摘要:
A method for filtering digital signals in a pressure transmitter. The transmitter includes a microprocessor. In each operating cycle of the microprocessor included in the transmitter, the method determines if there are any noise spikes in the signal at the input to the microprocessor representative of pressure and provides rejection for such spikes. The method also provides for a faster response to a step change in pressure than is provided by conventional filtering methods and also dampens small fluctuations in the filtered output signal.
摘要:
A pulsed pressure sensor circuit (11) with increased sensitivity for measuring low pressures. A pulse generation circuit (12) is enabled by a microprocessor (28) to output a voltage pulse. The voltage pulse biases a pressure sensor (17) which has a port exposed to a pressure to be sensed. The pressure sensor (17) outputs a differential voltage which is proportional to the pressure at the port. The differential voltage is amplified by an amplifier (23) which has an output coupled to the microprocessor (28). A voltage divider circuit (26) is coupled to the pulse generation circuit (12) and has an output coupled to the microprocessor (28). The microprocessor (28) samples the voltages at the output of the amplifier (23) and the output of the voltage divider circuit (26). Microprocessor (28) then calculates the pressure using the sampled voltages and data stored in memory.
摘要:
An on-line fishing depth indicator is adapted to be placed either in series or in parallel on a typical fishing line in combination with fishing bait. The indicator is adapted to read and store the maximum depth of the bait during a trolling operation under controlled conditions. This permits the user to determine the performance of the bait under certain, predefined conditions. The electronics and pressure transducers associated with the indicator are self-contained in the unit.
摘要:
A semiconductor strain sensor includes a silicon substrate, a strain resistive element and electrodes. The silicon substrate has a deformable portion which is deformed when stress is applied to it. The strain resistive element is formed on the deformable portion and has an at least a first layer and a second layer which form a heterojunction between them. The first layer is doped with impurities so that a two-dimensional carrier gas layer is formed in the second layer near the heterojunction. The two-dimensional carrier gas layer has carriers originating from the impurities. The electrodes electrically contact the two dimensional carrier gas layer. Change of resistance of the strain resistive element in accordance with the stress is detected through the electrodes.
摘要:
A semiconductor pressure sensor according to the present invention comprises a semiconductor substrate having a first surface, a second surface opposite to the first surface and a recess formed in the first surface, the recess defining an interior surface including a bottom surface; and a diffusion region extending from the adjacency of the bottom surface to the second surface. A pressure-sensitive resistance of the semiconductor pressure sensor is formed in the vicinity of the bottom surface of a diaphragm. Therefore, the pressure-sensitive resistance can be formed so as to be brought into alignment with the position of the diaphragm after the formation of the diaphragm. Accordingly, a semiconductor pressure sensor, which does not cause a displacement in position between the diaphragm and the pressure-sensitive resistance and is excellent in accuracy, can be easily fabricated. Further, since the pressure-sensitive resistance can be formed according to the shape of the diaphragm, the diaphragm can be reduced in size and fabricated in the form of a thin film.
摘要:
A semiconductor pressure sensor assembly, comprising a receptacle having a floor and including a first cavity recessed within a first portion of the floor, and a second cavity recessed within a second portion of the floor and connected to the first cavity at a first junction. A semiconductor pressure sensor is within the first cavity, and a plurality of bonding pads are disposed about a periphery of a top surface of the pressure sensor chip other than at a location of the first junction, a plurality of external conducting terminals are disposed about a periphery of the receptacle other than at the location of the first junction, and a plurality of wires connect the external conducting terminals to respective ones of the bonding pads. A gelatinous material is within the first and second cavities, and the second cavity serves as a first work region from which an excess of the gelatinous material within the first cavity can be removed.
摘要:
A semiconductor sensor has a plurality of field-effect transistors disposed on a semiconductor substrate at spaced intervals. The field-effect transistors have respective drains electrically connected parallel to each other, respective sources electrically connected parallel to each other, and gates electrically connected parallel to each other. While a gate bias voltage is being applied to each of the field-effect transistors, a stress applied to the semiconductor substrate is detected based on a change in a combined output of the field-effect transistors. A single comb-shaped field-effect transistor may be employed instead of the plurality of field effect transistors.
摘要:
A semiconductor pressure sensor is manufactured by integrally encapsulating a semiconductor pressure, sensor chip, a pedestal, leads, wires and a die pad in an outer package except for the surface of a diaphragm of the semiconductor pressure sensor chip and the reverse side of the die pad. The ratio of the thickness of the pedestal to the thickness of the semiconductor pressure sensor chip is 7.5 or less, while the ratio of the diameter of an opening formed in the outer package at the surface of the diaphragm and the diameter of the diaphragm is 1 or more. The thermal stress generated in the semiconductor pressure sensor chip can freely be reduced to a desired value, and a semiconductor pressure sensor exhibiting a desired accuracy can therefore be obtained. Furthermore, since the semiconductor pressure sensor can be manufactured by an ordinary IC manufacturing process, a semiconductor pressure sensor with reduced cost and having high quality can be produced.
摘要:
The present invention provides compensation for temperature in a transducer by connecting the adjustment resistors to the transducer itself to provide a correct transducer output. A number of switches are used to couple the adjustment resistors to the transducer circuit. An individual resistor may be coupled in parallel or in series with a transducer resistance. The control input for the switches are each coupled to a separate bit output of a multiple bit memory. The memory is programmed to control the duty cycle of the switches when addressed.
摘要:
A pressure sensor for use in an internal combustion engine includes a diaphragm member having a cylindrical part and a pressure receiving part which is subjected to an axial motion in an axial direction of the diaphragm member when a pressure in an external environment is applied to the pressure receiving part, a pressure detection member having pressure distributing parts and a piezoelectric part for generating a signal indicative of the applied pressure when it is stressed in response to the axial motion of the pressure receiving part, and a pressure transfer member for transferring the motion from the pressure receiving part to the pressure detection member, the pressure transfer member including a spherical member capable of rolling relative to the diaphragm member in a direction perpendicular to the axial direction of the diaphragm member at a position between the pressure receiving part and the pressure detection member.