摘要:
In a capacitive sensor apparatus, a capacitive sensor includes a plurality of physical-quantity-detection capacitors each having a movable electrode and a fixed electrode. A conversion device operates for converting an output signal of the capacitive sensor into an apparatus output signal. Each of the physical-quantity-detection capacitors is selectively connected and disconnected to and from the conversion device. A determination is made as to whether or not each of the physical-quantity-detection capacitors fails in response to the sensor output signal. When it is determined that a first one of the physical-quantity-detection capacitors fails, the first one is disconnected from the conversion device and a second one of the physical-quantity-detection capacitors is connected to the conversion device.
摘要:
A capacitive physical load sensor includes a substrate, which has fixed electrodes, and a diaphragm, which has movable electrodes. The diaphragm is located across a gap from the substrate, and retaining parts for the diaphragm are formed around the diaphragm. Protruding parts extend into the gap from the diaphragm or from the substrate. The protruding parts support the diaphragm at different levels of deformation to alter the characteristics of the diaphragm and extend its range.
摘要:
On a substrate, first and second capacitive portions are formed to have movable diaphragms having different areas for pressure measurement and diagnostic, wherein a communication structure is provided between the cavity spaces of the first and second capacitive portions to equalize the pressure in the first capacitive space to that of the second capacitive space. The different sizes provide different sensitivity for efficient diagnostic. The first and second capacitive portions can be made in one diaphragm, wherein the second capacitive portion is formed around the first capacitive portion. The cavity spaces of the first and second capacitive portions are connected. Moreover, between the first and second capacitive spaces, an insulation portion may be formed in a ring shape to support the diaphragm portion of the first capacitive portion and the diaphragm portion the second capacitive portion with communication portions.
摘要:
A reference voltage circuit includes an operational amplifier, a first fixed resistance resistor, a second fixed resistance resistor, a third fixed resistance resistor, a first diode and a second diode. The reference voltage circuit further includes a fourth fixed resistance resistor having an end connected to a non-inverting input terminal of the operational amplifier and the other end connected to the first diode. The reference voltage circuit is characterized by a value of the resistance of the fourth resistor being less than the resistance of the first resistor and a temperature coefficient of the fourth resistor being greater than any of the temperature coefficients of the first, second and third resistors.
摘要:
A reference voltage circuit includes an operational amplifier, a first fixed resistance resistor, a second fixed resistance resistor, a third fixed resistance resistor, a first diode and a second diode. The reference voltage circuit further includes a fourth fixed resistance resistor having an end connected to a non-inverting input terminal of the operational amplifier and the other end connected to the first diode. The reference voltage circuit is characterized by a value of the resistance of the fourth resistor being less than the resistance of the first resistor and a temperature coefficient of the fourth resistor being greater than any of the temperature coefficients of the first, second and third resistors.
摘要:
A microphone that identifies the direction along which acoustic waves propagate with one diaphragm, and has superior durability is provided. The microphone includes a circular diaphragm supported at a center portion thereof. When the diaphragm receives acoustic waves, each position around the center thereof will vibrate with a phase depending upon the direction of the acoustic waves. First electrodes are arranged on one surface of the diaphragm and second electrodes are arranged facing corresponding first electrodes to form a first capacitor. Third electrodes are arranged on the other surface of the diaphragm and fourth electrodes are arranged facing corresponding third electrodes to form a second capacitor. A controller applies a voltage to the second capacitors so that the capacitance of the first capacitors will be constant and identifies the direction along which the acoustic waves propagate based on the difference in the voltages applied to each of the second capacitors.
摘要:
A microphone that may identify the direction along which acoustic waves propagate with one diaphragm, and which has superior durability is provided. The microphone comprises a circular diaphragm. The diaphragm is supported at the center portion thereof. When the diaphragm receives acoustic waves, each position around the center thereof will vibrate with a phase depending upon the direction of the acoustic waves. First electrodes are arranged on one of the surfaces of the diaphragm. Second electrodes are arranged so that each second electrode faces corresponding first electrode with gap. Each first electrode and corresponding second electrode facing thereto form a first capacitor. Third electrodes are arranged on the other surface of the diaphragm. Fourth electrodes are arranged so that each fourth electrode faces corresponding third electrode with gap. Each third electrode and corresponding fourth electrode facing thereto form a second capacitor. The controller applies a voltage to each of the second capacitors so that the capacitance of each of the first capacitors will be a constant value. The controller identifies the direction along which the acoustic waves propagate based on the difference in the voltages applied to each of the second capacitors. Vibration of the diaphragm will be inhibited by the voltages applied to the second capacitors while the direction is identified based on the voltages. The durability of the diaphragm can be improved.
摘要:
In a semiconductor strain detector, the temperature characteristic of the output of a zero-point temperature compensating circuit is added to the zero-point temperature characteristic of the output of a bridge circuit composed of strain gauges, to perform a zero-point temperature compensation of the final output. Further, two kinds of diffusion resistors having different surface impurity densities are used in each amplifying circuit to perform a sensitivity-temperature compensation in which a temperature coefficient of sensitivity is considered up to the second-order term.
摘要:
In a MEMS structure, a first trench which penetrates the first layer, the second layer and the third layer is formed, and a second trench which penetrates the fifth layer, the forth layer and the third layer is formed. The first trench forms a first part of an outline of the movable portion in a view along the stacked direction. The second trench forms a second part of the outline of the movable portion in the view along the stacked direction. At least a part of the first trench overlaps with the first extending portion in the view along the stacked direction.
摘要:
An apparatus with a second movable portion that moves along an x-axis direction and a z-axis direction and a first movable portion that only moves along the z-axis direction is disclosed. The apparatus is provided with a fixed portion fixed to a support portion, a plurality of first spring portions connected to the fixed portion, a first movable portion connected to the plurality of first spring portions, a second spring portion connected to the first movable portion, and a second movable portion connected to the second spring portion. A spring constant of each of the plurality of first spring portions in the z-axis direction is lower than spring constants of each of the plurality of first spring portions in the x-axis and a y-axis directions respectively, and a spring constant of the second spring portion in the x-axis direction is lower than spring constants of the second spring portion in the y-axis and the z-axis directions respectively. The first movable portion is configured to move along the z-axis but not to move along the x-axis and the y-axis nor to rotate around the z-axis, and the second movable portion is configured to move along the x-axis and the z-axis with respect to the support portion.