CN211696655U

CN211696655U - Circuit for temperature compensation of symmetrical weight pressure sensor

Info

Publication number: CN211696655U
Application number: CN202020499168.2U
Authority: CN
Inventors: 黄健; 阚连君
Original assignee: Krell Precision Technology Yangzhou Co ltd
Current assignee: Krell Precision Technology Yangzhou Co ltd
Priority date: 2020-04-08
Filing date: 2020-04-08
Publication date: 2020-10-16
Anticipated expiration: 2030-04-08

Abstract

The utility model provides a circuit that temperature compensation was carried out to weight pressure sensor, belongs to measuring tool technical field, including the MCU treater, this MCU treater has ADC functional module, MCU's excitation power with circuit connection between the reference voltage interface of ADC functional module, characterized by, MCU's excitation power with be equipped with temperature sensing resistor on the connecting circuit between the reference voltage interface of ADC functional module, just MCU's excitation power with still be equipped with a plurality of standard resistance on the connecting circuit between the reference voltage interface of ADC functional module and be used for the partial pressure. The circuit of the utility model can be realized by adopting a common MCU processor, and the MCU processor is internally provided with an ADC functional module; the utility model discloses a circuit carries out temperature compensation to weighing pressure sensor, and the use quantity of temperature sensing resistance is only 1.

Description

Circuit for temperature compensation of symmetrical weight pressure sensor

Technical Field

The utility model belongs to the technical field of the measuring tool, concretely relates to circuit that temperature compensation was carried out to weight pressure sensor.

Background

With the progress of society, people pay more and more attention to their physical health, especially people who like sports, and rather, people need to monitor their health data, especially weight, every day. This requires the use of a weight, body fat scale. The key core of the method is a weighing pressure sensor, and if the weight measured by the weighing pressure sensor is inaccurate, all health data are false. At present, the weighing pressure sensor generally adopts a Wheatstone bridge principle, and the production process determines that the output characteristic of the weighing pressure sensor can change along with the change of temperature. In order to ensure that the weight scales and the body fat scales are used at different temperatures, the obtained weights are consistent, and then the weighing pressure sensor needs to be subjected to temperature compensation.

At present, the temperature characteristic of the weighing pressure sensor is compensated in the industry, and the following modes are generally adopted:

the first method is as follows: the MCU processor with an internal absolute temperature sensor is selected, the absolute temperature sensor in the MCU processor is used for detecting the ambient temperature of the weighing pressure sensor, and the MCU processor is matched for software compensation, so that the weights of the same object are consistent at different temperatures.

The second method comprises the following steps: the positive and negative ends of the excitation power supply of the weighing pressure sensor are respectively connected with a group of temperature sensing resistors and a standard resistor in parallel, so that the temperature changes, the excitation voltage of the weighing pressure sensor changes along with the change, and the weighing pressure sensor outputs the same voltage at different temperatures.

The above-described manner is limited as follows:

the first method is as follows: the limitation of this approach is that the MCU processor with the absolute temperature sensor inside needs to be selected, so that the MCU processor selection plane is narrow, and compared to an MCU processor without an internal absolute temperature sensor, the MCU processor with an absolute temperature sensor inside has a higher cost.

In the second mode, 2 temperature sensing resistors are required, and the cost is slightly lower than that in the first mode.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that overcome prior art not enough, provide a circuit that symmetrical heavy pressure sensor carries out temperature compensation.

The utility model provides an above-mentioned technical problem's technical scheme as follows:

the utility model provides a circuit that temperature compensation was carried out to weighing pressure sensor, includes the MCU treater, this MCU treater has ADC functional module, MCU's excitation power with circuit connection between the reference voltage interface of ADC functional module, characterized by, MCU's excitation power with be equipped with temperature sensing resistor on the connecting circuit between the reference voltage interface of ADC functional module, just MCU's excitation power with still be equipped with a plurality of standard resistance on the connecting circuit between the reference voltage interface of ADC functional module and be used for the partial pressure.

Further, the number of the temperature sensing resistors is one.

Further, the number of the standard resistors is at least 4.

Further, at least one standard resistor is connected with the temperature sensing resistor in parallel.

Further, the temperature characteristic of the temperature-sensitive resistor is opposite to the temperature characteristic of the weighing pressure sensor.

The utility model provides a reference voltage uses excitation power supply as the source, and the partial pressure by standard resistance produces, will excite the power supply and pass through these standard resistance partial pressures, and the voltage of partial pressure is reference voltage promptly. The utility model has the advantages that:

1. the circuit of the utility model can be realized by adopting a common MCU processor, and the MCU processor is internally provided with an ADC functional module;

2. the utility model discloses a circuit carries out temperature compensation to weighing pressure sensor, and the use quantity of temperature sensing resistance is only 1.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic diagram of a circuit structure for performing temperature compensation on a symmetrical weight pressure sensor according to embodiment 2 of the present invention;

FIG. 2 is a schematic circuit connection diagram of temperature compensation of the load pressure sensor of FIG. 1;

FIG. 3 is a schematic circuit diagram of the MCU processor of FIG. 1;

fig. 4 is a schematic circuit connection diagram of the weighing pressure sensor of fig. 1.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the present invention belongs.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience of description and simplicity of description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Example 1

A circuit for performing temperature compensation on a weighing pressure sensor comprises an MCU (microprogrammed control unit) processor, wherein the MCU processor can generate an excitation power supply through software program setting, an internal ADC (analog to digital converter) functional module of the MCU processor is provided with a reference voltage interface of the ADC module capable of being externally input and output, the input end of the reference voltage interface of the ADC functional module is respectively provided with 4 or more than 4 standard resistors, the excitation power supply of the standard resistors and the excitation power supply of the weighing pressure sensor are the same excitation power supply, and the excitation power supply can generate different voltages through the MCU processor through software setting.

Specifically, the reference voltage interface input end of the ADC functional module necessarily has only one temperature sensing resistor, and the temperature characteristic of the temperature sensing resistor is opposite to the temperature characteristic of the weighing sensor. The temperature sensing resistor is necessarily connected in parallel with a standard resistor. The excitation power supplies of 4 or more than 4 standard resistors at the input end of the reference voltage interface of the ADC module and the excitation power supply of the weighing pressure sensor are the same excitation power supply and are set and generated by software of the MCU processor.

Example 2

As shown in FIGS. 1-4, in a circuit for temperature compensation of a weighing pressure sensor, software of an MCU processor is configured to generate an excitation power supply, and the excitation power supply is connected with the weighing pressure sensor and used as an excitation power supply of the weighing pressure sensor, and is also connected with a temperature compensation circuit of the weighing pressure sensor and used as an excitation power supply of the temperature compensation circuit.

Specifically, as shown in fig. 1, the standard resistors 1, 2, and 3 are connected in series with the temperature sensing resistor, and the standard resistor 4 is connected in parallel with the temperature sensing resistor, in this connection manner, when the ambient temperature changes, the resistance value of the standard resistor 4 and the temperature sensing resistor connected in parallel also changes with the temperature, so that the reference voltage generated by dividing the voltage of the resistors also changes, and the temperature change curve of the reference voltage is complementary to the temperature change curve of the signal input of the weighing pressure sensor. In fig. 2, R28, R30 and R35 correspond to standard resistors 1, 2 and 3 respectively, R34 corresponds to standard resistor 4, and RT1 corresponds to temperature sensing resistor; the position of the temperature compensation circuit in fig. 3 is connected to fig. 2 by the electrical characteristics VREFP, VREN.

The utility model discloses to weighing pressure sensor's temperature characteristic, the reference voltage circuit of weighing pressure sensor ADC function (collection) module adopts temperature-sensing resistance and the parallelly connected method of standard resistance to realize that ADC collection module's reference voltage can change along with the change of temperature, its change curve reverse simulation weighing sensor's temperature characteristic, under reaching different temperatures, the weight numerical value that the output voltage value of the weighing pressure sensor weight that ADC collection module acquireed changes and calculates out does not change.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. The utility model provides a circuit that temperature compensation was carried out to weighing pressure sensor, includes the MCU treater, this MCU treater has ADC functional module, MCU's excitation power with circuit connection between the reference voltage interface of ADC functional module, characterized by, MCU's excitation power with be equipped with temperature sensing resistor on the connecting circuit between the reference voltage interface of ADC functional module, just MCU's excitation power with still be equipped with a plurality of standard resistance on the connecting circuit between the reference voltage interface of ADC functional module and be used for the partial pressure.

2. The circuit for temperature compensation of a ballast pressure sensor according to claim 1, wherein the number of said temperature-sensitive resistors is one.

3. The circuit of claim 2, wherein the number of said reference resistors is at least 4.

4. The circuit for temperature compensation of a symmetrical weight pressure sensor as claimed in claim 3, wherein at least one standard resistor is connected in parallel with said temperature sensing resistor.

5. The circuit for temperature compensation of a load cell as claimed in claim 1, wherein the temperature characteristic of the temperature sensitive resistor is opposite to the temperature characteristic of the load cell.