Electrostatically Induced Voltage Generated in Two Ungrounded Metal Cases When Charged Object Moves Away from the Cases

Abstract

Static electricity is used in numerous practical applications, such as copy machines and dust collectors. When a person gets up from a chair or walks in a room using an air conditioner, the person's body becomes charged. When a charged body approaches or moves away from the metal case of an electronic device, the electronic device suffurs a malfunction or failure due to the electrostatically induced voltage. The electrostatically induced voltage of a charged body moving away from a metal case is higher than the voltage induced when the charged body approaches the metal case. We conducted an experimental study on the electrostatically induced voltage generated in two ungrounded metal cases when a charged body moves away from the metal cases. The results showed that electrostatically induced voltages of 0.4 to 0.5 times was generated in the two ungrounded metal cases against the voltage of the charged body when each electrostatic induction electrode with a spark gap and each electromagnetic wave sensor is used of a noncontact electrostatic measuring device. We believe that these results will aid in the prevention of malfunction or failure of electronic devices.