Automatic brightness control circuit

Abstract

The utility model discloses an automatic brightness control circuit which comprises an integrated circuit, a photosensitive diode, a second resistor, a first triode, a second triode, a fourth resistor, a first LED, a second LED, a third triode, a fifth resistor, a first pin, a power supply and a second pin. The other end of the third resistor is electrically connected with a second triode, the collector electrode of the second triode is electrically connected with a fourth resistor, the other end of the fourth resistor is electrically connected with a first LED, and the first LED is connected with a second LED in parallel; according to the utility model, the automatic brightness control circuit is designed, the photosensitive diode is used as an ambient light detection element, and the defect that the backlight of the screen needs to be lightened through manual key pressing operation when a user watches the electronic clock at night is overcome through the induction detection of ambient light and the automatic control of the backlight brightness of the display screen, so that the use experience of the user is improved; meanwhile, the problem of turning on the display screen backlight under the condition of sufficient light in daytime is avoided, and electric energy is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of control circuits, and particularly relates to an automatic brightness control circuit. Background Technique

[0002] In daily life, electronic clocks are often used. It is a timing device that uses digital circuits to display time. Compared with traditional mechanical clocks and quartz clocks, electronic clocks have higher accuracy. It uses the crystal oscillator pulse signal in the integrated circuit to time, ensuring the accuracy of time. The electronic clock directly displays the time in digital form, without the need to read the time through a pointer like a mechanical clock, which is more intuitive and convenient. Usually, a display backlight is added to the electronic clock for users to view the screen content in a darker environment at night.

[0003] The existing backlight control of electronic clocks requires manual button operation to light up the screen, which is not convenient to use. And in a dark environment, it is difficult to perform button operations. At the same time, it is easy to forget to turn off the screen backlight, resulting in the backlight of the display still being on in a well-lit environment during the day, causing waste of electric energy. Content of the Utility Model

[0004] The purpose of the utility model is to provide an automatic brightness control circuit to solve the problems put forward in the above background technique.

[0005] To solve the above technical problems, the utility model provides the following technical solution: an automatic brightness control circuit, including a photosensitive diode, one end of the photosensitive diode is electrically connected to a first resistor, the other end of the photosensitive diode is electrically connected to a second resistor, a first triode is electrically connected to the first resistor, and the base of the first triode is connected in series to the photosensitive diode. The emitter of the first triode is electrically connected to a third resistor, the other end of the third resistor is electrically connected to a second triode, the collector of the second triode is electrically connected to a fourth resistor, the other end of the fourth resistor is electrically connected to a first LED, and a second LED is connected in parallel to the first LED.

[0006] As a further technical solution of the utility model, a third triode is electrically connected to the second LED, the emitter of the third triode is electrically connected to a fifth resistor, an integrated circuit is arranged on one side of the fifth resistor, a first pin is arranged on the integrated circuit, and the fifth resistor is electrically connected to the first pin.

[0007] As a further technical solution of the utility model, a second pin is arranged on the integrated circuit, and a power supply is electrically connected to the second pin.

[0008] As a further technical solution of the utility model, a first ground is electrically connected to the second resistor.

[0009] As a further technical solution of the present utility model, the emitter of the second triode is electrically connected to a second ground.

[0010] As a further technical solution of the present utility model, the emitter of the third triode is electrically connected to a third ground.

[0011] As a further technical solution of the present utility model, a fourth ground is electrically connected to the power supply.

[0012] Compared with the prior art, the beneficial effects achieved by the present utility model are as follows: The present utility model is designed with an automatic brightness control circuit. The photosensitive diode is used as an ambient light detection element. Through the induction and detection of ambient light, the automatic control of the backlight brightness of the display screen is realized, solving the drawback that it is necessary to manually press a key to turn on the screen backlight when looking at the electronic clock at night, improving the user experience, and at the same time avoiding the problem of turning on the display screen backlight when the light is sufficient during the day, saving electric energy. Description of the Drawings

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0014] Figure 1 It is the circuit structure diagram of the present utility model.

[0015] In the figure: 1. Integrated circuit; 2. First resistor; 3. Photosensitive diode; 4. Second resistor; 5. First triode; 6. Third resistor; 7. Second triode; 8. Fourth resistor; 9. First LED; 10. Second LED; 11. Third triode; 12. Fifth resistor; 13. First pin; 14. Power supply; 15. First ground; 16. Second ground; 17. Third ground; 18. Fourth ground; 19. Second pin. Detailed Embodiments

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present utility model belong to the scope of protection of the present utility model.

[0017] Please refer to the attached Figure 1, an embodiment provided by the present utility model: an automatic brightness control circuit, including a photosensitive diode 3, one end of the photosensitive diode 3 is electrically connected to a first resistor 2, the other end of the photosensitive diode 3 is electrically connected to a second resistor 4, a first triode 5 is electrically connected to the first resistor 2, and the base of the first triode 5 is connected in series to the photosensitive diode 3. The emitter of the first triode 5 is electrically connected to a third resistor 6, the other end of the third resistor 6 is electrically connected to a second triode 7, the collector of the second triode 7 is electrically connected to a fourth resistor 8, the other end of the fourth resistor 8 is electrically connected to a first LED 9, and a second LED 10 is connected in parallel to the first LED 9; a third triode 11 is electrically connected to the second LED 10, the emitter of the third triode 11 is electrically connected to a fifth resistor 12, a first integrated circuit 1 is provided on one side of the fifth resistor 12, a first pin 13 is provided on the integrated circuit 1, and the fifth resistor 12 is electrically connected to the first pin 13. The first pin 13, the fifth resistor 12 and the third triode 11 are used to manually control the lighting of the first LED 9 and the second LED 10; a second pin 19 is provided on the integrated circuit 1, a power supply 14 is electrically connected to the second pin 19, and the second pin 19 and the power supply 14 are used to supply power to the integrated circuit 1; a first ground 15 is electrically connected to the second resistor 4; the emitter of the second triode 7 is electrically connected to a second ground 16; the emitter of the third triode 11 is electrically connected to a third ground 17; a fourth ground 18 is electrically connected to the power supply 14. The first ground 15, the second ground 16, the third ground 17 and the fourth ground 18 are used to ensure the stability and reliability of the circuit and ensure the normal operation of the control circuit.

[0018] Working principle: When using the present utility model, in an environment with sufficient light during the day, the light irradiates on the photosensitive diode 3, the photosensitive diode 3 conducts, the first triode 5 cuts off, the second triode 7 cuts off, and the first LED 9 and the second LED 10 do not emit light. When in a dim environment at night, the photosensitive diode 3 cuts off, the first triode 5 conducts, and the second triode 7 is made to conduct through the third resistor 6. The lighting current of the first LED 9 and the second LED 10 is controlled through the third resistor 6 and the fourth resistor 8, so as to realize the first LED 9 and the second LED 10 to emit a faint light, and supply light for the display backlight. In addition, the first LED 9 and the second LED 10 can also be controlled to perform backlight lighting operations through the first pin 13 on the integrated circuit 1. The third triode 11 is made to conduct through the fifth resistor 12 to realize the manual operation of lighting the first LED 9 and the second LED 10; among them, the first resistor 2 and the second resistor 4 are used to limit the current and stabilize the voltage, the second pin 19 and the power supply 14 are used to supply power to the integrated circuit 1, and the first ground 15, the second ground 16, the third ground 17 and the fourth ground 18 are used to ensure the stability and reliability of the circuit and ensure the normal operation of the control circuit.

[0019] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0020] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative labor.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and are not intended to limit them. Although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims

1. An automatic brightness control circuit, comprising a photodiode (3), characterized in that: One end of the photosensitive diode (3) is electrically connected to a first resistor (2), the other end of the photosensitive diode (3) is electrically connected to a second resistor (4), the first resistor (2) is electrically connected to a first triode (5), and the base of the first triode (5) is connected in series to the photosensitive diode (3), the emitter of the first triode (5) is electrically connected to a third resistor (6), the other end of the third resistor (6) is electrically connected to a second triode (7), the collector of the second triode (7) is electrically connected to a fourth resistor (8), the other end of the fourth resistor (8) is electrically connected to a first LED (9), and the first LED (9) is connected in parallel to a second LED (10).

2. The automatic brightness control circuit according to claim 1, characterized in that: The second LED (10) is electrically connected to a third triode (11), the emitter of the third triode (11) is electrically connected to a fifth resistor (12), an integrated circuit (1) is provided on one side of the fifth resistor (12), a first pin (13) is provided on the integrated circuit (1), and the fifth resistor (12) is electrically connected to the first pin (13).

3. An automatic brightness control circuit according to claim 2, characterized in that: The integrated circuit (1) is provided with a second pin (19), and the second pin (19) is electrically connected to a power supply (14).

4. The automatic brightness control circuit according to claim 1, characterized in that: The second resistor (4) is electrically connected to a first ground (15).

5. The automatic brightness control circuit according to claim 1, characterized in that: The emitter of the second transistor (7) is electrically connected to a second ground (16).

6. The automatic brightness control circuit according to claim 2, characterized in that: The emitter of the third triode (11) is electrically connected to a third ground (17).

7. The automatic brightness control circuit according to claim 3, characterized in that: The power supply (14) is electrically connected to a fourth ground (18).

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