A circuit structure of a low-power, gradually brightening and gradually extinguishing sun visor lamp for a vehicle

Abstract

The utility model provides a circuit structure of a low-power, gradually-on-and-off sun visor lamp for a vehicle, which relates to the technical field of sun visor lamp circuit control, and comprises an input voltage VCC, a low-power LDO voltage regulator circuit, a delay control circuit, a low-power Hall chip circuit, a constant current circuit, and an LED light source, wherein the input voltage VCC is used to supply power to a back-end circuit, and the input voltage VCC is electrically connected to the low-power LDO voltage regulator circuit and the constant current circuit at the same time, the low-power LDO voltage regulator circuit is electrically connected to the delay control circuit and the low-power Hall chip circuit at the same time, and the constant current circuit is electrically connected to the LED light source. The circuit structure of the sun visor lamp of the utility model adopts a low-power LDO voltage regulator chip, a low-power Hall switch chip, and a delay control circuit lamp to control the light source of the sun visor lamp, thereby meeting the requirements of low power consumption and humanization.

Description

Technical Field

[0001] The utility model relates to the technical field of sun visor lamp circuit control, in particular to a circuit structure of a sun visor lamp for a vehicle with low power consumption and gradually turning on and off. Background Art

[0002] At present, the mainstream sun visor lamp circuit design in the market uses ordinary Hall switch circuit to directly control the on and off of the circuit to realize the lighting and extinguishing of the light source.

[0003] With the gradual popularization of low power consumption awareness, low power consumption design is also being promoted in the automotive industry. In some special environments, the gradual on and off method can give users a better experience. The main implementation method on the market now is to use the ordinary Hall switch chip to control the on and off of the circuit to achieve instant on and off of the light source.

[0004] The use of ordinary Hall switch chips to control the on and off of the circuit to light up the light source has obvious disadvantages:

[0005] First, when the light source is turned off, a lot of power consumption is also generated;

[0006] Second, the light source turns on or off instantly, which cannot meet the humanized needs of some customers.

[0007] In order to meet the increasing demand for low power consumption and humanization, the present invention proposes a low-power, gradually brightening and dimming sun visor lamp circuit for a vehicle, which uses a low-power LDO voltage regulator chip, a low-power Hall switch chip, and a delay control circuit to control the light source.

[0008] Therefore, there is room for improvement, and the utility model provides a low-power, gradually-on and gradually-off sun visor lamp circuit structure for a vehicle. Utility Model Content

[0009] In view of the shortcomings of the prior art, the utility model aims to provide a low-power, gradually brightening and gradually extinguishing sun visor lamp circuit structure for a vehicle, and the specific scheme is as follows:

[0010] A low-power, gradually-on and gradually-off sun visor lamp circuit structure for a vehicle includes an input voltage VCC, a low-power LDO voltage regulator circuit, a delay control circuit, a low-power Hall chip circuit, a constant current circuit, and an LED light source, wherein;

[0011] The input voltage VCC is used to power the back-end circuit, and the input voltage VCC is electrically connected to the low-power LDO voltage regulator circuit and the constant current circuit at the same time. The low-power LDO voltage regulator circuit is electrically connected to the delay control circuit and the low-power Hall chip circuit at the same time. The constant current circuit is electrically connected to the LED light source;

[0012] The delay control circuit is composed of an RC circuit and an NMOS tube. The RC circuit is used to delay the NMOS tube to control whether it is turned on or off, and the NMOS tube is used to control the current of the constant current circuit and the LED light source.

[0013] Low-power LDO voltage regulator circuit, used to power low-power Hall chip circuit and RC circuit;

[0014] A low-power Hall switch circuit is used to sense an external magnetic field and output a voltage signal, as well as discharge the RC circuit.

[0015] Furthermore, the sun visor lamp circuit also includes a ground terminal GND1, and the low-power LDO voltage regulator circuit, the delay control circuit, the low-power Hall chip circuit, and the constant current circuit are also electrically connected to the ground terminal GND1.

[0016] Further, the low power consumption LDO voltage regulator circuit includes a capacitor C9 and an LDO voltage regulator, and the LDO voltage regulator is used to output the voltage U1;

[0017] The Vin terminal of the LDO regulator is electrically connected to the capacitor C9, the Vout terminal of the LDO regulator is connected to the delay control circuit, and the GND of the LDO regulator and the capacitor C9 are both electrically connected to the ground terminal GND1.

[0018] Furthermore, the RC circuit in the delay control circuit includes a resistor R13, a resistor R14, and a capacitor C11, and the low-power Hall chip circuit includes a Hall chip and a capacitor C10;

[0019] The resistor R13 is electrically connected to the Vout terminal of the LDO regulator, and the resistor R13 is electrically connected to the NMOS tube. A resistor R14 and a capacitor C11 are connected in parallel between the resistor R13 and the NMOS tube. The resistor R14 is electrically connected to the Hall chip, and the Hall chip is electrically connected to the Vout terminal of the LDO regulator. A capacitor C10 is connected in parallel between the Hall chip and the Vout terminal of the LDO regulator.

[0020] The capacitor C10, the Hall chip, the capacitor C11, and the NMOS tube are all electrically connected to the ground terminal GND1.

[0021] Further, the constant current circuit includes a resistor R10, a resistor R11, a resistor R12, a composite diode D5, a PNP transistor, a capacitor C6, and a capacitor C8;

[0022] The resistor R12 is electrically connected to the NMOS tube, the composite diode D5 is electrically connected to the resistor R12, the resistor R11 is electrically connected to the composite diode D5, one end of the PNP transistor is electrically connected to the resistor R11, the other end of the PNP transistor is connected between the composite diode D5 and the resistor R12, the third end of the PNP transistor is electrically connected to the capacitor C8, and the capacitor C8 is connected between the resistor R12 and the NMOS tube;

[0023] Wherein, a resistor R10 is connected in parallel between the two ends of the resistor R11, a capacitor C6 is connected in parallel between the two ends of the PNP transistor, and an LED light source is connected in parallel between the two ends of the capacitor C8.

[0024] Furthermore, the sun visor lamp circuit also includes a transient overvoltage protection circuit, and the transient overvoltage protection circuit includes a TVS tube D6 and a capacitor C7;

[0025] One end of the TVS tube D6 is electrically connected to the input voltage VCC, and the other end is electrically connected to the ground terminal GND1;

[0026] Capacitor C7 is connected in parallel between the two ends of TVS tube D6.

[0027] Furthermore, the sun visor lamp circuit also includes an anti-reverse connection circuit, and the anti-reverse connection circuit includes a diode D4 and a resistor R9;

[0028] The diode D4 is electrically connected to the input voltage VCC. One end of the resistor R9 is electrically connected to the diode D4. The other end of the resistor R9 is electrically connected to the capacitor C9 and connected between the composite diode D5 and the resistor R11.

[0029] Furthermore, the sun visor lamp circuit also includes an overvoltage protection circuit, which includes a composite diode D7, and the composite diode D7 is connected in parallel to both ends of the NMOS tube.

[0030] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0031] (1) After the sun visor circuit structure is applied to the vehicle, the low-power Hall switch circuit senses the external magnetic field. When there is no magnetic field signal, the input voltage VCC is used to power the back-end circuit, and the low-power LDO voltage regulator circuit outputs the voltage U1 to power the low-power Hall switch circuit, and the RC circuit in the delay control circuit delays the NMOS tube to turn on; the low-power Hall switch circuit works, and does not receive a magnetic field signal, and the RC circuit will not be discharged; the constant current circuit works, and the NOMS tube controls the current flowing through the LED light source to slowly increase, and the LED light source gradually brightens until the current reaches the current value limited by the constant current circuit, and the brightness of the LED light source is stable.

[0032] After receiving the magnetic field signal, the low-power Hall switch circuit works to discharge the RC circuit. The voltage in the RC circuit decreases slowly, and the NOMS tube controls the current flowing through the LED light source to decrease slowly, and the LED light source gradually goes out.

[0033] Therefore, the circuit structure of the sun visor can control the LED light source to gradually brighten and dim in a timely manner, which is more humane.

[0034] (2) The circuit structure of this sun visor adopts low-power LDO voltage regulator circuit and low-power Hall switch circuit, which can achieve <20uA in the off state. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The figure is a schematic diagram of the working principle of an embodiment of the utility model. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with the embodiments and drawings, but the implementation methods of the present invention are not limited thereto.

[0037] The utility model proposes a low-power, gradually brightening and dimming sun visor light circuit structure for a vehicle, which is used to control the sun visor light to gradually brighten and dim. In order to achieve this function, the utility model adopts a low-power LDO voltage regulator chip, a low-power Hall switch chip, and a delay control circuit light to control the light source of the sun visor light, which is an LED light source in this embodiment.

[0038] The key points are:

[0039] 1. Use a low-power LDO voltage regulator chip to power a low-power Hall chip;

[0040] Second, a constant current circuit is used, which is controlled by a delay control circuit;

[0041] 3. A lower threshold is set for the voltage at the G pole of the NMOS tube.

[0042] Based on this, the sun visor circuit specifically includes an input voltage VCC, a low-power LDO voltage regulator circuit, a delay control circuit, a low-power Hall chip circuit, a constant current circuit, an LED light source, and a ground terminal GND1.

[0043] Among them, the input voltage VCC is used to power the back-end circuit, and the input voltage VCC is electrically connected to the low-power LDO voltage regulator circuit and the constant current circuit at the same time, the low-power LDO voltage regulator circuit is electrically connected to the delay control circuit and the low-power Hall chip circuit at the same time, and the constant current circuit is electrically connected to the LED light source;

[0044] The low-power LDO voltage stabilizing circuit, the delay control circuit, the low-power Hall chip circuit, and the constant current circuit are all electrically connected to the ground terminal GND1.

[0045] It should be noted that the delay control circuit is composed of an RC circuit and an NMOS tube. The RC circuit is used to delay the control of whether the NMOS tube is turned on or off, and the NMOS tube is used to control the current of the constant current circuit and the LED light source; the low-power LDO voltage regulator circuit is used to power the low-power Hall chip circuit and the RC circuit; the low-power Hall switch circuit is used to sense the external magnetic field and output a voltage signal, as well as to discharge the RC circuit.

[0046] The specific structures and electrical connection relationships of the above-mentioned circuits are described as follows:

[0047] Specifically, the low power consumption LDO voltage regulator circuit includes a capacitor C9 and an LDO voltage regulator, and the LDO voltage regulator is used to output the voltage U1;

[0048] The Vin terminal of the LDO regulator is electrically connected to the capacitor C9, the Vout terminal of the LDO regulator is connected to the delay control circuit, and the GND of the LDO regulator and the capacitor C9 are both electrically connected to the ground terminal GND1.

[0049] Specifically, the RC circuit in the delay control circuit includes a resistor R13, a resistor R14, and a capacitor C11, and the low-power Hall chip circuit includes a Hall chip and a capacitor C10;

[0050] The resistor R13 is electrically connected to the Vout terminal of the LDO regulator, and the resistor R13 is electrically connected to the NMOS tube. A resistor R14 and a capacitor C11 are connected in parallel between the resistor R13 and the NMOS tube. The resistor R14 is electrically connected to the Hall chip, and the Hall chip is electrically connected to the Vout terminal of the LDO regulator. A capacitor C10 is connected in parallel between the Hall chip and the Vout terminal of the LDO regulator.

[0051] The capacitor C10, the Hall chip, the capacitor C11, and the NMOS tube are all electrically connected to the ground terminal GND1.

[0052] Specifically, the constant current circuit includes a resistor R10, a resistor R11, a resistor R12, a composite diode D5, a PNP transistor, a capacitor C6, and a capacitor C8;

[0053] The resistor R12 is electrically connected to the NMOS tube, the composite diode D5 is electrically connected to the resistor R12, the resistor R11 is electrically connected to the composite diode D5, one end of the PNP transistor is electrically connected to the resistor R11, the other end of the PNP transistor is connected between the composite diode D5 and the resistor R12, the third end of the PNP transistor is electrically connected to the capacitor C8, and the capacitor C8 is connected between the resistor R12 and the NMOS tube;

[0054] Wherein, a resistor R10 is connected in parallel between the two ends of the resistor R11, a capacitor C6 is connected in parallel between the two ends of the PNP transistor, and an LED light source is connected in parallel between the two ends of the capacitor C8.

[0055] Optimized, the sun visor lamp circuit also includes a transient overvoltage protection circuit, which is used to protect the back-end circuit from damage when there is a momentary high voltage. The transient overvoltage protection circuit includes TVS tube D6 and capacitor C7;

[0056] One end of the TVS tube D6 is electrically connected to the input voltage VCC, and the other end is electrically connected to the ground terminal GND1;

[0057] Capacitor C7 is connected in parallel between the two ends of TVS tube D6.

[0058] Optimized, the sun visor light circuit also includes an anti-reverse connection circuit, whose function is to prevent the circuit from being damaged when the positive and negative poles of the power supply are connected in reverse. The anti-reverse connection circuit includes a diode D4 and a resistor R9;

[0059] The diode D4 is electrically connected to the input voltage VCC. One end of the resistor R9 is electrically connected to the diode D4. The other end of the resistor R9 is electrically connected to the capacitor C9 and connected between the composite diode D5 and the resistor R11.

[0060] The sun visor lamp circuit also includes an overvoltage protection circuit, which includes a composite diode D7, and the composite diode D7 is connected in parallel to the two ends of the NMOS tube.

[0061] In summary, the working process of the sun visor lamp circuit in the utility model is as follows:

[0062] When there is no magnetic field signal, the input voltage VCC passes through the transient overvoltage protection circuit and the anti-reverse connection circuit to power the back-end circuit;

[0063] The output voltage U1 of the low-power LDO voltage regulator circuit supplies power to the low-power Hall switch circuit, and slowly charges the capacitor C11 through the resistor R13. The voltage U2 at the capacitor C11 slowly increases until the voltage U2 = U1;

[0064] The low-power Hall switch circuit works, and no magnetic field signal is received, and the capacitor C11 will not be discharged through the resistor R14;

[0065] The constant current circuit works, and the NOMS tube controls the current flowing through the LED light source to increase slowly, and the LED light source gradually brightens until the current reaches the current value limited by the constant current circuit, and the brightness of the LED light source stabilizes.

[0066] After receiving the magnetic field signal, the low-power Hall switch circuit works to discharge the capacitor C11 through the resistor R14, and the voltage U2 decreases slowly until the voltage U2 reaches the set lower threshold U2', U2'=R14 / (R13+R14)*U1;

[0067] The NOMS tube controls the current flowing through the LED light source to slowly decrease, and the LED light source gradually goes out.

[0068] The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A low-power, gradually-on and gradually-off sun visor lamp circuit structure for a vehicle, characterized in that: It includes input voltage VCC, low power consumption LDO voltage regulator circuit, delay control circuit, low power consumption Hall chip circuit, constant current circuit, LED light source, among which; The input voltage VCC is used to power the back-end circuit, and the input voltage VCC is electrically connected to the low-power LDO voltage regulator circuit and the constant current circuit at the same time. The low-power LDO voltage regulator circuit is electrically connected to the delay control circuit and the low-power Hall chip circuit at the same time. The constant current circuit is electrically connected to the LED light source; The delay control circuit is composed of an RC circuit and an NMOS tube. The RC circuit is used to delay the NMOS tube to control whether it is turned on or off, and the NMOS tube is used to control the current of the constant current circuit and the LED light source. Low-power LDO voltage regulator circuit, used to power low-power Hall chip circuit and RC circuit; A low-power Hall switch circuit is used to sense an external magnetic field and output a voltage signal, as well as discharge the RC circuit.

2. The circuit structure of the low-power, gradually-on and gradually-off sun visor lamp for a vehicle according to claim 1, characterized in that: The sun visor lamp circuit also includes a ground terminal GND1, and a low-power LDO voltage stabilizing circuit, a delay control circuit, a low-power Hall chip circuit, and a constant current circuit are all electrically connected to the ground terminal GND1.

3. The circuit structure of the low-power, gradually-on and gradually-off sun visor lamp for a vehicle according to claim 2, characterized in that: The low power consumption LDO voltage regulator circuit includes a capacitor C9 and an LDO voltage regulator, and the LDO voltage regulator is used for outputting a voltage U1; The Vin terminal of the LDO regulator is electrically connected to the capacitor C9, the Vout terminal of the LDO regulator is connected to the delay control circuit, and the GND of the LDO regulator and the capacitor C9 are both electrically connected to the ground terminal GND1.

4. The circuit structure of the low-power, gradually-on and gradually-off sun visor lamp for a vehicle according to claim 3 is characterized in that: The RC circuit in the delay control circuit includes a resistor R13, a resistor R14, and a capacitor C11, and the low-power Hall chip circuit includes a Hall chip and a capacitor C10; The resistor R13 is electrically connected to the Vout terminal of the LDO regulator, and the resistor R13 is electrically connected to the NMOS tube. A resistor R14 and a capacitor C11 are connected in parallel between the resistor R13 and the NMOS tube. The resistor R14 is electrically connected to the Hall chip, and the Hall chip is electrically connected to the Vout terminal of the LDO regulator. A capacitor C10 is connected in parallel between the Hall chip and the Vout terminal of the LDO regulator. The capacitor C10, the Hall chip, the capacitor C11, and the NMOS tube are all electrically connected to the ground terminal GND1.

5. The circuit structure of the low-power, gradually-on and gradually-off sun visor lamp for a vehicle according to claim 4, characterized in that: The constant current circuit includes a resistor R10, a resistor R11, a resistor R12, a composite diode D5, a PNP transistor, a capacitor C6, and a capacitor C8; The resistor R12 is electrically connected to the NMOS tube, the composite diode D5 is electrically connected to the resistor R12, the resistor R11 is electrically connected to the composite diode D5, one end of the PNP transistor is electrically connected to the resistor R11, the other end of the PNP transistor is connected between the composite diode D5 and the resistor R12, the third end of the PNP transistor is electrically connected to the capacitor C8, and the capacitor C8 is connected between the resistor R12 and the NMOS tube; Wherein, a resistor R10 is connected in parallel between the two ends of the resistor R11, a capacitor C6 is connected in parallel between the two ends of the PNP transistor, and an LED light source is connected in parallel between the two ends of the capacitor C8.

6. The circuit structure of the low-power, gradually-on and gradually-off sun visor lamp for a vehicle according to claim 5, characterized in that: The sun visor lamp circuit also includes a transient overvoltage protection circuit, which includes a TVS tube D6 and a capacitor C7; One end of the TVS tube D6 is electrically connected to the input voltage VCC, and the other end is electrically connected to the ground terminal GND1; Capacitor C7 is connected in parallel between the two ends of TVS tube D6.

7. The circuit structure of the low-power, gradually-on and gradually-off sun visor lamp for a vehicle according to claim 6, characterized in that: The sun visor lamp circuit also includes an anti-reverse connection circuit, which includes a diode D4 and a resistor R9; The diode D4 is electrically connected to the input voltage VCC. One end of the resistor R9 is electrically connected to the diode D4. The other end of the resistor R9 is electrically connected to the capacitor C9 and connected between the composite diode D5 and the resistor R11.

8. The circuit structure of the low-power, gradually-on and gradually-off sun visor lamp for a vehicle according to claim 7, characterized in that: The sun visor lamp circuit also includes an overvoltage protection circuit, which includes a composite diode D7, and the composite diode D7 is connected in parallel to the two ends of the NMOS tube.

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