CN114727450A - LED lamp detection circuit and LED lamp driving system - Google Patents

Abstract

The invention discloses an LED lamp detection circuit, relates to the field of LED lamp control, and is mainly used for detecting LED lamps. The LED lamp detection circuit comprises a first power supply and a second power supply and is used for detecting the LED lamp. The first power supply outputs a first voltage, the second power supply outputs a second voltage, the first voltage is greater than the second voltage, and the difference value between the first voltage and the second voltage is greater than the conduction voltage of the LED lamp, so that the LED lamp can be lightened. Therefore, the detection of the LED lamp can be realized through the first power supply and the second power supply under the condition that the driving chip is not used, the condition that the detection of the LED lamp is not correct due to the fact that the driving chip is abnormal is avoided, and the accuracy and the reliability of detection of the LED lamp are improved. The invention also provides an LED lamp driving system which has the same beneficial effects as the LED lamp detection circuit.

Description

An LED lamp detection circuit and an LED lamp drive system

technical field

The invention relates to the field of LED lamp detection, in particular to an LED lamp detection circuit and an LED lamp drive system.

Background technique

In the prior art, the driving chip is connected to an LED (Light-Emitting Diode, light-emitting diode) lamp to realize the driving of the LED lamp. At this time, if it is necessary to detect whether the LED lamp is abnormal, the method is: controlling the driving chip to output different driving The current is used to make the LED lamp work with different luminous efficiency, so as to judge whether the LED lamp can work normally.

However, when the luminous efficiency of the LED lamp does not correspond to the driving current output by the driver chip, the LED lamp may be abnormal, or the driver chip may be abnormal. That is, the method in the prior art cannot accurately determine whether the LED lamp is abnormal.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an LED lamp detection circuit and an LED lamp driving system, which can realize the detection of the LED lamp without using the driver chip, and avoid the situation of wrong detection of the LED lamp caused by the abnormality of the driver chip. , which improves the accuracy and reliability of LED lamp detection.

In order to solve the above technical problems, the present invention provides an LED lamp detection circuit, including:

a first power supply whose output end is connected to the first end of the LED lamp, and is used for outputting a first voltage when detecting the LED lamp;

the output end is respectively connected with the second end of the LED lamp and the output end of the driving chip, the second power supply is used for outputting a second voltage when the LED lamp is detected;

The first voltage is greater than the second voltage, and the difference between the first voltage and the second voltage is not less than the working voltage of the LED lamp.

Preferably, it also includes:

One end of the switch circuit is connected to the output end of the second power supply, and the other end is connected to the output end of the driving chip, and is used for conducting the detection of the LED lamp.

Preferably, there are multiple LED lights;

There are a plurality of the switch circuits, and one-to-one correspondence with the plurality of the LED lamps.

Preferably, the switch circuit is a diode;

The cathode of the diode is connected to the output terminal of the second power supply, and the anode of the diode is connected to the output terminal of the driving chip.

Preferably, the switch circuit is a transistor;

Both the first end and the control end of the transistor are connected to the output end of the second power supply, and the second end of the transistor is connected to the output end of the driving chip.

Preferably, the transistor is a P-channel metal oxide semiconductor PMOS;

The gate of the PMOS is the control terminal of the transistor, one of the source and the drain of the PMOS is the first terminal of the transistor, and the other is the second terminal of the transistor.

Preferably, the second voltage is the power supply voltage of the driver chip;

The second end of the LED lamp and the output end of the driving chip are connected to the power supply end of the driving chip through the switch circuit.

Preferably, the second voltage is a constant value or a fluctuating value.

In order to solve the above technical problems, the present invention also provides an LED lamp system, which includes the above-mentioned LED lamp detection circuit, and also includes a driving chip and an LED lamp.

The present application provides an LED lamp detection circuit, including a first power source and a second power source, when detecting the LED lamp. The first power supply outputs a first voltage, the second power supply outputs a second voltage, and the first voltage is greater than the second voltage, and the difference between the first voltage and the second voltage is greater than the turn-on voltage of the LED lamp, so that the LED lamp can be lit . It can be seen that the first power supply and the second power supply in this application can realize the detection of the LED lamp without using the driving chip, avoid the situation of wrong detection of the LED lamp caused by the abnormality of the driving chip, and improve the detection of the LED lamp. Accuracy and reliability of lamp detection.

The present invention also provides an LED lamp driving system, which has the same beneficial effects as the LED lamp detection circuit described above.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the prior art and the accompanying drawings required in the embodiments. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a structural block diagram of an LED lamp detection circuit provided by the present invention;

2 is a specific structural block diagram of an LED lamp detection circuit provided by the present invention;

3 is a schematic diagram of a power output provided by the present invention;

4 is a schematic diagram of another power output provided by the present invention;

5 is a schematic diagram of a specific implementation of the first LED lamp detection circuit provided by the present invention;

6 is a schematic diagram of a specific implementation of a second LED lamp detection circuit provided by the present invention;

FIG. 7 is a schematic diagram of a specific implementation of a third LED lamp detection circuit provided by the present invention.

Detailed ways

The core of the present invention is to provide an LED lamp detection circuit and an LED lamp driving system, which can realize the detection of the LED lamp without using the driver chip, and avoid the situation of wrong detection of the LED lamp caused by the abnormality of the driver chip. , which improves the accuracy and reliability of LED lamp detection.

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Please refer to FIG. 1. FIG. 1 is a structural block diagram of an LED lamp detection circuit provided by the present invention. The circuit includes:

The first power supply 12 whose output end is connected to the first end of the LED lamp is used for outputting a first voltage when detecting the LED lamp;

The output end is respectively connected with the second end of the LED lamp and the output end of the driving chip 11 to the second power supply 13, for outputting the second voltage when the LED lamp is detected;

The first voltage is greater than the second voltage, and the difference between the first voltage and the second voltage is not less than the working voltage of the LED lamp.

Specifically, in the present application, when the LED lamp is connected to the driving chip 11, a power source is provided at both ends of the LED lamp, namely the first power source 12 and the second power source 13 described above, and then the LED lamp needs to be detected. When the first power supply 12 is controlled to output the first voltage, and the second power supply 13 is controlled to output the second voltage, even if the LED lamp is connected to the driving chip 11 , the detection of the LED lamp can be realized without using the driving chip 11 .

The first voltage is greater than the second voltage, the first power supply 12 is specifically connected to the positive pole of the LED lamp, the second power supply 13 is specifically connected to the negative pole of the LED lamp, and the difference between the first voltage and the second voltage is greater than the LED lamp conductance. Therefore, when the LED lamp is detected, the voltage difference between the two can make the LED lamp light normally. At this time, it is determined that the LED lamp can be used normally. Otherwise, it is determined that the LED lamp is abnormal and cannot be used normally.

Please refer to FIG. 2 , which is a specific structural block diagram of an LED lamp detection circuit provided by the present invention.

As a preferred embodiment, the second voltage is the power supply voltage of the driver chip;

The second terminal of the LED lamp and the output terminal of the driving chip 11 are connected to the power terminal of the driving chip 11 through a switch circuit.

Further, in order to reduce the cost of the circuit and reduce the use of the power supply module as much as possible, the second voltage here can be selected from the power supply voltage of the driver chip. Specifically, it can be, but is not limited to, be connected to the power supply terminal on the driver chip 11. , and then when the LED lamp needs to be detected, the first voltage output by the first power supply 12 can be directly controlled, and there is no need to control the second power supply 13, and there is no need to additionally set the second power supply 13. To a certain extent The cost of the detection circuit can be reduced.

In addition, please refer to FIG. 3 and FIG. 4 , FIG. 3 is a schematic diagram of a power output provided by the present invention, and FIG. 4 is a schematic diagram of another power output provided by the present invention.

Among them, VDD1 in FIG. 3 and FIG. 4 is the first voltage output by the first power supply 12, VDD1 is the second voltage output by the second power supply 13, and the time period when VDD1 increases corresponds to the detection of LED lights (ie is the time period of LED failure detection), ΔV is the difference between the first voltage and the second voltage, VDD2 can be a stable voltage value (as shown in Figure 3), or a floating voltage value (as shown in Figure 4) . As long as the LED lamp can be reliably turned on, it will not be limited in this application.

To sum up, in the present application, the first power supply 12 and the second power supply 13 can realize the detection of LED lights without using the driving chip 11, and avoid the situation of wrong detection of the LED lights caused by the abnormality of the driving chip 11. , which improves the accuracy and reliability of LED lamp detection.

On the basis of the above-mentioned embodiment:

As a preferred embodiment, it also includes:

One end of the switch circuit is connected to the output end of the second power supply 13 , and the other end is connected to the output end of the driving chip 11 , and is used for conducting the LED lamp detection.

Specifically, a switch circuit is also provided between the output end of the driving chip 11 and the second power supply 13 , which is turned on when the LED light needs to be detected, and is turned off when the LED light is not detected, so as to avoid the driving chip 11 The output driving current is backflowed to the second power supply 13 to prevent the second power supply 13 from being affected.

Among them, the switch circuit can be integrated inside the driver chip, as shown in Figure 5, at this time, there is no need to set up an independent switch circuit and driver chip, the volume is small, and the use is more convenient.

As a preferred embodiment, there are multiple LED lights;

There are multiple switch circuits and one-to-one correspondence with the multiple LED lights.

Wherein, when there are more than one LED lights, there are more than one switch circuits, and the switch circuits are in one-to-one correspondence with each LED light. For example, please refer to FIG. 5 , FIG. 6 and FIG. 7 . FIG. 5 is a schematic diagram of the specific implementation of the first LED lamp detection circuit provided by the present invention. In FIG. 5 , the switch circuit is integrated in the driver chip, wherein the driver chip includes data Receiver module, sequence control module and current source. The data receiving module controls the power source based on the input data signal and the clock control module based on the input control signal, so that the current source outputs the corresponding driving current and realizes the control of the LED lamp.

FIG. 6 is a schematic diagram of the specific implementation of the second type of LED lamp detection circuit provided by the present invention, and FIG. 7 is a schematic diagram of the specific implementation of the third type of LED lamp detection circuit provided by the present invention. Figures 5, 6 and 7 all take three LED lights, which are respectively red (R in the figure), green (G in the figure) and blue (B in the figure) as an example.

As a preferred embodiment, the switch circuit is a diode;

The cathode of the diode is connected to the output terminal of the second power supply 13 , and the anode of the diode is connected to the output terminal of the driving chip 11 .

This embodiment aims to provide a specific implementation of the switch circuit. Specifically, as shown in FIG. 7 , the switch circuit can be, but is not limited to, a diode. Using the unidirectional conduction characteristic of the diode, only the first power supply 12 and the second power supply When the voltage drop of the first voltage and the second voltage respectively output by 13 is relatively large, the diode is turned on to realize the detection of the LED lamp.

As a preferred embodiment, the switch circuit is a transistor;

The first terminal and the control terminal of the transistor are both connected to the output terminal of the second power supply 13 , and the second terminal of the transistor is connected to the output terminal of the driving chip 11 .

This embodiment aims to provide another specific implementation of the switch circuit. Specifically, as shown in FIG. 6 , the switch circuit can be, but is not limited to, a transistor. The transistor is provided with a control terminal, and only when the first power supply 12 and the second power supply 13 When the voltage drop of the first voltage and the second voltage respectively output is relatively large, specifically, when the first voltage is greater than the second voltage, the voltage difference between the control terminal and the second terminal of the transistor is relatively large, and the conduction of the transistor is reached. When the voltage is turned on, the transistor is turned on, thereby realizing the detection of the LED lamp.

It can be seen that the transistor in the present application can realize the function of the switching circuit, and the implementation manner is simple and reliable.

As a preferred embodiment, the transistor is a PMOS (positive channel Metal Oxide Semiconductor, P-channel metal oxide semiconductor);

The gate of the PMOS is the control terminal of the transistor, the drain of the PMOS is the first terminal of the transistor, and the source of the PMOS is the second terminal of the transistor.

Specifically, the transistor may be, but not limited to, a PMOS transistor, and the MOS transistor may be either a PMOS (positive channel Metal Oxide Semiconductor, P-channel metal oxide semiconductor) or an NMOS (nagetive channel Metal Oxide Semiconductor, P-channel metal oxide semiconductor). This embodiment is mainly applied to the parasitic diode in the MOS tube. Specifically, the anode of the parasitic diode is connected to the first power supply, and the cathode of the parasitic diode is connected to the second power supply. The parasitic diode is used to realize the function of the above switching circuit, and The implementation is simple and reliable.

In order to solve the above technical problem, the present invention also provides an LED lamp system, which includes the above-mentioned LED lamp detection circuit, and also includes a driving chip 11 and an LED lamp.

Wherein, the drive clock can include but is not limited to an input module, a timing control module, a data storage module, an output module, etc., wherein the input module is used to receive the control signal sent by the host computer, and the timing control module is used to receive the control signal sent by the host computer. The control signal generates a timing control signal, and the output module is used for sending the timing control signal to the LED light, so as to realize the driving of the LED light.

It should be noted that in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these entities or operations There is no such actual relationship or order between them. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

Professionals may further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two, in order to clearly illustrate the possibilities of hardware and software. Interchangeability, the above description has generally described the components and steps of each example in terms of functionality. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of the present invention.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (9)

1. An LED lamp detection circuit, comprising:

the first power supply is connected with the first end of the LED lamp at the output end and used for outputting first voltage when the LED lamp is detected;

the output end of the second power supply is respectively connected with the second end of the LED lamp and the output end of the driving chip and used for outputting a second voltage when the LED lamp is detected;

the first voltage is greater than the second voltage, and the difference between the first voltage and the second voltage is not less than the working voltage of the LED lamp.

2. The LED lamp detection circuit of claim 1, further comprising:

and the switching circuit is used for switching on the LED lamp during detection, and has one end connected with the output end of the second power supply and the other end connected with the output end of the driving chip.

3. The LED lamp detection circuit of claim 2, wherein the LED lamp is plural;

the switch circuits are multiple and correspond to the LED lamps one by one.

4. The LED lamp detection circuit of claim 2, wherein the switching circuit is a diode;

and the cathode of the diode is connected with the output end of the second power supply, and the anode of the diode is connected with the output end of the driving chip.

5. The LED lamp detection circuit of claim 2, wherein the switching circuit is a transistor;

and the first end and the control end of the transistor are both connected with the output end of the second power supply, and the second end of the transistor is connected with the output end of the driving chip.

6. The LED light detection circuit of claim 5 wherein the transistor is a P-channel metal oxide semiconductor PMOS;

the grid electrode of the PMOS is the control end of the transistor, one of the source electrode and the drain electrode of the PMOS is the first end of the transistor, and the other one is the second end of the transistor.

7. The LED lamp detection circuit of any of claims 2-6, wherein the second voltage is a supply voltage of the driver chip;

and the second end of the LED lamp and the output end of the driving chip are connected with the power end of the driving chip through the switch circuit.

8. The LED lamp detection circuit of any of claims 2-6, wherein the second voltage is a constant value or a fluctuating value.

9. An LED lamp driving system, comprising the LED lamp detection circuit as claimed in any one of claims 1 to 8, further comprising a driving chip and an LED lamp.

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