| 摘要 |
PURPOSE:To prevent the sensitivity of an angular velocity sensor from being affected by temperature variation by making the amplitude quantity of tuning-fork vibration proportional to the sensor sensitivity and varying the amplitude quantity with temperature according to the temperature variation of the sensitivity. CONSTITUTION:Charges induced at the electrodes of a piezoelectric bimorph element 102 for a motor are amplified 1, rectified 2, and smoothed 3 to become a DC voltage which is proportional to the amplitude of the tuning fork vibration. An amplifier 4 amplifies the output voltage of the amplifier 1 to drive a piezoelectric bimorph element 101 for driving. Then when the amplitude of the tuning force vibration increases, the charges induced at the electrodes of the elements 102 increase, the output voltage amplitude of the amplifier 1 increases, and the amplitude of the voltage applied to the element 101 decreases, so that the amplitude of the tuning fork vibration is held at a constant value. A temperature dependent resistor 14 increases in resistance value as the ambient temperature rises and the amplifier 1 decreases in amplification degree as the temperature rises. Therefore, the vibration of the tuning fork vibration becomes small in amplitude as the temperature rises and becomes large in amplitude when the temperature falls. Thus, temperature characteristics of the sensitivity which are a problem characteristic to the tuning fork structure vibration type angular velocity sensor can be corrected. |
