Inertia force sensor
View Patent ↗An inertial force sensor is provided in which each of switches is connected in parallel with each of resistors of low-pass filter and high-pass filter, respectively, and capacitor of high-pass filter can be boost charged by making switches on without mediate resistors.
1. An inertial force sensor comprising:
an oscillator and a sensory circuit for outputting an angular velocity signal after smoothing a detected signal outputted by the oscillator; wherein
the sensory circuit has a low-pass filter and a high-pass filter formed by connecting a resistor and a capacitor;
one end of the capacitor of the high-pass filter is connected to between the resistor and the capacitor of the low-pass filter;
an angular velocity signal is outputted after smoothing the detected signal through the low-pass filter and the high-pass filter; and
switches are respectively connected in parallel with the resistor of the low-pass filter and the resistor of the high-pass filter, and the capacitor of the high-pass filter is charged by making one or both of the switches on.
2. The inertial force sensor of claim 1 wherein:
the sensory circuit further comprises a noise filter;
the angular velocity signal to be outputted by the high-pass filter is outputted through the noise filter;
the noise filter has an amplifier;
the angular velocity signal is inputted to a non-inverted input terminal of the amplifier;
a voltage is applied to an inverted input terminal of the amplifier through an input resistor;
the angular velocity signal is outputted from an output terminal of the amplifier after being amplified; and
a voltage equivalent to the voltage applied to the inverted input terminal of the amplifier is applied to one end of the capacitor of the high-pass filter.
3. The inertial force sensor of claim 1 wherein:
the switches are provided at both ends of the capacitor of the high-pass filter; and
a front stage circuit and a rear stage circuit are connected through the switches.
4. The inertial force sensor of claim 3 further having a function of suspending supply of power to the front stage circuit or the rear stage circuit.