The design of a commercial induction cooker fault self-diagnosis system needs to focus on quickly locating the root cause of problems. This involves modular detection, multi-level signal processing, hardware redundancy, and software logic coordination, combined with fault code feedback and a user interface, to achieve comprehensive coverage from the underlying circuitry to the control logic. The core idea is to decompose the complex system into independent functional modules, design dedicated detection circuits for each module, and collect key parameters in real time through the main control chip. By comparing preset thresholds with historical data, the fault type and location can be quickly identified.
At the hardware level, a multi-level signal detection network needs to be constructed. Faults in commercial induction cookers typically originate from voltage fluctuations, current overload, abnormal temperature, or component aging. Therefore, a voltage detection circuit needs to be designed at the power input terminal. This circuit uses voltage divider resistors and comparators to monitor the mains voltage in real time. When the voltage exceeds the rated range, protection is triggered and a fault code is recorded. Current detection uses a current transformer to sample the main circuit current, which is then rectified and filtered before being input to the ADC port of the main control chip. Combined with PWM duty cycle analysis, the load status is assessed. If the current is abnormal but there is no load change, the fault can be identified as a power transistor or inverter circuit failure. Temperature detection needs to cover both cookware temperature and power transistor temperature. Cookware temperature is sensed via a thermistor through a ceramic panel, while power transistor temperature is directly detected by a surface-mount NTC thermistor on the heatsink. Both are converted into voltage signals by a voltage divider circuit, and the main control chip determines whether to trigger overheat protection.
On the software side, fault logic reasoning and self-learning functions need to be implemented. The main control chip needs to run a real-time operating system, managing data acquisition and processing from each detection module through multi-threading. When an abnormal signal is detected, the system first records the operating parameters at the time of the fault, such as the current power level, operating time, and ambient temperature, forming fault context information. Then, it calls the fault diagnosis tree, classifying and judging based on signal type and threshold deviation. For example, if the voltage detection circuit outputs a low level and the current detection has no input, the power line or fuse should be checked first; if the voltage is normal but the current is zero and the power transistor temperature has not risen, the drive circuit may be faulty. To improve diagnostic accuracy, the system can integrate a historical fault database, quickly matching similar scenarios and providing repair suggestions by comparing current fault characteristics with historical cases.
The interaction design needs to balance professionalism and ease of use. Users of commercial induction cookers may include non-professional operators; therefore, the fault self-diagnosis system must visually display fault codes via LED indicators, digital displays, or a touchscreen, while providing voice prompts or text explanations. For example, when the cookware temperature is detected to be too high, the system can flash a red indicator light and display "E3," while simultaneously announcing, "The cookware is dry-heating; please remove the cookware and allow it to cool." For faults requiring professional repair, such as IGBT breakdown or main control chip failure, the system should display a specific code and prompt "Please contact after-sales service" to prevent secondary damage due to user error.
Redundancy design and fault isolation are crucial for improving system reliability. Commercial induction cookers should employ a dual watchdog design in critical circuits. When the main control chip crashes due to interference, the backup watchdog can force a system reset, preventing the fault from escalating. Simultaneously, each detection module must be independently powered to prevent a single power supply failure from paralyzing the entire system. For example, the voltage detection circuit and current detection circuit can be powered by 18V and 5V regulated power supplies respectively. When one power supply is abnormal, the system can still maintain basic detection functions through the other power supply and prompt, "Power supply abnormal; please check module XX."
Self-learning and remote diagnostic functions further improve fault handling efficiency. By integrating machine learning algorithms into the main control chip, the system can analyze historical fault data, identify high-frequency fault patterns, and provide early warnings of potential risks. For example, if an induction cooker experiences an "E2" (power transistor overheating) fault for three consecutive months, the system can infer that the cooling fan is aging and prompt the user to replace it. Furthermore, the commercial induction cooker can be equipped with a 4G or Wi-Fi module to upload fault data to a cloud server, allowing manufacturer technicians to remotely analyze the cause of the fault and provide repair guidance or firmware upgrades, thus shortening on-site repair time.
