CN220067743U

CN220067743U - Lamp bead control circuit based on single-path driving

Info

Publication number: CN220067743U
Application number: CN202320697097.0U
Authority: CN
Inventors: 董陈; 朱正辉; 赵定金
Original assignee: Guangzhou Shenghe Electronics Co ltd
Current assignee: Guangzhou Shenghe Electronics Co ltd
Priority date: 2023-03-31
Filing date: 2023-03-31
Publication date: 2023-11-21
Anticipated expiration: 2033-03-31

Abstract

The utility model provides a lamp bead control circuit based on one-way driving, and relates to the technical field of lamp bead control circuits. The utility model comprises a control circuit, a driving circuit, a DC-DC circuit and a light-emitting circuit. The DC-DC circuit provides the required voltage for the whole circuit. The driving circuit stably outputs constant current to be used by the LED lamp. The light-emitting circuit comprises six sub-light-emitting circuits, and each sub-light-emitting circuit comprises an LED lamp. The six LED lamps are connected by a common cathode. Under the combined action of the circuit structures, the utility model realizes the effect of driving six parallel lamp beads in one way, and saves the use of components and the area of a circuit board. And the control circuit is connected into the light-emitting circuit through six paths of pins to independently control the six sub-light-emitting circuits, so that the independent control or the integral control of the color lamp beads is realized.

Description

Lamp bead control circuit based on single-path driving

Technical Field

The utility model relates to the technical field of lamp bead control circuits, in particular to a lamp bead control circuit based on one-way driving.

Background

The light emission and the brightness change of the electronic lamp beads depend on the control of the driving circuit. The current lamp bead control circuit is driven in a one-to-one mode, namely, one lamp bead corresponds to one path of driving circuit, and the number of the driving circuits is the same as that of the lamp bead circuits.

However, the bead control circuit of a bead circuit corresponding to a driving circuit requires a larger PCB to mount more components, and thus increases the economic cost and makes the product appear not compact enough. And the common lamp bead control circuit can only realize whether the lamp bead is lighted or not, but can not control the brightness degree of the lamp bead.

Disclosure of Invention

Aiming at the defects, the utility model provides a lamp bead control circuit based on one-way driving.

The utility model is realized by the following technical scheme: the utility model provides a realize lamp pearl control circuit based on single-way drive, including a control circuit, a drive circuit, power supply circuit and a lighting circuit, control circuit includes main control chip U1, crystal oscillator circuit S1 and reset circuit S2 insert respectively in main control chip U1, lighting circuit includes many sub-lighting circuit, every way sub-lighting circuit all includes the lamp pearl, control circuit and drive circuit ' S input electric connection, so that the PWM signal of control circuit output adjusts the size of drive circuit output current, drive circuit ' S same output and multichannel sub-lighting circuit ' S input electric connection, so that drive circuit passes through the lamp pearl luminous in the multichannel sub-lighting circuit of electric current drive, and control circuit is connected with the other inputs of multichannel sub-lighting circuit, so that the multichannel PWM signal of control circuit output adjusts the luminance of lamp pearl in the multichannel sub-lighting circuit, power supply circuit is used for supplying power to control circuit and drive circuit respectively.

Further, the DC-DC circuit comprises a first voltage reduction circuit, a second voltage reduction circuit and a third voltage reduction circuit, wherein the input end of the first voltage reduction circuit is connected with an external power supply, the output end of the first voltage reduction circuit is connected with the input end of the second voltage reduction circuit, the output end of the second voltage reduction circuit is connected with the input end of the third voltage reduction circuit, the output end of the third voltage reduction circuit is connected with a main control chip U1 and a reset circuit S2 in the control circuit, so that voltage signals output by the output end of the third voltage reduction circuit are used as input power supplies of the main control chip U1 and the reset circuit S2, and the output end of the first voltage reduction circuit is connected with the drive circuit, so that voltage signals output by the output end of the first voltage reduction circuit are used as input power supplies of the drive circuit.

Further, the first voltage reducing circuit comprises a voltage reducing chip U3, and the model of the voltage reducing chip U3 is XL1509-ADJ; the second voltage reducing circuit comprises a voltage reducing chip U4, and the model U4 is XL1509-5.0; the third voltage reducing circuit comprises a voltage reducing chip U2, and the model of the voltage reducing chip U2 is AMS117-3.3V.

Further, the voltage output by the output end of the first voltage reduction circuit is 12V direct current, the voltage output by the output end of the second voltage reduction circuit is 5V direct current, and the voltage output by the output end of the third voltage reduction circuit is 3.3V direct current.

Further, the main control chip U1 and the reset circuit S2 are respectively connected with 3.3V direct current, and the crystal oscillator circuit S1 and the reset circuit S2 are respectively electrically connected with the main control chip U1.

Further, the main control chip U1 is STM32F103C8T6.

Further, the driving circuit comprises a constant current chip U5, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R6, an NMOS tube Q1, an NMOS tube Q2, an inductor L1, a diode D1 and a diode D3, wherein the model of the constant current chip U5 is MBI6672, the model of the diode D3 is MBR20100, one common end of the capacitor C8 and the capacitor C9 is connected in parallel and then connected with 12V direct current, the other common end of the capacitor C8 and the capacitor C9 are connected in parallel and then grounded, the capacitor C8 and the capacitor C9 are filter capacitors, the 12V direct current filtered by the capacitor C8 and the capacitor C9 is connected in parallel and then connected with the pin 1 and the pin 14 of the constant current chip U5, one end of the resistor R3 and the resistor R4 are connected in parallel and then connected with the 12V direct current filtered by the capacitor C8 and the pin 12 of the NMOS tube Q1 respectively, the grid electrode of the NMOS tube Q1 is connected to a pin 11 of the constant current chip U5, the source electrode of the NMOS tube Q1 is connected to a pin 10 of the constant current chip U5, the source electrode of the NMOS tube Q1 is connected to the cathode of the diode D3 and one end of the inductor L1 respectively, the anode of the diode D3 is grounded, the other end of the inductor L1 is connected with one end of the resistor R2 and the drain electrode of the NMOS tube Q2 and then is connected to the input end of the light-emitting circuit together, the source electrode of the NMOS tube Q2 is grounded, the grid electrode of the NMOS tube Q2 is connected to a pin 7 of the constant current chip U5, a resistor R6 is connected between the drain electrode of the NMOS tube Q2 and the source electrode of the NMOS tube Q2 in series, the other end of the resistor R2 is connected to the pin 5 of the constant current chip U5 and one end of the capacitor C10 respectively after being connected in series with the resistor R1, the other end of the capacitor C10 is grounded, the pin 6 of the constant current chip U5 is connected to the pin 18 of the main control chip U1, and one end of the capacitor C11 is connected to the pin 10 of the constant current chip U5 respectively, the source electrode of the NMOS tube Q1, the cathode of the diode D3 and the common connection end of the inductor L1, the other end of the capacitor C11 is respectively connected with the pin 9 of the constant current chip U5 and the cathode of the diode D1, so that the capacitor C11 applies output voltage to the NMOS tube Q1 through the pin 10 and the pin 11 of the constant current chip U5, the anode of the diode D1 is respectively connected with the pin 8 of the constant current chip U5 and one end of the capacitor C12, and the other end of the capacitor C12 is grounded, so that the pin 8 of the constant current chip U5 and the capacitor C12 can charge the capacitor C11.

Further, the light-emitting circuit comprises six sub light-emitting circuits, the light-emitting circuit comprises six PMOS tubes, six NPN triodes, six LED lamps and twenty-four resistors, the six PMOS tubes are a PMOS tube Q3, a PMOS tube Q4, a PMOS tube Q5, a PMOS tube Q10, a PMOS tube Q11 and a PMOS tube Q12 respectively, the six NPN triodes are a triode Q7, a triode Q8, a triode Q9, a triode Q15, a triode Q16 and a triode Q17 respectively, the six LED lamps are an LED1, an LED2, an LED3, an LED4, an LED5 and an LED6 respectively, the twenty-four resistors are divided into six groups, each group comprises four resistors, one PMOS tube, one NPN triode and one LED lamp form one path of the light-emitting circuit, the six sub light-emitting circuits are in a parallel structure, the six sub light-emitting circuits are completely identical in structure, the one path of the six sub light-emitting circuits comprises a PPMOS tube Q3, a NPN triode Q7, a resistor R24, a resistor R26, a resistor R29, a resistor R36 and an LED1, one end of a resistor R36 is connected with an emitter of a triode Q7 and then commonly grounded, the other end of the resistor R36 is connected with one end of a resistor R29 and then commonly connected with a base electrode of the triode Q7, one end of the resistor R29 is connected with a PWM signal transmitted by a main control chip U1, a collector electrode of the triode Q7 is connected with one end of a resistor R26, the other end of the resistor R26 is connected with one end of a resistor R24 and then commonly connected with a grid electrode of a PMOS tube Q3, the other end of the resistor R24 is connected with a drain electrode of the PMOS tube Q3, a drain electrode of the PMOS tube Q3 is connected with an output end of a driving circuit, a source electrode of the PMOS tube Q3 is connected with an anode of an LED1, a source electrode of the PMOS tube in each sub-lighting circuit is connected with an anode of the LED lamp and a cathode of the LED lamp are grounded, a drain electrode of the PMOS tube in each sub-lighting circuit is connected with the same output end of the driving circuit, a base electrode of the NPN-type triode in series with one resistor in each sub-lighting circuit is connected with the main control chip U1, to receive PWM signals from the master control unit U1.

Further, the six LED lamps are connected by a common cathode.

Further, the lamp beads in the light-emitting circuit are all colored lamp beads.

The utility model has the beneficial effects that: the utility model provides a circuit for realizing lamp bead control based on one-way driving, which effectively reduces the use of components and the area of a circuit board, further reduces the economic cost and ensures that the product is smaller. The DC-DC circuit provides required voltage for the whole circuit, and is suitable for lamp beads and chips with various different voltage specifications. The driving circuit can stably output constant current for the LED lamp, the LED lamp is greatly influenced by current change, the service life of the LED lamp is prolonged by adopting constant current driving, and the luminous efficiency and stability of the LED lamp can be improved.

Drawings

FIG. 1 is a schematic block diagram of the present utility model;

FIG. 2 is a control circuit diagram of the present utility model;

FIG. 3 is a driving circuit diagram of the present utility model;

FIG. 4 is a power circuit diagram of the present utility model;

fig. 5 is a light-emitting circuit diagram of the present utility model.

Detailed Description

The utility model will be further described with reference to the accompanying drawings and detailed description below:

referring to fig. 1-5, a lamp bead control circuit based on one-way driving includes a control circuit, a driving circuit, a power supply circuit and a light emitting circuit. The power supply circuit is a DC-DC circuit, and the light-emitting circuit comprises six sub-light-emitting circuits which are connected in parallel. Each sub-lighting circuit comprises an LED lamp. The six LED lamps are connected by a common cathode, and the six LED lamps are all colored. The power supply circuit is connected with the control circuit and the driving circuit respectively, so that the power supply circuit supplies power to the control circuit and the driving circuit respectively. The control circuit is connected with the driving circuit, so that the PWM signal sent to the driving circuit by the control circuit controls the current output by the driving circuit. The driving circuit is connected with the light-emitting circuit, and the six parallel sub-light-emitting circuits are all connected with the same output port of the driving circuit, so that the driving circuit outputs constant current to the LED lamps in the six parallel sub-light-emitting circuits. The control circuit is connected with the light-emitting circuit, and six paths of parallel sub light-emitting circuits are respectively connected with six ports of the control circuit, so that the six paths of parallel sub light-emitting circuits respectively and independently receive PWM signals from the control circuit, and further the PWM signals output by the control circuit are used for adjusting the brightness of the lamp beads in the light-emitting circuit. Therefore, the six parallel sub-light emitting circuits can be controlled independently or in whole.

The control circuit comprises a main control chip U1, a crystal oscillator circuit S1 and a reset circuit S2, wherein the main control chip U1 and the reset circuit S2 are respectively connected with 3.3V direct current, and the crystal oscillator circuit S1 and the reset circuit S2 are respectively and electrically connected with the main control chip U1. The crystal oscillator circuit S1 comprises a capacitor C1, a capacitor C2 and a crystal oscillator, wherein two ends of the crystal oscillator are respectively connected with one end of the capacitor C1 and one end of the capacitor C2, and two ends of the crystal oscillator are respectively connected with a pin 5 and a pin 6 of the main control chip U1. The other end of the capacitor C1 and the other end of the capacitor C2 are grounded. The model U1 of the main control chip is STM32F103C8T6. The 3.3V dc power is supplied by a power supply circuit. The reset circuit S2 includes a resistor R23 and a capacitor C19, one end of the resistor R23 is connected to one end of the capacitor C19, the other end of the resistor R23 is connected to 3.3V dc, and the other end of the capacitor C19 is grounded. And the connection end of the resistor R23 and the capacitor C19 is commonly connected to the pin 7 of the main control chip U1. Pins 10, 11, 12, 13, 16 and 17 of the main control chip U1 are respectively connected into six sub-lighting circuits, so that each sub-lighting circuit receives PWM control signals output by the main control chip U1. The pin 8 of the main control chip U1 is connected to the pin 4 of the constant current chip U5 in the driving circuit, so that the PWM signal output by the pin 8 of the main control chip U1 controls the current output by the driving circuit to the light-emitting circuit. Pins 9, 24, 36 and 48 of the main control chip U1 are respectively connected with 3.3V direct current, and pins 8, 23, 35, 44 and 47 of the main control chip U1 are respectively grounded.

The driving circuit comprises a constant current chip U5, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R6, an NMOS tube Q1, an NMOS tube Q2, an inductor L1, a diode D1 and a diode D3. The model of the constant current chip U5 is MBI6672, and the model of the diode D3 is MBR20100. After the capacitor C8 and the capacitor C9 are connected in parallel, a common end is connected with 12V direct current, and the 12V direct current is provided by a power circuit. The other common ground after the capacitor C8 and the capacitor C9 are connected in parallel is connected to the ground, and the capacitor C8 and the capacitor C9 are both filter capacitors. The 12V direct current filtered by the capacitor C8 and the capacitor C9 is respectively connected to the pin 1 and the pin 14 of the constant current chip U5. Both the capacitor C8 and the capacitor C9 are filter capacitors. And one end of the resistor R3 and one end of the resistor R4 are connected in parallel and then connected with 12V direct current filtered by the capacitor C8 and the capacitor C9, and the other end of the resistor R3 and the other end of the resistor R4 are connected in parallel and then connected with the pin 12 of the constant current chip U5 and the drain electrode of the NMOS tube Q1 respectively. The grid electrode of the NMOS tube Q1 is connected to a pin 11 of the constant current chip U5, the source electrode of the NMOS tube Q1 is connected to a pin 10 of the constant current chip U5, the source electrode of the NMOS tube Q1 is respectively connected to the cathode of the diode D3 and one end of the inductor L1, the anode of the diode D3 is grounded, and the other end of the inductor L1 is connected with one end of the resistor R2 and the drain electrode of the NMOS tube Q2 and then is jointly used as the output end of the driving circuit to be connected to the input end of the light-emitting circuit. The source electrode of the NMOS tube Q2 is grounded, the grid electrode of the NMOS tube Q2 is connected to the pin 7 of the constant current chip U5, an R6 is connected in series between the drain electrode of the NMOS tube Q2 and the source electrode of the NMOS tube Q2, and the other end of the resistor R2 is connected in series with the resistor R1 and then is connected to the pin 5 of the constant current chip U5 and one end of the capacitor C10 respectively. The NMOS transistor Q1 is a switch function, and the NMOS transistor Q2 is a dimming function. The other end of the capacitor C10 is grounded, the pin 6 of the constant current chip U5 is grounded, and the pin 4 of the constant current chip U5 is connected to the pin 18 of the main control chip U1. One end of the capacitor C11 is respectively connected with the pin 10 of the constant current chip U5, the source electrode of the NMOS tube Q1, the cathode of the diode D3 and the common connection end of the inductor L1, and the other end of the capacitor C11 is respectively connected with the pin 9 of the constant current chip U5 and the cathode of the diode D1. The diode D3 is a freewheeling diode, and is used in combination with an inductive load, and when the current of the inductive load suddenly changes, a sudden change voltage is generated across the inductor L1, which may damage other elements. When the diode D3 is used, the current can be changed more gently, and the occurrence of the surge voltage is avoided. The capacitor C11 and the diode D1 are boot-strap type driving circuits. The bootstrap driving circuit is mainly used for providing a voltage higher than the source voltage at the gate of the main switch component so as to drive the N field effect transistor. When the freewheeling diode D3 is forward biased, the pin 8 of the constant current chip U5 charges the diode D1 and the capacitor C11. When the freewheeling diode D3 is reverse biased, the capacitor C11 maintains a voltage difference between the gate and the source of the NMOS transistor Q1 to ensure that the NMOS transistor Q1 maintains a conductive state. NMOS tube Q2 mainly realizes the parallel dimming function, provides smooth linear dimming and 10000:1 high resolution of dimming. When the NMOS Q1 is turned on, the output end is shorted together, the constant current chip U5 will work at the maximum cut-off time, where R1, R2, and C10 are used to control the cut-off time, so as to avoid abnormal noise generated by dimming and improve the dimming resolution. The inductance L1 is an energy storage function. The capacitor C12 is a voltage stabilizing capacitor, and when the NMOS transistor Q1 is turned off, the capacitor C12 provides instantaneous energy to charge the C11 of the driving circuit. Resistor R3 and resistor R4 are current sensing resistors. After the power supply is connected, a pin 3 of the constant current chip U5 receives a PWM signal with a duty ratio of 0% -100% of the main control chip U1, when the NMOS tube Q1 is conducted, the diode D3 is in a reverse bias state, the inductor L1 stores energy and provides current to the output end of the driving circuit, and at the moment, the current passes through the resistor R3 and the resistor R4 to realize detection of peak current of the inductor. When the NMOS Q1 is turned off, the diode D3 is biased forward, the inductor L1 starts to discharge and supply current to the output terminal of the driving circuit, and the voltage on the capacitor C12 starts to charge the diode D1 and the capacitor C11. When the voltage of the pin 5 of the constant current chip U5 reaches 1.25V, the constant current chip U5 pulls down the voltage level of the pin 5 to zero through the internal switch, and the NMOS transistor Q1 switch is turned on again. The driving circuit stably outputs constant current to be used by the LED lamp in the light-emitting circuit. The LED lamp is greatly influenced by current change, and the service life of the LED lamp is prolonged by adopting constant current driving; the luminous efficiency and stability of the LED lamp can be improved, and the light attenuation of the LED lamp can be reduced. The anode of the diode D1 is connected to the pin 8 of the constant current chip U5 and one end of the capacitor C12 respectively, and the other end of the capacitor C12 is grounded.

The lighting circuit includes six sub lighting circuits. The light-emitting circuit comprises six PMOS tubes, six NPN triodes, six LED lamps and twenty-four resistors, wherein the six PMOS tubes are a PMOS tube Q3, a PMOS tube Q4, a PMOS tube Q5, a PMOS tube Q10, a PMOS tube Q11 and a PMOS tube Q12 respectively. The six NPN triodes are respectively a triode Q7, a triode Q8, a triode Q9, a triode Q15, a triode Q16 and a triode Q17. The six LED lamps are respectively an LED1, an LED2, an LED3, an LED4, an LED5 and an LED6. Twenty four resistors are respectively a resistor R24, a resistor R26, a resistor R29, a resistor R36, a resistor R47, a resistor R52, a resistor R58 and a resistor R61, a resistor R22, a resistor R27, a resistor R31, a resistor R38, a resistor R48, a resistor R54, a resistor R59, a resistor R62, a resistor R5, a resistor R28, a resistor R32, a resistor R41, a resistor R49, a resistor R55, a resistor R60 and a resistor R63, twenty four resistors are divided into six groups, each group comprises four resistors, and the four resistors, one PMOS tube, one NPN triode and one LED lamp form one path of a light-emitting circuit, the six-way light-emitting circuit is of a parallel structure, the six sub-luminous circuits are completely identical in structure, one of the six sub-luminous circuits comprises a PPMOS tube Q3, an NPN triode Q7, a resistor R24, a resistor R26, a resistor R29, a resistor R36 and an LED1, one end of the resistor R36 is connected with an emitter of the triode Q7 and then commonly grounded, the other end of the resistor R36 is connected with one end of the resistor R29 and then commonly connected with a base electrode of the triode Q7, one end of the resistor R29 is connected with a PWM signal transmitted by a main control chip U1, the triode Q7 is conducted by the PWM signal, so that the PMOS tube Q3 is conducted, and the positive electrode of a lamp bead is also changed from 0 to positive electrode output of constant current driving along with the PWM signal with the duty ratio of 0% -100%. The collector of triode Q7 is connected with one end of resistance R26, and the other end of resistance R26 is connected with one end of resistance R24 and inserts PMOS tube Q3's grid jointly, and the drain electrode of PMOS tube Q3 is inserted to the other end of resistance R24 to PMOS tube Q3's drain electrode inserts drive circuit's output, and LED1 positive pole is inserted to PMOS tube Q3's source electrode, and LED1 negative pole ground connection, and the source electrode of PMOS tube all connects the LED lamp positive pole in each sub-lighting circuit, and the LED lamp negative pole all connects to ground, and the same output of drive circuit is all inserted to the drain electrode of PMOS tube in each sub-lighting circuit. The base electrode of the NPN triode in the six-sub luminous circuit is connected with a resistor in series and then is respectively connected with pins 10, 11, 12, 13, 16 and 17 of the main control chip U1 so as to respectively receive PWM signals with a duty ratio of 0% -100% from the main control chip U1. The triode is conducted by the PWM signal, so that the PMOS tube is conducted, the positive electrode of each color of the lamp bead is changed from 0 to the positive electrode of the constant current drive along with the PWM signal with the duty ratio of 0-100%, and the brightness of the LED lamp is smoothly adjusted from 0-100% because the D of the PMOS tube is the positive electrode of the constant current drive, the S of the PMOS tube is the positive electrode of each color of the lamp bead, and the constant current drive is the common cathode.

The power supply circuit is a DC-DC circuit, the DC-DC circuit comprises a first voltage reduction circuit, a second voltage reduction circuit and a third voltage reduction circuit, wherein the input end of the first voltage reduction circuit is connected with an external power supply, the output end of the first voltage reduction circuit is connected with the input end of the second voltage reduction circuit, the output end of the second voltage reduction circuit is connected with the input end of the third voltage reduction circuit, 3.3V direct current is output by the third voltage reduction circuit and connected with the main control chip U1 and the reset circuit S2 to serve as input power supplies of the main control chip U1 and the reset circuit S2, and 12V direct current is output by the first voltage reduction circuit and connected with the drive circuit to serve as input power supply of the drive circuit.

The first voltage drop circuit includes a voltage drop chip U3, a capacitor C7, a capacitor C93, a capacitor C94, a capacitor C95, a diode D6, an inductor L11, a resistor R124, and a resistor R125. The model U3 of the depressurization chip is XL1509-ADJ. One common end of the capacitor C7 and the capacitor C94 which are connected in parallel is respectively connected with an external power supply and the pin 1 of the voltage reduction chip U3, and the capacitor C7 and the capacitor C94 are both used for filtering the external power supply. The other common terminal of the capacitor C7 and the capacitor C94 connected in parallel is grounded. Pins 4, 5, 6, 7 and 8 of the buck chip U3 are all grounded. The cathode of the diode D6 is connected with one end of the inductor L11 and then is connected to the pin 2 of the buck chip U3, and the anode of the diode D6 is grounded. The diode D6 functions as a flywheel diode. The other end of the inductor L11 is connected with one end of the resistor R124, one end of the capacitor C93 and one end of the capacitor C95 to jointly output 12V direct current. The inductor L11 functions as energy storage. The other end of the resistor R124 is connected with one end of the resistor R125 and then is connected with the pin 3 of the buck chip U3, and the other end of the resistor R125 is grounded. The other end of the capacitor C93 is connected to the other end of the capacitor C95 and then commonly grounded. The capacitors C93 and C95 function as filtering and energy storage.

The second voltage drop circuit comprises a voltage dropping chip U4, a capacitor C18, an inductor L12 and a diode D2. The model U4 of the depressurization chip is XL1509-5.0. The 12V direct current output by the first voltage drop circuit is respectively connected to the pin 1 of the U4 and one end of the capacitor C18, and the other end of the capacitor C18 is grounded. Pins 4, 5, 6, 7, 8 of U4 are all grounded. The cathode of the diode D2 is connected with one end of the inductor L2 and then is connected to the pin 2 of the U4, and the anode of the diode D2 is grounded. The diode D2 functions as a flywheel diode. The other end of the inductor L2 is connected with the pin 3 of the U4 and then outputs the output voltage of the second voltage drop circuit. The inductor L2 functions as energy storage. The output voltage of the second voltage drop circuit is 5V.

The third voltage drop circuit comprises a voltage drop chip U2, a capacitor C3, a capacitor C4, a capacitor C5 and a capacitor C6. The model of the depressurization chip U2 is AMS117-3.3V. After the capacitor C3 and the capacitor C5 are connected in parallel, one common end is respectively connected with the output voltage of the second voltage drop circuit and the pin 3 of the voltage drop chip U2, and the other common end is grounded after the capacitor C3 and the capacitor C5 are connected in parallel. The capacitors C3 and C5 function as filtering and energy storage. Pin 1 of buck chip U2 is grounded. One end of the capacitor C4, one end of the capacitor C6 and the pin 2 of the buck chip U2 are connected and then commonly output the output voltage of the third voltage drop circuit. The output voltage of the third voltage drop circuit is 3.3V. The other end of the capacitor C4 and the other end of the capacitor C6 are grounded. The capacitors C6 and C4 act as filtering.

The utility model utilizes the power supply circuit to provide the required voltage for the whole circuit, the control circuit controls the magnitude of the output current of the driving circuit, the driving circuit outputs stable constant voltage to the six-sub-lighting circuit, and the control circuit controls the lighting and the brightness change of the LED lamp by outputting six PWM signals to the six-sub-lighting circuit.

Various other corresponding changes and modifications will occur to those skilled in the art from the foregoing description and the accompanying drawings, and all such changes and modifications are intended to be included within the scope of the present utility model as defined in the appended claims.

Claims

1. A lamp bead control circuit based on single-path driving is realized, which is characterized in that: the LED lamp comprises a control circuit, a driving circuit, a power supply circuit and a light-emitting circuit, wherein the control circuit comprises a main control chip U1, a crystal oscillator circuit S1 and a reset circuit S2, the crystal oscillator circuit S1 and the reset circuit S2 are respectively connected into the main control chip U1, the light-emitting circuit comprises a plurality of sub light-emitting circuits, each sub light-emitting circuit comprises a lamp bead, the control circuit is electrically connected with the input end of the driving circuit, PWM signals output by the control circuit are used for adjusting the output current of the driving circuit, the same output end of the driving circuit is electrically connected with the input ends of the plurality of sub light-emitting circuits, the driving circuit is used for driving the lamp beads in the plurality of sub light-emitting circuits to emit light through the currents, the control circuit is connected with the other input ends of the plurality of sub light-emitting circuits, and the power supply circuit is used for supplying power to the control circuit and the driving circuit respectively.

2. The single-pass drive based lamp bead control circuit of claim 1, wherein: the power supply circuit is a DC-DC circuit, the DC-DC circuit comprises a first voltage reduction circuit, a second voltage reduction circuit and a third voltage reduction circuit, wherein the input end of the first voltage reduction circuit is connected with an external power supply, the output end of the first voltage reduction circuit is connected with the input end of the second voltage reduction circuit, the output end of the second voltage reduction circuit is connected with the input end of the third voltage reduction circuit, the output end of the third voltage reduction circuit is connected with a main control chip U1 and a reset circuit S2 in the control circuit, so that voltage signals output by the output end of the third voltage reduction circuit are used as input power supplies of the main control chip U1 and the reset circuit S2, and the output end of the first voltage reduction circuit is connected with the drive circuit, so that voltage signals output by the output end of the first voltage reduction circuit are used as input power supplies of the drive circuit.

3. The single-pass drive based lamp bead control circuit of claim 2, wherein: the first voltage reduction circuit comprises a voltage reduction chip U3, wherein the model number of the voltage reduction chip U3 is XL1509-ADJ; the second voltage reducing circuit comprises a voltage reducing chip U4, and the model U4 is XL1509-5.0; the third voltage reducing circuit comprises a voltage reducing chip U2, and the model of the voltage reducing chip U2 is AMS117-3.3V.

4. The single-pass drive based lamp bead control circuit of claim 3, wherein: the voltage output by the output end of the first voltage reduction circuit is 12V direct current, the voltage output by the output end of the second voltage reduction circuit is 5V direct current, and the voltage output by the output end of the third voltage reduction circuit is 3.3V direct current.

5. The single-pass drive based lamp bead control circuit of claim 4, wherein: the main control chip U1 and the reset circuit S2 are respectively connected with 3.3V direct current, and the crystal oscillator circuit S1 and the reset circuit S2 are respectively electrically connected with the main control chip U1.

6. The single-pass drive based lamp bead control circuit of claim 5, wherein: the main control chip U1 is STM32F103C8T6.

7. The single-pass drive based lamp bead control circuit of claim 6, wherein: the driving circuit comprises a constant current chip U5, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R6, an NMOS tube Q1, an NMOS tube Q2, an inductor L1, a diode D1 and a diode D3, wherein the model of the constant current chip U5 is MBI6672, the model of the diode D3 is MBR20100, one common end of the capacitor C8 and the capacitor C9 is connected with 12V direct current in parallel, the other common end of the capacitor C8 and the capacitor C9 is connected with the ground after being connected with the other common end in parallel, the capacitor C8 and the capacitor C9 are filter capacitors, the 12V direct current filtered by the capacitor C8 and the capacitor C9 is connected with the pin 14 respectively, one end of the resistor R3 and the resistor R4 are connected with the 12V direct current filtered by the capacitor C8 and the capacitor C9 in parallel, the other end of the resistor R3 and the resistor R4 is connected with the pin 12 of the constant current chip U5 and the drain of the NMOS tube Q1 respectively, the grid electrode of the NMOS tube Q1 is connected to the pin 11 of the constant current chip U5 to control the on-off state of the NMOS tube Q1, the source electrode of the NMOS tube Q1 is connected to the pin 10 of the constant current chip U5, the source electrode of the NMOS tube Q1 is connected to the cathode of the diode D3 and one end of the inductor L1 respectively, the anode of the diode D3 is grounded, the other end of the inductor L1 is connected with one end of the resistor R2 and the drain electrode of the NMOS tube Q2 and then is connected to the input end of the light-emitting circuit together, the source electrode of the NMOS tube Q2 is grounded, the grid electrode of the NMOS tube Q2 is connected to the pin 7 of the constant current chip U5, a resistor R6 is connected between the drain electrode of the NMOS tube Q2 and the source electrode of the NMOS tube Q2 in series, the other end of the resistor R2 is connected to the pin 5 of the constant current chip U5 and one end of the capacitor C10 respectively in series, the other end of the capacitor C10 is grounded, the pin 6 of the constant current chip U5 is grounded, the pin 4 of the constant current chip U5 is connected to the pin 18 of the main control chip U1, one end of the capacitor C11 is connected to the pin 10 of the constant current chip U5 respectively, the source electrode of the NMOS tube Q1, the cathode of the diode D3 and the common connection end of the inductor L1, the other end of the capacitor C11 is respectively connected with the pin 9 of the constant current chip U5 and the cathode of the diode D1, so that the capacitor C11 applies output voltage to the NMOS tube Q1 through the pin 10 and the pin 11 of the constant current chip U5, the anode of the diode D1 is respectively connected with the pin 8 of the constant current chip U5 and one end of the capacitor C12, and the other end of the capacitor C12 is grounded, so that the pin 8 of the constant current chip U5 and the capacitor C12 can charge the capacitor C11.

8. The single-pass drive based lamp bead control circuit of claim 7, wherein: the lighting circuit comprises six sub lighting circuits, and the lighting circuit comprises six PMOS tubes, six NPN triodes, six LED lamps and twenty-four resistors, the six PMOS tubes are respectively PMOS tube Q3, PMOS tube Q4, PMOS tube Q5, PMOS tube Q10, PMOS tube Q11 and PMOS tube Q12, the six NPN triodes are respectively triode Q7, triode Q8, triode Q9, triode Q15, triode Q16 and triode Q17, the six LED lamps are respectively LED1, LED2, LED3, LED4, LED5 and LED6, the twenty-four resistors are respectively divided into six groups, each group comprises four resistors, one PMOS tube, one NPN triode and one LED lamp form one of the lighting circuits, the six sub lighting circuits are of parallel structure, and the six sub lighting circuits are completely the same in structure, wherein the six sub lighting circuits comprise PPMOS tube Q3, NPN triode Q7, resistor R24, resistor R26, resistor R29, resistor R36 and LED1, one end of a resistor R36 is connected with an emitter of a triode Q7 and then commonly grounded, the other end of the resistor R36 is connected with one end of a resistor R29 and then commonly connected with a base electrode of the triode Q7, one end of the resistor R29 is connected with a PWM signal transmitted by a main control chip U1, a collector electrode of the triode Q7 is connected with one end of a resistor R26, the other end of the resistor R26 is connected with one end of a resistor R24 and then commonly connected with a grid electrode of a PMOS tube Q3, the other end of the resistor R24 is connected with a drain electrode of the PMOS tube Q3, a drain electrode of the PMOS tube Q3 is connected with an output end of a driving circuit, a source electrode of the PMOS tube Q3 is connected with an anode of an LED1, a source electrode of the PMOS tube in each sub-lighting circuit is connected with an anode of the LED lamp and a cathode of the LED lamp are grounded, a drain electrode of the PMOS tube in each sub-lighting circuit is connected with the same output end of the driving circuit, a base electrode of the NPN-type triode in series with one resistor in each sub-lighting circuit is connected with the main control chip U1, to receive PWM signals from the master control unit U1.

9. The single-pass drive based lamp bead control circuit of claim 8, wherein: the six LED lamps are connected by a common cathode.

10. The single-pass drive based lamp bead control circuit of claim 9, wherein: the lamp beads in the light-emitting circuit are all colored lamp beads.