Pressure sensor

Abstract

The invention provides a pressure sensor with a small measurement error. An elastic membrane (3) is fixedly arranged at a combined part of an air cover and a shell; an iron core (4) is arranged at the center of the elastic membrane; an inductance coil (5) is wound on a framework of the shell; a circuit board (7) is arranged below the shell; the circuit board is provided with a memory device (71); the shell is fixedly provided with a frequency signal output terminal (8) and a memory signal input / output terminal (9); one end (81) of the frequency signal output terminal and one end (91) of the memory signal input / output terminal outward output signals; a middle part (82) of the frequency signal output terminal and a middle part (92) of the memory signal input / output terminal are fixed with the shell; the other end (83) of the frequency signal output terminal and the other end (93) of the memory signal input / output terminal are connected with the circuit board; and the memory device stores a frequency value obtained by outputting through the frequency signal output terminal under different pressures. The pressure sensor disclosed by the invention is applicable to being used as a water level pressure sensor.

Description

technical field [0001] The invention relates to a pressure sensor, in particular to a pressure sensor installed on washing machines, dishwashers and other household appliances for detecting the water level of the washing machines, dishwashers and other equipment when they are working. Background technique [0002] At present, the most widely used water level sensor for household appliances uses the following principle: water pressure is transmitted to the sensor air chamber through the air pipe to generate air pressure. When the core moves inside the coil, the inductance (L) of the coil changes approximately linearly with the displacement of the iron core, and the displacement of the iron core corresponds to the water level pressure. The displacement of the iron core is converted into the water level pressure, and the water level pressure and The relationship between the output inductance as figure 1 shown. [0003] The pressure sensor of Chinese invention patent ZL2008200...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims to solve the problem that the output frequency deviation of the current inductive pressure sensor is large, which leads to the decrease of the sensor precision. Therefore, a pressure sensor of the present invention is provided, and the pressure sensor has high measurement accuracy.

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