Piezo-actuator shock absorber damping force controlling system having abnormality detection function
October 24, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3573781 3819961 3828773 Oscillator-exciting system for ultrasonic liquid nebulizer Valve operating mechanism for internal combustion and like-valved engines Adjustable damping force type shock absorber Driving apparatus for ultrasonic motor Process and circuit for exciting an ultrasonic generator and its use for atomizing a liquid Drive system of actuator having piezoelectric device for use in motor vehicle Patent #: 5013955 InventorsAssigneeApplicationNo. 425716 filed on 10/24/1989US Classes:310/316.01, Input circuit for simultaneous electrical and mechanical output from piezoelectric element310/317, Input circuit for mechanical output from piezoelectric element310/328With mechanical energy coupling meansExaminersPrimary: Budd, Mark O.Attorney, Agent or FirmInternational ClassH01L 041/08AbstractA shock absorber system for controlling the damping forces of shock absorbers comprising a drive apparatus for operating a piezo-actuator which is constructed by laminating a plurality of piezoelectric elements. The drive apparatus comprises a high-voltage generation circuit for generating a high voltage and a charging and discharging circuit for applying the high voltage, generated by the high-voltage generation circuit, to the piezo-actuator and for discharging an electric charge charged in the piezo-actuator due to the application of the high voltage thereto, the charging and discharging results in expansion and contraction of the piezo-actuator. Also included in the drive apparatus is an abnormality detection circuit for detecting a charging current or a discharging current passing through a charging or discharging current passage coupled to the piezo-actuator at the time of charging or discharging by the charging and discharging circuit. The abnormality detection circuit determines an abnormality of the drive apparatus when the detected charging current or discharging current is below a predetermined value. | |
