CN113411932B - Constant brightness LED circuit and electronic equipment - Google Patents
Constant brightness LED circuit and electronic equipment Download PDFInfo
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- CN113411932B CN113411932B CN202110546037.4A CN202110546037A CN113411932B CN 113411932 B CN113411932 B CN 113411932B CN 202110546037 A CN202110546037 A CN 202110546037A CN 113411932 B CN113411932 B CN 113411932B
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/10—Controlling the intensity of the light
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
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- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The invention relates to a constant brightness LED circuit and an electronic device, comprising: the LED lamp and the power supply battery; the LED driving unit is connected with the LED lamp and is used for receiving a driving signal to drive the LED lamp to work; a storage unit for pre-storing a relationship list, wherein the relationship list defines a corresponding relationship between a PWM duty cycle of the driving signal and an output voltage of the power supply battery; the voltage monitoring unit is connected with the power supply battery and used for monitoring the real-time voltage of the power supply battery in the working process of the LED lamp; the control unit is connected with the storage unit and the voltage monitoring unit and is used for acquiring a target PWM duty ratio according to the real-time voltage and the relation list; the control unit is also connected with the LED driving unit and used for generating a target driving signal according to the target PWM duty ratio so as to drive the LED driving unit to work. By implementing the invention, the brightness of the LED can be kept constant when the power supply voltage of the battery is changed, and the user experience is improved.
Description
Technical Field
The invention relates to the technical field of LED lamps, in particular to a constant-brightness LED circuit and electronic equipment.
Background
In electronic products, LED lamps are increasingly used for indication, and in some battery-powered products, when the power supply voltage of a battery changes when the LED lamps are used for indication, the brightness of the LED indicator lamps also changes due to the change of the voltage. For example, when the battery supply voltage decreases, it also affects the supply voltage of the LED, resulting in a decrease in the brightness of the LED, affecting the user experience.
Disclosure of Invention
The invention aims to solve the technical problems of the prior art and provides a constant brightness LED circuit and electronic equipment.
The technical scheme adopted for solving the technical problems is as follows: a constant brightness LED circuit is constructed comprising: the LED lamp and the power supply battery; and
the LED driving unit is connected with the LED lamp and is used for receiving a driving signal to drive the LED lamp to work;
a storage unit for pre-storing a relationship list defining a correspondence between a PWM duty cycle of the driving signal and an output voltage of the power supply battery;
the voltage monitoring unit is connected with the power supply battery and used for monitoring the real-time voltage of the power supply battery in the working process of the LED lamp;
the control unit is connected with the storage unit and the voltage monitoring unit and is used for acquiring a target PWM duty ratio according to the real-time voltage and the relation list;
the control unit is further connected with the LED driving unit and used for generating a target driving signal according to the target PWM duty ratio so as to drive the LED driving unit to work.
Preferably, the LED lamp includes a plurality of LED light emitting units, and the LED driving unit includes a plurality of sub driving units correspondingly connected to the plurality of LED light emitting units, respectively;
the relation list defines the sub-corresponding relation between the PWM duty ratio of the driving signals respectively corresponding to the plurality of sub-driving units and the output voltage of the power supply battery;
the control unit is respectively connected with the plurality of sub-driving units and is used for acquiring target PWM duty ratios respectively corresponding to the sub-driving units according to the real-time voltage and the sub-corresponding relation so as to generate a plurality of target driving signals respectively corresponding to the plurality of sub-driving units.
Preferably, the control unit includes a plurality of PWM signal output terminals, and the control unit is connected to the plurality of sub-driving units through the plurality of PWM signal output terminals, respectively, to output target driving signals corresponding to the sub-driving units, respectively.
Preferably, the circuit further comprises switch units respectively connected with the circuit for receiving a switch signal to drive the corresponding sub-drive units to be turned on or off;
the control unit is connected with the switch unit and is used for generating the switch signal according to the target drive signal of the sub-drive unit.
Preferably, the generating the switching signal according to the target driving signal of the sub driving unit includes: when the target drive signal is at a high level, a high-level switching signal is generated, and when the target drive signal is at a low level, a low-level switching signal is generated.
Preferably, the control unit includes at least one PWM signal output terminal, and the control unit is connected to the plurality of sub-driving units through any one PWM signal output terminal to output the target driving signal.
Preferably, the switching unit includes a first switching tube, a first end of the first switching tube is connected with the control unit, a second end of the first switching tube is connected with a first end of a corresponding sub-driving unit through the LED lighting unit, and a third end of the first switching tube is connected with a supply voltage.
Preferably, the constant brightness LED circuit of the present invention further comprises a first judgment unit;
the first judging unit is connected with the voltage monitoring unit and is used for judging whether the real-time voltage is lower than a first preset value or not, and driving the control unit to acquire the target PWM duty ratio according to the real-time voltage and the relation list when the real-time voltage is lower than the first preset value.
Preferably, the constant brightness LED circuit of the present invention further comprises a second judgment unit;
the second judging unit is connected with the voltage monitoring unit and is used for judging whether the real-time voltage is lower than a second preset value or not, and driving the control unit to turn off the driving signal output when the real-time voltage is lower than the second preset value.
The invention also constructs an electronic device comprising a constant brightness LED circuit as described in any one of the above.
The constant brightness LED circuit and the electronic equipment have the following beneficial effects: when the battery power supply voltage changes, the brightness of the LED is maintained to be constant, and the user experience is improved.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a logic block diagram of one embodiment of a constant brightness LED circuit of the present invention;
FIG. 2 is a logic block diagram of another embodiment of a constant brightness LED circuit of the present invention;
FIG. 3 is a schematic diagram of a partial circuit of one embodiment of a constant brightness LED circuit according to the present invention;
FIG. 4 is a schematic diagram of the driving signals of FIG. 3;
FIG. 5 is a logic block diagram of another embodiment of a constant brightness LED circuit of the present invention;
FIG. 6 is a schematic diagram of a partial circuit of one embodiment of a constant brightness LED circuit according to the present invention;
fig. 7 is a schematic diagram of the driving signals in fig. 6.
Detailed Description
For a clearer understanding of technical features, objects and effects of the present invention, a detailed description of embodiments of the present invention will be made with reference to the accompanying drawings.
As shown in fig. 1, in a first embodiment of a constant brightness LED circuit of the present invention, it includes: an LED lamp 150 and a power supply battery 110; and an LED driving unit 140 connected to the LED lamp 150 for receiving a driving signal to drive the LED lamp 150 to operate; a storage unit 160 for pre-storing a relationship list defining a correspondence relationship between the PWM duty ratio of the driving signal and the output voltage of the power supply battery 110; the voltage monitoring unit 120 is connected with the power supply battery 110 and is used for monitoring the real-time voltage of the power supply battery 110 in the working process of the LED lamp 150; a control unit 130 connected to the storage unit 160 and the voltage monitoring unit 120, for obtaining a target PWM duty cycle according to the real-time voltage and the relationship list; the control unit 130 is further connected to the LED driving unit 140, and is configured to generate a target driving signal according to the target PWM duty cycle to drive the LED driving unit 140 to operate. Specifically, the LED lamp 150 is powered by the power supply battery 110, that is, the output voltage of the power supply battery 110 drives the LED to emit light or to turn off by the LED driving unit 140. The LED driving unit 140 outputs a target driving signal through the control unit 130 to drive the LED driving unit 140 to work so as to generate a corresponding driving voltage or current to drive the LED lamp 150 to emit light. The voltage detection unit is connected to the power supply battery 110, detects a real-time voltage of the power supply battery 110, and the control unit 130 obtains a PWM duty ratio corresponding to the real-time voltage from a relationship list pre-stored in the storage unit 160 according to the detected real-time voltage and generates a target driving signal according to the PWM duty ratio. By adjusting the PWM duty ratio, the average current input to the LED lamp 150 is kept constant, so that the brightness of the LED lamp 150 can be kept constant.
As shown in fig. 2 and 5, in an embodiment, the LED lamp 150 includes a plurality of LED light emitting units 151, and the LED driving unit 140 includes a plurality of sub driving units 141 respectively and correspondingly connected to the plurality of LED light emitting units 151; the relationship list defines sub-correspondence relationships between PWM duty ratios of driving signals respectively corresponding to the plurality of sub-driving units 141 and output voltages of the power supply battery 110; the control unit 130 is respectively connected to the plurality of sub-driving units 141, and is configured to obtain target PWM duty ratios corresponding to the sub-driving units 141 according to the real-time voltage and the sub-correspondence relationship, so as to generate a plurality of target driving signals corresponding to the plurality of sub-driving units 141. Specifically, a plurality of LED light emitting units 151 may be disposed in the LED lamp 150, where each LED light emitting unit 151 is correspondingly connected to one sub-driving unit 141, where the plurality of driving units form the LED driving unit 140, and the relationship list may include a plurality of sub-corresponding relationships corresponding to the sub-driving units 141, that is, each LED light emitting unit 151 may obtain a corresponding PWM duty ratio through the corresponding sub-driving unit 141 according to the corresponding sub-corresponding relationship, so as to implement individual current control for each LED light emitting unit 151.
As shown in fig. 2, the control unit 130 includes a plurality of PWM signal output terminals, and the control unit 130 is respectively connected to the plurality of sub-driving units 141 through the plurality of PWM signal output terminals to respectively output target driving signals corresponding to the sub-driving units 141. That is, the sub driving units 141 corresponding to the LED light emitting units 151 may be individually driven by different PWM signals, respectively. In the specific circuit shown in fig. 3, the LED light emitting unit 151 includes an LED1 and an LED2, where the driving unit corresponding to the LED1 includes a MOS transistor Q1, and the driving unit corresponding to the LED2 includes a MOS transistor Q2, which respectively receive driving signals input from different control terminals to drive the operation. In fig. 4, the corresponding time periods of the PWM1 and PWM2 driving signals output are the time period of the PWM1, where T1 corresponds to the output of the PWM1, the corresponding time period of the LED1, T2 corresponds to the output of the PWM2 signal, the corresponding time period of the LED2, and T is the duty cycle of the LED1 and the LED2, that is, the period of the control unit 130 generating the driving signals, which can be understood as the sub-period, where the PWM1 and PWM2 signals respectively drive the corresponding LED light emitting units 151 according to different duty ratios. In a specific circuit, r1=100r, r2=200r, vdd1=4v, vdd2=5v, the operating voltage of led1, vf1=2.8v, the operating voltage of led2, vf2=3v, the LED2 on time t1=1 ms (duty ratio=1/5=20%:), the LED2 on time t2=1 ms (duty ratio=1/5=20%), the PWM period t=5 ms: the average current of the LED1 is as follows: (VDD 1-VF 1)/r1 (T1/T) = (4-2.8)/100 (1/5) =0.0024a, led2 average current is: (VDD 2-VF 2)/r2× (T2/T) = (5-3)/200× (1/5) =0.002A, when VDD1 is changed, for example, to 4.5v, in order to maintain the average current of the LED1 unchanged (i.e., the brightness is unchanged), the corresponding T1 time after the change can be calculated as: (4.5-2.8)/100 (t 1/5) =0.0024A can be found that t1=1.42 ms, i.e. the duty cycle of LED1 becomes: 1.42/5=28.4%, i.e. when VDD1 is varied, the effect of maintaining the brightness of LED1 unchanged can be achieved by varying the duty cycle of LED 1. Wherein the duty cycle adjustment of the LEDs 2 may be similarly implemented.
As shown in fig. 5, in an embodiment, the constant brightness LED circuit of the present invention further includes a switching unit 142 respectively connected to receive a switching signal to drive the corresponding sub-driving unit 141 to be turned on or off; the control unit 130 is connected to the switching unit 142, and is configured to generate the switching signal according to the target driving signal of the sub driving unit 141. Specifically, in order to ensure that the driving signal drives the driving circuit corresponding to the corresponding LED light emitting unit 151, it may be provided that the LED light emitting unit 151 that is not driven remains in an off state, that is, the corresponding large sub-driving unit 141 is turned off by the switching unit 142, so as to ensure that only the LED light emitting unit 151 corresponding to the PWM duty ratio is in a high-level lighted state.
Optionally, the generating the switching signal according to the target driving signal of the sub driving unit 141 includes: when the target drive signal is at a high level, a high-level switching signal is generated, and when the target drive signal is at a low level, a low-level switching signal is generated. The process of controlling the driving unit by the switching unit 142 is to generate the target driving signal and generate the switching signal for driving the switching unit 142 to operate, wherein the switching unit 142 corresponds to the sub-driving unit 141, and when the driving signal of the sub-driving unit 141 is at a high level, this represents that the corresponding LED light emitting unit 151 is to be turned on at this time, and the corresponding sub-driving unit 141 is driven to be in an operating state by the switching signal. And when the driving signal of the sub driving unit 141 is at a low level, it represents that the corresponding LED light emitting unit 151 is turned off at this time, and the switching signal drives the corresponding sub driving unit 141 to be in an off state.
Optionally, the control unit 130 includes at least one PWM signal output terminal, and the control unit 130 is connected to the plurality of sub driving units 141 through any one PWM signal output terminal to output the target driving signal. Specifically, when the switching unit 142 is provided, the PWM control signal may be output through one PWM signal output terminal, and the switching unit 142 controls the corresponding sub-driving unit 141 to operate or turn off, which may be used in a time-sharing manner to realize the output level of the same PWM signal output terminal.
Optionally, the switching unit 142 includes a first switching tube, a first end of the first switching tube is connected to the control unit 130, a second end of the first switching tube is connected to a first end of the corresponding sub-driving unit 141 via the LED light emitting unit, and a third end of the first switching tube is connected to a supply voltage. In the specific circuit as shown in fig. 6, the LED light emitting unit 151 includes an LED1 and an LED2, where the driving unit corresponding to the LED1 includes a MOS transistor Q1, the switching unit 142 corresponding to the LED1 includes a MOS transistor Q11, the driving unit corresponding to the LED2 includes a MOS transistor Q2, and the switching unit 142 corresponding to the LED2 includes a MOS transistor Q21. The MOS tube Q1 and the MOS tube Q2 receive driving signals input from the same control end to drive the work. The MOS transistor Q11 and the MOS transistor Q21 are turned on or off by the control unit 130 output. As shown in fig. 7, during control, when PWM is in the t1 operation period, LED 1_off=0, so LED1 is illuminable; LED 2_off=1, so LED2 is not lit. When at time t2, LED2 is controlled to be LED 2_off=0, so LED2 is lighted; LED1 is not lit because LED 1_off=1.
Optionally, the constant brightness LED circuit of the present invention further includes a first judging unit; the first judging unit is connected to the voltage monitoring unit 120, and is configured to judge whether the real-time voltage is lower than a first preset value, and drive the control unit 130 to obtain the target PWM duty ratio according to the real-time voltage and the relationship list when the real-time voltage is lower than the first preset value. In the voltage detection process, whether the PWM duty cycle adjustment is performed or not can be selected according to the actual voltage. When the voltage is relatively high, for example, higher than a first preset value, the PWM duty cycle is not adjusted at this time, the brightness of the PWM duty cycle is also satisfied, and the PWM duty cycle is not adjusted at this time to adjust the brightness of the PWM duty cycle.
Optionally, the constant brightness LED circuit of the present invention further includes a second judging unit; the second judging unit is connected to the voltage monitoring unit 120, and is configured to judge whether the real-time voltage is lower than a second preset value, and drive the control unit 130 to turn off the driving signal output when the real-time voltage is lower than the second preset value. When the battery voltage decreases to a certain extent, that is, the PWM duty ratio is adjusted again at this time, the brightness requirement cannot be met, and at this time, the adjustment is not performed any more, so that the LED lamp 150 can be turned off directly, or the LED lamp 150 can be operated at a preset PWM duty ratio to maintain the lowest brightness.
In addition, an electronic device of the present invention includes the constant brightness LED circuit as described in any one of the above. That is, in a battery-powered device, the constant brightness of the LED operation can be achieved by the arrangement of the above-described circuit.
It is to be understood that the above examples only represent preferred embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the invention; it should be noted that, for a person skilled in the art, the above technical features can be freely combined, and several variations and modifications can be made without departing from the scope of the invention; therefore, all changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Claims (6)
1. A constant brightness LED circuit, comprising: the LED lamp and the power supply battery; and
the LED driving unit is connected with the LED lamp and is used for receiving a driving signal to drive the LED lamp to work;
a storage unit for pre-storing a relationship list defining a correspondence between a PWM duty cycle of the driving signal and an output voltage of the power supply battery;
the voltage monitoring unit is connected with the power supply battery and used for monitoring the real-time voltage of the power supply battery in the working process of the LED lamp;
the control unit is connected with the storage unit and the voltage monitoring unit and is used for acquiring a target PWM duty ratio according to the real-time voltage and the relation list;
a first judging unit connected with the voltage monitoring unit, wherein,
the first judging unit is used for judging whether the real-time voltage is lower than a first preset value or not, and driving the control unit to acquire the target PWM duty ratio according to the real-time voltage and the relation list when the real-time voltage is lower than the first preset value; and does not perform PWM duty cycle adjustment when the real-time voltage is higher than the first preset value;
the LED lamp comprises a plurality of LED light emitting units, and the LED driving unit comprises a plurality of sub driving units which are respectively and correspondingly connected with the plurality of LED light emitting units;
the relation list defines the sub-corresponding relation between the PWM duty ratio of the driving signals respectively corresponding to the plurality of sub-driving units and the output voltage of the power supply battery;
the control unit is respectively connected with the plurality of sub-driving units, and is used for acquiring target PWM duty ratios respectively corresponding to the sub-driving units according to the real-time voltage and the sub-corresponding relation, and sequentially generating a plurality of target driving signals respectively corresponding to the plurality of sub-driving units in a driving period, so that the sub-driving units corresponding to each LED light-emitting unit are respectively and independently driven through different PWM signals;
the control unit comprises a plurality of PWM signal output ends, and the control unit is respectively connected with the plurality of sub-driving units through the plurality of PWM signal output ends so as to respectively output target driving signals corresponding to the sub-driving units.
2. The constant brightness LED circuit of claim 1, further comprising switching units respectively connected to receive a switching signal to drive the corresponding sub-driving units on or off;
the control unit is connected with the switch unit and is used for generating the switch signal according to the target drive signal of the sub-drive unit.
3. The constant brightness LED circuit of claim 2, wherein the generating the switching signal from the target driving signal of the sub-driving unit comprises: when the target drive signal is at a high level, a high-level switching signal is generated, and when the target drive signal is at a low level, a low-level switching signal is generated.
4. The constant brightness LED circuit of claim 2, wherein the switching unit comprises a first switching tube, a first end of the first switching tube is connected to the control unit, a second end of the first switching tube is connected to a first end of a corresponding sub-driving unit via the LED lighting unit, and a third end of the first switching tube is connected to a supply voltage.
5. The constant brightness LED circuit of claim 1, further comprising a second determination unit;
the second judging unit is connected with the voltage monitoring unit and is used for judging whether the real-time voltage is lower than a second preset value or not, and driving the control unit to turn off the driving signal output when the real-time voltage is lower than the second preset value.
6. An electronic device comprising a constant brightness LED circuit as claimed in any one of claims 1 to 5.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110546037.4A CN113411932B (en) | 2021-05-19 | 2021-05-19 | Constant brightness LED circuit and electronic equipment |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110546037.4A CN113411932B (en) | 2021-05-19 | 2021-05-19 | Constant brightness LED circuit and electronic equipment |
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| CN113411932A CN113411932A (en) | 2021-09-17 |
| CN113411932B true CN113411932B (en) | 2023-11-28 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1961266A (en) * | 2004-03-26 | 2007-05-09 | 德克萨斯仪器股份有限公司 | System and method for driving a plurality of loads |
| CN101925214A (en) * | 2009-06-17 | 2010-12-22 | 海洋王照明科技股份有限公司 | LED constant current circuit and method |
| CN103220865A (en) * | 2013-04-27 | 2013-07-24 | 青岛歌尔声学科技有限公司 | Button-cell-powered LED (Light Emitting Diode) drive circuit and Bluetooth device |
| CN110519880A (en) * | 2019-07-15 | 2019-11-29 | 深圳和而泰小家电智能科技有限公司 | LED light source brightness control method, device and circuit, LED lamp and storage medium |
| CN112512172A (en) * | 2020-12-25 | 2021-03-16 | 深圳市瑞必达科技有限公司 | Low-cost self-adaptive input voltage ultralow standby dimming circuit |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7499007B2 (en) * | 2005-04-01 | 2009-03-03 | Analog Devices, Inc. | Maximizing efficiency of battery-powered LED drivers |
| US10999909B2 (en) * | 2016-10-13 | 2021-05-04 | Elmos Semiconductor Se | LED lighting device, particularly for vehicles |
-
2021
- 2021-05-19 CN CN202110546037.4A patent/CN113411932B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1961266A (en) * | 2004-03-26 | 2007-05-09 | 德克萨斯仪器股份有限公司 | System and method for driving a plurality of loads |
| CN101925214A (en) * | 2009-06-17 | 2010-12-22 | 海洋王照明科技股份有限公司 | LED constant current circuit and method |
| CN103220865A (en) * | 2013-04-27 | 2013-07-24 | 青岛歌尔声学科技有限公司 | Button-cell-powered LED (Light Emitting Diode) drive circuit and Bluetooth device |
| CN110519880A (en) * | 2019-07-15 | 2019-11-29 | 深圳和而泰小家电智能科技有限公司 | LED light source brightness control method, device and circuit, LED lamp and storage medium |
| CN112512172A (en) * | 2020-12-25 | 2021-03-16 | 深圳市瑞必达科技有限公司 | Low-cost self-adaptive input voltage ultralow standby dimming circuit |
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