PWM direct-current power regulator based on STM32 control

Abstract

The utility model discloses a PWM direct current power regulator based on STM32 control, which is used in combination with a temperature control instrument to regulate and control the temperature of a heating device in real time, and specifically comprises an STM32 main control chip and a PWM direct current power regulator, the input end of the STM32 main control chip is connected with the temperature control instrument, and the output end of the STM32 main control chip is connected with the PWM direct current power regulator. And the output end of the PWM direct-current power regulator is connected with the heating device. The STM32 main control chip is used for collecting signals from the temperature control instrument, PWM pulse width modulation is fully automatically achieved on the heating device in real time, the duty ratio of PWM is adjusted to control the output voltage, and therefore the temperature control precision and the energy-saving effect are effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of electronic design technology, specifically to a PWM DC power regulator based on STM32 control. Background Technology

[0002] A power regulator is a device that controls the electrical power consumption of a circuit within a certain range. Especially in the field of temperature control, constant temperature control at a fixed point is often required, which necessitates adjusting the output power of heating devices to achieve accurate temperature control.

[0003] Currently, commonly used temperature control heating typically uses contactors to control whether the heater is heating. These contactors only output two signals: open and closed, meaning the heater can only operate at full power or zero power. This results in poor energy efficiency and low temperature control accuracy. Utility Model Content

[0004] This invention provides a PWM DC power regulator based on STM32 control, which effectively solves the shortcomings of the prior art and improves temperature control accuracy and energy saving effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An STM32-based PWM DC power regulator, used in conjunction with a temperature controller, is disclosed to regulate the temperature of a heating element in real time. The regulator comprises an STM32 main control chip and a PWM DC power regulator. The input of the STM32 main control chip is connected to the temperature controller, and the output is connected to the PWM DC power regulator. The output of the PWM DC power regulator is connected to the heating element. The STM32 main control chip acquires signals from the temperature controller and performs real-time PWM pulse width modulation on the heating element, adjusting the PWM duty cycle to control the output voltage, thereby achieving high efficiency, energy saving, and high-precision temperature control.

[0007] As a preferred embodiment of the above scheme, the PWM DC power regulator includes a PWM signal isolation output circuit, which includes an optocoupler and a MOSFET. The STM32 main control chip outputs a PWM signal with a certain period and different duty cycle based on the analog signal collected by the internal AD converter. After being isolated and protected by the optocoupler, the signal is output to two parallel MOSFETs and then to the heating device through a Zener diode.

[0008] As a preferred embodiment of the above scheme, the PWM signal isolation output circuit further includes an isolation power supply connected to the optocoupler to provide isolation power to the optocoupler.

[0009] As a preferred embodiment of the above scheme, the STM32 main control chip is connected to the temperature control instrument through a signal conditioning circuit.

[0010] As a preferred embodiment of the above scheme, the signal conditioning circuit includes an instrumentation operational amplifier. The analog voltage or current signal output by the temperature control instrument is processed by the operational amplifier and then sent to the AD acquisition of the STM32 main control chip to convert the analog signal into a digital signal.

[0011] As a preferred embodiment of the above scheme, the signal conditioning circuit further includes a current signal input interface, a voltage signal input interface, and a signal selection switch. The current signal input interface is connected to the signal selection switch, the voltage signal input interface is connected to the signal selection switch after passing through a voltage divider resistor, the signal selection switch is connected to an instrumentation operational amplifier after passing through diode protection and low-pass filtering, and the instrumentation operational amplifier is connected to the STM32 main control chip after passing through a low-pass filter.

[0012] As a preferred embodiment of the above solution, the STM32 main control chip is connected to an external power supply. The external power supply is converted into DC power by an ACDC switching power supply, and then converted into power supply for the internal chip by a DCDC chip.

[0013] As a preferred embodiment of the above scheme, the external power supply is connected to a varistor and a thermistor after passing through a current fuse, and the varistor and the thermistor are connected to an AC / DC switching power supply.

[0014] Due to the above structure, the beneficial effects of this utility model are as follows:

[0015] This application uses an STM32 main control chip to acquire signals from a temperature control instrument, and implements PWM pulse width modulation on the heating device in real time and automatically. The duty cycle of the PWM is adjusted to control the output voltage, thereby effectively improving temperature control accuracy and energy saving. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0018] Figure 2 This is a design diagram of the PWM signal isolation output circuit of this utility model;

[0019] Figure 3 This is a design diagram of the signal conditioning circuit of this utility model;

[0020] Figure 4 This is the power supply circuit design diagram for this utility model. Detailed Implementation

[0021] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0022] like Figure 1 As shown, this embodiment provides a PWM DC power regulator based on STM32 control, which is used in conjunction with a temperature controller to regulate the temperature of a heating device in real time. It includes an STM32 main control chip and a PWM DC power regulator. The input terminal of the STM32 main control chip is connected to the temperature controller, and the output terminal is connected to the PWM DC power regulator. The output terminal of the PWM DC power regulator is connected to the heating device. The STM32 main control chip acquires signals from the temperature controller and performs real-time PWM pulse width modulation on the heating device, adjusting the PWM duty cycle to control the output voltage, thereby achieving high efficiency, energy saving, and high-precision temperature control.

[0023] in:

[0024] The PWM DC power regulator includes a PWM signal isolation output circuit, which comprises an optocoupler and MOSFETs. The STM32 main control chip outputs PWM signals with different duty cycles based on the analog signal acquired by its internal AD converter. After being isolated by the optocoupler, the signals are output to two parallel MOSFETs, and then through a Zener diode to the heating element. When the PWM output is high, the MOSFETs conduct, and the heating element heats up. When the output is low, the MOSFETs turn off, and the heating element stops heating. The parallel MOSFETs reduce the channel resistance, significantly increasing the on-state current at the same rated junction temperature. The PWM signal isolation output circuit also includes an isolation power supply connected to the optocoupler, providing isolated power to the optocoupler. The specific circuit is shown below. Figure 2 As shown, in the circuit:

[0025] U22 is an optocoupler that isolates the control signals from the STM32 main control chip from the subsequent drivers and serves to protect the control chip during startup.

[0026] Q4 and Q5 are MOSFETs. Connecting Q4 and Q5 in parallel reduces the channel resistance of the MOSFETs, and greatly increases the on-state current under the same rated junction temperature.

[0027] D1 is a Zener diode, which can ensure the stability of the output DC voltage;

[0028] U8 is an isolated power supply, providing isolated power to the optocoupler. This ensures the separation of control and power signal power supplies, protecting the control chip and enabling the STM32 control chip to operate safely and reliably.

[0029] The STM32 main control chip is connected to the temperature controller via a signal conditioning circuit. This signal conditioning circuit includes an operational amplifier (op-amp). The analog voltage or current signal output from the temperature controller is processed by the op-amp and then sent to the STM32 main control chip's AD converter to convert the analog signal into a digital signal. The signal conditioning circuit also includes a current signal input interface, a voltage signal input interface, and a signal selection switch. The current signal input interface is connected to the signal selection switch. The voltage signal input interface is connected to the signal selection switch via a voltage divider resistor. The signal selection switch is connected to the op-amp after diode protection and low-pass filtering. The op-amp is then connected to the STM32 main control chip after low-pass filtering. The specific circuit is shown below. Figure 3 As shown, in the circuit:

[0030] J2 is the current signal input interface, and R3 is used to convert the current signal into a voltage signal.

[0031] J3 is the voltage signal input interface, and R2, R4, and R5 are voltage divider resistors used for input protection.

[0032] P1 is a signal selection switch, which selects whether to input a voltage signal or a current signal, so that it can satisfy both current signal input and voltage signal input.

[0033] Q1 and Q3 are low-leakage-current dual diodes that can protect the subsequent operational amplifier;

[0034] R8 and C13, R10 and C17 form a low-pass filter to reduce high-frequency harmonic signal interference.

[0035] U16 is an instrumentation operational amplifier that conditions the differential signal, increases the AD input impedance, and facilitates the extraction of the signal voltage.

[0036] R11 and C18 form a low-pass filter to eliminate high-frequency interference signals entering the AD sampling.

[0037] The STM32 main control chip is connected to an external power supply. This external power supply is converted to DC by an AC-DC switching power supply, and then further converted to power the internal chips by a DC-DC chip. A series of protection measures are implemented after the external AC power supply enters. The external power supply passes through a fuse and is connected to a varistor and a thermistor, which are then connected to the AC-DC switching power supply. The specific circuit is as follows: Figure 4 As shown, in the circuit:

[0038] FUSE1 is a current fuse for current protection;

[0039] MOV1 is a varistor used for protection against lightning strikes and grid voltage fluctuations;

[0040] The NTC15D-11 is a thermistor, also used for overcurrent protection.

[0041] The U26 is an AC / DC module that converts 220V AC power to 12V DC power.

[0042] U3 is an LDO module that converts 12V DC to 5V;

[0043] U1 also serves as an LDO module to convert 5V power to 3.3V.

[0044] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A PWM DC power regulator based on STM32 control, used in conjunction with a temperature controller to regulate the temperature of a heating device in real time, characterized in that: STM32 master chip, PWM direct current power regulator are included; The input end of the STM32 master chip is connected with the temperature control instrument, and the output end is connected with the PWM direct current power regulator. The STM32 master chip collects signals from the temperature control instrument, and realizes pulse width modulation of the heater through real-time PWM pulse width modulation, adjusts the duty cycle of the PWM to control the output voltage, so as to achieve efficient energy saving and high-precision temperature control requirements.

2. The PWM DC power regulator based on STM32 control according to claim 1, characterized in that: The PWM direct current power regulator includes a PWM signal isolation output circuit, which includes an optocoupler and a MOS tube.

3. The PWM DC power regulator based on STM32 control according to claim 2, characterized in that: The STM32 master chip outputs a PWM signal with a certain period and different duty cycles according to the internal AD collected analog signal, and then outputs the signal to two parallel MOS tubes after isolation protection by the optocoupler, and then outputs the signal to the heater through a voltage stabilizing diode.

4. The PWM DC power regulator based on STM32 control according to claim 1, characterized in that: The PWM signal isolation output circuit also includes an isolation power supply connected with the optocoupler to provide an isolation power supply for the optocoupler.

5. The PWM DC power regulator based on STM32 control according to claim 4, characterized in that: The STM32 master chip is connected with the temperature control instrument through a signal conditioning circuit.

6. The PWM DC power regulator based on STM32 control according to claim 5, characterized in that: The signal conditioning circuit includes an instrument operational amplifier, and the analog voltage or current signal output by the temperature control instrument is adjusted and processed by the operational amplifier before being collected by the STM32 master chip to convert the analog signal into a digital signal.

7. The PWM DC power regulator based on STM32 control according to claim 1, characterized in that: The signal conditioning circuit also includes a current signal input interface, a voltage signal input interface, and a signal selection switch.

8. The PWM DC power regulator based on STM32 control according to claim 7, characterized in that: The current signal input interface is connected with the signal selection switch, and the voltage signal input interface is connected with the signal selection switch through a voltage dividing resistor. The signal selection switch is connected with the instrument operational amplifier after diode protection and low-pass filtering, and the instrument operational amplifier is connected with the STM32 master chip after low-pass filtering. The STM32 master chip is connected with an external power supply, which is converted into direct current by an ACDC switching power supply and then converted into internal chip power supply by a DCDC chip. The external power supply is connected with a pressure sensitive resistor and a thermistor after passing through a current fuse. The pressure sensitive resistor and the thermistor are connected with the ACDC switching power supply.

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