A PWM signal control circuit based on optical coupling isolation and a charging controller

Abstract

The utility model discloses a kind of PWM signal control circuit and charging controller based on opto-coupler isolation, wherein, PWM signal control circuit based on opto-coupler isolation includes opto-coupler isolation unit and MCU unit electrically connected together: the opto-coupler isolation unit is used to the MCU unit output high-low level isolated by opto-coupler;The MCU unit is used to output multiplex PWM signal according to the high-low level output.This utility model provides PWM signal control circuit and charging controller based on opto-coupler isolation, first solve the problem of limited charging controller PWM signal output, secondly this technical scheme can be integrated in charging controller and used, and can be used as high-speed PWM signal output module alone, only high-low level input can control PWM signal output, can be widely applied to various application scenarios needing isolated PWM signal control.

Description

Technical Field

[0001] This utility model relates to the field of electric vehicle charging technology, and in particular to a PWM signal control circuit and charging controller based on optocoupler isolation. Background Technology

[0002] The development of new energy electric vehicles is currently progressing rapidly, leading to the emergence of various charging piles and charging equipment. As the most important charging system for electric vehicles, charging piles require PWM signals for control of some functions. However, the number of PWM signal output pins for charging controllers is limited, and in extreme cases, there may be no PWM signal pins available. Furthermore, different functions have different ground signals, requiring isolation to control these functions, which existing charging controllers cannot meet. Utility Model Content

[0003] To overcome the shortcomings of the prior art, this utility model provides a PWM signal control circuit and a charging controller based on optocoupler isolation.

[0004] A PWM signal control circuit based on optocoupler isolation includes an optocoupler isolation unit and an MCU unit electrically connected together: the optocoupler isolation unit is used to output optocoupler-isolated high and low levels to the MCU unit; the MCU unit is used to output multiple PWM signals according to the high and low levels.

[0005] Optionally, the optocoupler isolation unit includes at least four input signals; of the four input signals, three of the input signals correspond to the control of the three primary colors of red, green and blue, respectively, and one of the input signals is a reserved signal;

[0006] The MCU unit outputs two PWM signals, which are used to control the color, brightness, and dimness of the preset light strip.

[0007] Optionally, the optocoupler isolation unit includes four optocouplers, each corresponding to one input signal, and connected via a pin connector.

[0008] Optionally, the reserved signal is used to reserve 485 communication and is connected to a 485 isolation chip, a 485 transceiver chip, and a power supply unit that supplies power to the 485 isolation chip via the pin connector.

[0009] Optionally, the MCU unit is further connected to a light strip power control unit, which is used to control the power signal of the preset light strip.

[0010] Optionally, an LED indicator is attached to the MCU unit, and the LED indicator is used to indicate the working status of the optocoupler-isolated PWM signal control circuit by flashing.

[0011] Optionally, it also includes a DIP switch electrically connected to the MCU unit, the DIP switch being used to control 485 address selection.

[0012] Optionally, it also includes a main control power supply unit for powering the optocoupler-isolated PWM signal control circuit.

[0013] Optionally, a programming circuit electrically connected to the MCU unit may also be included.

[0014] A charging controller is used in electric vehicle charging stations and includes the optocoupler-isolated PWM signal control circuit described above.

[0015] This invention relates to an optocoupler-isolated PWM signal control circuit and a charging controller. The optocoupler unit outputs high and low levels to control the MCU unit to output a high-speed PWM signal. When the frequency of the PWM signal output by the MCU is below 1MHz, the signal waveform remains almost undistorted. Simultaneously, the optocoupler provides 5kV RMS isolation voltage for the control signal. Compared with existing technologies, this invention firstly solves the problem of limited PWM signal output in charging controllers. Secondly, this solution can be integrated into a charging controller or used independently as a high-speed PWM signal output module. It controls the PWM signal output using only high and low level inputs, making it widely applicable to various applications requiring isolated PWM signal control. Attached Figure Description

[0016] Figure 1 This is a framework diagram of the PWM signal control circuit based on optocoupler isolation in an embodiment of this utility model;

[0017] Figure 2 This is a circuit diagram of the optocoupler isolation unit in an embodiment of this utility model;

[0018] Figure 3 This is a circuit schematic diagram of the MCU unit in an embodiment of this utility model;

[0019] Figure 4 This is a circuit diagram of the MCU unit outputting PWM signal to control the light strip in an embodiment of this utility model;

[0020] Figure 5 This is a circuit diagram of the LED strip power control unit in an embodiment of the present invention;

[0021] Figure 6 This is a circuit diagram of the 485 communication in an embodiment of this utility model;

[0022] Figure 7This is a circuit diagram illustrating the DIP switch controlling the 485 address selection in an embodiment of this utility model.

[0023] Figure 8 This is a circuit diagram of the main control power supply unit in an embodiment of this utility model;

[0024] Figure 9 This is a circuit diagram of the program burning circuit in an embodiment of this utility model. Detailed Implementation

[0025] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0026] See Figures 1 to 9 This paper provides a PWM signal control circuit based on optocoupler isolation, the overall framework of which is as follows: Figure 1 As shown, it includes an optocoupler isolation unit and an MCU unit that are electrically connected together: the optocoupler isolation unit is used to output optocoupler-isolated high and low levels to the MCU unit; the MCU unit is used to output multiple PWM signals according to the high and low levels.

[0027] The optocoupler isolation unit is used to output high and low levels that are optocoupled and isolated. This variable high and low level is used to control the MCU unit to flexibly output PWM signals, thereby solving the problem of limited PWM signal pins in the existing system. At the same time, optocoupler isolation can meet the isolation requirements for ground signals with different functions.

[0028] Furthermore, the optocoupler isolation unit includes at least four input signals D1; ​​among the four input signals, three input signals correspond to the control of the three primary colors of red, green and blue, respectively, and one input signal is a reserved signal; the MCU unit outputs two PWM signals, which are used to control the color, brightness and dimness changes of the preset light strip.

[0029] Specifically, in one implementation, such as Figure 2 As shown, it includes four optocoupler-isolated signals. DI1+, DI2+, and DI3+ correspond to the preset red, green, and blue primary color control of the LED strip, and control the MCU to output different PWM waves through high and low level changes, thereby controlling the color, brightness, and dimness of the LED strip. DI4+ is a reserved signal that can isolate 4kV DC.

[0030] The optocoupler isolation unit includes four optocouplers E1, E2, E3 and E4, which are LTV-816S-TA1. Each of the four optocouplers corresponds to one input signal and is connected through a 10-pin connector CON1, which is WJ15EDGVC-3.81-10P.

[0031] The implementation of the MCU unit is as follows Figure 3 As shown, U5 is an MCU, specifically a CMS32L051QN32, a 32-bit chip developed based on the ARM Cortex-M0+ core, used to output PWM signals. In one implementation, as... Figure 4 As shown, the MCU provides two PWM control channels, controlling the color, brightness, and dimming of the LED strip by outputting PWM waves. The UDD32C05L01 corresponds to a 2.7m LED strip with a current of 1.3A. Preferably, a green LED indicator D5 is mounted on the MCU unit. This indicator is used to display the operating status of the entire circuit through flashing; for example, flashing every 1 second indicates normal operation.

[0032] like Figure 5 The diagram shows the LED strip power control unit. Q8 and T1 are linked to control the LED power supply. When the MCU outputs a high-level A-POWER signal, LED_PWR+ changes from 0V to 12V.

[0033] Furthermore, the reserved signal is used to reserve 485 communication, and is connected to a 485 isolation chip, a 485 transceiver chip, and a power supply unit that powers the 485 isolation chip via pin connector CON1. ​​Specifically, as follows... Figure 6 The diagram shown is a circuit schematic for 485 communication. U1 is a 485 isolation chip, which electrically isolates the signals at both ends, suppressing interference and protecting the equipment from high voltage. U2 is a 485 transceiver chip; U3 is the bus-side power supply voltage for the isolation chip, and also has isolation function, capable of isolating DC 4kV. Preferably, as shown... Figure 7 As shown, it also includes a DIP switch SW1, which is used to control the 485 address selection. Specifically, the DIP switch is a DIP switch with a pin pitch of 2.54mm, a flat-to-raised design, and has 4 red DIP positions.

[0034] like Figure 8 As shown, it also includes a main control power supply unit for powering the optocoupler-isolated PWM signal control circuit. The power management chip U4 uses the SY8205FCC, which has synchronous buck regulation, accepts an input voltage of 4.5V-30V, outputs a maximum of 5A, and provides 5V power, with a maximum output power of 25W.

[0035] Furthermore, it also includes a programmable circuit electrically connected to the MCU unit. For example... Figure 9 As shown, U9 is a 232 chip that supports programming and reading MCU print information.

[0036] A charging controller is provided, which is used in electric vehicle charging piles and includes the optocoupler-isolated PWM signal control circuit as described above. Specifically, the optocoupler-isolated PWM signal control circuit can be integrated into the charging controller or used as a standalone PWM signal output module, offering high flexibility in implementation.

[0037] The above is a description of the present utility model to help understand it; however, the implementation of the present utility model is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A PWM signal control circuit based on optocoupler isolation, characterized in that, The system includes an optocoupler isolation unit and an MCU unit electrically connected together: the optocoupler isolation unit is used to output optocoupler-isolated high and low levels to the MCU unit; the MCU unit is used to output multiple PWM signals according to the high and low levels; The optocoupler isolation unit includes at least four input signals; of the four input signals, three of them correspond to the control of the three primary colors of red, green and blue, respectively, and one of them is a reserved signal. The MCU unit outputs two PWM signals, which are used to control the color, brightness, and dimness of the preset light strip.

2. The PWM signal control circuit based on optocoupler isolation as described in claim 1, characterized in that, The optocoupler isolation unit includes four optocouplers, each corresponding to one input signal, and connected via a pin connector.

3. The PWM signal control circuit based on optocoupler isolation as described in claim 2, characterized in that, The reserved signal is used to reserve 485 communication, and is connected to a 485 isolation chip, a 485 transceiver chip, and a power supply unit that supplies power to the 485 isolation chip through the pin connector.

4. The PWM signal control circuit based on optocoupler isolation as described in claim 1, characterized in that, The MCU unit is also connected to a light strip power control unit, which is used to control the power signal of the preset light strip.

5. The PWM signal control circuit based on optocoupler isolation as described in claim 1, characterized in that, The MCU unit is equipped with LED indicator lights, which are used to indicate the operating status of the optocoupler-isolated PWM signal control circuit by flashing.

6. The PWM signal control circuit based on optocoupler isolation as described in claim 3, characterized in that, It also includes a DIP switch electrically connected to the MCU unit, the DIP switch being used to control 485 address selection.

7. The PWM signal control circuit based on optocoupler isolation as described in any one of claims 1 to 6, characterized in that, It also includes a main control power supply unit that supplies power to the optocoupler-isolated PWM signal control circuit.

8. The PWM signal control circuit based on optocoupler isolation as described in claim 7, characterized in that, It also includes a program burning circuit electrically connected to the MCU unit.

9. A charging controller, characterized in that, The charging controller is used in electric vehicle charging piles and includes a PWM signal control circuit based on optocoupler isolation as described in any one of claims 1 to 8.

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