Sealed Micro Switch Likes It Humid: Meeting challenging requirements in industrial applications

摘要

Switching electrical power or signals has been a basic function for decades. One of the devices that perform this operation is a snap action based switch, manufactured in very large quantities by multiple manufacturers. The largest market segment in power switching (up to 15 Amps) is for applications with simple requirements, mostly in appliance related applications. A simple micro switch without any specific protection against water, dust or temperature will do the job. But for industrial applications the requirements become much more challenging. Water and dust proofing become an important consideration. All of a sudden an operating temperature range of - 10℃ to 80℃ is not sufficient anymore. Switches may be mounted on a machine which heats up when operating and therefore an operating temperature of 100-120℃ may be a needed requirement. Also, it is not uncommon having industrial equipment working outside where temperatures may drop to -40℃ and the equipment is still required to operate properly. Guaranteeing a high degree of sealing, while operating under a wide temperature range, demands very good choices in material and switch design.