CN114679811A - Light source driving circuit, method, luminaire and computer readable storage medium - Google Patents

Abstract

The circuit comprises a control chip, a first constant current driving circuit, a second constant current driving circuit and a current detection resistor, wherein the first constant current driving circuit and the second constant current driving circuit are connected with a first control end and a second control end of the control chip; the first control end and the second control end respectively output a first PWM control signal and a second PWM control signal according to a set period, in the set period, the time when the first PWM control signal is at a high level and the time when the second PWM control signal is at the high level are staggered, and the first PWM control signal and the second PWM control signal enable the first constant current driving circuit and the second constant current driving circuit to supply power to the load light source in a time-sharing mode so as to adjust the color temperature and the brightness of the load light source.

Description

Light source driving circuit, method, luminaire, and computer-readable storage medium

Technical Field

The present application relates to the field of electronic circuit technologies, and in particular, to a light source driving circuit, a light source driving method, a lamp, and a computer-readable storage medium.

Background

With the development of social progress and demand, the requirements of people on lamps in life are not limited to dimming of the lamps, and lighting products increasingly use CCT (rectified color temperature) double-color temperature design to realize dimming and color modulation of the lamps and meet the sensory requirements of different people. The light-adjusting precision and the light-adjusting depth are higher and higher, and the requirement is one thousandth or even one ten thousandth, and in order to obtain high precision and high reliability, a light source driving circuit is designed by combining a constant current chip and a detection resistor.

However, the known lamp needs to adopt a dual-output design with dual constant current chips for simultaneous dimming and color mixing, and each path adopts dual-line output, so that the lamp is incompatible with most of the commercial dual-color lamps or lamp panels, and the cost is increased.

Disclosure of Invention

In order to solve the existing technical problem, the application provides a light source driving circuit, a light source driving method and a light source driving lamp which are low in cost and easy to realize.

In order to achieve the above purpose, the technical solution of the embodiment of the present application is implemented as follows:

In a first aspect, an embodiment of the present application provides a light source driving circuit, which includes a control chip, a first constant current driving circuit connected to a first control end of the control chip, a second constant current driving circuit connected to a second control end of the control chip, and a current detection resistor connected to the first constant current driving circuit and the second constant current driving circuit, where the first constant current driving circuit includes a first constant current chip, the second constant current driving circuit includes a second constant current chip, a switching tube of the first constant current chip and a switching tube of the second constant current chip are connected to one end of a load light source, respectively, and the other end of the load light source is connected to the current detection resistor;

the first control end and the second control end respectively output a first PWM control signal and a second PWM control signal according to a set period, in the set period, the time when the first PWM control signal is at a high level and the time when the second PWM control signal is at a high level are staggered, and the first PWM control signal and the second PWM control signal enable the first constant current drive circuit and the second constant current drive circuit to supply power to the load light source in a time-sharing manner so as to adjust the color temperature and the brightness of the load light source.

In a second aspect, an embodiment of the present application provides a light source driving method applied to a light source driving circuit, including:

outputting a high-level control signal to a first constant current chip correspondingly connected in a first period of a set period, and outputting a low-level control signal or stopping outputting the control signal to a second constant current chip correspondingly connected in the first period of the set period;

in the first period, the first constant current chip is conducted with a load light source through a current detection resistor to form a working state, and the first constant current chip drives the load light source to emit light;

outputting a high-level control signal to a second constant current chip correspondingly connected in a second time period of the set period, and outputting a low-level control signal or stopping outputting the control signal to a first constant current chip correspondingly connected in the second time period of the set period; the first time period and the second time period are staggered with each other;

and in the second time period, the second constant current chip is conducted with the load light source through the current detection resistor to enter a working state, and the second constant current chip drives the load light source to emit light.

In a third aspect, an embodiment of the present application provides a lamp, including the light source driving circuit described in any embodiment of the present application and a load light source connected to the light source driving circuit, where one end of the load light source is connected to the switching tube of the first constant current chip and the switching tube of the second constant current chip, and the other end of the load light source is connected to the current detection resistor.

In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of the light source driving method according to the first aspect.

In the light source driving circuit, the light source driving method, the light fixture and the computer-readable storage medium according to the embodiments of the present application, the switching tube of the first constant current chip and the switching tube of the second constant current chip are respectively connected to one end of the load light source, the other end of the load light source is connected to the current detection resistor, the first control end and the second control end of the control chip respectively output the first PWM control signal and the second PWM control signal according to the set period, the time when the first PWM control signal is at the high level and the time when the second PWM control signal is at the high level are staggered with each other in the set period, the first PWM control signal and the second PWM control signal enable the first constant current driving circuit and the second constant current driving circuit to supply power to the load light source in a time-sharing manner to adjust the color temperature and the brightness of the load light source, and enable the constant current chip in a time-sharing manner by using the two PWM control signals, the two paths of constant current chips multiplex the same path of current detection resistor in a time-sharing manner to supply power to the load light source, so that the adjustment of the color temperature and the brightness of the load light source is realized, the wiring mode of each path of constant current chip and the load light source is not required to be changed, the compatibility is better, the circuit structure is simpler, and the realization is easy.

Drawings

FIG. 1 is a schematic diagram of a light source driving circuit according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a light source driving circuit according to another embodiment of the present application;

fig. 3 is a schematic diagram of a first constant current driving circuit and a second constant current driving circuit in an embodiment of the present application;

FIG. 4 is a diagram illustrating a control chip according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a voltage step-down circuit according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a first PWM control signal and a second PWM control signal according to an embodiment of the present application;

FIG. 7 is a schematic diagram of a first PWM control signal and a second PWM control signal according to another embodiment of the present application;

FIG. 8 is a schematic diagram of a first PWM control signal and a second PWM control signal according to another embodiment of the present application;

FIG. 9 is a flowchart illustrating a method for driving a light source according to an embodiment of the present disclosure;

FIG. 10 is a flow chart of a method for driving a light source according to another embodiment of the present application;

fig. 11 is a computer-readable storage medium according to an embodiment of the present application.

Detailed Description

The technical solution of the present application is further described in detail with reference to the drawings and specific embodiments of the specification.

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 present application is for the purpose of describing particular embodiments only and is not intended to be limiting of implementations of the present application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, merely for convenience of description and simplicity of description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present application. In the description of the present application, the meaning of "a plurality" is two or more unless otherwise specified.

In the description of the present application, it should be noted that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, a fixed connection, a detachable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in this application will be understood to be a specific case for those of ordinary skill in the art.

The inventor of the application researches the design of a double-chip double-output control circuit of a load light source, and summarizes the following schemes:

firstly, a load light source is connected between a switch tube and a detection resistor of a constant current chip, when double-chip double-path output control is adopted, the load light source is connected between the switch tube and a high-end detection resistor of the constant current chip and between the switch tube and a low-end detection resistor of the constant current chip, so that the two paths of constant current chips can only need four output lines to ensure that the performance is not influenced, however, the four-line design is not compatible with most lamps or lamp panels with double adjustment of color temperature and brightness in the market, and one output line is added, so that the cost is additionally increased;

secondly, in order to solve the problem of incompatibility caused by the design of four output lines, a load light source is moved between a detection resistor and an electrode ground in a loop to realize the common cathode three-line design; or the load light source is moved between the power supply and the detection resistor in the loop to realize the common-anode three-wire design, however, the load light source is connected to the front end of the constant current chip in series by the method, so that the voltages of the switch tube end and the detection resistor end are too low when the switch tube of the constant current chip is opened, the constant current chip cannot work normally or the performance index parameters of the whole circuit are seriously reduced.

The above scheme has the following defects: A. the dimming depth of the conventional constant current chip capable of directly sharing the positive or the negative can only reach 1 percent, and higher design requirements cannot be met, and four-wire output is required to be directly used when the high-end detection resistor or the low-end detection resistor is used, so that the cost is increased, and the interface is not compatible with the interfaces of the cold and warm color temperature lamps in the market. B. When the function of adjusting the output current by dialing is added to the outside, so that a user can adjust the output current to adapt to different lamps, two paths of current are adjusted by the same dialing, the current is required to be kept consistent, two dialing switches occupy space, the operation of the user is inconvenient, and the product cost is increased. C. The constant current chip such as a high-end detection resistor or a low-end detection resistor is used for carrying out three-wire circuit conversion design, starting or working problems can be caused, the problem that the lowest duty ratio of normal dimming and the lowest duty ratio of incoming call starting are inconsistent is caused in the dimming state, after 10% of power is suddenly cut off in dimming, the constant current chip cannot be started by the controller through memorizing and outputting the duty ratio, the duty ratio is often improved upwards to be lightened, and the product performance is greatly influenced. D. The constant current chip such as a high-end detection resistor or a low-end detection resistor is used for three-wire circuit conversion design, the constant current chip is connected in series behind a load light source and has the lowest working voltage, so that the front-end voltage needs to be designed to be higher, the problem of insufficient allowance can occur, the voltage and the voltage difference of the load light source are increased, and the efficiency is reduced. E. The three-wire circuit conversion design is carried out by using a constant current chip such as a high-end detection resistor or a low-end detection resistor, after the chip loads a light source, the load light source can be lightened by the power consumption of the chip, the PWM cannot be completely extinguished when the PWM is at a low level, a power supply/discharge resistor is required to be added and connected in parallel at two ends of the load light source, the resistor is input at a fixed voltage, the extinguishing points of different voltage loads can be inconsistent when the PWM is at a wide voltage load, the minimum duty ratio cannot be extinguished at the same time, and the minimum extinguishing points cannot be unified.

In order to solve the defects existing in the above schemes, the inventor of the present application has studied out a new light source driving circuit which uses two PWM control signals including a dimming signal and color temperature proportion information to respectively perform time-sharing enabling driving on two constant current chips, so that the two constant current chips share the same detection resistor, time sequence adopts two PWM control signals to perform time-sharing complementation and dislocation enabling so as to ensure that only one constant current chip is used in any time period by the detection resistor, and realizes adjustment of color temperature and brightness of the load light source 10 by using two PWM control signals to perform time-sharing complementation and dislocation enabling, thereby not changing the connection mode of each constant current chip and the load light source 10, and having better compatibility, simpler circuit structure and easy realization. Referring to fig. 1, a light source driving circuit is provided for an embodiment of the present application, and includes a control chip U2, a first constant current driving circuit connected to a first control end of the control chip U2, a second constant current driving circuit connected to a second control end of the control chip U2, and a current detection resistor R24 connected to the first constant current driving circuit and the second constant current driving circuit, where the first constant current driving circuit includes a first constant current chip U3, the second constant current driving circuit includes a second constant current chip U4, a switching tube of the first constant current chip U3 and a switching tube of the second constant current chip U4 are respectively used to be connected to one end of a load light source 10, and the other end of the load light source 10 is connected to the current detection resistor R24; the first control end and the second control end respectively output a first PWM control signal and a second PWM control signal according to a set period, in the set period, the time when the first PWM control signal is at a high level and the time when the second PWM control signal is at a high level are staggered, and the first PWM control signal and the second PWM control signal enable the first constant current drive circuit and the second constant current drive circuit to supply power to the load light source 10 in a time-sharing manner so as to adjust the color temperature and the brightness of the load light source 10.

In the above embodiment, the switch tube of the first constant current chip U3 and the switch tube of the second constant current chip U4 are respectively used to connect with one end of the load light source 10, the other end of the load light source 10 is connected with the current detection resistor R24, the first control end and the second control end respectively output the first PWM control signal and the second PWM control signal according to a set period, in the set period, the time when the first PWM control signal is at a high level and the time when the second PWM control signal is at a high level are staggered, the first PWM control signal and the second PWM control signal enable the first constant current driving circuit and the second constant current driving circuit to supply power to the load light source 10 in a time-sharing manner to adjust the color temperature and the brightness of the load light source 10, the constant current chip is enabled in a time-sharing manner by using the PWM control signal, the two constant current signals multiplex the same current detection resistor R24 in a time-sharing manner to supply power to the load light source 10, the color temperature and the brightness of the load light source 10 can be adjusted, so that the wiring mode of each constant current chip and the load light source 10 does not need to be changed, the compatibility is better, the circuit structure is simpler, and the realization is easy.

Referring to fig. 1, if one end of the load light source 10 is connected to the switching tube of the first constant current chip U3 and the switching tube of the second constant current chip U4, and the other end is connected to the current detection resistor R24, the current detection resistor R24 is connected between the dc power supply 12 and the load light source 10, and the current detection resistor R24 is connected to the common anode of the load light source 10; alternatively, referring to fig. 2, when one end of the load light source 10 is connected to the switching tube of the first constant current chip U3 and the switching tube of the second constant current chip U4, and the other end is connected to the current detection resistor R24, the current detection resistor R24 may be connected between the load light source 10 and an electrode ground, and the current detection resistor R24 is connected to the common cathode of the load light source 10. The control chip U2 outputs a first PWM control signal and a second PWM control signal to the first constant current chip U3 and the second constant current chip U4, respectively.

Referring to fig. 3, the first constant current chip U3 is the same as the second constant current chip U4, and each of the constant current chips includes a current detection terminal CS, a power supply voltage terminal VIN, a built-in switch terminal SW, and a luminance control terminal DIM. The built-in switch tube end SW is a drain of a built-in field effect transistor of the first constant current chip U3 and the second constant current chip U4, and since the first constant current chip U3 and the second constant current chip U4 have built-in field effect transistors, the connection of one end of the load light source 10 with the switch tube of the first constant current chip U3 and the switch tube of the second constant current chip U4 means that one end of the load light source 10 is connected with the built-in switch tube end SW of the first constant current chip U3 and the second constant current chip U4. The luminance control ends DIM of the first constant current chip U3 and the second constant current chip U4 are respectively connected with the first control end and the second control end of the control chip U2. The current detection resistor R24 is connected between the current detection terminal CS of the first constant current chip U3 and the power supply voltage terminal VIN. Two ends of the load light source 10 are respectively connected with the current detection end CS of the first constant current chip U3 and the built-in switch tube end SW, and are respectively connected with the current detection end CS of the second constant current chip U4 and the built-in switch tube end SW. According to the received first PWM control signal and the second PWM control signal sent by the control chip U2, when the first constant current chip U3 works, the second constant current chip U4 stops working, wherein the first constant current chip U3 and the second constant current chip U4 are connected with the control chip U8652; when the second constant current chip U4 works, the first constant current chip U3 stops working, the first constant current chip U3 and the second constant current chip U4 multiplex the current detection resistor R24 in a time-sharing mode, and the switching tube is controlled to be opened or closed by detecting whether the voltage at the two ends of the current detection resistor R24 reaches a rated threshold value.

The resistance value of the current detection resistor R24 can be selected according to the magnitude of the load current required to flow through the load light source 10. When the voltage across the load light source 10 tends to be stable, it can be approximately considered that the inductor current varies linearly, and the magnitude of the load current flowing through the load light source 10 is equal to the current flowing through the current detection resistor R24, so that the magnitude of the resistance of the current detection resistor R24 is linearly proportional to the magnitude of the load current, as shown in the following formula:

iled ═ K/Rcs (K is a constant)

Where Iled denotes a load current flowing through the load light source 10, and Rcs denotes a resistance value of the current detection resistor R24.

Referring to fig. 4, a schematic diagram of a control chip U2 according to an alternative embodiment of the present application is provided, in which the control chip U2 is a programmable logic device and includes a power supply terminal, a first PWM signal output terminal, and a second PWM signal output terminal. The power supply end is used for being connected with an output end of the voltage reduction circuit 15, and the first PWM signal output end and the second PWM signal output end are used as a first control end and a second control end of the control chip U2 and are respectively connected with a switching tube of the first constant current chip U3 and a switching tube of the second constant current chip U4.

Referring to fig. 5, a schematic diagram of a voltage dropping circuit 15 provided for an optional specific example of the present application is shown, where the voltage dropping circuit 15 supplies power to the control chip U2, the first constant current chip U3, and the second constant current chip U4, and includes a first output terminal VIN used for being connected to the power supply voltage terminals VIN of the first constant current chip U3 and the second constant current chip U4, and a second output terminal SW used for being connected to the power supply terminal of the control chip U2. The voltage reducing circuit 15 can be designed by using a known type of chip, such as the voltage reducing chip U1 of MP 9486.

In some embodiments, in the process of multiplexing the current detection resistor R24 in a time-sharing manner by the first constant current chip U3 and the second constant current chip U4 according to the received first PWM control signal and the received second PWM control signal sent by the control chip U2, the operations of the first constant current chip U3 and the second constant current chip U4 are kept consistent with the high level states of the corresponding first PWM control signal and the corresponding second PWM control signal, respectively. Referring to fig. 6, periods of the first PWM control signal and the second PWM control signal are equal, in a set period, a sum of a first duty ratio of the first PWM control signal and a second duty ratio of the second PWM control signal is 1, and a time-sharing duty ratio of the first PWM control signal and the second PWM control signal is a ratio of the first duty ratio to the second duty ratio. In a set period, when the first PWM control signal is at a high level, the second PWM control signal is at a low level correspondingly; when the first PWM control signal is at a low level, the second PWM control signal is at a high level correspondingly, so that at any moment, one and only one constant current chip is combined with the current detection resistor R24 to provide constant current control for the load light source.

Optionally, in a process that the first constant current chip U3 and the second constant current chip U4 enable the first constant current driving circuit and the second constant current driving circuit to supply power to the load light source 10 in a time-sharing manner, a high level of the first PWM control signal and a high level of the second PWM control signal may be staggered in a time-sharing manner. Referring to fig. 7, in the setting period, a sum of a first duty ratio of the first PWM control signal and a second duty ratio of the second PWM control signal is less than 1, and a time-sharing duty ratio of the first PWM control signal and the second PWM control signal is a ratio of the first duty ratio to the second duty ratio. That is, in a set period, when the first PWM control signal is at a high level, the second PWM control signal may be at a low level or at an empty level, and when the first PWM control signal is at a high level, the second PWM control signal may be at a low level or at an empty level, so as to ensure that only one constant current chip is combined with the current detection resistor R24 to provide constant current control to the load light source at any time.

The first PWM control signal and the second PWM control signal simultaneously include a dimming signal and color temperature ratio information, wherein the first constant current chip U3 and the second constant current chip U4 respectively control warm light and cold light, so that the first PWM control signal and the second PWM control signal respectively control warm light control pulse signals and cold light control pulse signals, which correspondingly control the first constant current chip U3 and the second constant current chip U4 to work. The total brightness of the load light source 10 includes information of cold and warm lights, taking the first constant current chip U3 to control warm lights and the second constant current chip U4 to control cold lights as an example, in the lights emitted by the load light source 10, the warm light proportion is the product of the total brightness and the first proportion of the first PWM control signal, and the cold light proportion is the product of the total brightness and the second proportion of the second PWM control signal. In this way, when the load light source 10 is controlled, the total brightness may be distributed according to the color temperature proportion, and the color temperature of the load light source 10 may be adjusted by changing the time-sharing ratio of the first PWM control signal and the second PWM control signal while keeping the size of the set period unchanged; and under the condition of changing the size of the set period and keeping the time-sharing ratio unchanged, the total brightness of the load light source 10 can be adjusted correspondingly.

Taking Dw as the warm color temperature duty ratio, Dc as the cold color temperature duty ratio, when the total brightness is D (0 ≦ D ≦ 1), the cold light duty ratio is D1 ═ D ≦ Dc, the first PWM control signal PWM1 ═ D1 ═ D ≦ Dc, the warm light duty ratio D2 ═ D ≦ Dw, and the second PWM control signal PWM2 ═ D2 ═ D ═ Dw ═ D (1-Dc). When the control signal adjusts the brightness of the load light source 10 through the two constant current chips, the setting period D can be changed, but the time ratios of PWM1 and PWM2 in the setting period are still kept as Dc: the ratio of Dw is distributed to realize that the color temperature is not changed but the brightness is changed; when the control signal adjusts the color temperature of the load light source 10 through the two constant current chips, only the Dc: the ratio of Dw, but keeping the set period constant, realizes the change of color temperature and the constant brightness. It is understood that, when the brightness and the color temperature of the load light source 10 need to be adjusted simultaneously, the brightness and the color temperature of the load light source 10 can be adjusted by changing the setting periods D, and Dc: the magnitude of Dw.

In another alternative embodiment, referring to fig. 8, the first PWM control signal and the second PWM control signal may also correspond to color temperature adjustment and brightness adjustment, respectively. For example, the control chip U2 provides a fixed high frequency PWM signal, and then distributes the high frequency PWM signal to the first control terminal and the second control terminal by using a relatively low frequency to output the first PWM control signal and the second PWM control signal. The first PWM control signal is a high-frequency PWM signal, the second PWM control signal is a low-frequency PWM signal, the first constant current chip U3 controls brightness, and the second constant current chip controls color temperature. When the brightness of the load light source 10 needs to be adjusted, the duty ratio of the high-frequency PWM signal may be directly adjusted, and when the color temperature of the load light source 10 needs to be adjusted, the duty ratio of the low-frequency may be adjusted, so that the output time ratio of the high-frequency PWM signal at the first control end and the second control end is changed according to the color temperature configuration.

In another aspect of the present embodiment, please refer to fig. 9, further providing a light source driving method, which can be applied to the light source driving circuit provided in any embodiment of the present application, the method includes the following steps:

and S11, the control chip outputs a high-level control signal to a first constant current chip correspondingly connected in a first period of a set period, and outputs a low-level control signal or stops outputting the control signal to a second constant current chip correspondingly connected in the first period of the set period.

And S12, in the first period, the first constant current chip is conducted with the load light source through the current detection resistor to enter a working state, and the first constant current chip drives the load light source to emit light.

S13, the control chip outputs a high-level control signal to a second correspondingly connected constant current chip in the second period of the set period, and outputs a low-level control signal or stops outputting the control signal to a first correspondingly connected constant current chip in the second period of the set period; the first and second periods of time are staggered with respect to one another.

And S14, in the second time period, the second constant current chip is conducted with the load light source through the current detection resistor to enter a working state, and the second constant current chip drives the load light source to emit light.

The number of the first time periods in one set period may be one or more, and the number of the second time periods in one set period may also be one or more. The sum of the first proportion of the first period in the first set period and the second proportion of the second period in the set period is equal to 1, or the sum of the first proportion and the second proportion is less than 1. Taking fig. 6 as an example, setting the period as D, the first period as Dw, the second period as Dc, and the sum of the first and second ratios equal to 1; taking fig. 7 as an example, setting the period as D, the first period as Dw, the second period as Dc, and the sum of the first and second ratios less than 1; taking fig. 8 as an example, the period is set such that the first period includes a plurality of separated first time intervals T1 and the second period includes a plurality of separated second time intervals T2.

When the control chip outputs a high-level control signal to the first constant current chip, the control chip outputs a low-level control signal or stops outputting the control signal to a second constant current chip which is correspondingly connected; and when the high-level control signal is output to the second constant current chip, the low-level control signal is output to the first constant current chip which is correspondingly connected or the control signal is stopped being output, so that the first constant current chip and the second constant current chip can multiplex the same path of current detection resistor in a time-sharing manner to supply power to the load light source, the adjustment of the color temperature and the brightness of the load light source is realized, the wiring mode of each path of constant current chip and the load light source does not need to be changed, the compatibility is better, the circuit structure is simpler and the realization is easy.

Optionally, referring to fig. 10, the light source driving method further includes:

s15, when a brightness adjusting instruction for the load light source is received, adjusting the duration of the setting period, and keeping the ratio of the first time period to the second time period in the adjusted setting period unchanged;

and S16, when receiving a color temperature adjusting instruction for the load light source, maintaining the duration of the setting period unchanged, and adjusting the ratio of the first time period to the second time period in the setting period.

The total brightness of the load light source comprises cold and warm light information, the first constant current chip and the second constant current chip respectively control cold light and warm light of the load light source, for example, the first constant current chip controls warm light, the second constant current chip controls cold light, in light emitted by the load light source, the warm light proportion is the product of the total brightness and a first proportion of the first duration in a set period, and the cold light proportion is the product of the total brightness and a second proportion of the second duration in the set period. Thus, when the load light source is controlled, the total brightness can be distributed according to the proportion of warm light and cold light, and under the condition of keeping the size of the set period unchanged, the ratio of the first time period to the second time period is changed, so that the color temperature of the load light source can be correspondingly adjusted; and under the condition of changing the size of the set period and keeping the ratio of the first time period to the second time period unchanged, the total brightness of the load light source can be correspondingly adjusted. It should be noted that the brightness adjustment and the color temperature adjustment of the load light source may be performed simultaneously, or only the brightness adjustment or only the color temperature adjustment may be performed.

In another aspect, the present application further provides a lamp, where the lamp includes the light source driving circuit in the foregoing embodiment and a load light source connected to the light source driving circuit, one end of the load light source is connected to the switching tube of the first constant current chip U3 and the switching tube of the second constant current chip U4, and the other end of the load light source is connected to the current detection resistor R24. The load light source can be an LED lamp or other light sources, and the lamp can be an LED lamp correspondingly.

The light source driving circuit, the light source driving method and the lamp with the light source driving circuit provided by the embodiment of the application have the following characteristics at least:

firstly, a three-wire common-positive or common-negative two-color temperature light source driving circuit is designed by adopting a two-way constant current chip, and the first constant current driving circuit and the second constant current driving circuit are enabled to supply power to the load light source 10 in a time-sharing manner through a first PWM control signal and a second PWM control signal so as to adjust the color temperature and the brightness of the load light source 10, keep good driving performance and the original wiring relation, and have good compatibility, lower cost and easier realization;

the second constant current chip U3, the first constant current chip U4 share the current detection resistor R24 in a time-sharing manner, the load light source 10 and the constant current chip are equivalently connected in parallel at two ends of output voltage, the input voltage can be closer to the load voltage of the load light source, and the effect is higher compared with the known effect that the load light source is connected in a load loop of the constant current chip in series;

The third constant current chip U3 and the second constant current chip U4 share the current detection resistor R24 in a time sharing mode, the original circuit of the constant current chip is kept, the constant current chip is controlled only by using an enabling pin (DIM) of the constant current chip, and the problem that starting points of the constant current chip are inconsistent or the chip cannot be started is solved;

fourthly, one current detection resistor R24 can be saved, space and cost are saved, the circuit is particularly suitable for occasions with dial adjustment detection resistors to control the maximum output current, and two driving currents formed by the first constant current chip U3 and the second constant current chip U4 are consistent, so that the circuit is more convenient for users to operate.

The embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium, and when executed by a processor, the computer program implements the processes of the foregoing rule processing method embodiments, and can achieve the same technical effects, and in order to avoid repetition, the details are not repeated here. The computer-readable storage medium includes, for example, a Read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk.

Fig. 11 is a block diagram of a computer-readable storage medium 800 according to an embodiment of the present disclosure. The computer readable storage medium 800 stores a program code, which can be called by a processor to execute the light source driving method provided by the above method embodiment, such as any one of fig. 9, 10, and 11. The computer-readable storage medium 800 may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read only memory), an EPROM, a hard disk, or a ROM. Alternatively, the computer-readable storage medium 800 includes a non-transitory computer-readable storage medium. The computer readable storage medium 800 has storage space for program code 810 to perform any of the method steps of the method described above. The program code can be read from or written to one or more computer program products. The program code 810 may be compressed, for example, in a suitable form.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and shall cover the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (13)

1. A light source driving circuit is characterized by comprising a control chip, a first constant current driving circuit connected with a first control end of the control chip, a second constant current driving circuit connected with a second control end of the control chip, and a current detection resistor connected with the first constant current driving circuit and the second constant current driving circuit, wherein the first constant current driving circuit comprises a first constant current chip, the second constant current driving circuit comprises a second constant current chip, a switching tube of the first constant current chip and a switching tube of the second constant current chip are respectively connected with one end of a load light source, and the other end of the load light source is connected with the current detection resistor;

the first control end and the second control end respectively output a first PWM control signal and a second PWM control signal according to a set period, in the set period, the time when the first PWM control signal is at a high level and the time when the second PWM control signal is at the high level are staggered, and the first PWM control signal and the second PWM control signal enable the first constant current drive circuit and the second constant current drive circuit to supply power to the load light source in a time-sharing manner so as to adjust the color temperature and the brightness of the load light source.

2. The light source driving circuit according to claim 1, wherein a sum of a first duty ratio of the first PWM control signal and a second duty ratio of the second PWM control signal is 1, and a time-division duty ratio of the first PWM control signal and the second PWM control signal is a ratio of the first duty ratio to the second duty ratio in the set period.

3. The light source driving circuit according to claim 1, wherein a sum of a first duty ratio of the first PWM control signal and a second duty ratio of the second PWM control signal is smaller than 1, and the time-division duty ratio of the first PWM control signal and the second PWM control signal is a ratio of the first duty ratio to the second duty ratio in the set period.

4. The light source driving circuit according to claim 2 or 3, wherein the first constant current chip controls warm light, and the second constant current chip controls cool light.

5. The light source driving circuit according to claim 4, wherein the duty light source emits light in which a warm light proportion is a product of a total luminance and the first proportion and a cool light proportion is a product of the total luminance and the second proportion.

6. The light source driving circuit according to claim 2 or 3, wherein the control chip adjusts the color temperature of the load light source with the total brightness of the load light source unchanged by changing the magnitude of the time-sharing ratio with the set period unchanged.

7. The light source driving circuit according to claim 2 or 3, wherein the control chip adjusts the total brightness of the load light source by changing the magnitude of the setting period and keeping the time-sharing ratio constant, so as to keep the color temperature of the load light source constant.

8. The light source driving circuit according to claim 2 or 3, wherein the first PWM control signal is a high frequency PWM signal, the second PWM control signal is a low frequency PWM signal, the first constant current chip controls luminance, and the second constant current chip controls color temperature.

9. The light source driving circuit according to claim 1, further comprising a voltage-reducing circuit connected to the control chip and a dc power supply connected to the voltage-reducing circuit.

10. A light source driving method is applied to a light source driving circuit, and is characterized by comprising the following steps:

outputting a high-level control signal to a first constant current chip correspondingly connected in a first period of a set period, and outputting a low-level control signal or stopping outputting the control signal to a second constant current chip correspondingly connected in the first period of the set period;

in the first period, the first constant current chip is conducted with a load light source through a current detection resistor to form a working state, and the first constant current chip drives the load light source to emit light;

Outputting a high-level control signal to a second constant current chip correspondingly connected in a second time period of the set period, and outputting a low-level control signal or stopping outputting the control signal to a first constant current chip correspondingly connected in the second time period of the set period; the first time period and the second time period are staggered with each other;

and in the second time period, the second constant current chip is conducted with the load light source through the current detection resistor to enter a working state, and the second constant current chip drives the load light source to emit light.

11. The light source driving method according to claim 10, further comprising:

when a brightness adjusting instruction for the load light source is received, adjusting the duration of the set period, and keeping the ratio of the first time period to the second time period in the adjusted set period unchanged; and/or

And when a color temperature adjusting instruction for the load light source is received, maintaining the duration of the set period unchanged, and adjusting the ratio of the first time period to the second time period in the set period.

12. A lamp, characterized by comprising the light source driving circuit according to any one of claims 1 to 9 and a load light source connected to the light source driving circuit, wherein one end of the load light source is connected to the switching tube of the first constant current chip and the switching tube of the second constant current chip, and the other end is connected to the current detection resistor.

13. A computer-readable storage medium, characterized in that a computer program is stored on the computer-readable storage medium, which computer program, when being executed by a processor, realizes the steps of the light source driving method according to any one of claims 10 to 11.

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