immediately turning off the LED light source 30 and preventing flickering.

[0024] Furthermore, in the above-described embodiments, the input terminal of the switching power supply may be directly connected to a DC power supply, or may be connected to an AC power supply via a rectifier circuit.

[0025] The present invention requires only connecting the control circuit 20 to either the PWMD pin 13 or the LD pin 14 built into the switching power supply 10, eliminating the need to modify the existing layout of the switching power supply 10. This configuration enables automatic on-off control of the LED light source, while also saving energy and making installation extremely convenient, thereby encouraging user adoption. The present invention primarily uses a photosensor 21 to detect ambient light intensity, thereby enabling automatic control of the LED light source without manual user interaction or disconnection from the power source. Furthermore, since most commercially available LED lamps use switching power supplies as their power source, users can achieve lighting control simply by connecting the control circuit disclosed herein to the existing PWMD or LD pin of a conventional switching power supply. The present invention features a simple and cost-effective circuit structure, making it easy for users to operate and manage.

Claims

1. 1. A lighting control system comprising: a switching power supply (10) including an input terminal (11) for connection to a power source and an output terminal (12) for connection to a light emitting diode (LED) light source (30), said switching power supply (10) further including a pulse width modulation dimming (PWMD) pin (13); and a control circuit (20) including a photosensor (21) and a resistor (22) connected in series, one end of the control circuit (20) being connected to a DC voltage (V) and the other end being grounded, the PWMD pin (13) being connected to a connection between the photosensor (21) and the resistor (22), the photosensor (21) being configured to sense ambient light intensity, and a control voltage that varies depending on the ambient light intensity being transmitted to the switching power supply (10) via the PWMD pin (13), thereby turning on or off the LED light source (30).

2. 2. The lighting control system of claim 1, wherein the resistor (22) is connected in series with the DC voltage (V), and the photosensor (21) is connected in series between the resistor (22) and the ground (23).

3. 2. The lighting control system of claim 1, wherein the photosensor (21) is connected in series with the DC voltage (V), the resistor (22) is connected in series between the photosensor (21) and the ground (23), and the PWMD pin (13) is connected to the connection between the photosensor (21) and the resistor (22) via an inverter (24).

4. 1. A lighting control system comprising: a switching power supply (10) including an input terminal (11) for connection to a power source and an output terminal (12) for connection to a light emitting diode (LED) light source (30), the switching power supply (10) further including a linear dimming (LD) pin (14); and a control circuit (20) including a photosensor (21) and a resistor (22) connected in series, one end of the control circuit (20) being connected to a DC voltage (V) and the other end being grounded, the LD pin (14) being connected to a connection between the photosensor (21) and the resistor (22), the photosensor (21) being configured to sense ambient light intensity, and a control voltage that varies depending on the ambient light intensity being transmitted to the switching power supply (10) via the LD pin (14), thereby turning the LED light source (30) on or off.

5. 5. The lighting control system of claim 4, wherein the resistor (22) is connected in series with the DC voltage (V), the photosensor (21) is connected in series between the resistor (22) and the ground (23), and the LD pin (14) is connected to a connection between the photosensor (21) and the resistor (22) via a diode (25).

6. 6. A lighting control system according to any one of claims 1 to 5, wherein the photosensor (21) is configured to change its electrical resistance in response to changes in ambient light intensity.

7. 6. The lighting control system according to claim 1, wherein the photosensor (21) is configured to sense ambient light intensity, and to decrease its electrical resistance when the ambient light intensity increases, and to increase its electrical resistance when the ambient light intensity decreases.

Images