CN220254719U

CN220254719U - Color-adjustable LED driving circuit

Info

Publication number: CN220254719U
Application number: CN202321359958.0U
Authority: CN
Inventors: 吕少华; 赵飞扬; 杭泽钢; 顾永波; 赵艺佼; 甘彩英
Original assignee: CH Lighting Technology Co Ltd
Current assignee: CH Lighting Technology Co Ltd
Priority date: 2023-05-30
Filing date: 2023-05-30
Publication date: 2023-12-26
Anticipated expiration: 2033-05-30

Abstract

The application relates to a color-adjustable LED drive circuit, including the rectification unit, filter unit, power conversion unit, the different luminescence unit of a plurality of colour temperatures that couple gradually, LED drive circuit still includes: the color matching unit comprises a switching element connected in series with the light emitting unit and a control element for outputting a PWM signal to control the conduction angle of the switching element, wherein the switching element is provided with an input end, an output end coupled to a ground wire and an enabling end coupled with the control element; the bleeder protection unit is provided with a first end coupled with the enabling end, a second end coupled with the ground wire and a third end used for detecting the voltage of the enabling end, and when the voltage of the enabling end is larger than a set value, the first end and the second end are conducted. The third end of the bleeder protection unit detects the voltage of the enabling end. If the voltage of the enabling end is raised due to the short circuit, the discharging protection unit is triggered through the third end, and the large current generated by the short circuit of the enabling end is discharged to the second end and the ground wire, so that the protection of the switching element and the control element is realized.

Description

Color-adjustable LED driving circuit

Technical Field

The application relates to the technical field of illumination, in particular to a color-adjustable LED driving circuit.

Background

The LED driving circuit capable of adjusting and controlling generally comprises a luminous lamp bead and a switching tube connected in series with the luminous lamp bead, so that an enabling end of the switching tube can receive PWM signals, and the brightness control of the luminous lamp bead is realized by changing output power through the PWM signals.

When the LED driving circuit is assembled into a solid device such as a specific LED lamp, the negative electrode of the luminous lamp bead and the high-voltage line are adjacent to each other and form two welding positions, and functional test is required before delivery. If the two welding positions are short-circuited due to poor welding process, current from the high-voltage line can enter the enabling end and the PWM signal generator, and the two are damaged.

The patent with publication number CN218006560U discloses a wide-range constant power control circuit based on MCU software control, which constructs a short-circuit protection module through MCU, but the action of the short-circuit protection module is controlled based on MCU software, the reaction speed is slower, the damage of circuit devices due to short circuit still can be caused, and the reliability of testing before delivery cannot be ensured.

Disclosure of Invention

In view of the above, it is desirable to provide a color tunable LED driving circuit.

The application provides a but LED drive circuit of mixing of colors, including the rectification unit, filter unit, power conversion unit, the different luminescence unit of a plurality of colour temperatures that couple gradually, LED drive circuit still includes:

the color matching unit comprises a switching element connected in series with the light emitting unit and a control element for outputting a PWM signal to control the conduction angle of the switching element, wherein the switching element is provided with an input end, an output end coupled to a ground wire and an enabling end coupled with the control element;

the bleeder protection unit is provided with a first end coupled with the enabling end, a second end coupled with the ground wire and a third end used for detecting the voltage of the enabling end, and when the voltage of the enabling end is larger than a set value, the first end and the second end are conducted.

The following provides several alternatives, but not as additional limitations to the above-described overall scheme, and only further additions or preferences, each of which may be individually combined for the above-described overall scheme, or may be combined among multiple alternatives, without technical or logical contradictions.

Optionally, the enable terminal is coupled to ground.

Optionally, the enable terminal is coupled to ground via a resistor.

Optionally, the third terminal is coupled to the input terminal via a pull-up resistor, and is coupled to the output terminal via a pull-down resistor.

Optionally, the bleeder protection unit includes a triode, a collector of the triode is coupled to the first terminal, an emitter of the triode is coupled to the second terminal, and a base of the triode is coupled to the third terminal.

Optionally, the pull-up resistor is connected with an electric energy absorption unit in parallel.

Optionally, the electric energy absorbing unit includes a capacitor.

Optionally, the pull-down resistor is connected in parallel with a voltage stabilizing unit.

Optionally, the voltage stabilizing unit includes a voltage stabilizing diode, and a cathode of the voltage stabilizing diode is coupled to the third terminal.

The color-adjustable LED driving circuit has the following technical effects:

the voltage of the enabling end is detected by the third end of the discharging protection unit, if the voltage of the enabling end rises due to short circuit, the discharging protection unit is triggered and conducted through the third end, and high current generated by short circuit of the enabling end is discharged to the second end and the ground wire, so that protection of a switching element and a control element is achieved.

Drawings

FIG. 1 is a schematic diagram of a color tunable LED driving circuit according to an embodiment of the present application (the broken line indicates the detection of the enable end by the third end of the bleeder protection unit);

FIG. 2 is a schematic diagram of a partial circuit of a bleed protection unit according to an embodiment of the present application;

FIG. 3 is a schematic partial circuit diagram of a first bleed protection unit according to an embodiment of the present application;

reference numerals in the drawings are described as follows:

100. a rectifying unit; 200. a filtering unit; 300. a power conversion unit;

400. a light emitting unit; 400a, a first light emitting unit; 400b, a second light emitting unit;

510. a switching element; 510a, a first switching element; 511. an input end; 512. an output end; 513. an enable terminal; 510b, a second switching element; 520. a control element;

600. a bleed protection unit; 600a, a first bleed protection unit; 601. a first end; 602. a second end; 603. a third end; 600b, a second bleed protection unit;

700. an electric energy absorption unit; 800. and a voltage stabilizing unit.

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made clearly and completely with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

It will be understood 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 an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements 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 herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

In this application, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number, order of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless explicitly defined otherwise.

In this application, the terms "comprises," "comprising," and "having," 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 expressly listed but may include other elements not expressly listed or inherent to such article or apparatus.

In this application, the terms "corresponding", "matched", "compatible", such as "B corresponding to a", "a corresponding to B", or "B corresponding to a", mean that B has a correspondence with the shape, position, or function of a, from which B can be determined. Determining B from a does not mean determining B from a alone, but may also be based on a and/or other information.

Referring to fig. 1 to 2, in an embodiment of the present application, a color-tunable LED driving circuit is provided, which includes a rectifying unit 100, a filtering unit 200, a power converting unit 300, and a plurality of light emitting units 400 with different color temperatures, which are sequentially coupled. The light emitting unit 400 includes at least a first light emitting unit 400a and a second light emitting unit 400b having different color temperatures, for example, warm white and cool white, respectively.

The LED driving circuit further includes a color mixing unit and a discharge protection unit 600. The color matching unit includes a switching element 510 connected in series with the light emitting unit 400 and a control element 520 outputting a PWM signal to control the conduction angle of the switching element 510.

The switching element 510 includes, for example, a first switching element 510a corresponding to the first light emitting unit 400a connected in series, and a second switching element 510b corresponding to the second light emitting unit 400b connected in series. The control element 520 may be one and has an output end for controlling each switching element, for example, an output end OU1 for controlling the first switching element 510a and an output end OU2 for controlling the second switching element 510b, which respectively output corresponding PWM signals (PWM 1 and PWM 2) to realize the sub-control of the first switching element 510a and the second switching element 510b, thereby realizing the sub-control of the two light emitting beads.

Hereinafter, the operation mechanism of the light emitting unit 400, the switching element 510, and the drain protection unit 600 will be described by taking the first light emitting unit 400a, the first switching element 510a, and the first drain protection unit 600a as examples. The second light emitting unit 400b, the second switching element 510b, and the second bleed protection unit 600b operate in the same manner.

The first switching element 510a has an input terminal 511, an output terminal 512 coupled to ground, and an enable terminal 513 coupled to the control element 520. The first bleeder protection unit 600a has a first terminal 601 coupled to the enable terminal 513, a second terminal 602 coupled to the ground, and a third terminal 603 for detecting the voltage of the enable terminal 513, and when the voltage and/or current of the enable terminal 513 is greater than a set value, the first terminal 601 and the second terminal 602 are turned on.

The power conversion unit 300 of the LED driving circuit outputs a dc bus Vb, and the ground and the high voltage line, for example, the dc bus Vb, may be shorted due to the proximity of the solder joint, and the negative electrode of the light emitting unit is coupled to the ground SGAND. In the factory power-on test, if the ground line and the high-voltage line are adjacent to each other at the welding point, a large current will enter the enabling terminal 513 of the first switching element 510a and the output terminal OU1 of the control element 520, and will cause irreversible damage to the two.

In this embodiment, the voltage of the enabling terminal 513 is detected through the third terminal 603 of the first bleeder protection unit 600a, when the power-up is performed, if a short circuit occurs, the voltage of the enabling terminal 513 is increased, the first bleeder protection unit 600a is triggered, and the first terminal 601 and the second terminal 602 are triggered to be conducted under the action of the third terminal 603, so that the large current of the enabling terminal 513 is discharged to the second terminal 602, and protection of the switching element 510 and the control element 520 is achieved.

Further, referring to fig. 2, the enable terminal 513 is coupled to ground SGAND, e.g., the enable terminal 513 is coupled to ground via a resistor R11. The third terminal 603 is coupled to ground SGAND to enable voltage detection at the enable terminal 513. It will be appreciated that when a short circuit occurs, the voltage at ground SGND increases locally, with a tendency to bleed power to all surrounding lines, at which point the voltage at enable terminal 513 increases. In this embodiment, the third terminal 603 is coupled to the ground line SGAND, so as to indirectly implement the detection of the enable terminal 513, thereby completing the detection function.

Further, the third terminal 603 is coupled to the input terminal 511 via a pull-up resistor R20, and is coupled to the output terminal 512 via a pull-down resistor R21. The bleeder protection unit 600 comprises a transistor Q1 having a collector coupled to a first terminal 601, an emitter coupled to a second terminal 602, and a base coupled to a third terminal 603.

The pull-up resistor R20 and the pull-down resistor R21 are configured such that the voltage of the base is less than the trigger voltage, e.g., 0.7V, in the normal state, to prevent the malfunction of the first bleed-off protection unit 600 a. The ground SGAND voltage rises in the short circuit condition, and the base voltage exceeds 0.7V. The collector coupled to the first terminal 601 is correspondingly conductive to the emitter coupled to the second terminal 602, thereby realizing the triggering of the conduction of the first terminal 601 and the second terminal 602.

Referring to fig. 2 and 3, a power absorbing unit 700 is connected in parallel to the pull-up resistor, and the power absorbing unit 700 may be, for example, a capacitor C9. The pull-down resistor is connected in parallel with a voltage stabilizing unit 800, for example, a voltage stabilizing diode D4, and a cathode of the voltage stabilizing diode is coupled to the third terminal 603.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description. When technical features of different embodiments are embodied in the same drawing, the drawing can be regarded as a combination of the embodiments concerned also being disclosed at the same time.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application.

Claims

1. The utility model provides a but LED drive circuit of mixing of colors, includes rectification unit, filter unit, power conversion unit, the different luminescence unit of a plurality of colour temperatures that couple gradually, its characterized in that, LED drive circuit still includes:

2. The LED driving circuit of claim 1, wherein the enable terminal is coupled to ground.

3. The LED driving circuit of claim 2, wherein the enable terminal is coupled to ground via a resistor.

4. The LED driving circuit of claim 1, wherein the third terminal is coupled to the input terminal via a pull-up resistor and to the output terminal via a pull-down resistor.

5. The LED driver circuit of claim 4, wherein the bleeder protection unit comprises a transistor having a collector coupled to the first terminal, an emitter coupled to the second terminal, and a base coupled to the third terminal.

6. The LED driving circuit of claim 4, wherein the pull-up resistor is connected in parallel with an electrical energy absorbing unit.

7. The LED driving circuit of claim 6, wherein the power absorbing unit comprises a capacitor.

8. The LED driving circuit of claim 4, wherein the pull-down resistor is connected in parallel with a voltage stabilizing unit.

9. The LED driving circuit of claim 8, wherein the voltage stabilizing unit comprises a voltage stabilizing diode, and a cathode of the voltage stabilizing diode is coupled to the third terminal.