A switch is a device used to control the ON/OFF circuit of the electric appliance in daily life and used to control the operation of automatic machines in industrial plants. There are various types of switches, including micro switches, limit switches, foot switches and contact switches. Each type has different features. For example, micro switches are compact and push button switches which suitable for controlling small work systems or limit switches that use to control the positioning and/or limiting the working distance of the machine which is good for automatic work control etc.