An inertia switch includes a stack of a base plate and a base cover. The base plate provided inside a liquid storage chamber and a sensing chamber communicating with a liquid storage chamber. The liquid storage chamber contains working fluid, and the sensing chamber equipped with a sensing electrode extending to and connected to an external equipment that tend to interact with the inertia switch. The electricity-conductive liquid is utilized as a medium for inertia detection. Furthermore, by the width, depth and angle of the flow channel design, when the liquid material flows into the sensing chamber through the channel after a time delay, a sensing signal is obtained by the sensing electrodes through a change of a resistance value or a capacitance value to actuate the switch. The inertia switch has a simple structure and is low cost. |