How does the industrial control circuit board for an electric pressure cooker LCD achieve real-time closed-loop control of pressure, temperature, and time?
Publish Time: 2025-08-20
As a representative of modern smart kitchen appliances, the core control capabilities of an electric pressure cooker LCD rely on the highly coordinated integration of its built-in industrial control circuit board and LCD display system. Through sophisticated feedback mechanisms and algorithmic control, the system achieves millisecond-level real-time closed-loop control of pressure, temperature, and cooking time within the cooker, ensuring a safe, efficient, and precise cooking process.Dynamic Closed-Loop Pressure Control MechanismPressure control is key to the safe operation of an electric pressure cooker LCD. A pressure sensor inside the cooker continuously collects internal air pressure data, typically outputting a millivolt-level voltage signal. The industrial control circuit board converts the analog signal into a digital value using a high-precision analog-to-digital converter (ADC) and passes it to the embedded microcontroller (MCU) for processing. The MCU has pre-stored target pressure curves for different cooking modes, such as "High Pressure Quick Cook" or "Low Pressure Slow Cook." The system compares the measured pressure value with the target value in real time. If the deviation exceeds a set threshold, an adjustment mechanism is immediately activated. If the pressure is too low, the heating cycle is extended or the heating power is increased. If the pressure is too high, the heating circuit is disconnected and a small amount of exhaust is performed via a controlled solenoid valve. This entire process forms a dynamic feedback loop, achieving precise and stable pressure control.Intelligent Temperature Sensing and PID RegulationThe closed-loop temperature control relies on a highly sensitive NTC thermistor or digital temperature sensor, typically mounted on the bottom of the heating plate or on the contact surface with the inner pot. The sensor provides real-time feedback on temperature changes, and the circuit board uses a linearization algorithm to convert the resistance value into an accurate temperature reading. In the initial heating phase, the system uses full power to quickly increase the temperature. When approaching the target temperature, the MCU activates the PID control algorithm, dynamically adjusting the duty cycle of the heating pulses based on the difference between the current temperature and the set value, achieving "progressive temperature control." For example, in soup-making mode, the system maintains a gentle boil between 98°C and 105°C to prevent excessive boiling and overflowing. Temperature data is also used to determine whether to enter the pressure-holding phase, and this is linked to the pressure signal to improve control accuracy.Adaptive Collaborative Time ControlTime control isn't a simple countdown; it's an adaptive process based on pressure and temperature feedback. After the user sets the cooking program via the LCD, the MCU invokes the corresponding control logic. For example, in the "Beef Stew" mode, the system first heats to high pressure and then maintains it for 20 minutes. However, the actual heating speed is affected by factors such as voltage fluctuations and the amount of ingredients. Therefore, the circuit board doesn't rely on a fixed timer; instead, it dynamically adjusts the heating time based on the rate of pressure rise. The hold timer only starts when the pressure reaches the set value and remains stable for several seconds. If the pressure drops midway, the timer is paused until it resumes. This "condition-triggered timing" ensures consistent cooking results.Real-time LCD Feedback and Human-Machine CollaborationThe LCD screen is not only an information display window; it's also a crucial component of a closed-loop system. It displays the current pressure level (such as "high pressure" or "medium pressure"), actual temperature, and remaining time in real time, allowing users to intuitively understand the cooking progress. Importantly, the screen status is driven in real time by the industrial control circuit board, and all displayed data is derived from sensor feedback and MCU calculations. If the system detects an anomaly (such as overtemperature or overpressure), an immediate warning pops up and the system enters protection mode. Users can also modify parameters on the screen, and the circuit board instantly adjusts the control strategy, achieving a dynamic closed-loop collaboration between human and machine.Multiple Safety Protections and System Fault ToleranceTo ensure the reliability of the closed-loop system, the industrial control circuit board has built-in multiple protection mechanisms. For example, if the pressure sensor fails, the system uses logic based on the temperature rise rate and heating time to prevent dry cooking. If the NTC is open or short-circuited, the MCU automatically reduces power and issues an alarm. Furthermore, the system features a hardware watchdog and software self-test routines to prevent program errors. All control logic is rigorously verified to ensure stable operation under various operating conditions.In summary, the electric pressure cooker LCD achieves highly coordinated and real-time closed-loop management of pressure, temperature, and time by integrating sensor feedback, intelligent algorithms, and execution control on the industrial control circuit board. This not only improves cooking quality but also establishes a comprehensive safety assurance system, demonstrating the deep integration and innovation of control technology in modern smart home appliances.
