1 Problem with Mechanical Knobs and Rotary Encoders

There are many products in home appliances that use knobs, such as microwave ovens, water dispensers, air fryers, cook-tops and so on. Figure 1-1 showcases just a few examples of knobs on home appliances. At present, there are two mainstream knob designs: mechanical and rotary encoder. Mechanical knobs are bulky and unsightly, and these knobs wear out after long-term use, which affects their service life. The contact based rotary encoder knob is easily disturbed by the environment, such as water and dust. Contact based rotary encoder knobs are not practical in many scenarios. The price of these knobs can also be expensive. This document introduces a knob design based on the 3D Hall-effect sensor which can avoid the shortcomings of the above-mentioned designs. The 3D Hall-effect sensor has the advantages of small size, long life, low cost, and these sensors are not easily disturbed by the environment.

Figure 1-1 Knobs Used in Appliances