induction cooking touch key solution -凯发旗舰厅

compared to mechanical and resistive touch buttons, capacitive touch buttons are not only durable, cost-effective, simple to install, waterproof and stain resistant, but also provide functions such as rollers and sliding bars.

*the capacitive touch button forms a resistance capacitance network through a resistor and the capacitance of the sensing electrode, and detects the capacitance changes caused by human touch through charging/discharging time. the induction electrode can be directly drawn on the pcb board in the form of buttons, rollers, or sliding bars, or can be made into a spring inserted on the pcb board, and touch control function can also be achieved through the insulation layer.

*while heating the pan, the induction cooking generates forward or reverse current to the induction electrode on the circuit board, which will shorten or increase the charging and discharging time of the keys, and will have a great impact on the detection of keys, or even cause misoperation. common methods are hardware shielding and zero crossing detection to eliminate the impact of electromagnetic radiation on keys. our solution provides design specifications for induction electrodes and wiring, effectively reducing the impact of parasitic capacitance in induction electrode wiring on button sensitivity.

*the hardware zero crossing detection increases the complexity of the hardware circuit design and increases the cost of the solution. our solution is aimed at the working environment of the induction cooking and uses software to detect the zero crossing, thus reducing the cost and effectively solving the interference of induction cooking power devices on the touch keys.

*because the quality of domestic power grids is different, in some areas with poor quality, power grid fluctuations are likely to affect the normal operation of induction cooking touch keys. if power isolation is not available, the electromagnetic radiation generated when the induction cooking works will make the signals seen more disorderly. in the experiment, it was found that using isolation from the external power grid or using software filtering can significantly improve the button effect. our solution adopts software frequency hopping filtering technology to effectively isolate power frequency interference.

*in the use of induction cooking, water or oil splashing on the touch panel often causes the button to be triggered by mistake. our solution uses optimized advanced software algorithm to reliably distinguish water splashing and oil splashing from the state of finger pressing.

*when the induction cooking is working, it generates a large amount of heat and moisture. the panel temperature/humidity and the circuit board temperature/humidity will have a relatively wide range of fluctuations. with the passage of time, the panel and pcb will experience aging of different programs, which will affect the accuracy of key detection. our solution has automatic calibration function, real-time update of environment detection, and intelligent environment adaptation.