CN116916490A

CN116916490A - lighting circuit

Info

Publication number: CN116916490A
Application number: CN202310891116.8A
Authority: CN
Inventors: 李响; 刘会明
Original assignee: Shenzhen Zhouming Technology Co Ltd
Current assignee: Shenzhen Zhouming Technology Co Ltd
Priority date: 2023-07-19
Filing date: 2023-07-19
Publication date: 2023-10-20

Abstract

The present application relates to a lighting circuit. The lighting circuit comprises an LED lamp assembly, a sampling circuit, a switching circuit and a control circuit. The input end of the LED lamp assembly is used for accessing a power supply voltage; the sampling circuit is connected with the input end of the LED lamp assembly and is used for sampling the power supply voltage; the switch circuit is connected with the LED lamp assembly; the control circuit is respectively connected with the sampling circuit and the switching circuit, and is used for determining the starting quantity of the LED lamps started in the LED lamp assembly according to sampling voltage parameters output by the sampling circuit and controlling the corresponding quantity of the LED lamps in the LED lamp assembly to be started through the switching circuit based on the starting quantity. The lighting circuit can dynamically adjust the quantity of the LED lamps in the LED lamp assembly according to the power supply voltage input to the LED lamp assembly, and ensures that each LED lamp in the LED lamp assembly works in a proper voltage state, thereby improving the influence of the fluctuating input voltage on the lamp.

Description

Lighting circuit

Technical Field

The application relates to the technical field of illumination, in particular to an illumination circuit.

Background

In recent years, LEDs (Light Emitting Diode, light emitting diodes) are increasingly used as an energy-saving and environment-friendly product. For example, in the field of illumination, LED illumination lamps have advantages of high efficiency, high integration, and long life, and are increasingly used. However, the range of the allowable input voltage fluctuation of the LED lamp is limited, and when the fluctuation of the input voltage is too large, the service life of the LED lamp can be influenced, and even the LED lamp can be damaged.

Disclosure of Invention

Based on this, it is necessary to provide a lighting circuit for solving the technical problem that the service life of the LED lamp is affected by the fluctuating input voltage, and the number of LED lamps turned on in the LED lamp assembly can be dynamically controlled according to the input voltage, so as to reduce the influence of the fluctuating input voltage on the lamp.

A lighting circuit, comprising:

the LED lamp assembly comprises a plurality of connected LED lamps, and the input end of the LED lamp assembly is used for accessing power supply voltage;

the sampling circuit is connected with the input end of the LED lamp assembly and is used for sampling the power supply voltage;

the switch circuit is connected with the LED lamp assembly;

and the control circuit is respectively connected with the sampling circuit and the switching circuit and is used for determining the starting quantity of the LED lamps started in the LED lamp assembly according to the sampling voltage parameter output by the sampling circuit and controlling the corresponding quantity of the LED lamps in the LED lamp assembly to be started through the switching circuit based on the starting quantity.

In one embodiment, the lighting circuit further comprises a constant current circuit, and the constant current circuit is connected with the output end of the LED lamp assembly and the control circuit;

the control circuit is used for determining a regulating current value of the constant current circuit according to the sampling voltage parameter output by the sampling circuit and controlling the working state of the constant current circuit based on the regulating current value.

In one embodiment, one LED lamp in the LED lamp assembly is a normally-on lamp, and the rest LED lamps are all circulating lamps; the opening number is n, and n is a natural number;

when n is 0, the control circuit controls all the LED lamps in the LED lamp assembly to be turned off through the switch circuit and the constant current circuit;

when n is 1, the control circuit controls the normally-on lamps to be turned on through the switch circuit and the constant current circuit, and controls all the circulating lamps to be turned off;

when n is more than 2, the control circuit controls the normally-on lamp to be started through the switch circuit and the constant current circuit, and simultaneously controls n-1 circulating lamps to be started in a circulating way.

In one embodiment, the switching circuit includes a plurality of switching units, the number of the switching units is equal to that of the circulating lamps, each switching unit is connected to the control circuit, and each switching unit is correspondingly connected to one circulating lamp and is used for respectively controlling the on states of the connected circulating lamps.

In one embodiment, the switch unit comprises an optocoupler, a first triode and a first resistor;

the collector of the triode and the collector of the first triode in the optocoupler are respectively connected with the anode of the corresponding circulating lamp, and the emitter of the first triode and the first end of the first resistor are respectively connected with the cathode of the corresponding circulating lamp; the base electrode of the first triode and the second end of the first resistor are respectively connected with the emitter electrode of the triode in the optocoupler; and a cathode of the light emitting diode in the optocoupler is connected with the control circuit, and an anode of the light emitting diode is connected with a power supply.

In one embodiment, the control circuit is further configured to control the constant current circuit to be turned off when the sampled voltage parameter is lower than a preset turn-on voltage threshold.

In one embodiment, the control circuit is further configured to determine a real-time voltage value and a maximum voltage value within a preset time period according to the sampled voltage parameter output by the sampling circuit;

and determining the starting quantity of the LED lamps started in the LED lamp assembly according to the magnitude relation between the real-time voltage value and the starting voltage of the LED lamps and the magnitude relation between the maximum voltage value and the threshold voltage of the LED lamps.

In one embodiment, the constant current circuit comprises a second triode, a second resistor, a third resistor and a capacitor; the collector electrode of the second triode is connected with the output end of the LED lamp assembly, the emitter electrode of the second triode is grounded through the second resistor, the base electrode of the second triode is grounded through the capacitor, and the base electrode of the second triode is also connected with the control circuit through the third resistor.

In one embodiment, the lighting circuit further comprises a communication circuit connected to the control circuit.

In one embodiment, the lighting circuit further comprises a rectifying circuit, and the rectifying circuit is used for rectifying the mains supply and outputting the supply voltage.

The lighting circuit comprises an LED lamp assembly, a sampling circuit, a switching circuit and a control circuit. The input end of the LED lamp assembly is used for being connected with a power supply voltage; the sampling circuit is connected with the input end of the LED lamp assembly and is used for sampling the power supply voltage; the switch circuit is connected with the LED lamp assembly; the control circuit is respectively connected with the sampling circuit and the switching circuit, and is used for determining the starting quantity of the LED lamps started in the LED lamp assembly according to sampling voltage parameters output by the sampling circuit and controlling the corresponding quantity of the LED lamps in the LED lamp assembly to be started through the switching circuit based on the starting quantity. Therefore, the lighting circuit can dynamically adjust the quantity of the LED lamps in the LED lamp assembly according to the magnitude of the power supply voltage input to the LED lamp assembly, and ensures that each LED lamp in the LED lamp assembly works in a proper voltage state, thereby improving the influence of the fluctuating input voltage on the lamp.

Drawings

FIG. 1 is a schematic block diagram of an illumination circuit in one embodiment;

FIG. 2 is a schematic block diagram of an illumination circuit according to another embodiment;

FIG. 3 is a schematic waveform diagram of a supply voltage in one embodiment;

FIG. 4 is a schematic block diagram of a lighting circuit in yet another embodiment;

FIG. 5 is a schematic diagram of a circuit configuration of a lighting circuit according to another embodiment;

fig. 6 is a schematic diagram of the workflow of the control circuit in the lighting circuit in one embodiment.

Detailed Description

In order that the application may be readily understood, a more complete description of the application will be rendered by reference to the appended drawings. Embodiments of the application are illustrated in the accompanying drawings. This application 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.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that the terms first, second, etc. as used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element. For example, a first resistance may be referred to as a second resistance, and similarly, a second resistance may be referred to as a first resistance, without departing from the scope of the application. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

It is to be understood that in the following embodiments, "connected" is understood to mean "electrically connected", "communicatively connected", etc., if the connected circuits, modules, units, etc., have electrical or data transfer between them.

It is understood that "at least one" means one or more and "a plurality" means two or more. "at least part of an element" means part or all of the element.

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," and/or the like, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. Also, the term "and/or" as used in this specification includes any and all combinations of the associated listed items.

In one embodiment, as shown in fig. 1, there is provided a lighting circuit comprising: the LED lamp assembly 100, the sampling circuit 200, the switching circuit 300, and the control circuit 400. The input of the LED lamp assembly 100 is used to tap in the supply voltage. The sampling circuit 200 is connected to an input end of the LED lamp assembly 100, and is configured to sample a supply voltage and output a corresponding sampled voltage parameter. The switching circuit 300 is connected to the LED lamp assembly 100. The control circuit 400 is respectively connected to the sampling circuit 200 and the switching circuit 300, and is configured to determine the number of turned-on LED lamps in the LED lamp assembly 100 according to the sampling voltage parameter output by the sampling circuit 200, and control the corresponding number of LED lamps in the LED lamp assembly 100 to be turned on through the switching circuit 300 based on the number of turned-on LED lamps.

The LED lamp assembly 100 includes a plurality of connected LED lamps, and a connection manner between the plurality of LED lamps may be flexibly set according to actual situations. For example, the plurality of LED lamps may be connected in series or in parallel, which is not limited in this embodiment. It should be noted that, the LED lamp in the embodiment of the present application may include only one group of LEDs, or may include multiple groups of LEDs. The parameters of each LED lamp may be the same or different, and for convenience in explaining the principle of the lighting circuit, the following description will take the example that the parameters of the plurality of LED lamps included in the LED lamp assembly 100 are the same.

The control circuit 400 obtains the sampling voltage parameter through the sampling circuit 200, the sampling frequency needs to be specifically determined in combination with specific parameters of the power supply voltage, lighting requirements and other conditions, and correspondingly, the control circuit 400 determines the number of turned-on LED lamps in the LED lamp assembly 100 by combining the sampling voltage parameter and the turned-on voltage of the LED lamps in the LED lamp assembly 100 when receiving the sampling voltage parameter output by the sampling circuit 200 once. Specifically, assuming that the turn-on voltage of each LED is 10V, when the power supply voltage is determined to be 25V according to the sampling voltage parameter, the turn-on number may be determined to be 2; when the power supply voltage is determined to be 35V according to the sampling voltage parameter, the starting number can be determined to be 3; and the like, so as to dynamically adjust the starting quantity of the LED lamps according to the fluctuation state of the power supply voltage.

Further, after determining the number of turned-on LEDs, the control circuit 400 controls the switch circuit 300 according to the number of turned-on LEDs, so as to control the corresponding number of turned-on LEDs in the LED lamp assembly 100 through the switch circuit 300. That is, when the control circuit 400 determines that the turn-on number is 2 according to the currently received sampling voltage parameter, 2 LED lamps in the LED lamp assembly 100 are controlled to be turned on through the switching circuit 300; when the control circuit 400 determines that the turn-on number is 3 according to the next sampling voltage parameter, the switching circuit 300 controls 3 LED lamps in the LED lamp assembly 100 to turn on. Therefore, the number of the LED lamps in the actual on state is dynamically adjusted, the on LED lamps are in a high-power working state, and a better luminous effect is achieved.

The lighting circuit includes an LED lamp assembly 100, a sampling circuit 200, a switching circuit 300, and a control circuit 400. The input of the LED lamp assembly 100 is used to tap in the supply voltage. The sampling circuit 200 is connected to an input end of the LED lamp assembly 100, and is configured to sample a supply voltage and output a corresponding sampled voltage parameter. The switching circuit 300 is connected to the LED lamp assembly 100. The control circuit 400 is respectively connected to the sampling circuit 200 and the switching circuit 300, and is configured to determine the number of turned-on LED lamps in the LED lamp assembly 100 according to the sampling voltage parameter output by the sampling circuit 200, and control the corresponding number of LED lamps in the LED lamp assembly 100 to be turned on through the switching circuit 300 based on the number of turned-on LED lamps. Therefore, the lighting circuit can dynamically adjust the number of the LED lamps in the LED lamp assembly 100 according to the power supply voltage input to the LED lamp assembly 100, and ensure that each LED lamp in the LED lamp assembly 100 works in a proper voltage state, thereby improving the influence of the fluctuating input voltage on the lamp.

In practical implementation, the source of the supply voltage may be set according to practical situations, and in one embodiment, as shown in fig. 2, the lighting circuit may further include a rectifying circuit 500, where the rectifying circuit 500 is configured to rectify the mains supply and output the supply voltage.

The commercial power can be 220V commercial power or 380V commercial power, and when 380V commercial power is used, the lighting circuit can be used in environments such as tunnels with only three-phase 380V commercial power, and the application range is wide. When the mains supply fluctuates, the power supply voltage output by the rectifying circuit 500 also fluctuates accordingly, and the lighting circuit can dynamically adjust the current working state according to the fluctuating power supply voltage, namely, has certain anti-interference capability to cope with the fluctuation of the mains supply, and has higher reliability and stability of lighting.

In practical implementation, the output end of the rectifying circuit 500 may be directly connected to the input end of the LED lamp assembly 100; circuits such as filtering and voltage stabilizing can be added between the output end of the rectifying circuit 500 and the input end of the LED lamp assembly 100 according to actual needs, and those skilled in the art can adaptively set the circuit according to actual situations.

In this embodiment, when setting the sampling frequency, the setting may be performed in combination with the frequency of the mains supply, and the specific setting mode is not limited. Illustratively, taking the rectifying circuit 500 to rectify a 50HZ, three-phase 380V mains, the waveform of the rectified supply voltage varies in amplitude between 466.81-538.16V as illustrated in fig. 3, with the frequency after rectification approximately equal to 300HZ. When the sampling frequency is set, the setting needs to be performed in combination with 300HZ to collect the maximum value in each period, so as to more timely adjust the number and the state of the turned-on LED lamps in the LED lamp assembly 100.

In another embodiment, the power supply voltage may also be derived from a dc power supply, specifically, the input terminal of the LED lamp assembly 100 is used to connect to the dc power supply to access the power supply voltage, and the form of the dc power supply is not limited.

In one embodiment, as shown in fig. 4, the lighting circuit further includes a constant current circuit 600, where the constant current circuit 600 is connected to the output terminal of the LED lamp assembly 100 and the control circuit 400, respectively; the control circuit 400 is configured to determine a regulated current value of the constant current circuit 600 according to the sampled voltage parameter output by the sampling circuit 200, and control an operating state of the constant current circuit 600 based on the regulated current value.

The constant current circuit 600 is connected to the output end of the LED lamp assembly 100, and the adjusted current value is the current value flowing through the LED lamp in the on state in the LED lamp assembly 100, so that the current of the LED lamp in the on state can be adjusted by controlling the working state of the constant current circuit 600.

It can be understood that when the LED lamp is turned on, if the current flowing through the LED lamp matches the power supply voltage thereof, the power and the light emitting state of the LED lamp can be both in a better state. In this embodiment, by setting the constant current circuit 600, the control circuit 400 can determine the number of the LED lamps corresponding to the on state in the LED lamp assembly 100 and the adjustment current value of the constant current circuit 600 according to the sampling voltage parameter output by the sampling circuit 100, and control the constant current circuit 600 to adjust the current to the adjustment current value, and control the on state of the LED lamps corresponding to the number in the LED lamp assembly 100 through the switch circuit 300. Therefore, the current value of the constant current circuit 600 can be dynamically adjusted according to the power supply voltage, and the number of turned-on LED lamps can be adjusted, so that the LED lamps in the turned-on state can be ensured to work under proper voltage and current parameters.

Specifically, taking the rectification circuit 500 to rectify the 50HZ and three-phase 380V mains supply as illustrated in fig. 3, the control circuit 400 adjusts the current value of the constant current circuit 600 when the number of LEDs turned on changes every time the control circuit detects that the power supply voltage changes, so that the current waveform of the LEDs in the turned-on state is closer to the voltage waveform, and the LEDs in the turned-on state can achieve the optimal luminous power and luminous effect.

Further, the constant current circuit 600 can also be used for overvoltage protection. Specifically, the control circuit 400 is further configured to control the regulated current value of the constant current circuit 600 to decrease when the sampled voltage parameter is higher than the overvoltage threshold value. In actual practice, the over-voltage threshold may be determined in combination with the number of LED lamps in the LED lamp assembly 100 and the parameters of each LED lamp.

When the sampled voltage parameter is above the overvoltage threshold, it is indicated that the LED lamp in the LED lamp assembly 100 is not sufficiently tolerant to the higher supply voltage at this time, and therefore the LED lamp may be protected in a current reducing manner. When the regulated current value of the control constant current circuit 600 is reduced, the specific degree of reduction may be set in association with the actual situation, which is not limited in this embodiment. If necessary, the current value may be adjusted to zero, that is, the constant current circuit 600 turns off the circuit where the LED lamp assembly 100 is located, and turns off each LED lamp, thereby realizing overvoltage protection.

In addition, the control circuit 400 may be further configured to control the constant current circuit 600 to be turned off when the sampled voltage parameter is lower than a preset turn-on voltage threshold. The preset starting voltage threshold needs to be determined in combination with the actual parameters of each LED lamp in the assembly 100, when the sampling voltage parameter is lower than the preset starting voltage threshold, it is indicated that the current power supply voltage cannot drive any LED lamp to stably emit light, and at this time, the control circuit 400 controls the constant current circuit 600 to be turned off, so that each LED lamp is turned off, and the low voltage protection of the whole circuit is realized through the constant current circuit 600.

In one embodiment, the control circuit 400 is further configured to determine a real-time voltage value according to the sampled voltage parameter output by the sampling circuit 200, and a maximum voltage value within a preset time period; the number of turned-on LED lamps in the LED lamp assembly 100 is determined according to the magnitude relation of the real-time voltage value and the turn-on voltage of the LED lamps and according to the magnitude relation of the maximum voltage value and the threshold voltage of the LED lamps.

The threshold voltage of the LED lamp may be set according to the starting voltage of the LED lamp, for example, the starting voltage of the LED lamp is added with a certain additional voltage to obtain the threshold voltage of the LED lamp, and the additional voltage may be selected according to specific parameters of the LED lamp. The length of the preset time period also needs to be set in combination with the actual situation, and ideally, the maximum voltage value in the preset time period can reflect the maximum value of the power supply voltage in one period. This is because if the power supply voltage sampled when the LED lamp is turned on is near the peak of the rectified voltage waveform, the LED lamp is turned off quickly to form flickering, which affects the lighting effect.

In this embodiment, if the real-time voltage value of the power supply voltage acquired at the current acquisition time is greater than the sum of the turn-on voltages of n LED lamps and less than the sum of the turn-on voltages of n+1 LED lamps, and the maximum voltage value in the preset time period before the current acquisition time is greater than the sum of the threshold voltages of n LED lamps, it is determined that the turn-on number of the LED lamps turned on in the LED lamp assembly 100 is n. Therefore, the starting quantity of the LED lamps is limited by the double voltage conditions through the real-time voltage value at the current acquisition moment and the maximum voltage value in the preset time period, so that the stability of the LED lamps in the illumination process can be ensured, the stroboscopic problem is improved, and the illumination effect is improved.

In one embodiment, the control circuit 400 may also control the turning on of a corresponding number of LED lamps in the LED lamp assembly 100 through the switching circuit 300 and the constant current circuit 600. Illustratively, when the control circuit 400 determines that the number of turns on is 0, all the LED lamps in the LED lamp assembly 100 may be controlled to be turned off by the switching circuit 300 and the constant current circuit 600; when the control circuit 400 determines that the number of turns on is 1 or more, 1 or more LED lamps in the LED lamp assembly 100 are controlled to turn on through the switching circuit 300 and the constant current circuit 600. Thereby controlling the LED lamp assembly 100 by combining the switching circuit 300 and the constant current circuit 600, and further ensuring the reliability of the control.

In one embodiment, one of the LED lamps in the LED lamp assembly 100 is a normally on lamp and the remaining LED lamps are all circulating lamps. The control circuit 400 determines that the number of turned-on LED lamps in the LED lamp assembly 100 is n, which is a natural number. When n is 0, the control circuit 400 controls all the LED lamps in the LED lamp assembly 100 to be turned off through the switching circuit 300 and the constant current circuit 600. When n is 1, the control circuit 400 controls the normally-on lamps to be turned on and controls all the circulation lamps to be turned off through the switching circuit 300 and the constant current circuit 600. When n is 2 or more, the control circuit 400 controls the normally-on lamp to be turned on through the switching circuit 300 and the constant current circuit 600, and simultaneously controls n-1 cycle lamps to be turned on in a circulating manner.

Specifically, referring to fig. 5, in the embodiment shown in fig. 5, the LED lamp assembly 100 includes 6 serially connected LED lamps, the lamp LED0 is a normally on lamp, the lamp LED1, the lamp LED2, the lamp LED3, the lamp LED4 and the lamp LED5 are all circulating lamps, and the switch circuit 300 is connected to each circulating lamp. Wherein the anode of the lamp LED5 is used as the input end of the LED lamp assembly 100, and the cathode of the lamp LED0 is used as the output end of the LED lamp assembly 100.

If the number n of turned-on LEDs is 0, the control circuit 400 may directly control the turn-off of the constant current circuit 600 to control all the LEDs in the LED lamp assembly 100 to be turned off through the switch circuit 300 and the constant current circuit 600; the switching circuit 300 may also be used to control the turn-off of each cycle lamp, and simultaneously control the turn-off of the constant current circuit 600, so as to control the turn-off of the normally-on lamp.

If the number n of turned-on lamps is 1, the control circuit 400 controls each cycle lamp to be turned off through the switching circuit 300, and controls the normally-on lamps to be turned on through the constant current circuit 600, and provides current matched with the power supply voltage for the normally-on lamps.

If the number n of turned-on lamps is 2 or more, the control circuit 400 controls the regulated current value of the constant current circuit 600 according to the supply voltage, and at this time, the normally-on lamps are turned on, and at the same time, the n-1 circulating lamps are controlled to be turned on in a circulating manner by the switching circuit 300. Illustratively, assuming that the number n of turned-on LED lamps in the LED lamp assembly 100 is 3, the normally-on LED0 is turned on, and at the same time, 2 of the circulating lamps LED1-LED5 are turned on in a circulating manner. It can be understood that the control circuit 400 may be preset with a circulation lighting table, in which circulation groups corresponding to the number of turned-on lamps are set, and the circulation groups include circulation sequences corresponding to the number of turned-on lamps, and the control circuit 400 sequentially controls the turned-on lamps according to the circulation groups in the process of controlling the circulation lighting of the circulation lamps.

It should be noted that, in the process of controlling the circulation lighting of the circulation lamp, the control circuit 400 may make the state switching time of the circulation lamp less than the time of human eyes to recognize and flash, so that the human eyes feel a more stable lighting effect, and the strobe problem is improved.

The lighting circuit in this embodiment can timely adjust the state of each LED lamp in the LED lamp assembly 100 when the commercial power fluctuates, so that the LED lamp in the on state is in a proper voltage and current state, thereby improving the influence of the fluctuating voltage on each LED lamp, and simultaneously improving the overall lighting effect of the lighting circuit.

In one embodiment, as shown in fig. 5, the switch circuit 300 may include a plurality of switch units 310, where the number of switch units 310 is equal to the number of circulating lamps, each switch unit 310 is connected to the control circuit 400, and each switch unit 310 is correspondingly connected to a circulating lamp to respectively control the on states of the connected circulating lamps.

Specifically, if the on number n is 0, the control circuit 400 controls the constant current circuit 600 to be turned off; if the number n of the turned-on lamps is 1, the control circuit 400 controls the circulation lamps LED1-LED5 to be turned off through each switch unit 310, and only the normally-on lamp LED0 is turned on; if the number n of turned-on lamps is 2 or more, the control circuit 400 controls the corresponding switching units 310 according to the number and the cycle sequence of the turned-on lamps to turn on n-1 cycle lamps in a cycle.

In this embodiment, by setting the switch unit 310 corresponding to each circulating lamp, the states of each LED lamp in the LED lamp assembly 100 are dynamically adjusted according to the power supply voltage, and the power of each LED lamp in the on state is the same, so that the lighting effect is close, and the overall lighting effect of the lighting circuit is more stable.

In another embodiment, the number of the switch units 310 may be equal to the total number of the LED lamps in the LED lamp assembly 100, each switch unit 310 is connected to the control circuit 400, and each switch unit 310 is correspondingly connected to an LED lamp for respectively controlling the on state of the connected LED lamp, which can be set by those skilled in the art according to actual requirements.

In one embodiment, the switching unit 310 includes an optocoupler, a first triode, and a first resistor; the collector of the triode and the collector of the first triode in the optical coupler are respectively connected with the anode of the corresponding circulating lamp, and the emitter of the first triode and the first end of the first resistor are respectively connected with the cathode of the corresponding circulating lamp; the base electrode of the first triode and the second end of the first resistor are respectively connected with the emitter electrode of the triode in the optocoupler; the cathode of the light emitting diode in the optocoupler is connected with the control circuit, and the anode is connected with the power supply.

In practical implementation, when the anode of the light emitting diode in the optocoupler is connected with a power supply, the anode can be connected with the power supply through a resistor, and the anode can be set by a person skilled in the art according to an actual circuit.

Specifically, taking the embodiment shown in fig. 5 as an example, the switching unit 310 connected to the circulating lamp LED1 includes an optocoupler U1, a first triode Q1 and a first resistor R1, where a collector of the triode and a collector of the first triode Q1 in the optocoupler U1 are respectively connected to an anode of the corresponding circulating lamp LED1, and an emitter of the first triode Q1 and a first end of the first resistor R1 are respectively connected to a cathode of the corresponding circulating lamp LED 1; the base electrode of the first triode Q1 and the second end of the first resistor R1 are respectively connected with the emitter electrode of the triode in the optocoupler U1; the cathode of the light emitting diode in the optocoupler U1 is connected with the control circuit 400, and the anode is connected with the power supply VCC through the resistor R6. The switch unit 310 connected with the circulating lamp LED2 comprises an optocoupler U2, a first triode Q2 and a first resistor R2, wherein the collector of the triode and the collector of the first triode Q2 in the optocoupler U2 are respectively connected with the anode of the corresponding circulating lamp LED2, and the emitter of the first triode Q2 and the first end of the first resistor R2 are respectively connected with the cathode of the corresponding circulating lamp LED 2; the base electrode of the first triode Q2 and the second end of the first resistor R2 are respectively connected with the emitter electrode of the triode in the optocoupler U2; the cathode of the light emitting diode in the optocoupler U2 is connected with the control circuit 400, and the anode is connected with the power supply VCC through the resistor R7. The switch unit 310 connected with the circulating lamp LED3 comprises an optocoupler U3, a first triode Q3 and a first resistor R3, wherein a collector electrode of the triode and a collector electrode of the first triode Q3 in the optocoupler U3 are respectively connected with an anode of the corresponding circulating lamp LED3, and an emitter electrode of the first triode Q3 and a first end of the first resistor R3 are respectively connected with a cathode of the corresponding circulating lamp LED 3; the base electrode of the first triode Q3 and the second end of the first resistor R3 are respectively connected with the emitter electrode of the triode in the optocoupler U3; the cathode of the light emitting diode in the optocoupler U3 is connected with the control circuit 400, and the anode is connected with the power supply VCC through the resistor R8. The switch unit 310 connected with the circulation lamp LED4 comprises an optocoupler U4, a first triode Q4 and a first resistor R4, wherein the collector of the triode and the collector of the first triode Q4 in the optocoupler U4 are respectively connected with the anode of the corresponding circulation lamp LED4, and the emitter of the first triode Q4 and the first end of the first resistor R4 are respectively connected with the cathode of the corresponding circulation lamp LED 4; the base electrode of the first triode Q4 and the second end of the first resistor R4 are respectively connected with the emitter electrode of the triode in the optocoupler U4; the cathode of the light emitting diode in the optocoupler U4 is connected with the control circuit 400, and the anode is connected with the power supply VCC through the resistor R9. The switch unit 310 connected with the circulation lamp LED5 comprises an optocoupler U5, a first triode Q5 and a first resistor R5, wherein a collector electrode of the triode and a collector electrode of the first triode Q5 in the optocoupler U5 are respectively connected with an anode of the corresponding circulation lamp LED5, and an emitter electrode of the first triode Q5 and a first end of the first resistor R5 are respectively connected with a cathode of the corresponding circulation lamp LED 5; the base electrode of the first triode Q5 and the second end of the first resistor R5 are respectively connected with the emitter electrode of the triode in the optocoupler U5; the cathode of the light emitting diode in the optocoupler U5 is connected with the control circuit 400, and the anode is connected with the power supply VCC through the resistor R10.

The power VCC may be sized according to practical situations, and the switching unit 310 may take other forms, not limited to the forms already mentioned in the above embodiments, as long as it can achieve the corresponding functions.

In one embodiment, the constant current circuit 600 includes a second triode Q6, a second resistor R11, a third resistor R12, and a capacitor C1; the collector of the second triode Q6 is connected with the output end of the LED lamp assembly 100, the emitter of the second triode Q6 is grounded through a second resistor R11, the base of the second triode Q6 is grounded through a capacitor C1, and the base of the second triode Q6 is also connected with the control circuit 400 through a third resistor R12.

In this embodiment, the control circuit 400 can control the constant current circuit 600 through the PWM signal, and when the duty ratio of the PWM signal is changed, the on time of the second transistor Q6 is also changed, so as to control the current flowing through the second transistor Q6, so as to adjust the current flowing through the LED lamp in the on state.

Specifically, when the power supply voltage increases, the control circuit 400 controls a greater number of LED lamps to be turned on cyclically through each switching unit 310, and increases the duty ratio of the PWM signal, so that the current of the LED lamps in the on state increases accordingly, and the effects that the lit lamps are more, the current flowing through is more, and the power efficiency of the lamps are higher are achieved when the power supply voltage is high. When the power supply voltage decreases, the control circuit 400 decreases the number of turned-on LED lamps through each switching unit 310, and simultaneously decreases the duty ratio of the PWM signal, so that the current of the LED lamps in the turned-on state decreases accordingly, and when the low power supply voltage is reached, the turned-on lamps are fewer, and the flowing current is smaller, so that the effect of adjusting along with the power supply voltage can be achieved.

The specific structures of the sampling circuit 200, the control circuit 400, and the rectifying circuit 500 are not limited, and in one embodiment, the sampling circuit 200 may include a resistor R13 and a resistor R14, where a first end of the resistor R13 is connected to an input end of the LED lamp assembly 100, and a second end of the resistor R13 is grounded through the resistor R14; the connection point of the resistor R13 and the resistor R14 is used as an output end of the sampling circuit 200 and is connected to the control circuit 400. Thus, the control circuit 400 collects the sampled voltage parameter of the connection point of the resistor R13 and the resistor R14, and can determine the supply voltage value.

In one embodiment, the control circuit 400 includes a control chip U6 and a displacement buffer U7 with serial input and parallel output, where the control chip U6 is connected to the sampling circuit 200, the constant current circuit 600, and the displacement buffer U7 is connected to each of the switch units 310 in the switch circuit 300. The control chip U6 is used for determining the starting quantity of the LED lamps started in the LED lamp assembly 100 according to the sampling voltage parameters output by the sampling circuit 200, and sending corresponding circulating signals to the displacement buffer U7 based on the starting quantity; the displacement buffer U7 controls the corresponding number of the circulating LED lamps in the LED lamp assembly 100 to be turned on through the switching circuit 300 according to the circulating signals. The control chip U6 is also used for determining the regulating current value of the constant current circuit 600 according to the sampling voltage parameter, and controlling the working state of the constant current circuit 600 based on the regulating current value. The control chip U6 may be a controller chip such as an MCU (Microcontroller Unit, micro control unit), FPGA (Field-Programmable Gate Array, field programmable gate array) or the like.

In one embodiment, the rectifying circuit 500 may include a connector J1, a diode D2, a diode D3, a diode D4, a diode D5, and a diode D6, the connector J1 being configured to introduce three-phase 380V mains, the a phase being connected to an anode of the diode D3 and a cathode of the diode D6, respectively, the B phase being connected to an anode of the diode D2 and a cathode of the diode D5, respectively, and the C phase being connected to an anode of the diode D1 and a cathode of the diode D4, respectively. The anode of the diode D4, the anode of the diode D5 and the anode of the diode D6 are all grounded, and the cathode of the diode D1, the cathode of the diode D2 and the cathode of the diode D3 are all connected with the input end of the LED lamp assembly 100 for inputting the supply voltage.

Based on the above embodiments, the lighting circuit may further include a communication circuit 700 connected to the control circuit 400, where the control circuit 400 receives instructions such as dimming information through the communication circuit 700, and the dimming information may include information such as a cycle sequence, LED on power, and the like, and may specifically be set according to actual lighting requirements.

The communication circuit 700 may be a wired communication circuit or a wireless communication circuit. In one embodiment, the communication circuit 700 includes a serial port receiving unit 710 and a serial port transmitting unit 720, where the serial port receiving unit 710 and the serial port transmitting unit 720 are respectively connected to the control circuit 400.

In actual implementation, the serial port receiving unit 710 and the serial port transmitting unit 720 may each be connected to the connector J2, and an external circuit may be connected through the connector J2. The serial port can be RS-485, RS-422 or RS-232, etc. In the embodiment, a serial port communication mode is adopted, so that the control is simple and the data transmission is fast.

In one embodiment, the serial port receiving unit 710 includes an optocoupler U8 and a resistor R15, where a collector of a triode in the optocoupler U8 is connected to a control chip U6 in the control circuit 400, and an emitter is grounded; the anode of the light emitting diode in the optocoupler U8 receives the dimming information sent by an external circuit through the resistor 15, and the cathode is grounded. The serial port sending unit 720 comprises an optocoupler U9, a resistor R16 and a resistor R17, wherein the anode of a light emitting diode in the optocoupler U9 is connected with a control chip U6 in the control circuit 400, and the cathode is grounded through the resistor R16; the collector of the triode in the optocoupler U9 sends information to an external circuit through a resistor 17, and the emitter is grounded. It is to be understood that the illustrated circuitry of the communication circuit 700 is merely exemplary and is not limited to such circuitry.

The operation of the control circuit 400 in the above embodiment will be described with reference to fig. 6:

first, the rectifying circuit 500 rectifies the three-phase 380 mains supply to obtain a supply voltage as shown in fig. 3. The control circuit 400 then samples the power supply voltage at intervals by the sampling circuit 200 to determine the maximum voltage value of the power supply voltage and the current real-time voltage value; the sampling period may be a duration of a period corresponding to greater than 300HZ.

After each time the control circuit 400 obtains the maximum voltage value and the current real-time voltage value, the number of turned-on LED lamps in the LED lamp assembly 100 is determined according to the detected power supply voltage, and if the number of turned-on LED lamps is unchanged (i.e., there is no LED lamp that needs to be turned on or off newly added), the LED lamps are controlled to maintain the current circulation state. If the number of turned-on LEDs is changed (i.e., there are additional LEDs to be turned on or turned off), the cycle is redetermined according to the number of turned-on LEDs currently determined, the current value of the constant current circuit 600 is redetermined, and the duty ratio of the PWM signal is updated according to the current value of the current value, so that the LED in the turned-on state can achieve optimal light emitting power and light emitting effect.

The lighting circuit can normally work within the range of 380 VAC+/-20% of three phases, and has strong anti-fluctuation capability. The number and the current of the LEDs can be dynamically adjusted and started according to the voltage in the working process of the lighting circuit, the lighting power is high, the stroboscopic phenomenon is avoided, and the lighting effect is excellent. In addition, the lighting circuit can be welded on the light source board together with the lamp beads, components such as a transformer, an inductor, an electrolytic capacitor and the like are not needed, and the driving circuit is greatly simplified in hardware.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. 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 application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A lighting circuit, comprising:

the switch circuit is connected with the LED lamp assembly;

2. A lighting circuit as recited in claim 1, further comprising a constant current circuit, said constant current circuit connecting an output of said LED lamp assembly and said control circuit;

3. A lighting circuit as recited in claim 2, wherein one of said LED light assemblies is a normally on light and the remaining LED lights are all circulating lights; the opening number is n, and n is a natural number;

4. A lighting circuit as recited in claim 3, wherein said switching circuit comprises a plurality of switching units, said switching units being equal in number to said circulating lamps, each of said switching units being connected to said control circuit, each of said switching units being correspondingly connected to one of said circulating lamps for respectively controlling an on state of said connected circulating lamps.

5. The lighting circuit of claim 4, wherein the switching unit comprises an optocoupler, a first transistor, and a first resistor;

6. A lighting circuit as recited in claim 2, wherein,

the control circuit is also used for controlling the constant current circuit to be disconnected when the sampling voltage parameter is lower than a preset starting voltage threshold value.

7. A lighting circuit as recited in claim 1, wherein,

the control circuit is also used for determining a real-time voltage value and a maximum voltage value in a preset time period according to the sampling voltage parameter output by the sampling circuit;

8. The lighting circuit of claim 1, wherein the constant current circuit comprises a second transistor, a second resistor, a third resistor, and a capacitor; the collector electrode of the second triode is connected with the output end of the LED lamp assembly, the emitter electrode of the second triode is grounded through the second resistor, the base electrode of the second triode is grounded through the capacitor, and the base electrode of the second triode is also connected with the control circuit through the third resistor.

9. A lighting circuit as recited in claim 1, further comprising a communication circuit connected to said control circuit.

10. A lighting circuit as recited in any one of claims 1-9, wherein the lighting circuit further comprises a rectifier circuit for rectifying mains and outputting a supply voltage.