The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 15, 2002
Filed:
Feb. 21, 2002
Howard L. North, Jr., Oldwick, NJ (US);
Other;
Abstract
Electronic damping may be provided to a piezoelectric positioner by developing a voltage signal proportional to the current through the dynamic impedance portion of the positioner impedance and then reducing the voltage applied to the positioner in proportion to this voltage signal. This dynamic impedance portion of the positioner impedance consists of an inductance, a resistance, and a capacitance in series. The inductance is the electrical equivalent of the positioner distributed mass and its load mass. The capacitor is the electrical equivalent of the compliance of the positioner and its support structure. The resistor is the electrical equivalent of the damping of the positioner and its load. The voltage signal proportional to the current through this dynamic impedance is obtained by subtracting from a first voltage proportional to the total current through the positioner a second voltage proportional to the current through the static capacitance portion of the positioner impedance. This first voltage is obtained from a resistor in series with the positioner. This second voltage is not obtainable directly but is equal to a third voltage synthesized by a model impedance comprising a capacitor and resistor in series having the same RC time constant as that of the positioner static capacitance and the resistor in series with the positioner where both resistor/capacitor combinations are energized by the same voltage driving the positioner.