The precise control of the speed, time and force by the industrial control circuit board of the dough kneading machine is achieved through a closed-loop system of "sensor feedback - chip processing - actuator adjustment". The core control chip is the "nerve center" of this system, and its performance directly determines the control accuracy and response speed. This synergistic mechanism not only adapts to the dynamic changes of the dough state during the kneading process, but also can stably maintain the preset parameters to meet the production requirements of different pastries.
The precise control of the speed depends on pulse width modulation (PWM) technology and real-time feedback adjustment. The industrial control circuit board outputs PWM signals to the motor driver through the core chip. The duty cycle of the signal determines the power supply time of the motor - the higher the duty cycle, the faster the motor speed. At the same time, the encoder at the end of the motor shaft will collect the actual speed in real time and transmit the pulse signal back to the chip. The chip compares the preset speed with the actual value and dynamically adjusts the PWM duty cycle (if the difference exceeds 5%, it will be corrected immediately) to ensure that the speed deviation is controlled within ±2r/min. For example, making puff pastry dough requires low-speed kneading (80-100r/min). The chip uses high-frequency PWM signals (usually above 20kHz) to avoid motor vibration and ensure stable speed.
The core of time control is the timing module and program logic scheduling of the chip. The control chip has a built-in high-precision timer (such as a 16-bit timer) that supports millisecond-level timing. When the user sets the kneading time (such as 5 minutes), the chip starts the timer and counts in real time, and processes the time node through the program interrupt mechanism. For example, when setting a segmented program of "stirring at low speed for the first 2 minutes and kneading at high speed for the last 3 minutes", the chip will trigger an interrupt when the timing reaches 2 minutes, switching the PWM parameters to adjust the speed. To avoid timing errors, some high-end circuit boards also integrate real-time clocks (RTCs), which are calibrated by external crystal oscillators (usually 32.768kHz) to ensure that the cumulative timing error does not exceed 1 second per day.
Force control is achieved through torque feedback and power regulation, relying on the coordinated processing of sensors and chips. The kneading force corresponds to the motor output torque. The industrial control circuit board installs a torque sensor (such as a strain gauge) between the motor and the kneading roller. The sensor converts the mechanical force into an electrical signal (millivolt voltage), which is processed by the signal amplification circuit and transmitted to the ADC (analog-to-digital conversion) interface of the chip. The chip converts the analog signal into a digital quantity and compares it with the preset force threshold: if the torque is insufficient (such as hard dough), the chip increases the motor drive current (by adjusting the driver output voltage); if the torque is too large (such as dough adhesion), the current is reduced to avoid motor overload. The response time of the entire adjustment process is less than 100 milliseconds, ensuring that the force is stable in the set range.
The primary characteristics of the core control chip are powerful processing power and multi-tasking scheduling capabilities. At present, most mainstream chips are 32-bit MCUs (such as STM32 series, PIC32 series), with a main frequency of 80-168MHz. They can process multiple data such as speed feedback, time counting, torque signal, etc. at the same time, and support real-time operating system (RTOS). Tasks can be scheduled according to priority - for example, the torque overload signal has the highest priority, ensuring that the chip can respond first and reduce the load quickly to avoid equipment damage. Compared with 8-bit MCUs, the computing speed of 32-bit chips is increased by 5-10 times, meeting the real-time operation requirements of complex control algorithms.
The rich interface and expansion capability of the chip are the key to realizing integrated control. The core control chip is usually equipped with multiple general-purpose input and output ports (GPIO), PWM output channels (at least 4 channels), ADC interface (12-bit accuracy or above) and communication interface (UART, I2C). GPIO is used to connect the operation panel (such as buttons and indicator lights), PWM channels independently control the main and auxiliary motors, high-precision ADC ensures accurate conversion of torque sensor signals, and the communication interface supports extended display screens (such as OLED screen display parameters) or external storage modules (save more than 10 sets of kneading programs). This modular design allows the circuit board to adapt to different models of dough kneading machines.
Anti-interference characteristics are the guarantee for the chip to adapt to harsh environments. The working environment of the dough kneading machine is subject to flour dust, motor electromagnetic interference and vibration. The core control chip enhances stability through hardware design: built-in power management module (PMIC), supports wide voltage input (8-36V), resists power grid fluctuations; chip pins use ESD protection (contact discharge ±8kV) to avoid electrostatic damage during operation; some models also integrate a watchdog timer (WDT). If the program "runs away" due to interference, the WDT will force a chip reset within 100ms to ensure that the device resumes normal operation after restarting.
The dough kneading machine industrial control circuit board achieves the control of speed, time and force through "closed-loop feedback + precise adjustment", and the core control chip becomes the core support of this system with its high processing power, rich interfaces and strong anti-interference. This design not only meets the stringent requirements of pastry making for parameter accuracy, but also adapts to complex working environments. It is the key technical node for the dough kneading machine to upgrade from "mechanical operation" to "intelligent control".
