An adaptive control circuit for a heating element

Abstract

The utility model discloses a kind of adaptive control circuit of heating body, including MCU temperature control circuit, temperature control circuit, temperature feedback device, current detection circuit, voltage detection circuit, protection detection circuit and temperature display device.The control circuit can automatically identify the heating core type connected, according to the deviation of set temperature and actual temperature output PWM control signal, drive temperature control circuit to carry out temperature rising or cooling adjustment;Temperature, current, voltage are monitored in real time by a variety of detection circuits, and protection mechanism is started under abnormal state, simultaneously, working state is fed back in real time by display device.The control circuit is strong in adaptability, safe and reliable, and is applicable to a variety of heating application scenarios.

Description

Technical Field

[0001] This utility model relates to a control circuit, specifically to an adaptive control circuit for a heating element. Background Technology

[0002] With the widespread application of industrial and consumer equipment such as electronic welding and electrothermal treatment, the heating element, as the core heating component, directly determines the heating efficiency and temperature stability of the equipment. In existing technologies, most common heating element control circuits are dedicated control systems, meaning the controller is designed with parameter matching and circuit configuration specific to the heating core's specifications. While this approach can meet the performance requirements of specific application scenarios, it suffers from poor adaptability and cannot effectively accommodate the various heating cores with significantly different specifications and parameters available on the market.

[0003] Currently, there are many types of heating elements on the market, with varying operating voltages (commonly 12V and 24V), rated power, and resistance values, as well as differences in material properties such as NTC / PTC temperature resistance characteristics. This means that a controller can often only be used with one or a few types of heating elements. Once the heating element is replaced, the user must reconfigure the controller or replace the entire control system, which not only increases the barrier to entry but also significantly increases the overall cost and maintenance complexity of the equipment.

[0004] Furthermore, traditional heating element control circuits mostly employ a single voltage or current drive method, lacking dynamic identification and regulation capabilities. They cannot adjust in real time according to the thermal characteristics of the heating element, resulting in low control accuracy, slow temperature recovery response, and poor temperature control stability. Meanwhile, while some solutions possess simple temperature feedback functions, the feedback path is not integrated with the heating element, causing thermal coupling response lag, making it difficult to meet the requirements of high-precision welding, heat treatment, and other applications with high demands for temperature regulation response and stability.

[0005] Therefore, there is an urgent need to provide a heating element control circuit that is compatible with multiple heating elements and has automatic identification and adaptive control capabilities, so that the control system can automatically match control parameters and modes according to the type of heating element connected, thereby achieving wider adaptability, more accurate temperature control effect, and higher system stability and user convenience. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides an adaptive control circuit for a heating element, which effectively overcomes the shortcomings of existing technologies.

[0007] This utility model is achieved through the following technical solution: an adaptive control circuit for a heating element, comprising:

[0008] The MCU temperature control circuit is used to receive detection signals, identify the parameter type of the connected heating element, calculate the control signal based on the deviation between the set temperature and the actual temperature, and output the PWM control signal.

[0009] A temperature control circuit, connected to the MCU temperature control circuit, is used to receive PWM control signals and drive the heating element to heat up or cool down.

[0010] A temperature feedback device, connected to the MCU temperature control circuit, is used to detect the temperature of the heating element and transmit the temperature feedback signal to the MCU temperature control circuit.

[0011] The current detection circuit is used to detect the operating current through the heating element and provide a current feedback signal to the MCU temperature control circuit.

[0012] The voltage detection circuit is used to detect the input voltage of the heating element and output the voltage detection signal to the MCU temperature control circuit.

[0013] A protection detection circuit, connected to the MCU temperature control circuit, is used to monitor whether the system experiences abnormalities such as overcurrent, overvoltage, overheating, or dry burning and to trigger protection measures.

[0014] A temperature display device is connected to the MCU temperature control circuit and is used to display the set temperature, the actual temperature, and alarm information.

[0015] As a preferred technical solution, the MCU temperature control circuit includes functional modules for detecting power supply voltage, current AD conversion, PWM output control, heating element insertion identification, and sleep / wake-up detection.

[0016] As a preferred technical solution, the temperature control circuit consists of an amplification and driving module composed of resistors, capacitors, transistors and driving chips, and a switching circuit.

[0017] As a preferred technical solution, the temperature feedback device includes an amplifier circuit composed of resistors and a harmonic filter circuit composed of capacitors.

[0018] As a preferred technical solution, the current detection circuit includes a detection resistor and a harmonic filter for detecting the operating current of the heating element.

[0019] As a preferred technical solution, the voltage detection circuit consists of a voltage divider circuit composed of resistors and capacitors to detect the input voltage of the heating element.

[0020] As a preferred technical solution, the protection detection circuit includes a detection circuit and a logic control unit, which is used to identify abnormal operating states and output a shutdown signal to the MCU.

[0021] As a preferred technical solution, the temperature display device is a digital display module, which can display the set value, the current temperature value, and temperature deviation information.

[0022] The beneficial effects of this utility model are: by setting the identification logic and parameter model in the MCU, this utility model can identify and judge the connected heating element according to key indicators such as resistance, current and voltage, and automatically match a suitable control strategy without manual setting, which greatly improves the versatility and adaptability of the control circuit.

[0023] The controller of this utility model can automatically switch between voltage control, current control or power control modes according to the characteristics of different heating elements to achieve more precise temperature regulation. It can also be combined with the internal PID control algorithm to achieve rapid heating and constant temperature, meeting the application scenarios with high response requirements.

[0024] The circuit of this invention supports the integration of a temperature sensing device (such as an NTC thermistor) into the heating element and directly performs closed-loop feedback control with the MCU, which improves the coupling between temperature detection and regulation, resulting in faster thermal response and more stable temperature recovery.

[0025] The control circuit of this utility model is equipped with a protection and detection module, which has the ability to monitor and handle various abnormal operating conditions. When the system detects a risky condition, it can cut off the heating output in time to prevent equipment damage or safety accidents, thereby improving the stability and reliability of the system. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a system block diagram of the present invention;

[0028] Figure 2 This is a circuit diagram of the MCU temperature control circuit of this utility model;

[0029] Figure 3 This is a circuit diagram of the temperature control circuit of this utility model;

[0030] Figure 4 This is a circuit diagram of the temperature feedback device of this utility model;

[0031] Figure 5 This is a circuit diagram of the current detection circuit of this utility model;

[0032] Figure 6 This is a voltage detection circuit diagram of the present invention;

[0033] Figure 7 This is the protection and detection circuit diagram of this utility model. Detailed Implementation

[0034] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0035] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0036] like Figures 1-7 As shown, the adaptive control circuit of the heating element of this utility model is described in detail below.

[0037] The adaptive control circuit for the heating element described in this embodiment integrates an MCU temperature control circuit, a temperature feedback device, a current detection circuit, a voltage detection circuit, a protection detection circuit, and a temperature display device. The circuits work together to achieve intelligent identification, control, and protection of different types of heating elements, thereby improving the system's versatility, stability, and safety.

[0038] The MCU temperature control circuit, as the core of the control system, mainly undertakes functions such as data acquisition, identification and judgment, temperature control algorithm calculation, and PWM signal output. It integrates multiple functional modules, including a power supply voltage detection module, a current AD sampling and conversion module, a PWM output control module, a heating element insertion detection module, and a sleep / wake-up detection module. After the device is powered on, the MCU first identifies the presence of a valid load through the heating element insertion detection module. If a load is confirmed, it activates the power supply detection module and the voltage and current identification unit to obtain the electrical characteristic parameters of the current heating element, such as its resistance, voltage, and current. The MCU compares these parameters with a preset parameter library to determine the type of heating element and automatically matches an appropriate temperature control strategy. During normal control cycles, the MCU continuously receives temperature feedback signals and compares the actual temperature with the set temperature. It calculates the error signal using a PID control algorithm and then outputs a PWM control signal with the corresponding duty cycle to the subsequent temperature control circuit to achieve precise heating control of the heating element.

[0039] The temperature control circuit receives PWM control signals from the MCU and converts them into drive signals to control the heating state of the heating element. In this embodiment, the temperature control circuit consists of a set of amplification drive modules and power switch modules, mainly including resistors R63, R44, R54, R45, R55, and R75, capacitors C37 and C39, transistors Q5 and Q6, and driver chip IC4, etc.

[0040] The PWM signal, amplified by the amplification driver module, controls the conduction states of transistors Q1 and Q2 in the switching circuit, thereby indirectly regulating the operating voltage across the heating element and achieving temperature control. Furthermore, to reduce high-frequency interference generated by the switching signal on the power supply side, a harmonic filter circuit composed of capacitor C27 is introduced into the control circuit to smooth the PWM waveform and suppress electromagnetic interference, ensuring stable system operation.

[0041] The temperature feedback device is used to monitor the surface or internal temperature of the heating element in real time and transmit the measured temperature signal to the MCU temperature control circuit. In a specific implementation, the temperature feedback device includes a thermistor (such as an NTC thermistor) and is equipped with an amplifier circuit and a filter circuit. The amplifier circuit consists of resistors R49, R56, R69, R50, R51, and R73, which can linearly amplify the analog voltage signal output by the thermistor.

[0042] Meanwhile, the filtering circuit, composed of capacitors C30, C31, and C32, is used to filter out high-frequency noise carried in the temperature detection signal, ensuring the accuracy and stability of the feedback signal. Through the temperature feedback device, the MCU can accurately obtain the real-time temperature of the heating element, realizing closed-loop control.

[0043] The current detection circuit is used to detect the actual operating current flowing through the heating element, so as to assist the MCU in identifying the heating element and monitoring its working status.

[0044] This circuit uses sensing resistors R87 and R88 connected in series in the power supply path of the heating element, and determines the current magnitude by measuring the voltage drop across them. To eliminate the influence of power supply noise on detection accuracy, the current detection circuit is also equipped with a harmonic filter composed of R85 and C50 to perform low-pass processing on the current signal, improving the stability of the AD sampling signal.

[0045] The voltage detection circuit is used to detect the input voltage applied across the heating element, which helps the MCU to identify the electrical characteristics of the heating element and implement voltage limit protection.

[0046] This circuit uses a voltage divider composed of resistors R46 and R52 to reduce the high-voltage signal to a sampling level acceptable to the MCU, and then uses a filter network composed of capacitor C33 to smooth the signal. The sampled signal is finally transmitted to the MCU's AD sampling port for subsequent voltage identification and voltage anomaly monitoring functions.

[0047] The protection and detection circuit is used to identify fault states such as overcurrent, overvoltage, overtemperature or dry burning that may occur during system operation, and to trigger the protection mechanism in a timely manner to prevent damage to the circuit or heating element;

[0048] In this embodiment, the protection detection circuit consists of detection elements R91, R94, R95, capacitors C51, C52, and C53, and integrated circuit IC6. This circuit can comprehensively analyze whether signals such as temperature, current, and voltage exceed preset thresholds. If an abnormal state is detected, a control signal is output to the MCU through IC6 to trigger forced power-off or alarm processing logic, thereby enhancing the system's safety protection capabilities.

[0049] The temperature display device is connected to the MCU temperature control circuit to display parameters such as the current operating temperature, target temperature, temperature deviation value, and alarm status in real time, thereby enhancing the user's visual operation experience.

[0050] In implementation, the temperature display device uses a digital display module or an OLED screen, via I... 2 It communicates with the MCU via C or SPI bus to dynamically refresh the set temperature and the current detected temperature, and displays error codes or warning signs when the system is abnormal, which helps users to quickly identify and handle problems.

[0051] This adaptive control circuit integrates multiple signal acquisition, identification and judgment, PWM control, feedback adjustment, and anomaly protection modules to form a highly integrated, stable, and adaptable control system. This system can not only identify various types of heating elements and adaptively adjust control parameters, but also possesses a complete closed-loop control and anomaly protection mechanism. It is particularly suitable for high-precision temperature control requirements in scenarios such as electronic welding, electrothermal repair, and intelligent constant-temperature heating, and has broad application prospects and industrial value.

[0052] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions conceived without inventive effort should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope defined in the claims.

Claims

1. An adaptive control circuit for a heating element, characterized in that, include: The MCU temperature control circuit is used to receive detection signals, identify the parameter type of the connected heating element, calculate the control signal based on the deviation between the set temperature and the actual temperature, and output the PWM control signal. A temperature control circuit, connected to the MCU temperature control circuit, is used to receive PWM control signals and drive the heating element to heat up or cool down. A temperature feedback device, connected to the MCU temperature control circuit, is used to detect the temperature of the heating element and transmit the temperature feedback signal to the MCU temperature control circuit. The current detection circuit is used to detect the operating current through the heating element and provide a current feedback signal to the MCU temperature control circuit. The voltage detection circuit is used to detect the input voltage of the heating element and output the voltage detection signal to the MCU temperature control circuit. A protection detection circuit, connected to the MCU temperature control circuit, is used to monitor whether the system experiences overcurrent, overvoltage, overheating, or dry burning abnormalities and trigger protection measures. A temperature display device is connected to the MCU temperature control circuit and is used to display the set temperature, the actual temperature, and alarm information.

2. The adaptive control circuit for the heating element according to claim 1, characterized in that: The MCU temperature control circuit includes functional modules for detecting power supply voltage, current AD conversion, PWM output control, heating element insertion identification, and sleep / wake-up detection.

3. The adaptive control circuit for the heating element according to claim 1, characterized in that: The temperature control circuit consists of an amplification and driving module composed of resistors, capacitors, transistors, and a driving chip, as well as a switching circuit.

4. The adaptive control circuit for the heating element according to claim 1, characterized in that: The temperature feedback device includes an amplifier circuit composed of resistors and a harmonic filter circuit composed of capacitors.

5. The adaptive control circuit for the heating element according to claim 1, characterized in that: The current detection circuit includes a detection resistor and a harmonic filter for detecting the operating current of the heating element.

6. The adaptive control circuit for the heating element according to claim 1, characterized in that: The voltage detection circuit consists of a voltage divider circuit composed of resistors and capacitors, used to detect the input voltage of the heating element.

7. The adaptive control circuit for the heating element according to claim 1, characterized in that: The protection detection circuit includes a detection circuit and a logic control unit, which is used to identify abnormal operating states and output a shutdown signal to the MCU.

8. The adaptive control circuit for the heating element according to claim 1, characterized in that: The temperature display device is a digital display module that can display the set value, the current temperature value, and temperature deviation information.

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