CN219107725U

CN219107725U - LED lamp protection circuit and lithium battery

Info

Publication number: CN219107725U
Application number: CN202223059117.6U
Authority: CN
Inventors: 梁志锋; 朱玉龙; 吴伟; 吴翔龙; 陈志军; 叶国华; 张志平
Original assignee: Guangdong Greenway Technology Co Ltd
Current assignee: Guangdong Greenway Technology Co Ltd
Priority date: 2022-11-16
Filing date: 2022-11-16
Publication date: 2023-05-30
Anticipated expiration: 2032-11-16

Abstract

The application provides an LED lamp protection circuit and lithium battery. The LED lamp protection circuit comprises an input circuit and a buck regulator; the input circuit comprises a first resistor, a first capacitor and a frequency modulation inductor, wherein the second end of the first resistor is used for being connected with the positive electrode of the LED lamp, the first end of the first capacitor is connected with the positive electrode of the LED lamp, and the second end of the first capacitor is connected with the negative electrode of the LED lamp; the first detection end of the buck regulator is connected with the first end of the first resistor, the second detection end of the buck regulator is connected with the second end of the first resistor, and the current-limiting output end of the buck regulator is connected with the first end of the frequency modulation inductor. When the voltage of the first resistor is detected to be overlarge by the voltage reducing regulator, the current limiting output end of the voltage reducing regulator stops outputting current to the LED lamp so as to reduce the current flowing through the LED and avoid the condition that the current of the LED is overlarge.

Description

LED lamp protection circuit and lithium battery

Technical Field

The utility model relates to the technical field of LED lamps, in particular to an LED lamp protection circuit and a lithium battery.

Background

An LED (Light Emitting Diode ) is one of semiconductor diodes, and is a solid-state semiconductor device capable of converting electric energy into visible light. The light emitting diode is composed of a PN junction as a common diode and also has unidirectional conductivity. Compared with incandescent bulbs and neon bulbs, the light emitting diode is characterized in that: the LED has the characteristics of low working voltage, low working current, good shock resistance and shock resistance, high reliability and long service life, and can conveniently modulate the intensity of light emission by modulating the intensity of passing current. The forward volt-ampere characteristic of the LED is very steep (the forward dynamic resistance is very small), the normal power supply of the LED is difficult, the LED cannot be directly powered by a voltage source like a common incandescent lamp, otherwise, the voltage fluctuation is slightly increased, and the current is increased to the extent that the LED is burnt. In order to stabilize the operating current of the LED, various LED driving circuits having a "ballasting function" have been developed to ensure that the LED operates normally and reliably.

However, in a lithium battery system, many LED driving circuits are connected in series with a resistor on an LED circuit to perform a current limiting function, but the current limiting function is not very good, that is, when the voltage fluctuates, the current increases, and even the LED is burned out, resulting in a shortened life of the LED.

Disclosure of Invention

The utility model aims to overcome the defects in the prior art and provides an LED lamp protection circuit and a lithium battery, which effectively prolong the service life.

The aim of the utility model is realized by the following technical scheme:

an LED lamp protection circuit comprising: an input circuit and a buck regulator; the input circuit comprises a first resistor, a first capacitor and a frequency modulation inductor, wherein the first end of the first resistor is used for being connected with the output end of the lithium battery, the second end of the first resistor is used for being connected with the positive electrode of the LED lamp, the first end of the first capacitor is connected with the positive electrode of the LED lamp, the second end of the first capacitor is connected with the negative electrode of the LED lamp, and the second end of the first capacitor is also connected with the second end of the frequency modulation inductor; the first detection end of the step-down regulator is connected with the first end of the first resistor, the second detection end of the step-down regulator is connected with the second end of the first resistor, and the current-limiting output end of the step-down regulator is connected with the first end of the frequency modulation inductor so as to stop outputting when the voltage on the first resistor is larger than the preset voltage.

In one embodiment, the buck regulator is model SY8703ABC.

In one embodiment, the input circuit further includes a protection diode, the current-limiting output terminal of the buck regulator is connected to an anode of the protection diode, and a cathode of the protection diode is connected to a first terminal of the first resistor.

In one embodiment, the input circuit further comprises a fuse, a first end of the fuse is connected with the output end of the lithium battery, and a second end of the fuse is connected with the first end of the first resistor.

In one embodiment, the input circuit further includes a second capacitor, and the first end of the first resistor is grounded through the second capacitor.

In one embodiment, the input circuit further includes a third capacitor, the first end of the first resistor is grounded through the third capacitor, and a capacitance value of the third capacitor is larger than a capacitance value of the second capacitor.

In one embodiment, the LED lamp protection circuit further includes a second resistor and a third resistor, a first end of the second resistor is connected to an output control end of the LED control motherboard, a second end of the second resistor is connected to an enable end of the buck regulator, and a second end of the second resistor is grounded through the third resistor.

In one embodiment, at least one of the second resistor and the third resistor is a variable resistor.

In one embodiment, the input circuit further includes an anti-static magnetic bead, a first end of the anti-static magnetic bead is connected to the current-limiting output end of the buck regulator, and a first end of the anti-static magnetic bead is grounded.

A lithium battery comprises the LED lamp protection circuit in any embodiment.

Compared with the prior art, the utility model has at least the following advantages:

when the voltage on the first resistor is detected to be overlarge by the voltage reducing regulator, the current limiting output end of the voltage reducing regulator stops outputting current to the LED lamp so as to reduce the current flowing through the LED, avoid the condition that the current of the LED is overlarge, effectively protect the normal work of the LED lamp and effectively prolong the service life of the LED lamp.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a circuit diagram of an LED lamp protection circuit in an embodiment.

Detailed Description

In order that the utility model may be readily understood, a more complete description of the utility model will be rendered by reference to the appended drawings. The drawings illustrate preferred embodiments of the utility model. This utility model may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

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 utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The utility model relates to an LED lamp protection circuit. In one embodiment, the LED lamp protection circuit includes an input circuit and a buck regulator. The input circuit comprises a first resistor, a first capacitor and a frequency modulation inductor. The first end of the first resistor is used for being connected with the output end of the lithium battery, and the second end of the first resistor is used for being connected with the positive electrode of the LED lamp. The first end of the first capacitor is connected with the positive electrode of the LED lamp, the second end of the first capacitor is connected with the negative electrode of the LED lamp, and the second end of the first capacitor is also connected with the second end of the frequency modulation inductor. The first detection end of the step-down regulator is connected with the first end of the first resistor, the second detection end of the step-down regulator is connected with the second end of the first resistor, and the current-limiting output end of the step-down regulator is connected with the first end of the frequency modulation inductor so as to stop outputting when the voltage on the first resistor is larger than the preset voltage. When the voltage on the first resistor is detected to be overlarge by the voltage reducing regulator, the current limiting output end of the voltage reducing regulator stops outputting current to the LED lamp so as to reduce the current flowing through the LED, avoid the condition that the current of the LED is overlarge, effectively protect the normal work of the LED lamp and effectively prolong the service life of the LED lamp.

Fig. 1 is a circuit diagram of an LED lamp protection circuit according to an embodiment of the utility model.

The LED lamp protection circuit 10 of an embodiment includes an input circuit and a buck regulator U5. The input circuit comprises a first resistor RS2, a first capacitor C47 and a frequency modulation inductor L2. The first end of the first resistor RS2 is used for being connected with the output end of the lithium battery, and the second end of the first resistor RS2 is used for being connected with the positive electrode of the LED lamp. The first end of the first capacitor C47 is connected with the positive electrode of the LED lamp, the second end of the first capacitor C47 is connected with the negative electrode of the LED lamp, and the second end of the first capacitor C47 is also connected with the second end of the frequency modulation inductor L2. The first detection end SEN of the buck regulator U5 is connected to the first end of the first resistor RS2, the second detection end IN of the buck regulator U5 is connected to the second end of the first resistor RS2, and the current-limiting output end of the buck regulator U5 is connected to the first end of the frequency modulation inductor L2, so that the output is stopped when the voltage on the first resistor RS2 is greater than the preset voltage.

In this embodiment, when the buck regulator U5 detects that the voltage on the first resistor RS2 is too large, the current-limiting output end of the buck regulator U5 stops outputting current to the LED lamp, so as to reduce the current flowing on the LED, avoid the situation that the current of the LED is too large, and effectively protect the normal operation of the LED lamp, thereby effectively improving the service life of the LED lamp.

In one embodiment, the buck regulator U5 is model SY8703ABC. In this embodiment, the buck regulator U5 is a high efficiency buck regulator U5 capable of driving 1.0A white LEDs from an input of up to 30V. The buck regulator U5 integrates MOSFETs and internal compensation, and the switching frequency of 1MHz allows the use of very small inductors, which, along with the small SOT23-6 package, enables a very small LED driver design, ensuring normal use of the LED lamp.

In one embodiment, referring to fig. 1, the input circuit further includes a protection diode D14, the current-limiting output terminal of the buck regulator U5 is connected to the positive electrode of the protection diode D14, and the negative electrode of the protection diode D14 is connected to the first end of the first resistor RS 2. In this embodiment, the protection diode D14 is connected to the current-limiting output end of the buck regulator U5 and the first end of the first resistor RS2, that is, the protection diode D14 is connected in series between the buck regulator U5 and the first resistor RS 2. When the down-regulator U5 stops outputting, the reverse charging voltage on the down-regulator U5 is released through the protection diode D14, so as to increase the turn-off recovery speed of the down-regulator U5, thereby increasing the response speed of the down-regulator U5.

In one embodiment, referring to fig. 1, the input circuit further includes a fuse F3, a first end of the fuse F3 is connected to the output terminal of the lithium battery, and a second end of the fuse F3 is connected to the first end of the first resistor RS 2. In this embodiment, the fuse F3 is connected to the output end of the lithium battery and the first end of the first resistor RS2, that is, the fuse F3 is connected in series with the first resistor RS2, so that the fuse F3 divides the voltage on the first resistor RS2, thereby avoiding the overlarge voltage loaded on the first resistor RS2, and simultaneously avoiding the overlarge voltage on the LED lamp, and effectively protecting the LED lamp.

In one embodiment, referring to fig. 1, the input circuit further includes a second capacitor C48, and the first end of the first resistor RS2 is grounded through the second capacitor C48. In this embodiment, the second capacitor C48 is connected to the first end of the first resistor RS2, specifically, the first end of the second capacitor C48 is connected to the first end of the first resistor RS2, and the second end of the second capacitor C48 is grounded, so that the second capacitor C48 performs filtering processing on the current flowing into the LED lamp, so as to improve the stability of the current on the LED lamp, and ensure the normal operation of the LED lamp.

Further, the input circuit further includes a third capacitor C49, the first end of the first resistor RS2 is grounded through the third capacitor C49, and the capacitance value of the third capacitor C49 is greater than the capacitance value of the second capacitor C48. In this embodiment, the third capacitor C49 is connected to the first end of the first resistor RS2, specifically, the first end of the third capacitor C49 is connected to the first end of the first resistor RS2, and the second end of the third capacitor C49 is grounded, so that the third capacitor C49 is connected in parallel to the second capacitor C48, so that the third capacitor C49 and the second capacitor C48 form two-stage filtering. The capacitance value of the third capacitor C49 is greater than that of the second capacitor C48, so that the third capacitor C49 filters low-frequency noise, and the second capacitor C48 filters high-frequency noise, so as to improve the working stability of the LED.

In one embodiment, referring to fig. 1, the LED lamp protection circuit further includes a second resistor R20 and a third resistor R51, wherein a first end of the second resistor R20 is connected to an output control end of the LED control motherboard, a second end of the second resistor R20 is connected to an enable end EN of the buck regulator U5, and a second end of the second resistor R20 is further grounded through the third resistor R51. In this embodiment, the second resistor R20 and the third resistor R51 form a voltage dividing circuit, and the voltage applied to the third resistor R51 is the voltage on the enable terminal EN of the buck regulator U5. Therefore, the working state of the buck regulator U5 is adjusted according to the voltage output by the output control end of the LED control main board, so that the LED lamp is subjected to current limiting protection. In another embodiment, at least one of the second resistor R20 and the third resistor R51 is a variable resistor, and the on-off working voltage of the buck regulator U5 is adjusted by adjusting the resistance ratio between the second resistor R20 and the third resistor R51.

In one embodiment, referring to the figure, the input circuit further includes an anti-static magnetic bead D18, a first end of the anti-static magnetic bead D18 is connected to the current-limiting output end of the buck regulator U5, and a first end of the anti-static magnetic bead D18 is grounded. In this embodiment, the antistatic bead D18 is connected to the current-limiting output end of the buck regulator U5, and the antistatic bead D18 eliminates static electricity of the buck regulator U5, so as to improve antistatic capability of the buck regulator U5, thereby further ensuring accurate current-limiting protection of the buck regulator U5 on the LED lamp.

In one embodiment, the application further provides a lithium battery, which comprises the LED lamp protection circuit in any embodiment. In this embodiment, the LED lamp protection circuit includes an input circuit and a buck regulator. The input circuit comprises a first resistor, a first capacitor and a frequency modulation inductor. The first end of the first resistor is used for being connected with the output end of the lithium battery, and the second end of the first resistor is used for being connected with the positive electrode of the LED lamp. The first end of the first capacitor is connected with the positive electrode of the LED lamp, the second end of the first capacitor is connected with the negative electrode of the LED lamp, and the second end of the first capacitor is also connected with the second end of the frequency modulation inductor. The first detection end of the step-down regulator is connected with the first end of the first resistor, the second detection end of the step-down regulator is connected with the second end of the first resistor, and the current-limiting output end of the step-down regulator is connected with the first end of the frequency modulation inductor so as to stop outputting when the voltage on the first resistor is larger than the preset voltage. When the voltage on the first resistor is detected to be overlarge by the voltage reducing regulator, the current limiting output end of the voltage reducing regulator stops outputting current to the LED lamp so as to reduce the current flowing through the LED, avoid the overlarge current of the LED, effectively protect the normal work of the LED lamp, effectively prolong the service life of the LED lamp and further prolong the service life of the lithium battery.

The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims

1. An LED lamp protection circuit, comprising:

the input circuit comprises a first resistor, a first capacitor and a frequency modulation inductor, wherein the first end of the first resistor is used for being connected with the output end of the lithium battery, the second end of the first resistor is used for being connected with the positive electrode of the LED lamp, the first end of the first capacitor is connected with the positive electrode of the LED lamp, the second end of the first capacitor is connected with the negative electrode of the LED lamp, and the second end of the first capacitor is also connected with the second end of the frequency modulation inductor;

the first detection end of the buck regulator is connected with the first end of the first resistor, the second detection end of the buck regulator is connected with the second end of the first resistor, and the current-limiting output end of the buck regulator is connected with the first end of the frequency modulation inductor so as to stop outputting when the voltage on the first resistor is larger than the preset voltage.

2. The LED lamp protection circuit of claim 1, wherein the buck regulator is model SY8703ABC.

3. The LED lamp protection circuit of claim 1, wherein the input circuit further comprises a protection diode, the current limiting output of the buck regulator is connected to the anode of the protection diode, and the cathode of the protection diode is connected to the first end of the first resistor.

4. The LED lamp protection circuit of claim 1, wherein the input circuit further comprises a fuse, a first end of the fuse being connected to the output of the lithium battery, a second end of the fuse being connected to the first end of the first resistor.

5. The LED lamp protection circuit of claim 1, wherein the input circuit further comprises a second capacitor, the first end of the first resistor being grounded through the second capacitor.

6. The LED lamp protection circuit of claim 5, wherein the input circuit further comprises a third capacitor, the first end of the first resistor is grounded through the third capacitor, and a capacitance of the third capacitor is greater than a capacitance of the second capacitor.

7. The LED lamp protection circuit of claim 1, further comprising a second resistor and a third resistor, wherein a first end of the second resistor is configured to be connected to an output control end of an LED control motherboard, a second end of the second resistor is connected to an enable end of the buck regulator, and a second end of the second resistor is further grounded through the third resistor.

8. The LED lamp protection circuit of claim 7, wherein at least one of the second resistor and the third resistor is a variable resistor.

9. The LED lamp protection circuit of claim 1, wherein the input circuit further comprises an anti-static electromagnetic bead, a first end of the anti-static electromagnetic bead being connected to the current limiting output of the buck regulator, the first end of the anti-static electromagnetic bead being grounded.

10. A lithium battery comprising the LED lamp protection circuit according to any one of claims 1 to 9.