Patent ID: 6147433
Filing Date: 2000-11-14
Classification: F02D,H01L

Abstract:
A method for charging or discharging a piezoelectric element, comprising the steps of:providing, by a component having inductive properties, at least one of a charging current and a discharging current to the piezoelectric element via at least one of a charging circuit and a discharging circuit;repeatedly actuating a switch in the at least one of the charging circuit and the discharging circuit so that during at least one of a charging and discharging of the piezoelectric element, the piezoelectric element is brought to a predetermined voltage by at least one of a predetermined average charging current and a predetermined average discharging current;continuously measuring the at least one of the charging current and discharging current;readjusting the at least one of the charging current and discharging current by correspondingly opening and closing the switch so that the at least one of the charging current and the discharging current are maintained within a defined range around a set-point current; andmeasuring a time from one of a particular incident and instant to one of i) the at least one of the charging and discharging current has reached one of an upper limit and lower limit of the defined range, and ii) a voltage at the piezoelectric element reached a set-point voltage.