CN216291513U

CN216291513U - LED drive circuit with adjustable color temperature

Info

Publication number: CN216291513U
Application number: CN202122367275.7U
Authority: CN
Inventors: 吕少华; 陶秋成; 曹胜军; 蒲纪忠; 甘彩英; 赵艺佼
Original assignee: CH Lighting Technology Co Ltd
Current assignee: CH Lighting Technology Co Ltd
Priority date: 2021-09-26
Filing date: 2021-09-26
Publication date: 2022-04-12
Anticipated expiration: 2031-09-26

Abstract

The application discloses colour temperature adjustable LED drive circuit, including rectification filter unit, regulating switch and LED light source, the LED light source includes first LED lamp pearl and second LED lamp pearl that the colour temperature is different, regulating switch has first pin, second pin, third pin and fourth pin, the third pin is the input pin, and all the other pins are the output pin, first pin only couples first LED lamp pearl, the fourth pin only couples second LED lamp pearl, first LED lamp pearl and second LED lamp pearl are coupled to the second pin simultaneously, have concatenated the current-limiting unit of adjustable second LED lamp pearl electric current on the circuit of coupling second pin and second LED lamp pearl. The current flowing through the second LED lamp bead is adjusted through the current limiting unit, so that the current difference between the first LED lamp bead and the second LED lamp bead with different color temperatures is changed, and color temperature adjustment is achieved.

Description

LED drive circuit with adjustable color temperature

Technical Field

The application relates to the technical field of LED lighting, in particular to an LED drive circuit with adjustable color temperature.

Background

Through switching on one or more of different colour temperature LED lamp pearls among the prior art to the realization is adjusted luminance. Taking the two LEDs 1 and 2 with different color temperatures as an example, the color temperature light of the LED1, the color temperature light of the LED2, and the mixed color temperature light of the LED1 and the LED2 can be emitted respectively. Therefore, the scope of adjustable color temperature in the prior art is limited by the types of the color temperatures of the LED lamp beads.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide a color temperature adjustable LED driving circuit.

The utility model provides a colour temperature adjustable LED drive circuit, including rectification filter unit, regulating switch and LED light source, the LED light source includes first LED lamp pearl and the second LED lamp pearl that the colour temperature is different, regulating switch has first pin, second pin, third pin and fourth pin, the third pin is the input pin, and all the other pins are the output pin, first pin only couples first LED lamp pearl, the fourth pin only couples second LED lamp pearl, first LED lamp pearl and second LED lamp pearl are coupled to the second pin simultaneously, and the current-limiting unit of adjustable second LED lamp pearl electric current has been concatenated on coupling the circuit of second pin and second LED lamp pearl.

Several alternatives are provided below, but not as an additional limitation to the above general solution, but merely as a further addition or preference, each alternative being combinable individually for the above general solution or among several alternatives without technical or logical contradictions.

Optionally, the current limiting unit is an adjustable resistor.

Optionally, the power supply further comprises an anti-jamming circuit, wherein one end of the anti-jamming circuit is coupled with the alternating current, and the other end of the anti-jamming circuit is coupled with the rectifying and filtering unit.

Optionally, the rectification and filtering unit includes a rectifier bridge having a first input terminal and a second input terminal, the anti-jamming circuit is coupled to the rectifier bridge, and the anti-jamming circuit includes:

a capacitor C1, a first terminal of which is coupled to the first input terminal of the rectifier bridge;

an inductor L1, having one end coupled to the second end of the capacitor C1 and the other end coupled to the second input terminal of the rectifier bridge;

and the resistor R1 is connected with the inductor L1 in parallel.

Optionally, the power conversion unit is further included, the power conversion unit includes a control chip U1 with a power supply end and an output end,

the power supply end is coupled with the rectifying and filtering unit, and the output end is coupled with a third pin of the regulating switch.

Optionally, the output terminal is coupled to the third pin of the regulating switch through an output sub-circuit, where the output sub-circuit includes an inductor T1, a diode D2, and a resistor RS 2;

the first end of the inductor T1 is coupled to the output end, and the second end is coupled to the third pin of the regulating switch;

the resistor RS2 has a first terminal coupled to the output terminal and a second terminal coupled to the cathode of the diode D2;

the anode of the diode D2 is coupled to the low potential terminal of the LED light source.

Optionally, the output sub-circuit further includes an RC parallel circuit, and the RC parallel circuit includes a capacitor R6 and a resistor R5 connected in parallel with each other;

the RC parallel circuit has one end coupled to the second end of the inductor T1 and the other end coupled to the anode of the diode D2.

Optionally, the output sub-circuit further includes an RC series circuit, the RC series circuit is connected in parallel between the output terminal and the positive electrode of the diode D2, and includes a resistor RS1, a capacitor C4, and a resistor R6, which are connected in series in sequence.

Optionally, a capacitor C3 is further included, and one end of the capacitor C3 is coupled to the power supply terminal, and the other end is coupled to the cathode of the diode D2.

The LED drive circuit with the adjustable color temperature at least has the following technical effects:

the current flowing through the second LED lamp bead is adjusted through the current limiting unit, so that the current difference between the first LED lamp bead and the second LED lamp bead with different color temperatures is changed, and color temperature adjustment is achieved.

Drawings

Fig. 1 is a schematic partial structure diagram of a color temperature adjustable LED driving circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic circuit diagram of a rectifying and filtering unit according to an embodiment of the present application;

FIG. 3 is a schematic circuit diagram of a power conversion unit according to an embodiment of the present disclosure;

the reference numerals in the figures are illustrated as follows:

1. a first pin; 2. a second pin; 3. a third pin; 4. a fourth pin;

20. a current limiting unit; 30. an adjustment switch; 31. a first LED lamp bead; 32. a second LED lamp bead; 40. a rectification filter unit; 41. and an anti-interference circuit.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It is noted that when an element is referred to as being "coupled" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present. Unless defined otherwise, 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 in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In this application, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any particular order or number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In this application, the terms "comprises" and "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a system, article, or apparatus that comprises a list of elements is not necessarily limited to those elements explicitly listed, but may include other elements not expressly listed or inherent to such system or apparatus.

Referring to fig. 1, an embodiment of the present application provides an LED driving circuit with an adjustable color temperature, which includes a rectifying and filtering unit, a regulating switch 30, and an LED light source, where the rectifying and filtering unit outputs a dc bus Vbus after receiving an ac power, and the dc bus Vbus is coupled to a high-potential end LED + of the LED light source to supply power to the LED light source. The LED light source comprises a first LED lamp bead 31 (simply referred to as a lamp bead A) and a second LED lamp bead 32 (simply referred to as a lamp bead B) which are different in color temperature. Illustratively, the color temperature of the lamp bead A is yellow, and the color temperature of the lamp bead B is white.

The adjustment switch 30 has four pins, namely a first pin, a second pin, a third pin and a fourth pin, wherein the third pin is used as an input pin, and the first pin, the second pin and the fourth pin are all used as output pins. The third pin 3 of the adjustment switch 30 can be electrically connected to any other pin by actuation. Specifically, the third pin 3 is coupled with the direct current bus Vbus, the first pin 1 is only coupled with the lamp bead a, the 4 th pin is only coupled with the lamp bead B, and the second pin 2 is coupled with the lamp bead a and the lamp bead B. In a power supply state, when the third pin 3 is electrically connected with the first pin 1, the lamp bead A emits light, for example, an LED light source emits yellow light; when the third pin 3 is electrically connected with the second pin 2, the lamp bead B emits light, for example, the LED light source emits white light; when the third pin 3 and the fourth pin 4 form an electrical connection, the lamp bead a and the lamp bead B emit light simultaneously, for example, the LED light source emits a mixed light of yellow and white.

In this embodiment, second pin 2 is coupled with lamp pearl A and lamp pearl B through different circuits, and second pin 2 is coupled with lamp pearl B through a current-limiting unit 20, and this current-limiting unit 20 can change the electric current through lamp pearl B. Because the light intensity of the LED light source is in direct proportion to the current flowing through the LED light source, when the current flowing through the lamp bead B is independently changed (the current of the lamp bead A is kept unchanged, and the current of the lamp bead B is changed), the light intensity of the lamp bead A is kept unchanged, the light intensity of the lamp bead B is changed, the color temperature of mixed light is gradually changed, and the color temperature is adjusted.

Further, in order to reduce the cost of the circuit device and improve the convenience of adjusting the color temperature, the current limiting unit 20 is an adjustable resistor. For example, the adjustable resistor is a rotary rheostat or a slide rheostat, linear dimming is realized by changing the resistance value of the adjustable resistor, and the smoothness of dimming is greatly enhanced. Compared with the dimming idea in the prior art, the embodiment greatly reduces the hardware cost and avoids the problem of unstable output current waveform caused by PWM dimming in the prior art.

Referring to fig. 2, the rectifying and filtering unit 40 includes a rectifying bridge BD1 for inputting ac power and outputting dc power, and the rectifying bridge BD1 has a first input terminal (pin 1), a second input terminal (pin 3), a first output terminal (pin 2), and a second output terminal (pin 4), wherein the first output terminal (pin 2) is connected to the dc bus Vbus. Two input ends (pin 3 and pin 1) of the rectifier bridge are respectively coupled with two incoming line ends (L line and N line) of the alternating current.

The color temperature adjustable LED driving circuit further includes an anti-jamming circuit 41, wherein one end of the anti-jamming circuit 41 is coupled to the alternating current, and the other end is coupled to the rectifying and filtering unit 40. The anti-jamming circuit 41 comprises a capacitor C1, an inductor L1 and a resistor R1. Wherein, the first terminal of the capacitor C1 is coupled to the first input terminal of the rectifier bridge BD1 (pin 1); one end of the inductor L1 is coupled to the second end of the capacitor C1, and the other end is coupled to the second input terminal (pin 3) of the rectifier bridge; and the resistor R1 is connected with the inductor L1 in parallel.

Referring to fig. 3, the LED driving circuit with adjustable color temperature further includes a power conversion unit, the power conversion unit includes a control chip U1 having a power supply terminal VCC (4 pin) coupled to the rectifying and filtering unit 40 and an output terminal CS (3 pin) coupled to the third pin 3 of the regulating switch 30.

To supply the LED light source, the output terminal CS is coupled to the third pin 3 of the regulating switch 30 through an output sub-circuit, which includes an inductor T1, a diode D2 and a resistor RS 2. The first end of the inductor T1 is coupled to the output terminal, and the second end is coupled to the third pin 3 of the regulating switch 30; a first end of the resistor RS2 is coupled to the output end, and a second end is coupled to the cathode of the diode D2; the anode of the diode D2 is coupled to the low potential terminal of the LED light source. Further, the output sub-circuit further comprises an RC parallel circuit, and the RC parallel circuit comprises a capacitor R6 and a resistor R5 which are connected in parallel with each other. The RC parallel circuit has one end coupled to the second end of the inductor T1 and the other end coupled to the anode of the diode D2. Further, the output sub-circuit further comprises an RC series circuit, the RC series circuit is connected between the output end and the anode of the diode D2 in parallel, and the RC series circuit comprises a resistor RS1, a capacitor C4 and a resistor R6 which are sequentially connected in series.

In order to realize the power supply of the control chip U1, the LED driving circuit further includes a capacitor C3 for supplying power to the control chip U1, wherein one end of the capacitor C3 is coupled to the power supply terminal, and the other end is coupled to the cathode of the diode D2. It can be understood that the capacitor C3 supplies power to the control chip U1 when the power conversion unit is operating normally, and supplies power to the control chip U1 through the power supply terminal of the control chip U1 coupled to the dc bus Vbus when the power conversion unit is operating in the startup state.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features. When technical features in different embodiments are represented in the same drawing, it can be seen that the drawing also discloses a combination of the embodiments concerned.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application.

Claims

1. LED drive circuit of colour temperature adjustable, including rectification filter unit, regulating switch and LED light source, the LED light source includes first LED lamp pearl and second LED lamp pearl that the colour temperature is different, regulating switch has first pin, second pin, third pin and fourth pin, the third pin is the input pin, and all the other pins are the output pin, first pin only couples first LED lamp pearl, the fourth pin only couples second LED lamp pearl, first LED lamp pearl and second LED lamp pearl are coupled to the second pin simultaneously, its characterized in that couples the current-limiting unit of adjustable second LED lamp pearl electric current on the circuit of second pin and second LED lamp pearl.

2. The LED driving circuit according to claim 1, wherein the current limiting unit is an adjustable resistor.

3. The LED driving circuit according to claim 1, further comprising an anti-jamming circuit, wherein one end of the anti-jamming circuit is coupled to the alternating current, and the other end of the anti-jamming circuit is coupled to the rectifying and filtering unit.

4. The LED driving circuit of claim 3, wherein the rectifying-filtering unit comprises a rectifying bridge having a first input terminal and a second input terminal, the immunity circuit is coupled to the rectifying bridge, the immunity circuit comprises:

and the resistor R1 is connected with the inductor L1 in parallel.

5. The LED driving circuit according to claim 1, further comprising a power conversion unit, wherein the power conversion unit comprises a control chip U1 with a power supply terminal and an output terminal,

6. The LED driving circuit according to claim 5, wherein the output terminal is coupled to the third pin of the regulating switch through an output sub-circuit, the output sub-circuit comprising an inductor T1, a diode D2, and a resistor RS 2;

7. The LED driving circuit according to claim 6, wherein the output sub-circuit further comprises an RC parallel circuit comprising a capacitor R6 and a resistor R5 connected in parallel with each other;

8. The LED driving circuit as claimed in claim 6, wherein the output sub-circuit further comprises an RC series circuit connected in parallel between the output terminal and the anode of the diode D2, and comprising a resistor RS1, a capacitor C4 and a resistor R6 connected in series.

9. The LED driving circuit as claimed in claim 6, further comprising a capacitor C3, wherein one end of the capacitor C3 is coupled to the power supply terminal, and the other end is coupled to the cathode of the diode D2.