Bouncing of a Reed Switch due to Coulomb´s Electrostatic Force

We proposed a method for suppressing arc ignition in mechanical contact devices using a transient current switch and a capacitor. However, a movable electrode in a conventional electromechanical contact device would often show bounce during a making and breaking operation against the opposite electrode. The frequent bounces would be troublesome. We studied phenomena with conventional reed switches using very slow make/break operation. Judging from measured data and FEM analysis, Coulomb´s electrostatic force should not be neglected in order to suppress bounces. For the electric circuit analysis of breaking operation, we clarified the capacitance of the contacts just after the rupture of the metal bridge using FEM analysis. With the capacitance, we can estimate the contacting force due to the Coulomb´s electrostatic force.