Constant current control circuit of mobile lighting device

Abstract

The utility model discloses a constant current control circuit of a mobile lighting device, comprising a power supply module, a voltage stabilizing circuit, an MCU control circuit and a step-down constant current circuit, the power supply module is connected with the MCU control circuit, the MCU control circuit is connected with the voltage stabilizing circuit, the MCU control circuit is connected with the step-down constant current circuit, the MCU control circuit outputs PWM to the step-down constant current circuit, and the step-down constant current circuit is connected with the voltage stabilizing circuit. And the brightness of the LED lamp is controlled through the step-down constant-current circuit. According to the utility model, the MCU control circuit is matched with the step-down constant current circuit to output stable voltage and current, so that the brightness of the LED is effectively controlled, and the performance is more stable.

Description

Technical Field

[0001] The utility model relates to a mobile lighting device, in particular to a constant current control circuit of the mobile lighting device. Background Art

[0002] A mobile lighting device is an easy-to-use appliance, such as a flashlight. The application number in the prior art is CN201920856164.2, and the name is a new type of flashlight. When the flashlight is not lighting, the tail cover is inserted into the bottom cover, and the insulating boss on the tail cover pushes the battery up, and the negative pole of the battery is separated from the second conductor, so that the entire closed circuit is disconnected, and the light-emitting body (lamp bead) does not light up. When the flashlight is needed for lighting, it is only necessary to pull the lamp housing together with the bottom cover from the tail cover, and the bottom cover is separated from the tail cover. The light-emitting body forms a closed circuit through the metal spring, the first conductor, the second conductor and the battery, and the light-emitting body (lamp bead) enters the light-emitting state. However, this type of flashlight has the following problems: it is difficult to maintain an effective constant current state. When lighting, it is difficult to ensure the brightness of the light, and it is difficult to achieve effective adjustment of the brightness of the light. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a constant current control circuit for a mobile lighting device.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A constant current control circuit for a mobile lighting device includes a power module, a voltage stabilizing circuit, an MCU control circuit, and a step-down constant current circuit. The power module is connected to the MCU control circuit, which is connected to the voltage stabilizing circuit, which is connected to the step-down constant current circuit. The MCU control circuit outputs PWM to the step-down constant current circuit, and the brightness of the LED lamp is controlled by the step-down constant current circuit.

[0006] As a further improvement, the MCU control circuit includes a button S1, a MOS tube Q1, a control chip U2, a transistor Q3 and a voltage detection module. One end of the button S1 is grounded, and the other end is connected in parallel to the negative electrodes of the diodes D3 and D4. The positive electrode of the diode D3 is connected to the resistor R2 and the MOS tube Q1 respectively through the resistor R18. The MOS tube Q1 is connected to the resistor R2 and the power module. The MOS tube Q1 is connected to the voltage stabilizing circuit, the transistor Q3 and the voltage detection module respectively. The voltage stabilizing circuit transmits the voltage to the control chip U2 after voltage stabilization. The control chip U2 is connected to the voltage detection module and the positive electrode of the diode D4 respectively. The control chip U2 outputs PWM to the step-down shunt circuit.

[0007] As a further improvement, the MOS transistor Q1 has an S pin, a G pin, and a D pin. The resistor R18 is connected to the G pin of the MOS transistor Q1. The S pin of the MOS transistor Q1 is connected to the resistor R2 and to the power module. The D pin of the MOS transistor Q1 is connected to the voltage stabilization circuit and the voltage detection circuit respectively. The G pin of the MOS transistor Q1 is connected to the collector of the transistor Q3 through the resistor R3. The base of the transistor Q3 is connected to the control chip U2 through the resistor R11. A resistor R25 is connected between the base and emitter of the transistor Q3. The positive electrode of the diode D4 is connected to the control chip U2 through the resistor R19. The voltage output by the voltage stabilization circuit is connected to the control chip U2 through the resistor R19.

[0008] As a further improvement, the voltage detection module includes a resistor R1, a resistor R8 and a capacitor C8, the resistor R1 and the resistor R8 are connected in series, the capacitor C8 is connected in parallel at both ends of the resistor R8, the resistor R1 is connected to the D pin of the MOS tube Q1, the resistor R8 is grounded, and the control chip U2 is connected to the capacitor C8.

[0009] As a further improvement, the step-down constant current circuit includes a step-down constant current chip U3, which receives the PWM output by the MCU control circuit through the resistor R5. The step-down constant current chip is connected to the resistors R4 and R9 connected in parallel. The resistors R4 and R9 are connected to the magnetic bead L7 and then to the negative electrode of the diode D5. The positive electrode of the diode D5 is connected to the step-down constant current chip U3, and the resistor R5 is connected in series with the resistor R22 and the inductor L8. The step-down constant current chip U3 is connected to the capacitor C2, the capacitor C2 is connected to the resistor R22, the magnetic bead L8 is grounded, the step-down constant current chip U3 is connected to the LED lamp, and the LED lamp is also connected to the resistor R4 and the resistor R9. The LED lamp is connected in parallel with the capacitor C12, the resistor C12 is connected to the capacitor C16, and the capacitor C16 is connected to the step-down constant current chip U3 through the inductor L1.

[0010] As a further improvement, the model of the step-down constant current chip U3 is OC5260, the model of the control chip U2 is PY32F002, and the model of the MOS tube Q7 is AO4407A.

[0011] As a further improvement, there is at least one LED lamp. When more than two LED lamps are provided, the LED lamps are connected in parallel.

[0012] As a further improvement, the voltage stabilizing circuit includes a chip U1 and a diode D2. The output end of the chip U1 is connected in parallel with capacitors C6 and C7. The input end of the chip U1 is connected with capacitor C5. Capacitors C5, C6 and C7 are all grounded. The cathode of the diode D2 is connected to the input end of the chip U1, and the anode of the diode D2 is connected to the D pin of the MOS tube Q1.

[0013] As a further improvement, the model of the chip U1 is HT7150.

[0014] As a further improvement, the power module includes a battery, a diode D1, a capacitor C10 and a fuse. One end of the battery is connected to the capacitor C10 and grounded, the capacitor C10 is connected to the cathode of the diode D1, the anode of the diode D1 is connected to the fuse, the fuse is connected to the other end of the battery, and the cathode of the diode D1 is connected to the resistor R2 and the S pin of the MOS tube Q1 through the magnetic bead L4.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects:

[0016] By combining the MCU control circuit with the step-down constant current circuit, precise control of the switch is achieved, and both the current and voltage are effectively controlled, thus effectively controlling the brightness of the LED lamp and making the current and voltage more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the circuit framework of the utility model;

[0018] Figure 2 This is a schematic diagram of the connection principle of the MCU control circuit in the present utility model;

[0019] Figure 3 This is a schematic diagram of the principle of the step-down constant current circuit in this utility model. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention.

[0021] In the description of the present invention, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like are used to indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, removable connections, or integral connections. They may refer to mechanical connections or electrical connections. They may refer to direct connections or indirect connections through an intermediary, and they may refer to internal communication between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0023] refer to Figure 1-3 The figure shows a constant current control circuit for a mobile lighting device, comprising a power module, a voltage regulator circuit, an MCU control circuit, and a step-down constant current circuit. The power module is connected to the MCU control circuit, which is in turn connected to the voltage regulator circuit, which is then connected to the step-down constant current circuit. The MCU control circuit outputs PWM to the step-down constant current circuit, which then controls the brightness of the LED light. The power module provides power, the MCU control circuit enables and controls the device, and the voltage regulator circuit stabilizes the voltage to maintain voltage stability. This voltage is maintained throughout operation, and the output voltage is reduced to achieve constant current output, maintaining the brightness of the LED light.

[0024] The power module includes a battery, a diode D1, a capacitor C10, and a fuse. One end of the battery is connected to the capacitor C10 and grounded. The capacitor C10 is connected to the cathode of the diode D1. The anode of the diode D1 is connected to the fuse. The fuse is connected to the other end of the battery. The cathode of the diode D1 is connected to the resistor R2 and the S pin of the MOS tube Q1 through the magnetic bead L4. The battery can be a rechargeable lithium battery. The fuse can be disconnected when a fault occurs, thereby improving safety. The capacitor C10 is used to achieve charging and discharging. The battery B1 of the power module is passed through the fuse F1, the forward conduction of the diode D1, and filtering by the capacitor C10, and is transmitted from the magnetic bead L4 to output power for anti-EMC.

[0025] The MCU control circuit includes a button S1, a MOS transistor Q1, a control chip U2, a transistor Q3, and a voltage detection module. One end of button S1 is grounded, and the other end is connected in parallel to the cathodes of diodes D3 and D4. The anode of diode D3 is connected to resistor R2 and MOS transistor Q1 via resistor R18. MOS transistor Q1 is connected to resistor R2 and a power module. MOS transistor Q1 is connected to a voltage regulator circuit, transistor Q3, and a voltage detection module. The voltage regulator circuit stabilizes the voltage and transmits it to the control chip U2. The control chip U2 is connected to the voltage detection module and the anode of diode D4. The control chip U2 outputs PWM to the step-down shunt circuit. MOS transistor Q1 performs the start and stop functions, implementing start-stop control.

[0026] The MOS transistor Q1 has an S pin, a G pin, and a D pin. Resistor R18 is connected to the G pin of the MOS transistor Q1. The S pin of the MOS transistor Q1 is connected to resistor R2 and to the magnetic bead L4 of the power module. The D pin of the MOS transistor Q1 is connected to the voltage stabilization circuit and the voltage detection circuit respectively. The G pin of the MOS transistor Q1 is connected to the collector of the transistor Q3 through resistor R3. The base of the transistor Q3 is connected to the control chip U2 through resistor R11. A resistor R25 is connected between the base and emitter of the transistor Q3. The anode of the diode D4 is connected to the control chip U2 through resistor R19. The voltage output by the voltage stabilization circuit is connected to the control chip U2 through resistor R19.

[0027] After the MOS tube Q1 receives the power from the power module, the current is stabilized by the voltage stabilization circuit, and then the stabilized voltage is transmitted to the control chip U2 to ensure voltage stability.

[0028] The voltage detection module includes a resistor R1, a resistor R8 and a capacitor C8. The resistors R1 and R8 are connected in series, and the capacitor C8 is connected in parallel to both ends of the resistor R8. The resistor R1 is connected to the D pin of the MOS tube Q1, the resistor R8 is grounded, and the control chip U2 is connected to the capacitor C8. The voltage detection module is mainly used to detect the capacity of the battery.

[0029] The voltage stabilizing circuit includes a chip U1 and a diode D2. The output end of the chip U1 is connected in parallel with capacitors C6 and C7. The input end of the chip U1 is connected to capacitor C5. Capacitors C5, C6, and C7 are all grounded. The cathode of the diode D2 is connected to the input end of the chip U1, and the anode of the diode D2 is connected to the D pin of the MOS tube Q1.

[0030] When the MCU control circuit is operating: Pressing button S1 causes the anode of diode D3 to go low. MOS transistor Q1, through the sampling and voltage division of resistors R2 and R18, turns on, turning on the power supply. Power flows out of the voltage regulator circuit. It then flows forward through diode D2, filtered by capacitor C5, and reaches the regulated output of chip U1. This voltage is filtered by capacitors C6 and C7, providing a stable voltage to power control chip U2, thus operating MC circuit U. The MCU control chip opens pin 6, outputting a high level. Resistors R11 and R25 limit the current and divide the voltage, turning on transistor Q3. The sampling and voltage division of resistors R2 and R3 turns on MOS transistor Q1. Control chip U2 is activated by pressing button S1, causing diode D4 to go low. The control chip outputs a PWM signal through pin 3, which is fed to the step-down constant current circuit to control the current and, consequently, the LED brightness. When the control chip U2 detects the signal that the button S1 is pressed, it closes pin 6 and outputs a low level. The resistors R11 and R25 limit the current and divide the voltage, and the transistor Q3 is turned off, which turns off the MOS tube Q1 and processes the shutdown state.

[0031] The step-down constant current circuit includes a step-down constant current chip U3, which receives the PWM output by the MCU control circuit through a resistor R5. The step-down constant current chip is connected to resistors R4 and R9 connected in parallel. The resistors R4 and R9 are connected to the magnetic bead L7 and then to the negative electrode of the diode D5. The positive electrode of the diode D5 is connected to the step-down constant current chip U3, the resistor R5 is connected in series with the resistor R22 and the inductor L8, the step-down constant current chip U3 is connected to the capacitor C2, the capacitor C2 is connected to the resistor R22, the magnetic bead L8 is grounded, the step-down constant current chip U3 is connected to the LED lamp, the LED lamp is also connected to the resistor R4 and the resistor R9, the LED lamp is connected in parallel with the capacitor C12, the resistor C12 is connected to the capacitor C16, and the capacitor C16 is connected to the step-down constant current chip U3 through the inductor L1.

[0032] The model of the step-down constant current chip U3 is OC5260, the model of the control chip U2 is PY32F002, the model of the MOS tube Q7 is AO4407A, and the model of the chip U1 is HT7150.

[0033] The step-down constant current chip U3 sets the output current of the LED lamp through resistors R4 and R9. The diode D5, ferrite bead L7, capacitor C1, ferrite bead L1, LED lamp, capacitor C16, and capacitor C12 form a switching current detection step-down LED constant current drive controller. The 3rd pin of the control chip U2 outputs PWM through resistor R6 to control the 6th pin of the step-down constant current chip U3 to control the brightness of the LED1 lamp.

[0034] It should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A constant current control circuit for a mobile lighting device, characterized in that: It includes a power module, a voltage stabilizing circuit, an MCU control circuit and a step-down constant current circuit. The power module is connected to the MCU control circuit, the MCU control circuit is connected to the voltage stabilizing circuit, the MCU control circuit is connected to the step-down constant current circuit, and the MCU control circuit outputs PWM to the step-down constant current circuit to control the brightness of the LED lamp through the step-down constant current circuit.

2. The constant current control circuit of the mobile lighting device according to claim 1, characterized in that: The MCU control circuit includes a button S1, a MOS transistor Q1, a control chip U2, a transistor Q3 and a voltage detection module. One end of the button S1 is grounded, and the other end is connected in parallel to the cathodes of diodes D3 and D4. The anode of diode D3 is connected to resistor R2 and MOS transistor Q1 respectively through resistor R18. MOS transistor Q1 is connected to resistor R2 and a power module. MOS transistor Q1 is connected to a voltage stabilizing circuit, a transistor Q3 and a voltage detection module respectively. The voltage stabilizing circuit stabilizes the voltage and transmits it to the control chip U2. The control chip U2 is connected to the voltage detection module and the anode of diode D4 respectively. The control chip U2 outputs PWM to the step-down current-regulating circuit.

3. The constant current control circuit of the mobile lighting device according to claim 2, characterized in that: The MOS transistor Q1 has an S pin, a G pin, and a D pin. Resistor R18 is connected to the G pin of the MOS transistor Q1. The S pin of the MOS transistor Q1 is connected to resistor R2 and to a power module. The D pin of the MOS transistor Q1 is connected to a voltage stabilization circuit and a voltage detection circuit, respectively. The G pin of the MOS transistor Q1 is connected to the collector of the transistor Q3 via resistor R3. The base of the transistor Q3 is connected to the control chip U2 via resistor R11. A resistor R25 is connected between the base and emitter of the transistor Q3. The anode of the diode D4 is connected to the control chip U2 via resistor R19. The voltage output by the voltage stabilization circuit is connected to the control chip U2 via resistor R19.

4. The constant current control circuit of the mobile lighting device according to claim 3, characterized in that: The voltage detection module includes a resistor R1, a resistor R8 and a capacitor C8. The resistors R1 and R8 are connected in series, and the capacitor C8 is connected in parallel to both ends of the resistor R8. The resistor R1 is connected to the D pin of the MOS tube Q1, the resistor R8 is grounded, and the control chip U2 is connected to the capacitor C8.

5. The constant current control circuit of the mobile lighting device according to claim 3, characterized in that: The step-down constant current circuit includes a step-down constant current chip U3, which receives the PWM output by the MCU control circuit through a resistor R5. The step-down constant current chip is connected to resistors R4 and R9 connected in parallel. The resistors R4 and R9 are connected to the magnetic bead L7 and then to the negative electrode of the diode D5. The positive electrode of the diode D5 is connected to the step-down constant current chip U3, the resistor R5 is connected in series with the resistor R22 and the inductor L8, the step-down constant current chip U3 is connected to the capacitor C2, the capacitor C2 is connected to the resistor R22, the magnetic bead L8 is grounded, the step-down constant current chip U3 is connected to the LED lamp, the LED lamp is also connected to the resistor R4 and the resistor R9, the LED lamp is connected in parallel with the capacitor C12, the resistor C12 is connected to the capacitor C16, and the capacitor C16 is connected to the step-down constant current chip U3 through the inductor L1.

6. The constant current control circuit of the mobile lighting device according to claim 5, characterized in that: The model of the step-down constant current chip U3 is OC5260, the model of the control chip U2 is PY32F002, and the model of the MOS tube Q7 is AO4407A.

7. The constant current control circuit of the mobile lighting device according to claim 5, characterized in that: There is at least one LED lamp. When two or more LED lamps are provided, the LED lamps are connected in parallel.

8. The constant current control circuit of the mobile lighting device according to claim 3, characterized in that: The voltage stabilizing circuit includes a chip U1 and a diode D2. The output end of the chip U1 is connected in parallel with capacitors C6 and C7. The input end of the chip U1 is connected to capacitor C5. Capacitors C5, C6, and C7 are all grounded. The cathode of the diode D2 is connected to the input end of the chip U1, and the anode of the diode D2 is connected to the D pin of the MOS tube Q1.

9. The constant current control circuit of the mobile lighting device according to claim 5, characterized in that: The model of the chip U1 is HT7150.

10. The constant current control circuit of the mobile lighting device according to claim 3, characterized in that: The power module includes a battery, a diode D1, a capacitor C10, and a fuse. One end of the battery is connected to the capacitor C10 and grounded. The capacitor C10 is connected to the cathode of the diode D1. The anode of the diode D1 is connected to the fuse. The fuse is connected to the other end of the battery. The cathode of the diode D1 is connected to the resistor R2 and the S pin of the MOS tube Q1 through a magnetic bead L4.

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