The present invention provides a thermal flow meter that includes a sensor flow path along which flows a fluid being measured, an upstream-side electrical resistance element provided on the sensor flow path, a downstream-side electrical resistance element provided downstream of the upstream-side electrical resistance element, a sensor output generator that, based on respective voltages that are output in accordance with changes in the upstream-side and downstream-side electrical resistance elements, generates a sensor output in accordance with the flow rate of the fluid being measured, a slope effect estimator that, based on at least a Prandtl number of the fluid being measured, estimates a slope effect that is generated in the sensor output in accordance with an attitude of the sensor flow path, and a flow rate calculator that corrects the slope effect from the sensor output, and calculates the flow rate of the fluid being measured.

The present invention provides a thermal flow meter that includes a sensor flow path along which flows a fluid being measured, an upstream-side electrical resistance element provided on the sensor flow path, a downstream-side electrical resistance element provided downstream of the upstream-side electrical resistance element, a sensor output generator that, based on respective voltages that are output in accordance with changes in the upstream-side and downstream-side electrical resistance elements, generates a sensor output in accordance with the flow rate of the fluid being measured, a slope effect estimator that, based on at least a Prandtl number of the fluid being measured, estimates a slope effect that is generated in the sensor output in accordance with an attitude of the sensor flow path, and a flow rate calculator that corrects the slope effect from the sensor output, and calculates the flow rate of the fluid being measured.

An object of the present invention is to provide a sensor unit that can detect a wide range of physical quantity changes with a higher degree of freedom than in the conventional art and is capable of reporting detection information, and a multiple-type sensor using the sensor unit. A flow sensor in the present invention includes a board, a sensor that is arranged on the board and detects a physical quantity change, a plurality of external connection terminals that are electrically connected to the sensor, and a reporting part that reports detection information of the sensor to the outside. In the present invention, a wide range of physical quantity changes can be detected with a higher degree of freedom. Connecting a plurality of sensor units enables use for various applications.

Provided is a vehicle-mounted system capable of transmitting a command to a first system from a second system during a period in which the first system communicates with the second system according to a unidirectional communication protocol. A vehicle-mounted system 100 includes a sensor 10 (first system) and an ECU (second system). The sensor 10 outputs a message signal including a pause pulse to the communication line DATA according to SENT (a unidirectional communication protocol). The ECU 20 is connected to the communication line DATA, and transmits a command to the sensor 10 using the falling period of the pause pulse.

The application discloses a time-of-flight generating circuit, coupled to a first transducer and a second transducer, wherein there is a distance greater than zero between the first transducer and the second transducer, and a fluid having a flow speed flows sequentially through the first transducer and the second transducer, wherein the time-of-flight generating circuit includes: a transmitter, coupled to the first transducer; a receiver, coupled to the second transducer; a signal processing circuit, coupled to the transmitter and the receiver; and a correlation circuit, a measuring circuit and a transformation circuit, coupled to the signal processing circuit. The application also discloses a chip, flow meter, and method of the same.

The application discloses a time-of-flight generating circuit, coupled to a first transducer and a second transducer, wherein there is a distance greater than zero between the first transducer and the second transducer, and a fluid having a flow speed flows sequentially through the first transducer and the second transducer, wherein the time-of-flight generating circuit includes: a transmitter, coupled to the first transducer; a receiver, coupled to the second transducer; a signal processing circuit, coupled to the transmitter and the receiver; and a correlation circuit, a measuring circuit and a transformation circuit, coupled to the signal processing circuit. The application also discloses a chip, flow meter, and method of the same.

An anemometer and method for analyzing fluid flow is described. In one embodiment, a transistor sensor is heated by applying power to cause its base-emitter junction to rise from an ambient first temperature to a second temperature. The power is removed, and the Vbe is measured at intervals as the junction cools. The Vbe equates to a temperature of the junction. The temperature exponentially decreases, and the time constant of the decay corresponds to the fluid flow velocity. A best fit curve analysis is performed on the temperature decay curve, and the time constant of the exponential decay is derived by a data processor. A transfer function correlates the time constant to the fluid flow velocity. The transistor is thermally coupled to a metal rod heat sink extending from the package, and the characteristics of the rod are controlled to adjust the performance of the anemometer.

An anemometer and method for analyzing fluid flow is described. In one embodiment, a transistor sensor is heated by applying power to cause its base-emitter junction to rise from an ambient first temperature to a second temperature. The power is removed, and the Vbe is measured at intervals as the junction cools. The Vbe equates to a temperature of the junction. The temperature exponentially decreases, and the time constant of the decay corresponds to the fluid flow velocity. A best fit curve analysis is performed on the temperature decay curve, and the time constant of the exponential decay is derived by a data processor. A transfer function correlates the time constant to the fluid flow velocity. The transistor is thermally coupled to a metal rod heat sink extending from the package, and the characteristics of the rod are controlled to adjust the performance of the anemometer.

The purpose of the present invention is to provide a highly accurate and highly reliable physical quantity sensor wherein an error due to stress applied to a sensor element of the physical quantity sensor is reduced. This physical quantity sensor device is provided with: a hollow section formed in a Si substrate; an insulating film covering the hollow section; and a heating section formed in the insulating film. The sensor device is also provided with a detection element that detects the temperature of the insulating film above the hollow section, the detection element is provided with a first silicon element and a second silicon element, and the first silicon element and the second silicon element are doped with different impurities, respectively.

A thermal sensor comprises an active element (41), e.g., a heater or cooler, at least one temperature sensor (31), and processing circuitry (50). The processing circuitry causes a change of power supplied to the active element (41). It then determines, at a plurality of times, a thermal parameter based on an output signal of the temperature sensors and analyzes the transient behavior of the thermal parameter. Based on this analysis, the processing circuitry determines a contamination signal that is indicative of a contamination on a sensing surface of the thermal sensor. If the thermal sensor comprises a plurality of temperature sensors arranged in different sectors of the sensing surface, a multi-sector thermal signal can be derived from the outputs of the sensors, and determination of the contamination signal can be based on the multi-sector thermal signal.