CN219107708U

CN219107708U - Dimming system based on USB bus

Info

Publication number: CN219107708U
Application number: CN202223293513.5U
Authority: CN
Inventors: 崔周培; 曾范昌; 蔡欣荣; 张琦; 张曙光; 张庆力; 张志琴; 万丰; 周吉; 刘姜伟
Original assignee: 716th Research Institute of CSIC
Current assignee: 716th Research Institute of CSIC
Priority date: 2022-12-08
Filing date: 2022-12-08
Publication date: 2023-05-30
Anticipated expiration: 2032-12-08

Abstract

The utility model discloses a dimming system based on a USB bus, which comprises a USB interface circuit, a central processing unit MCU, a dimming circuit and a power supply circuit; the USB interface circuit, the dimming circuit and the power supply circuit are all connected with the central processing unit MCU. The utility model realizes the rapid transmission of dimming instructions based on the USB bus and the MCU, can drive up to 128 paths of LEDs to realize on/off, flicker and flicker rate change and brightness 256-level change, uses the PWM dimming chip to drive the LED circuit, has good dimming effect, and can control the flicker and flicker rate change of the LEDs; the device has the characteristics of few used components, low power consumption, high efficiency, energy conservation, rich dimming function, strong practicability and the like, and is high in expandability and convenient to control.

Description

Dimming system based on USB bus

Technical Field

The utility model belongs to the electrical field, and particularly relates to a dimming system based on a USB bus.

Background

With the development of society, intelligent dimming systems are becoming more and more a focus of attention, and the combination of dimming technology and microcontroller technology has important meaning and value. In industrial systems, methods of changing the impedance of a light source path and adjusting the voltage of a light source end are often used to realize brightness adjustment of an LED; the method is characterized in that the LED circuit is serially added with the analog devices or the digital potentiometers, so that the LED circuit is large in use quantity and power consumption, and is not beneficial to energy conservation and not beneficial to improving the dimming effect.

Disclosure of Invention

In order to solve the technical defects in the prior art, the utility model provides a dimming system based on a USB bus.

The technical solution for realizing the purpose of the utility model is as follows:

a dimming system based on a USB bus comprises a USB interface circuit, a central processing unit MCU, a dimming circuit and a power supply circuit;

the USB interface circuit, the dimming circuit and the power supply circuit are all connected with the central processing unit MCU.

Further, the USB interface circuit comprises a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a first triode;

one end of the first resistor is input with an external DP signal, the other end of the first resistor is connected with a USBDP pin of the central processing unit MCU, one end of the second resistor is input with an external DM signal, and the other end of the second resistor is connected with a USBDM pin of the central processing unit MCU;

one end of the first capacitor is connected with the USBDP pin of the central processing unit MCU, the other end of the first capacitor is grounded to GND, one end of the second capacitor is connected with the USBDM pin of the central processing unit MCU, and the other end of the second capacitor is grounded to GND;

one end of the third resistor is connected with the USBDP pin of the central processing unit MCU, the other end of the third resistor is connected with the collector electrode of the first triode, the base electrode of the first triode is connected with the USB_CONNECT pin of the central processing unit MCU, and the emitter of the first triode is connected with 3.3V voltage.

Further, the dimming circuit comprises a plurality of integrated circuit chips, and each integrated circuit chip is connected to the central processing unit MCU in parallel to drive the LEDs of the integrated circuit chips.

Further, the circuits of each integrated circuit chip are the same, and taking the first integrated circuit chip as an example, the circuit comprises an eighteenth resistor, a forty-third capacitor and a sixty-first capacitor;

the

pins

1, 2, 3 and 12 of the first integrated circuit chip are grounded GND, the pin 24 of the first integrated circuit chip is simultaneously connected with 3.3V voltage and one end of a forty-third capacitor, and the other end of the forty-third capacitor is grounded GND;

one end of the eighteenth resistor is connected with the 24 pins of the first integrated circuit chip, the other end of the eighteenth resistor is connected with the 21 pins of the first integrated circuit chip, one end of the sixty-first capacitor is connected with the 21 pins of the first integrated circuit chip, and the other end of the sixty-first capacitor is grounded to GND.

Further, 8 integrated circuit chips are arranged in total.

Further, the power supply circuit comprises a power supply chip, a third electrolytic capacitor, a fourth capacitor, a fifth capacitor and a sixth electrolytic capacitor;

the positive electrode of the third electrolytic capacitor is connected with external 5V voltage, the negative electrode of the third electrolytic capacitor is grounded GND, one end of the fourth capacitor is connected with external 5V voltage, the other end of the fourth capacitor is grounded GND, and the 1 pin of the power chip is connected with external 5V voltage, and the 2 pin of the power chip is grounded GND;

the 3 feet of the power chip outputs 3.3V voltage, one end of the fifth capacitor is connected with the 3 feet of the power chip, the other end of the fifth capacitor is grounded to GND, and the anode of the sixth electrolytic capacitor is connected with the 3 feet of the power chip and the cathode of the sixth electrolytic capacitor is grounded to GND.

Further, the integrated circuit chip adopts a PCA9532 integrated circuit chip.

Furthermore, the power chip adopts a MIC29300-3.3WU model chip.

Compared with the prior art, the utility model has the remarkable advantages that:

(1) The utility model realizes the rapid transmission of dimming instructions based on the USB bus and the MCU, and can drive up to 128 paths of LEDs to realize the on-off, flicker and flicker rate change and brightness 256-level change;

(2) The LED circuit is driven by the PWM dimming chip, so that the dimming effect is good, and the flickering of the LED can be controlled, and the flickering rate is variable; the device has the characteristics of few used components, low power consumption, high efficiency, energy conservation, rich dimming function, strong practicability and the like, and is high in expandability and convenient to control.

The utility model is described in further detail below with reference to the drawings and the detailed description.

Drawings

Fig. 1 is a schematic diagram of a dimming system architecture based on a USB bus according to the present utility model.

Fig. 2 is a schematic diagram of a USB interface circuit according to an embodiment of the present utility model.

Fig. 3 is a schematic diagram of a dimming circuit according to an embodiment of the utility model.

Fig. 4 is a schematic diagram of a power circuit in an embodiment of the utility model.

Detailed Description

It is easy to understand that various embodiments of the present utility model can be envisioned by those of ordinary skill in the art without altering the true spirit of the present utility model in light of the present teachings. Accordingly, the following detailed description and drawings are merely illustrative of the utility model and are not intended to be exhaustive or to limit or restrict the utility model. Rather, these embodiments are provided so that this disclosure will be thorough and complete by those skilled in the art. Preferred embodiments of the present utility model are described in detail below with reference to the attached drawing figures, which form a part of the present application and are used in conjunction with embodiments of the present utility model to illustrate the innovative concepts of the present utility model.

Examples

Referring to fig. 1, a dimming system based on a USB bus includes a USB interface circuit, a central processing unit MCU, a dimming circuit, and a power supply circuit;

The USB interface circuit comprises an RC circuit and a triode pull-up circuit which are connected with each other, the RC circuit carries out impedance matching on external USB bus USBDP and USBDM digital signals and then outputs the signals to the central processing unit MCU, and the triode pull-up circuit is used for pulling up a USBDP signal line to a high level when power-on initialization is carried out; the central processing unit MCU obtains a dimming command of the upper computer through the USB bus and sends the dimming command to the dimming circuit through the I2C bus; the dimming circuit obtains dimming command data of the MCU through an I2C bus and directly drives the multi-path LEDs to be switched on, switched off, twinkled and changed in brightness 256 levels; the power supply circuit converts 5V of external input into 3.3V through the three-terminal voltage regulator chip and supplies power to the central processing unit MCU and the dimming circuit.

Further, referring to fig. 2, the USB interface circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, a second capacitor C2, and a first triode Q1;

one end of the first resistor R1 is input with an external USB bus DP signal, the other end of the first resistor R1 is connected with a USBDP pin of the central processing unit MCU, one end of the second resistor R2 is input with an external USB bus DM signal, and the other end of the second resistor R2 is connected with a USBDM pin of the central processing unit MCU;

one end of the first capacitor C1 is connected with a USBDP pin of the central processing unit MCU, the other end of the first capacitor C2 is grounded to GND, and one end of the second capacitor C2 is connected with a USBDM pin of the central processing unit MCU, and the other end of the second capacitor C2 is grounded to GND;

one end of the third resistor R3 is connected with the USBDP pin of the central processing unit MCU, the other end of the third resistor R3 is connected with the collector of the first triode Q1, the base of the first triode Q1 is connected with the USB_CONNECT pin of the central processing unit MCU, and the transmitter of the first triode Q1 is connected with 3.3V voltage.

When the CPU MCU is initially powered on, the USB_CONNECT pin of the CPU MCU outputs a low level, the first triode Q1 of the driving switch pulls up the USBDP pin of the CPU MCU through the third resistor R3, and equipment initialization is completed.

Further, referring to fig. 3, the dimming circuit includes a plurality of integrated circuit chips, each of which is connected in parallel to the central processing unit MCU, to drive the LEDs of the integrated circuit chips.

In the embodiment, 8 integrated circuit chips are used, and PCA9532 integrated circuits are used as the chips;

8 PCA9532 integrated circuits are connected in a pull-up mode or a pull-down mode through

pins

1, 2 and 3, and 8 integrated circuits are configured to be 000-111 in address respectively; the 22 nd pin SCL and the 23 rd pin SDA of the 8 PCA9532 integrated circuit are connected to the SCL pin and the SDA pin of the central processing unit MCU in parallel. The single PCA9532 integrated circuit is used as a slave, and according to the address configuration, the data sent by the central processing unit MCU in the form of a host through the I2C bus is received, and 16 paths of LEDs connected to the single PCA9532 integrated circuit are driven to realize the on/off, flicker rate change and brightness change.

Further, the circuits of each integrated circuit chip are the same, taking the first integrated circuit chip D3 as an example, including an eighteenth resistor R18, a forty-third capacitor C43, and a sixty-first capacitor C61;

the

pins

1, 2, 3 and 12 of the first integrated circuit chip D3 are grounded GND, the pin 24 of the first integrated circuit chip D3 is simultaneously connected to the 3.3V voltage and one end of the forty-third capacitor C43, and the other end of the forty-third capacitor C43 is grounded GND;

one end of the eighteenth resistor R18 is connected to the 24 pin of the first integrated circuit chip D3, the other end of the eighteenth resistor R18 is connected to the 21 pin of the first integrated circuit chip D3, one end of the sixty-first capacitor C61 is connected to the 21 pin of the first integrated circuit chip D3, and the other end of the sixty-first capacitor C61 is grounded GND.

The circuit connections of the remaining 7 PCA9532 integrated circuits are shown in fig. 3.

Further, referring to fig. 4, the power supply circuit includes a power supply chip D1, a third electrolytic capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a sixth electrolytic capacitor C6;

the positive electrode of the third electrolytic capacitor C3 is connected with external 5V voltage, the negative electrode of the third electrolytic capacitor C3 is grounded GND, one end of the fourth capacitor C4 is connected with external 5V voltage, the other end of the fourth capacitor C4 is grounded GND, the 1 pin of the power chip D1 is connected with external 5V voltage, and the 2 pin of the power chip D is grounded GND;

the 3 feet of the power chip D1 outputs 3.3V voltage, one end of the fifth capacitor C5 is connected with the 3 feet of the power chip D1, the other end of the fifth capacitor C5 is grounded to GND, and the positive electrode of the sixth electrolytic capacitor C6 is connected with the 3 feet of the power chip D1, and the negative electrode of the sixth electrolytic capacitor C6 is grounded to GND.

Further, the power chip D1 is a MIC29300-3.3WU type chip.

The utility model realizes the rapid transmission of dimming instructions based on the USB bus and the MCU, can drive up to 128 paths of LEDs to realize the on/off, flicker and flicker rate change and brightness 256-level change, uses fewer components and has low power consumption, has the characteristics of high efficiency, energy saving, rich dimming functions, strong practicability and the like, and has strong expandability and is convenient to control.

The foregoing embodiments illustrate and describe the basic principles, principal features of the utility model. It will be understood by those skilled in the art that the present utility model is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present utility model, and various changes and modifications may be made without departing from the spirit and scope of the utility model, which is defined in the appended claims.

Claims

1. The dimming system based on the USB bus is characterized by comprising a USB interface circuit, a central processing unit MCU, a dimming circuit and a power supply circuit;

2. The USB bus-based dimming system of claim 1, wherein the USB interface circuit comprises a first resistor (R1), a second resistor (R2), a third resistor (R3), a first capacitor (C1), a second capacitor (C2), a first transistor (Q1);

one end of the first resistor (R1) is input with an external DP signal, the other end of the first resistor is connected with a USBDP pin of the central processing unit MCU, one end of the second resistor (R2) is input with an external DM signal, and the other end of the second resistor is connected with a USBDM pin of the central processing unit MCU;

one end of the first capacitor (C1) is connected with a USBDP pin of the central processing unit MCU, the other end of the first capacitor is grounded to GND, one end of the second capacitor (C2) is connected with a USBDM pin of the central processing unit MCU, and the other end of the second capacitor is grounded to GND;

one end of the third resistor (R3) is connected with the USBDP pin of the central processing unit MCU, the other end of the third resistor is connected with the collector of the first triode (Q1), the base of the first triode (Q1) is connected with the USB_CONNECT pin of the central processing unit MCU, and the transmitter of the first triode (Q1) is connected with 3.3V voltage.

3. The USB bus-based dimming system of claim 1, wherein the dimming circuit comprises a plurality of integrated circuit chips, each integrated circuit chip being connected in parallel to the central processing unit MCU, driving the LEDs of the integrated circuit chips.

4. A USB bus-based dimming system according to claim 3, wherein the circuitry of each of the integrated circuit chips is identical, and wherein the first integrated circuit chip (D3) comprises an eighteenth resistor (R18), a forty-third capacitor (C43), and a sixty-first capacitor (C61);

the pins 1, 2, 3 and 12 of the first integrated circuit chip (D3) are grounded to GND, the pin 24 of the first integrated circuit chip (D3) is simultaneously connected with 3.3V voltage and one end of a forty-third capacitor (C43), and the other end of the forty-third capacitor (C43) is grounded to GND;

one end of the eighteenth resistor (R18) is connected with the 24 pin of the first integrated circuit chip (D3), the other end of the eighteenth resistor (R18) is connected with the 21 pin of the first integrated circuit chip (D3), one end of the sixteenth capacitor (C61) is connected with the 21 pin of the first integrated circuit chip (D3), and the other end of the sixteenth capacitor (C61) is grounded GND.

5. The USB bus-based dimming system of claim 3 or 4, wherein the integrated circuit chip is provided with 8 chips in total.

6. The USB bus-based dimming system according to claim 1, wherein the power circuit comprises a power chip (D1), a third electrolytic capacitor (C3), a fourth capacitor (C4), a fifth capacitor (C5), a sixth electrolytic capacitor (C6);

the positive electrode of the third electrolytic capacitor (C3) is connected with external 5V voltage, the negative electrode of the third electrolytic capacitor (C3) is grounded GND, one end of the fourth capacitor (C4) is connected with external 5V voltage, the other end of the fourth capacitor is grounded GND, the 1 pin of the power chip (D1) is connected with external 5V voltage, and the 2 pin of the power chip is grounded GND;

the 3 feet of the power chip (D1) output 3.3V voltage, one end of the fifth capacitor (C5) is connected with the 3 feet of the power chip (D1), the other end of the fifth capacitor is grounded to GND, the positive electrode of the sixth electrolytic capacitor (C6) is connected with the 3 feet of the power chip (D1), and the negative electrode of the sixth electrolytic capacitor is grounded to GND.

7. The USB bus-based dimming system of claim 3 or 4, wherein the integrated circuit chip employs a PCA9532 integrated circuit chip.

8. The USB bus-based dimming system according to claim 6, wherein the power chip (D1) is a MIC29300-3.3WU model chip.