CN117425248A - LED driving circuit and driving method - Google Patents

Abstract

The invention discloses an LED driving system, which comprises a plurality of stages of LED driving circuits, wherein each stage of LED driving circuit is connected in parallel between the positive electrode and the negative electrode of a power supply, each stage of LED driving circuit comprises an LED module, a sampling judging circuit, a first driving circuit and a second driving circuit, the LED module is connected between the positive electrode and the negative electrode of the power supply, the first driving circuit is connected between the positive electrode of the power supply and the LED module, the second driving circuit is connected between the negative electrode of the power supply and the LED module, the sampling judging circuit is connected between the first driving circuit and the LED module, and the sampling judging circuit is used for sampling current and controlling the on-off of the first driving circuit. The invention can effectively solve the problem that the light emitting diode of the LED module is always bright.

Description

LED driving circuit and driving method

Technical Field

The invention relates to the technical field of semiconductors, in particular to an LED driving circuit and a driving method.

Background

Since LEDs are semiconductor devices that are sensitive in characteristics and have negative temperature characteristics, they need to be stabilized and protected in their operating states during application, thus creating a driving concept. The LED has higher requirements on a driving power supply, unlike a common incandescent bulb, the LED can be directly connected with 220V alternating current mains supply, the LED is driven by 2-3V low voltage, a complex conversion circuit needs to be designed, different power adapters are required to be equipped for different purposes, and when the LED is used as a display or other lighting equipment or backlight source, the LED needs to be driven by constant current, and the main reason is that: 1. the driving current is prevented from exceeding the maximum rated value, and the reliability is prevented from being influenced. 2. The expected brightness requirement is obtained, and the consistency of the brightness and the chromaticity of each LED is ensured. The constant current source generally adopts the MOS tube to carry out constant current drive, and after the MOS tube loses efficacy, the LED can be in a normally-on state, and is easy to cause the damage of the LED, and because of lacking a driving circuit to shunt, the brightness of the LED can be obviously higher than the brightness of surrounding LEDs, and the effect is obvious.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an LED driving system and a driving method thereof.

The technical scheme adopted for solving the technical problems is as follows: the utility model provides a LED actuating system, including multistage LED drive circuit, every stage of LED drive circuit all connects between the positive and negative pole of power supply, every stage of LED drive circuit all includes LED module, sample judgement circuit, first drive circuit and second drive circuit, the LED module is connected between the positive and negative pole of power supply, first drive circuit connects the positive pole of power supply with between the LED module, the second drive circuit is connected the negative pole of power supply with between the LED module, sample judgement circuit connects first drive circuit with between the LED module, sample judgement circuit still is connected the power supply, sample judgement circuit is used for the sample electric current and control the switching on/off of LED module.

As a preferred scheme, the LED driving circuit further comprises a sampling comparison circuit, the sampling comparison circuit is connected between the second driving circuit and the LED module, and the sampling comparison circuit is used for sampling current and controlling the on-off of the second driving circuit so as to control the on-off of the LED module.

Preferably, the LED driving circuit further includes a logic analysis circuit, the logic analysis circuit is connected between the sampling comparison circuit and the second driving circuit, and the logic analysis circuit is configured to receive an electrical signal fed back by the sampling comparison circuit and control on-off of the second driving circuit.

Preferably, the LED driving circuit further includes a signal shaping and amplifying circuit, and the signal shaping and amplifying circuit is connected to the sampling comparison circuit and the logic analysis circuit.

As a preferable scheme, the logic analysis circuits of the LED driving circuits of each stage are sequentially connected.

As a preferred scheme, the first driving circuit includes a triode Q1, an emitter of the triode Q1 is connected with a power supply, a collector of the triode Q1 is connected with an anode of the light emitting diode D1 of the LED module, a base of the triode Q1 is connected with the sampling judgment circuit, and the sampling judgment circuit is further connected between the collector of the triode Q1 and the anode of the light emitting diode D1 of the LED module.

As a preferred scheme, the second driving circuit further comprises a triode Q2, a collector electrode of the triode Q2 is connected with a cathode of the light emitting diode D1 of the LED module, an emitter electrode of the triode Q2 is connected with a cathode of the power supply, a base electrode of the triode Q2 is connected with the logic analysis circuit, and the sampling comparison circuit is connected between the collector electrode of the triode Q2 and the cathode of the light emitting diode D1 of the LED module.

The other technical scheme adopted for solving the technical problems is as follows: there is provided an LED driving method, the method including:

acquiring an anode electrical signal of an LED module of a previous stage LED driving circuit;

judging whether the positive electrode electric signal meets the requirements or not;

if yes, acquiring a negative electrode electric signal of an LED module of the previous stage LED driving circuit;

judging whether the negative electrode electric signal meets the requirements;

if yes, controlling the LED module of the previous stage LED driving circuit to emit light, and outputting a logic signal to the next stage LED driving circuit;

and the next-stage LED driving circuit emits light according to the logic signals and controls the LED modules of the multi-stage LED driving circuit to emit light.

Preferably, the method further comprises:

judging whether the positive electrode electric signal meets the requirements or not;

if the two values do not match, the LED module of the previous stage LED driving circuit is controlled not to emit light.

Preferably, the method further comprises:

judging whether the negative electrode electric signal meets the requirements;

if the LED driving signals do not accord with the logic signals, the LED module of the previous stage LED driving circuit is controlled to not emit light, and the logic signals are output to the next stage LED driving circuit;

and the next-stage LED driving circuit emits light according to the logic signals and controls the LED modules of the multi-stage LED driving circuit to emit light.

The invention provides an LED driving system and a driving method thereof, wherein the LED driving system comprises a plurality of stages of LED driving circuits, and each stage of LED driving circuit comprises an LED module, a sampling judging circuit, a first driving circuit and a second driving circuit. Therefore, each stage of LED driving circuit is provided with a sampling judging circuit for sampling circuit current, when the first driving circuit has a short circuit problem, the sampling judging circuit can rapidly feed back to the power supply, and the circuit from the power supply to the LED module is cut off in time, so that the problem that the LED module is always bright due to the short circuit of the circuit is avoided.

Drawings

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular descriptions of exemplary embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the exemplary embodiments of the invention.

FIG. 1 is a block diagram of an LED drive system according to an embodiment of the present invention;

fig. 2 is a block diagram of an LED driving circuit of an LED driving system according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While embodiments of the present invention are illustrated in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It should be understood that although the terms "first," "second," "third," etc. may be used herein to describe various information, these information should not be limited by these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the invention. 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 invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Unless specifically stated or limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected or detachably connected or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

The invention provides an LED driving system, which comprises a plurality of stages of LED driving circuits 200, wherein each stage of LED driving circuit 200 is connected between the anode and the cathode of a power supply 100, each stage of LED driving circuit 200 comprises an LED module 20, a sampling judging circuit 30, a first driving circuit 40 and a second driving circuit 50, the LED module 20 is connected between the anode and the cathode of the power supply 100, the first driving circuit 40 is connected between the anode of the power supply 100 and the LED module 20, the second driving circuit 50 is connected between the cathode of the power supply 100 and the LED module 20, the sampling judging circuit 30 is connected between the first driving circuit 40 and the LED module 20, the sampling judging circuit 30 is also connected with the power supply 100, and the sampling judging circuit 30 is used for sampling current and controlling the on/off of the LED module 20.

Further, the LED driving circuit 200 further includes a sampling comparison circuit 60, the sampling comparison circuit 60 is connected between the second driving circuit 50 and the LED module 20, and the sampling comparison circuit 60 is used for sampling current and controlling on/off of the second driving circuit 50, so as to control on/off of the LED module 20.

Further, the LED driving circuit 200 further includes a logic analysis circuit 70, where the logic analysis circuit 70 is connected between the sampling comparison circuit 60 and the second driving circuit 50, and the logic analysis circuit 70 is configured to receive an electrical signal fed back by the sampling comparison circuit 60 and control on/off of the second driving circuit 50.

Further, the LED driving circuit 200 further includes a signal shaping and amplifying circuit 80, and the signal shaping and amplifying circuit 80 is connected to the sampling and comparing circuit 60 and the logic analyzing circuit 70.

Further, the logic analysis circuits 70 of the LED driving circuits 200 of each stage are sequentially connected.

Further, the first driving circuit 40 includes a transistor Q1, an emitter of the transistor Q1 is connected to the power supply 100, a collector of the transistor Q1 is connected to an anode of the light emitting diode D1 of the LED module 20, a base of the transistor Q1 is connected to the sampling and judging circuit 30, and the sampling and judging circuit 30 is further connected between the collector of the transistor Q1 and the anode of the light emitting diode D1 of the LED module 20.

Further, the second driving circuit 50 further includes a triode Q2, a collector of the triode Q2 is connected to a cathode of the light emitting diode D1 of the LED module 20, an emitter of the triode Q2 is connected to a cathode of the power supply 100, a base of the triode Q2 is connected to the logic analysis circuit 70, and the sampling comparison circuit 60 is connected between the collector of the triode Q2 and the cathode of the light emitting diode D1 of the LED module 20.

The LED driving system provided by the present invention includes a plurality of LED driving circuits 200, and each LED driving circuit 200 includes an LED module 20, a sampling judgment circuit 30, a first driving circuit 40 and a second driving circuit 50. Therefore, each stage of the LED driving circuit 200 has the sampling judgment circuit 30 to sample the circuit current, when the first driving circuit 40 has the short circuit problem, the sampling judgment circuit 30 can rapidly feed back to the power supply 100, and timely cut off the loop from the power supply 100 to the LED module 20, thereby avoiding the problem that the LED module 20 is always on due to the short circuit of the loop.

The other technical scheme adopted for solving the technical problems is as follows: there is provided an LED driving method, the method including:

acquiring an anode electrical signal of an LED module of a previous stage LED driving circuit;

judging whether the positive electrode electric signal meets the requirements or not;

if yes, acquiring a negative electrode electric signal of an LED module of the previous stage LED driving circuit;

judging whether the negative electrode electric signal meets the requirements;

if yes, controlling the LED module of the previous stage LED driving circuit to emit light, and outputting a logic signal to the next stage LED driving circuit;

and the next-stage LED driving circuit emits light according to the logic signals and controls the LED modules of the multi-stage LED driving circuit to emit light.

Claims (10)

1. The LED driving system is characterized by comprising a plurality of stages of LED driving circuits, wherein each stage of LED driving circuit is connected between the positive electrode and the negative electrode of a power supply, each stage of LED driving circuit comprises an LED module, a sampling judging circuit, a first driving circuit and a second driving circuit, the LED module is connected between the positive electrode and the negative electrode of the power supply, the first driving circuit is connected between the positive electrode and the LED module of the power supply, the second driving circuit is connected between the negative electrode and the LED module of the power supply, the sampling judging circuit is connected between the first driving circuit and the LED module, the sampling judging circuit is also connected with the power supply, and the sampling judging circuit is used for sampling current and controlling the on/off of the LED module.

2. The LED driving system according to claim 1, wherein the LED driving circuit further comprises a sampling comparison circuit, the sampling comparison circuit is connected between the second driving circuit and the LED module, and the sampling comparison circuit is used for sampling current and controlling on/off of the second driving circuit, so as to control on/off of the LED module.

3. The LED driving system according to claim 2, wherein the LED driving circuit further comprises a logic analysis circuit connected between the sampling comparison circuit and the second driving circuit, the logic analysis circuit being configured to receive an electrical signal fed back by the sampling comparison circuit and control on/off of the second driving circuit.

4. The LED driving system of claim 3, further comprising a signal shaping amplification circuit connecting the sample comparison circuit and the logic analysis circuit.

5. A LED driving system according to claim 3, wherein the logic analysis circuits of each stage of LED driving circuit are connected sequentially.

6. The LED driving system according to claim 1, wherein the first driving circuit comprises a transistor Q1, an emitter of the transistor Q1 is connected to a power supply, a collector of the transistor Q1 is connected to an anode of the light emitting diode D1 of the LED module, a base of the transistor Q1 is connected to the sampling judgment circuit, and the sampling judgment circuit is further connected between the collector of the transistor Q1 and the anode of the light emitting diode D1 of the LED module.

7. The LED driving system according to claim 3, wherein the second driving circuit further comprises a transistor Q2, a collector of the transistor Q2 is connected to a cathode of the light emitting diode D1 of the LED module, an emitter of the transistor Q2 is connected to a cathode of the power supply, a base of the transistor Q2 is connected to the logic analysis circuit, and the sampling comparison circuit is connected between the collector of the transistor Q2 and the cathode of the light emitting diode D1 of the LED module.

8. A method of driving an LED, the method comprising:

acquiring an anode electrical signal of an LED module of a previous stage LED driving circuit;

judging whether the positive electrode electric signal meets the requirements or not;

if yes, acquiring a negative electrode electric signal of an LED module of the previous stage LED driving circuit;

judging whether the negative electrode electric signal meets the requirements;

if yes, controlling the LED module of the previous stage LED driving circuit to emit light, and outputting a logic signal to the next stage LED driving circuit;

and the next-stage LED driving circuit emits light according to the logic signals and controls the LED modules of the multi-stage LED driving circuit to emit light.

9. The LED driving method according to claim 8, further comprising:

judging whether the positive electrode electric signal meets the requirements or not;

if the two values do not match, the LED module of the previous stage LED driving circuit is controlled not to emit light.

10. The LED driving method according to claim 8, further comprising:

judging whether the negative electrode electric signal meets the requirements;

if the LED driving signals do not accord with the logic signals, the LED module of the previous stage LED driving circuit is controlled to not emit light, and the logic signals are output to the next stage LED driving circuit;

and the next-stage LED driving circuit emits light according to the logic signals and controls the LED modules of the multi-stage LED driving circuit to emit light.