Power regulation circuit, regulation method and constant-power thermal mass flow meter

Abstract

The invention provides a power regulation circuit, a regulation method and a constant-power thermal mass flow meter. The voltage at two ends of a temperature measurement sensor and the voltage at two ends of a linear element are firstly detected, and then the actual power of the temperature measurement sensor is calculated based on the voltage at two ends of the temperature measurement sensor and the voltage at two ends of the linear element; an intermediate voltage is determined according to the voltage at the two ends of the temperature measurement sensor and the voltage at the two ends of the linear element, the intermediate voltage is compared with an externally input threshold voltage, and the flow state of the intermediate medium at the current moment and the power state of the driving power at the current moment are judged; and the driving power is selected according to the flow state of the intermediate medium at the current moment and the power state of the driving power at the current moment, power adjustment is carried out based on the driving power and the actual power of the temperature measurement sensor, and constant power is output to the temperature measurement sensor. Power adjustment can be carried out, so that the temperature measurement sensor is in a constant power state, and the original reliability of the temperature measurement sensor can be maintained at a high temperature.

Description

technical field [0001] The invention relates to the technical field of measurement and measurement, in particular to a power regulating circuit and a power regulating method for a constant power thermal mass flowmeter, and a constant power thermal mass flowmeter including the power regulating circuit. Background technique [0002] Since the constant power thermal mass flowmeter has the advantages of small pressure loss, wide measurement range, and direct measurement of mass flow, it has also received more and more attention and application in the field of measurement and measurement. However, for the current constant power thermal mass flowmeters, the power of the internal temperature sensor is basically kept constant. When there is no intermediate medium (such as gas) flow, the heat cannot be taken away, resulting in the temperature sensor probe. The temperature can be heated to hundreds of degrees Celsius by the heat that is not taken away. However, at high temperatures o...

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Problems solved by technology

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a power regulation circuit for constant power thermal mass flowmeters, which is used to solve the problem of the temperature sensor detecting the intermediate medium due to the lack of intermediate medium flow. Problems that cause the temperature sensor to overheat

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