H type LiTaO{sub}3 piezoelectric gyroscope for higher sensitivity and stability with a transformer

摘要

To improve sensitivity and stability the authors are studying a vibrational H-type gyroscope using a LiTaO{sub}3 single crystal with sharply suppressed leakage output. We have introduced the additional transducer to monitor the driving mode directly and an automatic compensation method for the temperature characteristics of sensitivity and drift. A stray capacitance between a drive electrode and a detection electrode is a disturbance of the compensation. The unnecessary electrostatic coupling is suppressed by using a transformer for a balanced drive. Therefore, the automatic compensation method is acceptable and the drift is suppressed to 9.3 that of a conventional LiTaO{sub}3 gyroscope. As the input impedance of the gyroscope is as large as 400kΩ, the driving voltage can be easily increased by the small transformer. Therefore, the sensitivity is in proportion to the increase of drive volt. It was experimentally confirmed that the sensitivity of the gyroscope became about 10 times.