CN213462411U - LED power supply circuit - Google Patents
LED power supply circuit Download PDFInfo
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- CN213462411U CN213462411U CN202021577268.9U CN202021577268U CN213462411U CN 213462411 U CN213462411 U CN 213462411U CN 202021577268 U CN202021577268 U CN 202021577268U CN 213462411 U CN213462411 U CN 213462411U
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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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Abstract
An LED power supply circuit comprises a switch control circuit, a plurality of paths of light-emitting circuits and a current stabilizing circuit, wherein a power supply input end of the switch control circuit is connected with a power supply, the plurality of paths of light-emitting circuits are connected between a power supply output end and a public end of the switch control circuit in parallel, and each path of light-emitting circuit comprises a resistor R1 and a light-emitting diode D1 which are sequentially arranged along the current flow direction; the current stabilizing circuit comprises a triode Q2 and a plurality of triodes Q1 corresponding to the multi-path light-emitting circuits one by one, a triode Q1 is respectively connected between a resistor R1 and a light-emitting diode D1 of each path of light-emitting circuit in series, an emitting electrode of a triode Q1 is connected with a resistor R1, and a collector electrode of a triode Q1 is connected with a light-emitting diode D1. The utility model discloses an accurate stable current control still has the effect of restraining the temperature drift simultaneously to obtain even light luminance.
Description
Technical Field
The utility model relates to an on-vehicle circuit field, concretely relates to LED power supply circuit to as the control circuit of on-vehicle navigation key lamp.
Background
With the rapid development of automobile electronic technology, consumers have higher and higher requirements on the quality of automobiles, the quality of automobiles is essentially formed by combining tens of millions of small details, and the uniformity of interior lighting is one of the tens of millions of details. Automobile manufacturers such as the public use specific devices to strictly test the brightness of the light on the navigation keypad to ensure the uniformity.
As shown in fig. 1, the control circuit is a control circuit for key lights commonly used in car navigation equipment, and in the figure, when the forward conduction voltage drop of an LED (light emitting diode) is VF, the current I flowing through each LED is (8V-VF)/1K. In practice, the range of the VF variation of the LEDs of the same model is 1.8V to 2.4V, and as can be known from the formula of I ═ 8V-VF, the range of the LED current variation is 5.6mA to 6.2mA, that is, the current variation range of each LED is large, the magnitude of the current of each LED is not stably controllable, and thus uniform light brightness cannot be obtained.
The LEDs belong to diodes whose forward voltage drop VF decreases by about 2mV for every 1 ℃ increase when the temperature increases, according to the temperature characteristics of the LEDs. The operating temperature range of the car navigator part is-40 ℃ to 85 ℃, so the VF variation range of the LED is estimated as follows: 0 to 125 × 2 ═ 250mV, in a conventional circuit, the current formula of the LED is I ═ 8V-VF)/1K, and then the variation range of the LED current in the environment of-40 ℃ to 85 ℃ is: 0 to 0.4mA, and the operating current of the vehicle LED is usually set around 5mA, and the 0.4mA has reached a variation of about 10%, which causes a brightness variation of about 10%, and thus also leads to a non-uniform brightness of the lamp.
SUMMERY OF THE UTILITY MODEL
The utility model discloses a solve the above-mentioned problem that prior art exists, provide one kind and can provide accurate and stabilization current's LED supply circuit.
In order to achieve the above object, the present invention provides an LED power supply circuit, which includes a switch control circuit, multiple light emitting circuits and a current stabilizing circuit, wherein a power input end of the switch control circuit is connected to a power supply VCC1, the multiple light emitting circuits are connected in parallel between a power output end and a common end of the switch control circuit, and each light emitting circuit includes a resistor R1 and a light emitting diode D1 sequentially arranged along a current flow direction;
the current stabilizing circuit comprises a triode Q2 and a plurality of triodes Q1 corresponding to the multi-path light-emitting circuits one by one, one triode Q1 is respectively connected in series between a resistor R1 and a light-emitting diode D1 of each path of light-emitting circuit, an emitting electrode of the triode Q1 is connected with the resistor R1, and a collector electrode of the triode Q1 is connected with the light-emitting diode D1;
the base of triode Q2 with all triode Q1's base is connected, triode Q2's projecting pole is connected with power VCC2, be connected with resistance R2 between triode Q2's projecting pole and the base, be connected with resistance R3 between triode Q2's the collecting electrode and the common port, be connected with resistance R4 between triode Q2's base and the common port.
As a further preferable embodiment of the present invention, the resistance of the resistor R2 is the same as the resistance of the resistor R4.
As a further preferred technical scheme of the utility model, resistance R1 and resistance R3 are 1K ohm, resistance R2 and resistance R4 are 4.7K ohm.
As a further preferred technical solution of the present invention, the voltage of the power supply VCC1 is 8V, and the voltage of the power supply VCC2 is 3.3V.
As a further preferable technical solution of the present invention, the switch control circuit includes a triode Q3 and a triode Q4, an emitter of the triode Q3 is connected to the power supply VCC1 as a power input end, a collector of the triode Q3 is connected to each of the resistors R1 in each light emitting circuit as a power output end, a resistor R5 and a resistor R6 are connected in series between a base of the triode Q3 and the collector of the triode Q4, a connection point between the resistor R5 and the resistor R6 is connected to a resistor R7 between the emitter of the triode Q3, the emitter of the triode Q4 is connected to a common terminal, a base of the triode Q4 is connected to the external switch trigger signal KEY _ LED _ PWM through a resistor R8, and a resistor R9 is further connected between the base of the triode Q4 and the common terminal.
As a further preferred technical scheme of the utility model, still be equipped with the low pass filter circuit between switch control circuit's power input end and the power supply VCC 1.
As a further preferable technical solution of the present invention, the low pass filter circuit includes an inductor L1, an capacitor C1 and an capacitor C2, both ends of the inductor L1 are respectively connected to the power supply VCC1 and the emitter of the transistor Q3, the capacitor C1 and the capacitor C2 are connected in parallel between the emitter and the common terminal of the transistor Q3.
The utility model discloses a LED power supply circuit, through adopting above-mentioned technical scheme, can reach following beneficial effect:
1) a current stabilizing circuit is added, so that the current flowing through each path of the light-emitting diode D1 is stable and controllable, and the stability of the light brightness of all the light-emitting diodes D1 is ensured;
2) the circuit also has the function of inhibiting temperature drift, and when the ambient temperature changes (-40 ℃ -85 ℃), the current of each light-emitting diode does not change, so that the brightness of the light can be kept stable.
Drawings
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
FIG. 1 is a schematic circuit diagram of a control circuit for key lights in a conventional car navigation device;
fig. 2 is a circuit diagram of an example provided by the LED power supply circuit of the present invention.
The purpose of the present invention is to provide a novel and improved method and apparatus for operating a computer.
Detailed Description
The present invention will be further described with reference to the accompanying drawings and the detailed description. In the preferred embodiments, the terms "upper", "lower", "left", "right", "middle" and "a" are used for the sake of clarity only, and are not intended to limit the scope of the invention, its relative relationship between the terms and their derivatives, and the scope of the invention should be understood as being limited by the claims.
As shown in fig. 2, the utility model provides a LED power supply circuit, including on-off control circuit, multichannel luminescent circuit and stationary flow circuit, on-off control circuit's power input end is connected with power supply VCC1, and the multichannel luminescent circuit connects in parallel between on-off control circuit's power output end and public end, and on-off control circuit controls the break-make of power supply VCC1 to make all luminescent circuits switch on or break off simultaneously, and each way luminescent circuit all includes resistance R1 and emitting diode D1 that set gradually along the current flow direction, and in this embodiment, there are five luminescent circuits in total;
the current stabilizing circuit comprises a triode Q2 and a plurality of triodes Q1 corresponding to the multi-path light-emitting circuits one by one, one triode Q1 is respectively connected in series between a resistor R1 and a light-emitting diode D1 of each path of light-emitting circuit, an emitting electrode of the triode Q1 is connected with the resistor R1, and a collector electrode of the triode Q1 is connected with the light-emitting diode D1;
the base of triode Q2 with all triode Q1's base is connected, triode Q2's projecting pole is connected with power VCC2, be connected with resistance R2 between triode Q2's projecting pole and the base, be connected with resistance R3 between triode Q2's the collecting electrode and the common port, be connected with resistance R4 between triode Q2's base and the common port.
The base, collector and emitter of transistor Q1 are labeled B, C and E, respectively, and the voltage of B electrode of transistor Q1 is equal to VCC2-VBEThe voltage of E of the transistor Q1 is equal to the voltage of B + VBEThen the current through the led D1 in each light emitting circuit is equal to (VCC1-VCC2)/R1, and R1 is the current adjusting resistor of each light emitting circuit, so that the current through the led D1 is stable and controllable. Wherein, VBEIs the voltage between the collector and emitter of transistor Q1.
In an embodiment, the resistors R1 and R3 are both 1K ohm, the resistors R2 and R4 form a bias voltage to turn on the transistor Q2, the resistances of the resistors R2 and R4 are both 4.7K ohm, the voltage of the power supply VCC1 is 8V, and the voltage of the power supply VCC2 is 3.3V.
As shown in fig. 2, the switch control circuit includes a transistor Q3 and a transistor Q4, an emitter of the transistor Q3 is connected to the power supply VCC1 as a power input end, a collector of the transistor Q3 is connected to each resistor R1 in each light emitting circuit as a power output end, a resistor R5 and a resistor R6 are connected in series between a base of the transistor Q3 and the collector of the transistor Q4, a resistor R7 is connected between a connection point between the resistor R5 and the resistor R6 and an emitter of the transistor Q3, an emitter of the transistor Q4 is connected to a common terminal, a base of the transistor Q4 is connected to an external switch trigger signal KEY _ LED _ PWM through a resistor R8, and a resistor R9 is connected between the base of the transistor Q4 and the common terminal. The switch trigger signal KEY _ LED _ PWM is a control command signal sent by the vehicle-mounted controller, and controls the on/off of the transistor Q4, so that the on/off of the transistor Q3 is controlled, when the transistor Q3 is turned on, the multi-path light emitting circuit is turned on with the power supply VCC1, otherwise, the multi-path light emitting circuit is turned off with the power supply VCC 1.
Further preferably, a low-pass filter circuit is further arranged between a power input end of the switch control circuit and the power supply VCC1, the low-pass filter circuit comprises an inductor L1, a capacitor C1 and a capacitor C2, two ends of the inductor L1 are respectively connected with the power supply VCC1 and an emitter of the triode Q3, and the capacitor C1 and the capacitor C2 are connected in parallel between the emitter and a common end of the triode Q3.
The utility model discloses a LED power supply circuit has following beneficial effect:
the circuit ensures that the current flowing through each LED D1 is stable and controllable, thereby ensuring the stability of the brightness of all the LEDs D1.
The LED power supply circuit also has the function of inhibiting temperature drift, the current I of the light-emitting diode D1 is (8V-3.3V)/1K is 4.7mA, and is independent of the VF of the LED, so that the current of the light-emitting diode D1 is not changed due to the change of the VF of the LED when the temperature is changed, namely, the current of each light-emitting diode D1 is not changed when the environmental temperature is changed (-40 ℃ -85 ℃), and the brightness of the LED can also be kept stable.
The LED power supply circuit is provided with the low-pass filter circuit, and can effectively reduce the interference to the AM frequency band of the vehicle-mounted radio, and the low-pass filter circuit can effectively reduce the emission intensity of the antenna, so that the purpose of reducing the interference is achieved.
Although specific embodiments of the present invention have been described above, it will be appreciated by those skilled in the art that these are merely examples and that many changes and modifications may be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims.
Claims (7)
1. An LED power supply circuit is characterized by comprising a switch control circuit, multiple paths of light-emitting circuits and a current stabilizing circuit, wherein a power supply input end of the switch control circuit is connected with a power supply VCC1, the multiple paths of light-emitting circuits are connected in parallel between a power supply output end and a common end of the switch control circuit, and each path of light-emitting circuit comprises a resistor R1 and a light-emitting diode D1 which are sequentially arranged along a current flow direction;
the current stabilizing circuit comprises a triode Q2 and a plurality of triodes Q1 corresponding to the multi-path light-emitting circuits one by one, one triode Q1 is respectively connected in series between a resistor R1 and a light-emitting diode D1 of each path of light-emitting circuit, an emitting electrode of the triode Q1 is connected with the resistor R1, and a collector electrode of the triode Q1 is connected with the light-emitting diode D1;
the base of triode Q2 with all triode Q1's base is connected, triode Q2's projecting pole is connected with power VCC2, be connected with resistance R2 between triode Q2's projecting pole and the base, be connected with resistance R3 between triode Q2's the collecting electrode and the common port, be connected with resistance R4 between triode Q2's base and the common port.
2. The LED power supply circuit of claim 1, wherein the resistor R2 has the same resistance as the resistor R4.
3. The LED power supply circuit of claim 2, wherein the resistors R1 and R3 are both 1K ohm, and the resistors R2 and R4 are both 4.7K ohm.
4. The LED power supply circuit of claim 3, wherein the voltage of the power supply VCC1 is 8V and the voltage of the power supply VCC2 is 3.3V.
5. The LED power supply circuit as claimed in claim 1, wherein the switch control circuit comprises a transistor Q3 and a transistor Q4, an emitter of the transistor Q3 is connected as a power input terminal to the power supply VCC1, a collector of the transistor Q3 is connected as a power output terminal to each resistor R1 in each lighting circuit, a resistor R5 and a resistor R6 are connected in series between a base of the transistor Q3 and a collector of the transistor Q4, a resistor R7 is connected between a connection point of the resistor R5 and the resistor R6 and an emitter of the transistor Q3, an emitter of the transistor Q4 is connected to a common terminal, a base of the transistor Q4 is connected to an external switch trigger signal KEY _ LED _ PWM through a resistor R8, and a resistor R9 is connected between the base of the transistor Q4 and the common terminal.
6. The LED power supply circuit of claim 5, wherein a low pass filter circuit is further disposed between the power input terminal of the switch control circuit and a power supply VCC 1.
7. The LED power supply circuit as claimed in claim 6, wherein the low pass filter circuit comprises an inductor L1, a capacitor C1 and a capacitor C2, two ends of the inductor L1 are respectively connected to the power supply VCC1 and the emitter of the transistor Q3, and the capacitor C1 and the capacitor C2 are connected in parallel between the emitter and the common terminal of the transistor Q3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021577268.9U CN213462411U (en) | 2020-07-31 | 2020-07-31 | LED power supply circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021577268.9U CN213462411U (en) | 2020-07-31 | 2020-07-31 | LED power supply circuit |
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| Publication Number | Publication Date |
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| CN213462411U true CN213462411U (en) | 2021-06-15 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202021577268.9U Active CN213462411U (en) | 2020-07-31 | 2020-07-31 | LED power supply circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117612479A (en) * | 2023-11-24 | 2024-02-27 | 深圳御光新材料有限公司 | Selection circuit, LED display device and LED lamp strip |
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2020
- 2020-07-31 CN CN202021577268.9U patent/CN213462411U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117612479A (en) * | 2023-11-24 | 2024-02-27 | 深圳御光新材料有限公司 | Selection circuit, LED display device and LED lamp strip |
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| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220905 Address after: Room JT5510, Building 2, No. 3131, Jinshajiang Road, Zhenxin Street, Jiading District, Shanghai, 200000 Patentee after: Shanghai Auto Union World Information Technology Co.,Ltd. Address before: 518000 2nd floor, building B, phase I, gaoxinxin science and Technology Industrial Park, Liuxian 1st Road, 67 District, Xin'an street, Bao'an District, Shenzhen City, Guangdong Province Patentee before: SHENZHEN AUTOLINK INFORMATION TECHNOLOGY Co.,Ltd. |
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| TR01 | Transfer of patent right |