Electrostatically Induced Voltage in Metal Box When Charged Object Like Hand Moves Away from the Box to Three Directions

A static electricity is useful energy, but it becomes a source of the malfunction or failure of electronic device. This type of the electrostatic problem cannot be ignored. An electronic device in a metal case of a box causes easily not only an error but also failure by the induced voltage of less than 10 V level. The voltage of a charged human body handling the electronic device exceeds occasionally 10 kV level. When the charged human body operates the electronic device by a charged hand, the high induced voltage is generated in the metal case. In the experimental study, the induced voltage is measured using a real experimental setup when the charged object moves away from a partly opened metal case to the direction of the left or the right or the back. The measurement of the induced voltage in the metal case is performed using a spark gap and an electromagnetic wave sensor. The results show the induced voltages in the metal case are -0.6 times of the voltage of a charged object when the charged object moves away from the metal box. The results will be helpful to solve the malfunction or failure of the electronic device caused by the induced voltage.