CN209930579U - Automatic dimming circuit - Google Patents
Automatic dimming circuit Download PDFInfo
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- CN209930579U CN209930579U CN201920620789.9U CN201920620789U CN209930579U CN 209930579 U CN209930579 U CN 209930579U CN 201920620789 U CN201920620789 U CN 201920620789U CN 209930579 U CN209930579 U CN 209930579U
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Abstract
The utility model discloses an automatic dimming circuit, which is characterized by comprising a voltage regulating circuit, an adjustable constant current source circuit and an LED light circuit; the output end of the voltage regulating circuit is connected with the input end of the adjustable constant current source circuit, the output end of the adjustable constant current source circuit is connected with the input end of the LED light circuit, and the output end of the LED light circuit is connected with the LED lamp. The utility model discloses a to the regulation of adjustable constant current source circuit medium current to the automatic adjustting of lighteness of LED lamp has been realized.
Description
Technical Field
The utility model relates to a visual system field, in particular to automatic dimming circuit.
Background
The existing light source is formed by connecting an LED lamp bead and a current-limiting resistor in series, the light intensity and the brightness are controlled by the current-limiting resistor, and the current-limiting resistor is a fixed value, so that the light intensity and the brightness are fixed values. Therefore, the dynamic range of the image is small when the image is imaged, the brightness of the image cannot be automatically adjusted along with the change of the light source, and the quality of the image is influenced.
Disclosure of Invention
In order to overcome the defects of the prior art, the utility model provides an automatic dimming circuit for realize LED's automatic dimming function.
In order to achieve the above object, the present invention provides the following technical solutions:
the automatic dimming circuit comprises a voltage regulating circuit, an adjustable constant current source circuit and an LED light circuit; the output end of the voltage regulating circuit is connected with the input end of the adjustable constant current source circuit, the output end of the adjustable constant current source circuit is connected with the input end of the LED light circuit, and the output end of the LED light circuit is connected with the LED lamp.
Preferably, the voltage regulating circuit comprises a D/A conversion module U1, VDD is connected with one end of LB1, the other end of LB1 is respectively connected with a Vcc port of U1 and one end of a second capacitor, and the other end of the second capacitor is grounded; the CS-LD port, the SCK port and the SPI port of the U1 are respectively connected with the DAC-CS-LD port, the DAC-SCK port and the DAC-SPI port in the MCU; the GND port of U1 is grounded; the VOUT port of U1 is connected to one end of a third resistor, the other end of which is connected to one end of a first capacitor, respectively, and the other end of the first capacitor is grounded.
Preferably, the adjustable constant current source circuit comprises an adjustable constant current source U2, the SET port of U2 is connected with the other end of the third resistor, the OUT0 port, the OUT1 port and the OUT2 port of U2 are all connected with one end of a fourth resistor, and the other end of the fourth resistor is grounded; the IN0 port and the IN1 port of the U2 are respectively connected with one end of the first resistor and one end of the second resistor, the other end of the second resistor is connected with one end of the third capacitor, and the other end of the third capacitor is grounded.
Preferably, the LED lighting circuit comprises a light emitting diode and a power supply voltage Vcc; the Vcc connection is connected to the anode of the light emitting diode, and the cathode of the light emitting diode is connected to the other end of the first resistor R1.
Preferably, the number of the light emitting diodes is n, n is a positive integer, and the n light emitting diodes are connected in parallel.
To sum up, owing to adopted above-mentioned technical scheme, compare with prior art, the utility model discloses following beneficial effect has at least:
the circuit of the utility model adopts a single transmission line to adjust all the LED lamps, thereby saving space and cost; the LED lamp can realize automatic brightness adjustment through current change, and the image quality is improved.
Description of the drawings:
fig. 1 is a schematic diagram of an automatic dimming circuit according to an exemplary embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to examples and specific embodiments. However, it should not be understood that the scope of the above-mentioned subject matter is limited to the following embodiments, and all the technologies realized based on the present invention are within the scope of the present invention.
In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships illustrated in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.
In the description of the present invention, unless otherwise specified and limited, it is to be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, mechanically or electrically connected, or may be connected between two elements through an intermediate medium, or may be directly connected or indirectly connected, and specific meanings of the terms may be understood by those skilled in the art according to specific situations.
Fig. 1 is a schematic diagram of an automatic dimming circuit according to an embodiment of the present invention. As shown in fig. 1, the automatic dimming circuit includes a voltage regulation circuit 10, an adjustable constant current source circuit 20 and an LED lamp circuit 30; the output end of the voltage regulating circuit 10 is connected with the input end of the adjustable constant current source circuit 20, the output end of the adjustable constant current source circuit 20 is connected with the input end of the LED light circuit 30, and the output end of the LED light circuit 30 is connected with the LED lamp, so that the automatic regulation of the brightness of the LED lamp is controlled. The voltage regulating circuit comprises an MCU and is used for collecting the brightness of the LED and regulating the voltage. In this embodiment, the MCU may adopt a single chip microcomputer as a microcontroller, and the model may be TMS320VC 5402.
In this embodiment, the voltage regulator circuit 10 includes a D/a conversion module U1, VDD is connected to one end of the LB1, the other end of the LB1 is connected to the Vcc port of the U1 and one end of the second capacitor C2, respectively, and the other end of the second capacitor C2 is grounded; the CS-LD port, the SCK port and the SPI port of the U1 are respectively connected with the DAC-CS-LD port, the DAC-SCK port and the DAC-SPI port in the MCU; the GND port of U1 is grounded; the VOUT port of the U1 is connected to one end of a third resistor R3, the other end of the third resistor R3 is connected to one end of a first capacitor C1, and the other end of the first capacitor C1 is grounded. In this embodiment, U1 may be model LTC2630CSC 6; LB1 is magnetic bead, which is used to suppress the high frequency noise and peak interference of the power supply.
In this embodiment, the adjustable constant current source circuit 20 includes an adjustable constant current source U2, the SET port of U2 is connected to the other end of the third resistor, the OUT0 port, the OUT1 port, and the OUT2 port of U2 are all connected to one end of a fourth resistor R4, and the other end of the fourth resistor R4 is grounded; an IN0 port and an IN1 port of the U2 are connected to one end of a first resistor R1 and one end of a second resistor R2, respectively, the other end of the second resistor R2 is connected to one end of a third capacitor C3, and the other end of the third capacitor C3 is grounded.
In this embodiment, the LED lighting circuit 30 includes a light emitting diode and a power supply voltage Vcc; vcc is connected to the anode of the led, and the cathode of the led is connected to the other end of the first resistor R1. In the embodiment, the number of the light emitting diodes and the number of the LED lamps can be adjusted according to the working requirement, and the number is preferably 4 in the embodiment; for example, a first LED D1 may be connected to a first LED lamp, a second LED D2 may be connected to a second LED lamp, a third LED D3 may be connected to a third LED lamp, and a fourth LED D4 may be connected to a fourth LED lamp, each in parallel.
The working principle of the automatic dimming circuit provided by the embodiment is as follows:
MCU real-time sampling through existing image digital sensorCollecting image data (e.g. current) to calculate LED brightness PledAnd comparing the brightness with a preset brightness threshold range P in the MCU, if P is not the sameledNot within a preset brightness threshold (i.e. P)led＜PminOr Pled＞Pmax) The MCU can control the output voltage of the U1 through the SPI port, thereby controlling the current I in the adjustable constant current source circuit 2020And the adjustable constant current source circuit 20 and the LED automatic dimming circuit 30 are connected in series, the current I20Will cause a current I in the LED automatic dimming circuit 3030The synchronous change of the LED brightness adjusting device plays a role in adjusting the brightness of the LED. In this example, I20＝V10/R4，V10Is the output voltage of U1.
For example, when Pled＜PminThe MCU controls the output voltage V of U110Step-up, voltage V10Is transmitted to the adjustable constant current source U2 to cause the current I in the adjustable constant current source circuit 2020Is (I)20＝V10/R4), then the current I20Will induce a current I through the LED lamp after being transmitted to the LED lamp circuit 3030And is increased, thereby controlling the brightness of the LED to be increased.
It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.
Claims (5)
1. The automatic dimming circuit is characterized by comprising a voltage regulating circuit, an adjustable constant current source circuit and an LED light circuit; the output end of the voltage regulating circuit is connected with the input end of the adjustable constant current source circuit, the output end of the adjustable constant current source circuit is connected with the input end of the LED light circuit, and the output end of the LED light circuit is connected with the LED lamp; the voltage regulating circuit comprises an MCU (microprogrammed control unit) which is used for collecting the brightness of the LED and regulating the voltage.
2. The automatic dimming circuit of claim 1, wherein the voltage regulation circuit comprises a D/a conversion module U1, VDD is connected to one terminal of LB1, the other terminal of LB1 is connected to Vcc port of U1 and one terminal of a second capacitor, respectively, the other terminal of the second capacitor is grounded; the CS-LD port, the SCK port and the SPI port of the U1 are respectively connected with the DAC-CS-LD port, the DAC-SCK port and the DAC-SPI port in the MCU; the GND port of U1 is grounded; the VOUT port of U1 is connected to one end of a third resistor, the other end of which is connected to one end of a first capacitor, respectively, and the other end of the first capacitor is grounded.
3. The automatic dimming circuit of claim 1, wherein the adjustable constant current source circuit comprises an adjustable constant current source U2, the SET port of U2 is connected to the other end of the third resistor, the OUT0 port, the OUT1 port, and the OUT2 port of U2 are connected to one end of a fourth resistor, and the other end of the fourth resistor is grounded; the IN0 port and the IN1 port of the U2 are respectively connected with one end of the first resistor and one end of the second resistor, the other end of the second resistor is connected with one end of the third capacitor, and the other end of the third capacitor is grounded.
4. The automatic dimming circuit of claim 1, wherein the LED light circuit comprises a light emitting diode and a supply voltage Vcc; the Vcc connection is connected to the anode of the light emitting diode, and the cathode of the light emitting diode is connected to the other end of the first resistor R1.
5. The automatic dimming circuit of claim 4, wherein the number of light emitting diodes is n, n being a positive integer, the n light emitting diodes being connected in parallel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920620789.9U CN209930579U (en) | 2019-04-30 | 2019-04-30 | Automatic dimming circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920620789.9U CN209930579U (en) | 2019-04-30 | 2019-04-30 | Automatic dimming circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209930579U true CN209930579U (en) | 2020-01-10 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920620789.9U Active CN209930579U (en) | 2019-04-30 | 2019-04-30 | Automatic dimming circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209930579U (en) |
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2019
- 2019-04-30 CN CN201920620789.9U patent/CN209930579U/en active Active
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| Date | Code | Title | Description |
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20211215 Address after: 401120 1-1, 2-1, 3-1, building 5, No. 18, Cuiping Lane 2, Huixing street, Yubei District, Chongqing Patentee after: Chongqing Jinshan Medical Technology Research Institute Co.,Ltd. Address before: 401121 An office building in Jinshan International Industrial City, 18 Neixuan Avenue, Huixing Street, Yubei District, Chongqing Patentee before: CHONGQING JINSHAN MEDICAL APPLIANCE Co.,Ltd. |
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| TR01 | Transfer of patent right |