CN216565659U

CN216565659U - Follow current circuit, LED light source circuit, lighting device and lighting system

Info

Publication number: CN216565659U
Application number: CN202122837655.2U
Authority: CN
Inventors: 舒钊
Original assignee: Hangzhou Huacheng Software Technology Co Ltd
Current assignee: Hangzhou Huacheng Software Technology Co Ltd
Priority date: 2021-11-18
Filing date: 2021-11-18
Publication date: 2022-05-17
Anticipated expiration: 2031-11-18

Abstract

The application relates to a follow current circuit, an LED light source circuit, a lighting device and a lighting system, wherein the follow current circuit comprises a follow current circuit, a hysteresis comparator unit and a relay unit; the input end of the optical coupling unit is connected with the LED lamp in the working circuit of the series LED lamp in parallel, the output end of the optical coupling unit is connected with the input end of the hysteresis comparator unit, the output end of the hysteresis comparator unit is connected with the relay unit, and the relay unit is in a normally open state and is connected with the LED lamp in the working circuit of the series LED lamp in parallel; when the series LED lamp working circuit has the failure open circuit LED lamp, the voltage at the output end of the optical coupling unit changes, the hysteresis comparator unit outputs high level to drive the relay unit to be switched on, the failure open circuit LED lamp is short-circuited, other LED lamps in the series LED lamp working circuit can continue to normally work, and the working efficiency of the series LED lamp working circuit is effectively improved.

Description

Follow current circuit, LED light source circuit, lighting device and lighting system

Technical Field

The present application relates to the field of LED lighting circuits, and in particular, to a freewheel circuit, an LED light source circuit, a lighting device, and a lighting system.

Background

With the development of economy, energy conservation and emission reduction become one of the most concerned problems in the world. The field of lighting is no exception, and the demand for LED lighting is increasing at present. The LED light source circuit is generally formed by connecting a group of LED lamps in series, and in the using process, once a certain LED lamp in the working circuit of the series LED lamps is broken, other series LED lamps cannot work, and the working efficiency is low. For the situation, the LED lamps can only be manually detected one by one at present, the LED lamp with the open circuit is found out, and then the LED lamp with the open circuit is replaced by a new LED lamp, so that the normal operation of the working circuit of the series LED lamp is realized again.

Therefore, in the prior art, when a certain LED lamp is broken in the working circuit of the series LED lamp, the rest LED lamps cannot work normally, so that the working efficiency of the working circuit of the series LED lamp is low, which becomes a technical problem to be solved urgently.

SUMMERY OF THE UTILITY MODEL

Therefore, it is necessary to provide a freewheeling circuit, an LED light source circuit, a lighting device and a lighting system to solve the problem in the related art that when a certain LED lamp in a serial LED lamp operating circuit is turned off, the remaining LED lamps cannot operate normally, which results in low operating efficiency of the serial LED lamp operating circuit.

In a first aspect, an embodiment of the present application provides a freewheeling circuit, which is applied to a working circuit of a series LED lamp, and includes an optical coupling unit, a hysteresis comparator unit, and a relay unit;

the input end of the optical coupling unit is connected with the LED lamp in the working circuit of the series LED lamp in parallel, the output end of the optical coupling unit is connected with the input end of the hysteresis comparator unit, the output end of the hysteresis comparator unit is connected with the relay unit, and the relay unit is in a normally open state and is connected with the LED lamp in the working circuit of the series LED lamp in parallel;

when the working circuit of the series LED lamp has an LED lamp which is in failure and broken circuit, the voltage at the output end of the optical coupling unit changes, the hysteresis comparator unit outputs high level to drive the relay unit to be conducted, and the LED lamp which is in failure and broken circuit is in short circuit.

In some of these embodiments, the light coupling unit includes a first power source, a first resistor, a second resistor, and a light coupler;

the optical coupler comprises a light emitting diode and a photosensitive device; the photosensitive device is in the illumination range of the light emitting diode;

one end of the first resistor is connected with the anode of the light emitting diode, and the other end of the first resistor and the cathode of the light emitting diode are used as input ends of the optocoupler unit and are respectively connected with the anode and the cathode of the LED lamp in the working circuit of the series LED lamp;

one end of the second resistor is connected with the first power supply, and the other end of the second resistor is connected with the photosensitive device; the other end of the photosensitive device, which is not connected with the second resistor, is grounded; and the end of the second resistor connected with the photosensitive device is used as the output end of the optical coupling unit and is connected with the input end of the hysteresis comparator unit.

In some of these embodiments, the hysteresis comparator unit includes a comparator, a third resistor, and an inverter;

the positive phase input end of the comparator is used as the input end of the hysteresis comparator unit and is connected with the output end of the optical coupling unit; the inverting input end of the comparator is connected with a constant voltage, and the output end of the comparator is connected with the input end of the phase inverter; the output end of the inverter is used as the output end of the hysteresis comparator unit and is connected with the relay unit; one end of the third resistor is connected with the positive phase input end of the comparator, and the other end of the third resistor is connected with the output end of the comparator.

In some embodiments, the inverting input terminals of the comparator are respectively connected with a fourth resistor and a fifth resistor;

the fourth resistor is connected with a second power supply, and the fifth resistor is grounded.

In some of these embodiments, the inverter includes a PMOS transistor and a third power supply; the grid electrode of the PMOS tube is connected with the output end of the comparator, the source electrode of the PMOS tube is connected with a third power supply, and the drain electrode of the PMOS tube is used as the output end of the hysteresis comparator unit and is connected with the relay unit.

In some of these embodiments, the second power source and the third power source are the same power source.

In some of these embodiments, the photosensitive device comprises a photosensitive semiconductor tube or a photoresistor.

In a second aspect, there is provided in this embodiment an LED light source circuit comprising a series LED lamp operating circuit and at least one freewheel circuit as described in the first aspect.

In some embodiments, the serial LED lamp working circuit comprises an LED lamp power supply and a plurality of LED lamps connected in series with the LED lamp power supply;

the power supply of the LED lamp is a constant current source or a driving chip.

In a third aspect, there is provided in this embodiment a lighting device comprising a plurality of LED light source circuits as described in the second aspect.

In a fourth aspect, there is provided a lighting system comprising a control switch and a plurality of lighting devices of the third aspect; wherein the control switch controls the power supply of the LED light source circuit of the lighting device.

The follow current circuit comprises an optical coupling unit, a hysteresis comparator unit and a relay unit; the input end of the optical coupling unit is connected with the LED lamps in the working circuit of the series LED lamps in parallel, the output end of the optical coupling unit is connected with the input end of the hysteresis comparator unit, the output end of the hysteresis comparator unit is connected with the relay unit, and the relay unit is in a normally open state and is connected with the LED lamps in the working circuit of the series LED lamps in parallel. When the working circuit of the series LED lamp has the failure and open circuit LED lamp, the voltage at the output end of the optical coupling unit changes, the hysteresis comparator unit outputs high level to drive the relay unit to be switched on, the failure and open circuit LED lamp is short-circuited, and other LED lamps in the working circuit of the series LED lamp can continue to work normally. This application is through mutually supporting of opto-coupler unit, hysteresis comparator unit and relay unit, and under certain LED lamp took place the condition of opening circuit in the LED lamp working circuit of establishing ties, the LED lamp that need not change and open circuit, other LED lamps in the LED lamp working circuit of establishing ties can continue normal work, have effectively improved the work efficiency of the LED lamp working circuit of establishing ties.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic diagram of a freewheel circuit according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a freewheel circuit according to an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a freewheel circuit according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a freewheel circuit according to a fourth embodiment of the present application;

fig. 5 is a schematic structural diagram of a freewheel circuit according to an embodiment of the present application;

FIG. 6 is a schematic structural diagram of an LED light source circuit provided according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of an illumination device provided according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments provided in the present application without any inventive step are within the scope of protection of the present application.

It is obvious that the drawings in the following description are only examples or embodiments of the present application, and that it is also possible for a person skilled in the art to apply the present application to other similar contexts on the basis of these drawings without inventive effort. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of ordinary skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments without conflict.

Unless defined otherwise, technical or scientific terms referred to herein shall have the ordinary meaning as understood by those of ordinary skill in the art to which this application belongs. Reference to "a," "an," "the," and similar words throughout this application are not to be construed as limiting in number, and may refer to the singular or the plural. The present application is directed to the use of the terms "including," "comprising," "having," and any variations thereof, which are intended to cover non-exclusive inclusions; for example, a process, method, system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to the listed steps or elements, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. Reference to "connected," "coupled," and the like in this application is not intended to be limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality" as referred to herein means two or more. "and/or" describes the association relationship of the associated object, indicating that there may be three relationships, for example, "a and/or B" may indicate: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. Reference herein to the terms "first," "second," "third," and the like, are merely to distinguish similar objects and do not denote a particular ordering for the objects.

As shown in fig. 1, a freewheeling circuit 10 provided in the first embodiment of the present application is applied to a series LED lamp operating circuit 01, and includes an optical coupling unit 11, a hysteresis comparator unit 12, and a relay unit 13.

The input end of the optical coupling unit 11 is connected in parallel with the LED lamp 011 in the series LED lamp working circuit 01, the output end of the optical coupling unit 11 is connected with the input end of the hysteresis comparator unit 12, the output end of the hysteresis comparator unit 12 is connected with the relay unit 13, and the relay unit 13 is in a normally open state and is connected in parallel with the LED lamp 011 in the series LED lamp working circuit 01.

When the series-connected LED lamp working circuit 01 has a failed open-circuit LED lamp, for example, the LED lamp 011 is open-circuit, the voltage at the output end of the optical coupling unit 11 changes, the hysteresis comparator unit 12 outputs a high level, the relay unit 13 is driven to be turned on, and the failed open-circuit LED lamp 01 is short-circuited.

Specifically, under the condition that the LED lamp 011 in the series LED lamp operating circuit 01 is not broken, since the resistance of the optical coupling unit 11 is large, the current distributed by the optical coupling unit 11 is small, and the voltage ratio of the output end of the optical coupling unit 11 is determined to be higher by the basic output characteristics of the optical coupling unit 11. When the voltage at the output end of the optical coupler unit 11 is relatively high, the output level of the hysteresis comparator unit 12 is a low level due to the characteristics of the hysteresis comparator unit 12, and the relay unit 13 is in a normally open state at this time.

When the LED lamp 011 in the series LED lamp operating circuit 01 is broken, the current of the optical coupling unit 11 is increased, the voltage ratio of the output end of the optical coupling unit 11 is determined to be smaller by the basic output characteristic of the optical coupling unit 11, when the voltage of the output end of the optical coupling unit 11 is smaller, the output level of the hysteresis comparator unit 12 is high level due to the characteristic of the hysteresis comparator unit 12, the driving relay unit 13 is switched on, the LED lamp 011 which is broken in failure is short-circuited, the current of the series LED lamp operating circuit 01 passes through the driving relay unit 13, and other LED lamps in the series LED lamp operating circuit 01 can continue to work normally.

When the current of the series LED lamp working circuit 01 passes through the driving relay unit 13, the current distributed by the optical coupler unit 11 is small, the voltage ratio of the output end of the optical coupler unit 11 is determined by the basic output characteristic of the optical coupler unit 11, but based on the characteristic of the hysteresis comparator unit 12, the hysteresis comparator unit 12 is still in the hysteresis area of level conversion at this time, the level conversion does not occur at the output end of the hysteresis comparator unit 12 at this time, the conduction state of the relay unit 13 can be continuously maintained, and other LED lamps of the series LED lamp working circuit 01 can continuously and normally work.

When a certain LED lamp in the working circuit 01 of the series LED lamp is broken, the LED lamp which is broken is found out by manually detecting the LED lamps one by one in the prior art, and then the broken LED lamp is replaced by a new LED lamp, so that the working circuit 01 of the series LED lamp is ensured to normally work. However, the circuit maintenance work is time-consuming and labor-consuming, and the operation efficiency of the series LED lamp operation circuit 01 is low. This application is through mutually supporting of opto-coupler unit 11, hysteresis comparator unit 12 and relay unit 13, and under certain LED lamp emergence condition of opening circuit in series connection LED lamp working circuit 01, the LED lamp that need not change and open circuit, other LED lamps in the series connection LED lamp working circuit 01 can continue normal work, effectively improve the work efficiency of series connection LED lamp working circuit 01.

As shown in fig. 2, the freewheel circuit 20 provided in the second embodiment of the present application includes an optical coupler unit 21, a hysteresis comparator unit 22, and a relay unit 23; the optical coupler unit 21 includes a first power source 213, a first resistor 211, a second resistor 214, and an optical coupler; the optocoupler includes a light emitting diode 212 and a photosensor 215; the light sensing device 215 is within the illumination range of the light emitting diode 212.

One end of the first resistor 211 is connected to the anode of the light emitting diode 212, and the other end of the first resistor 211 and the cathode of the light emitting diode 212 are used as input ends of the optical coupling unit 21, and are respectively connected to the anode and the cathode of the LED lamp 011 in the series LED lamp operating circuit 01.

One end of the second resistor 214 is connected to the first power source 213, and the other end is connected to the photosensitive device 215; the other end of the photosensitive device 215 not connected to the second resistor 214 is grounded; the end of the second resistor 214 connected to the photosensor 215 is used as the output end of the optical coupler unit 21, and is connected to the input end of the hysteresis comparator unit 22.

Specifically, when the LED lamp 011 in the serial LED lamp operating circuit 01 is not disconnected, the resistance of the first resistor 211 is large, the current distributed by the branch circuit formed by the first resistor 211 and the light emitting diode 212 is small, the light emitting diode 212 does not emit light or the light is very weak, and the resistance of the photosensor 215 is large. The resistance of the photo sensor 215 varies according to the intensity of the light emitted from the led 212, and the stronger the light emitted from the led 212 is, the smaller the resistance of the photo sensor 215 is. As can be seen from fig. 2, the output voltage of the first power source 213 is divided by the second resistor 214 and the photosensitive device 215, and the larger the resistance of the photosensitive device 215 is, the larger the output voltage of the optical coupler unit 21 is. Since the current resistance of the photosensor 215 is large, the output voltage of the optical coupling unit 21 is relatively high at this time. The output level of the hysteresis comparator unit 22 is determined to be low by the characteristics of the hysteresis comparator unit 22, and the relay unit 23 is in a normally open state.

When the LED lamp 011 in the serial LED lamp operating circuit 01 is disconnected, the current in the serial LED lamp operating circuit 01 almost flows to the branch circuit formed by the first resistor 211 and the light emitting diode 212, and the light emitting diode 212 is turned on to emit light normally under the influence of the light emitting diode 212, and the resistance of the photosensor 215 is decreased. Because the resistance value of the current photosensitive device 215 is reduced, the output voltage of the optical coupling unit 21 is relatively low at this time, the output level of the hysteresis comparator unit 22 is determined to be a high level at this time by the characteristics of the hysteresis comparator unit 22, the driving relay unit 23 is switched on, the failed and open-circuit LED lamp 011 is short-circuited, the current of the series LED lamp working circuit 01 passes through the driving relay unit 23, and other LED lamps in the series LED lamp working circuit 01 can continue to work normally.

When the current of the series LED lamp operating circuit 01 passes through the driving relay unit 23, the current distributed by the branch circuit formed by the first resistor 211 and the light emitting diode 212 is very small, which results in a very large resistance of the photosensor 215, and at this time, the output voltage of the optocoupler unit 21 is relatively high. However, based on the characteristics of the hysteresis comparator unit 22, the hysteresis comparator unit 22 is still in the hysteresis region of level conversion, at this time, the output voltage does not undergo level conversion, the on state of the relay unit 23 can be maintained continuously, and other LED lamps of the series LED lamp operating circuit 01 can continue to operate normally.

The photosensitive device 215 includes a photosensitive semiconductor or a photoresistor, as one of the embodiments.

As shown in fig. 3, a freewheel circuit 30 according to a third embodiment of the present application includes an optical coupler unit 31, a hysteresis comparator unit 32, and a relay unit 33; the hysteresis comparator unit 32 includes a comparator 321, a third resistor 322, and an inverter 323;

the positive phase input end of the comparator 321 is used as the input end of the hysteresis comparator unit 32, and is connected with the output end of the optical coupler unit 31; the inverting input end of the comparator 321 is connected with a constant voltage, and the output end of the comparator 321 is connected with the input end of the inverter 323; the output end of the inverter 323 serves as the output end of the hysteresis comparator unit 32, and is connected to the relay unit 33; one end of the third resistor 322 is connected to the non-inverting input terminal of the comparator 321, and the other end is connected to the output terminal of the comparator 321.

Specifically, under the condition that the LED lamp 011 in the series LED lamp operating circuit 01 is not broken, since the resistance of the optical coupling unit 31 is large, the current distributed by the optical coupling unit 31 is small, and the voltage ratio of the output end of the optical coupling unit 31 is determined to be high by the output characteristic of the optical coupling unit 31. When the voltage at the output end of the optical coupling unit 31 is higher, the voltage at the non-inverting input end of the comparator 321 is higher than the voltage at the inverting input end of the comparator 321, the comparator 321 outputs a high level, the high level is changed into a low level through the inverter 323, and the relay unit 33 is in a normally open state at this time.

When the LED lamp 011 in the series LED lamp operating circuit 01 is disconnected, the current of the optical coupling unit 31 increases, the output characteristic of the optical coupling unit 31 determines that the voltage ratio of the output end of the optical coupling unit 11 is smaller, when the voltage of the output end of the optical coupling unit 31 is smaller, the voltage of the positive phase input end of the comparator 321 is smaller than the voltage of the negative phase input end of the comparator 321, the comparator 321 outputs a low level, the low level is changed into a high level after passing through the phase inverter 323, the driving relay unit 33 is switched on, the LED lamp 011 which is failed to be disconnected is short-circuited, the current of the series LED lamp operating circuit 01 passes through the driving relay unit 33, and other LED lamps in the series LED lamp operating circuit 01 can continue to work normally.

When the current of the series LED lamp working circuit 01 passes through the driving relay unit 33, the current distributed by the optical coupling unit 31 is very small, the output characteristic of the optical coupling unit 31 determines that the voltage ratio of the output end of the optical coupling unit 31 is higher, although the voltage at the non-inverting input terminal of the comparator 321 is greater than the voltage at the inverting input terminal of the comparator 321 at this time, however, due to the existence of the third resistor 322, the comparator 321 has a hysteresis region of level transition, at this time, a difference value between the voltage at the non-inverting input terminal of the comparator 321 and the voltage at the inverting input terminal of the comparator 321 is still in the hysteresis region of level transition, no level transition occurs at the output terminal of the comparator 321 at this time, the comparator 321 still outputs a low level, the inverter 323 continues to output a high level, the on state of the relay unit 33 can continue to be maintained, and other LED lamps of the series LED lamp operating circuit 01 can continue to operate normally.

As shown in fig. 4, a freewheel circuit 40 according to a fourth embodiment of the present application includes an optical coupler unit 41, a hysteresis comparator unit 42, and a relay unit 43; the hysteresis comparator unit 42 includes a comparator 421, a third resistor 422, and an inverter 423; the inverting input terminal of the comparator 421 is connected to the fourth resistor 424 and the fifth resistor 425 respectively; the fourth resistor 424 is connected to the second power source 426 and the fifth resistor 425 is connected to ground.

Specifically, assuming that the voltage value output by the second power source 426 is Vcc, the resistance of the fourth resistor 424 is R4, and the resistance of the fifth resistor 425 is R5, the voltage at the inverting input terminal of the comparator 421 is Vcc × R5/(R4+ R5), the voltage at the inverting input terminal of the comparator 421 is a constant voltage, and the voltage value at the inverting input terminal of the actual comparator 421 can be adjusted by adjusting the resistances of the fourth resistor 424 and the fifth resistor 425.

As shown in fig. 5, a fifth embodiment of the present application provides a freewheel circuit 50, which includes an optical coupler unit 51, a hysteresis comparator unit 52, and a relay unit 53; the hysteresis comparator unit 52 includes a comparator 521, a third resistor 522, and an inverter 523; the inverting input end of the comparator 521 is connected with the fourth resistor 524 and the fifth resistor 525 respectively; the fourth resistor 524 is connected to the second power source 526, and the fifth resistor 525 is connected to ground.

The inverter 523 includes a PMOS transistor 528 and a third power supply 527; the gate of the PMOS transistor 528 is connected to the output terminal of the comparator 521, the source of the PMOS transistor 528 is connected to the third power supply 527, and the drain of the PMOS transistor 528 serves as the output terminal of the hysteresis comparator unit 52 and is connected to the relay unit 53.

Specifically, the third power supply 527 outputs a constant voltage, and the output level is a high level. When the LED lamp 011 in the series LED lamp operating circuit 01 is not disconnected, the comparator 521 outputs a high level, the gate of the PMOS transistor 528 and the source of the PMOS transistor 528 are both high, and the conductive characteristic of the PMOS transistor 528 shows that the drain of the PMOS transistor 528 outputs a low level, and the relay unit 53 is normally open.

When the LED lamp 011 in the series LED lamp operating circuit 01 is open-circuited, the comparator 521 outputs a low level, the gate of the PMOS transistor 528 is a low level and the source of the PMOS transistor 528 is a high level, as can be seen from the conductive property of the PMOS transistor 528, the drain of the PMOS transistor 528 outputs a high level, the driving relay unit 53 is turned on, the LED lamp 011 which is open-circuited in failure is short-circuited, the current of the series LED lamp operating circuit 01 passes through the driving relay unit 53, and the other LED lamps in the series LED lamp operating circuit 01 can continue to operate normally.

When the current of the serial LED lamp working circuit 01 passes through the driving relay unit 53, the difference between the voltage at the positive input terminal of the comparator 521 and the voltage at the negative input terminal of the comparator 521 is still in the hysteresis region of level conversion, the level conversion does not occur at the output terminal of the comparator 521, the comparator 521 still outputs a low level at this time, the PMOS transistor 528 continues to output a high level, the conduction state of the relay unit 53 can continue to be maintained, and other LED lamps of the serial LED lamp working circuit 01 can continue to normally operate.

Continuing with fig. 5, as one embodiment, the second power supply 526 and the third power supply 527 are the same power supply.

Specifically, the second power supply 526 and the third power supply 527 use the same power supply, which can effectively reduce the cost of the freewheel circuit 50.

As shown in fig. 6, the present embodiment provides an LED light source circuit 60, which includes a series LED lamp operating circuit 61 and at least one freewheeling circuit 10.

Specifically, since the LED light source circuit 60 includes a plurality of series-connected LED lamps 63, each LED lamp 63 may be disconnected, in order to ensure that the LED light source circuit 60 works normally, a freewheeling circuit 10 may be disposed at two ends of each LED lamp 63.

In one embodiment, in order to save cost, a flywheel circuit 10 is provided at each end of a predetermined number of LED lamps 63, for example, a flywheel circuit 10 is provided at each end of two LED lamps 63. In the LED lamps 63 sharing one freewheel circuit 10, assuming that one of the LED lamps 63 is open-circuited, due to the existence of the freewheel circuit 10, it can be ensured that the LED lamps other than the LED lamps currently sharing one freewheel circuit 10 can normally operate.

In one embodiment, the serial LED lamp operating circuit 60 includes an LED lamp power supply 62 and a plurality of LED lamps 63 connected in series with the LED lamp power supply;

the LED lamp power supply 62 is a constant current source or a driver chip.

The flywheel circuit 10 in the present embodiment may be replaced with the flywheel circuit 20, the flywheel circuit 30, the flywheel circuit 40, or the flywheel circuit 50 in the foregoing embodiments, and the same function may be achieved.

As shown in fig. 7, the present embodiment provides an illumination device 70 including a plurality of LED light source circuits 60.

By providing a plurality of LED light source circuits 60 in the lighting device 70, the lighting device 70 can be ensured to operate continuously and normally.

The embodiment of the present application also provides an illumination system, which includes a control switch and a plurality of illumination devices 70; wherein the control switch controls the power supply of the LED light source circuit of the lighting device 70.

By providing a plurality of lighting devices 70 in the lighting system and controlling the power supply of the LED light source circuit of the lighting devices 70 by the control switch, the lighting system can be ensured to continuously and normally operate.

It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to be limiting. All other embodiments, which can be derived by a person skilled in the art from the examples provided herein without any inventive step, shall fall within the scope of protection of the present application.

It is obvious that the drawings are only examples or embodiments of the present application, and it is obvious to those skilled in the art that the present application can be applied to other similar cases according to the drawings without creative efforts. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.

The term "embodiment" is used herein to mean that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is to be expressly or implicitly understood by one of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

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 scope of the patent protection. 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. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A follow current circuit is applied to a working circuit of a series LED lamp and is characterized by comprising an optical coupling unit, a hysteresis comparator unit and a relay unit;

2. The freewheel circuit according to claim 1 characterized in that, the opto-coupler unit includes a first power supply, a first resistor, a second resistor and an opto-coupler;

3. The freewheel circuit according to claim 1 characterized in that, the hysteresis comparator unit comprises a comparator, a third resistor and an inverter;

4. The free-wheeling circuit of claim 3, wherein the inverting inputs of the comparator are connected to a fourth resistor and a fifth resistor, respectively;

5. The freewheel circuit according to claim 4 characterized in that, the inverter includes PMOS pipe and third power supply; the grid electrode of the PMOS tube is connected with the output end of the comparator, the source electrode of the PMOS tube is connected with a third power supply, and the drain electrode of the PMOS tube is used as the output end of the hysteresis comparator unit and is connected with the relay unit.

6. The freewheel circuit according to claim 5 characterized in that, the second power supply and the third power supply are the same power supply.

7. The freewheel circuit according to claim 2 characterized in that, the photosensitive device comprises photosensitive semiconductor tube or photosensitive resistor.

8. An LED light source circuit comprising a series LED lamp operating circuit and at least one freewheel circuit as claimed in any one of claims 1-6.

9. The LED light source circuit of claim 8, wherein the series LED lamp operating circuit comprises an LED lamp power supply and a plurality of LED lamps connected in series with the LED lamp power supply;

10. A lighting device comprising a plurality of LED light source circuits of claim 8 or 9.

11. A lighting system comprising a control switch and a plurality of lighting devices of claim 10; wherein the control switch controls the power supply of the LED light source circuit of the lighting device.