CN211453722U

CN211453722U - PWM temperature compensation circuit for Wheatstone bridge

Info

Publication number: CN211453722U
Application number: CN201921480692.9U
Authority: CN
Inventors: 袁郭竣
Original assignee: Ningbo Taifengyuan Electric Co ltd
Current assignee: Ningbo Taifengyuan Electric Co ltd
Priority date: 2019-09-06
Filing date: 2019-09-06
Publication date: 2020-09-08
Anticipated expiration: 2029-09-06

Abstract

The utility model discloses a PWM temperature compensation circuit for wheatstone bridge, including customization Microcontroller Chip (MCU), temperature sensor, filter circuit and voltage follower, the input of customization Microcontroller Chip (MCU) and temperature sensor's output electric connection, the output of customization Microcontroller Chip (MCU) and filter circuit's input electric connection. A PWM temperature compensation circuit for wheatstone electric bridge, can take notes ambient temperature through temperature sensor to give MCU with the temperature value transmission, MCU preserves EEPROM data memory with temperature value and current PWM modulation parameter. MCU communicates with the outside through external communication interface, can realize that outside host computer program or computer carry out data transmission and software control to MCU, utilizes the unbalanced problem that PWM technique solution Wheatstone bridge voltage leads to along with temperature variation, is favorable to people's use to bring better use prospect.

Description

PWM temperature compensation circuit for Wheatstone bridge

Technical Field

The utility model relates to a sensor temperature compensation circuit technical field, in particular to PWM temperature compensation circuit for wheatstone bridge.

Background

At present, a tunnel magneto-resistance chip (TMR) and a Hall chip (Hall) built by a Wheatstone bridge are utilized to develop a current sensor, the zero output of the current sensor can change along with the change of temperature, the change is determined by the principle of the TMR chip and the Hall chip, the current sensor belongs to an uncontrollable factor, the problem is solved, an external temperature compensation circuit is generally added for correction, and therefore, a PWM temperature compensation circuit for the Wheatstone bridge is provided.

Disclosure of Invention

A primary object of the present invention is to provide a PWM temperature compensation circuit for wheatstone bridge, which can effectively solve the problems in the background art.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a PWM temperature compensation circuit for wheatstone bridge, includes customization micro control chip (MCU), temperature sensor, filter circuit and voltage follower, customization micro control chip's (MCU) input and temperature sensor's output electric connection, customization micro control chip's (MCU) output and filter circuit's input electric connection, the input of voltage follower and filter circuit's output electric connection.

The temperature sensor and the voltage follower can adopt temperature sensors of different models according to the voltage of actual requirements.

Preferably, the customized micro control chip (MCU) is internally integrated with a high resolution digital-to-analog conversion module, an EEPROM data memory and an external communication interface, an output end of the external communication interface is electrically connected with an input end of the customized micro control chip (MCU), the customized micro control chip (MCU) is electrically connected with the EEPROM data memory, and an output end of the high resolution digital-to-analog conversion module is electrically connected with an input end of the customized micro control chip (MCU).

Preferably, a wheatstone bridge is disposed at one end of the high resolution digital-to-analog conversion module, a V1 port and a V2 port are disposed outside the wheatstone bridge, and an R1 resistor, an R2 resistor, an R3 resistor, and an R4 resistor are disposed inside the wheatstone bridge.

Preferably, the high resolution digital-to-analog conversion module is electrically connected with a V1 port and a V2 port.

Preferably, one end of the voltage follower is electrically connected to the V2 port.

Compared with the prior art, the utility model discloses following beneficial effect has: this a PWM temperature compensating circuit for wheatstone bridge can record ambient temperature through temperature sensor to transmit the temperature value for MCU, MCU saves temperature value and current PWM modulation parameter in EEPROM data memory. MCU communicates with the outside through external communication interface, can realize that outside host computer program or computer carry out data transmission and software control to MCU, utilizes the unbalanced problem that PWM technique solution Wheatstone bridge voltage leads to along with temperature variation, is favorable to people's use, and is comparatively practical.

Drawings

Fig. 1 is a schematic circuit diagram of a PWM temperature compensation circuit for a wheatstone bridge according to the present invention.

Detailed Description

In order to make the technical means, creation features, achievement purposes and functions of the present invention easy to understand, the present invention is further described below with reference to the following embodiments.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element to which the reference is made must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, and for example, "connected" may be either fixedly connected or detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in FIG. 1, a PWM temperature compensation circuit for Wheatstone bridge, including customization little control chip (MCU), temperature sensor, filter circuit and voltage follower, the input of customization little control chip (MCU) and temperature sensor's output electric connection, the output of customization little control chip (MCU) and filter circuit's input electric connection, the input of voltage follower and filter circuit's output electric connection.

The high-resolution digital-to-analog conversion module, the EEPROM data memory and the external communication interface are integrated in the customized micro control chip (MCU), the output end of the external communication interface is electrically connected with the input end of the customized micro control chip (MCU), the customized micro control chip (MCU) is electrically connected with the EEPROM data memory, and the output end of the high-resolution digital-to-analog conversion module is electrically connected with the input end of the customized micro control chip (MCU); one end of the high-resolution digital-to-analog conversion module is provided with a Wheatstone bridge, a V1 port and a V2 port are arranged outside the Wheatstone bridge, and an R1 resistor, an R2 resistor, an R3 resistor and an R4 resistor are arranged inside the Wheatstone bridge; the high-resolution digital-to-analog conversion module is electrically connected with the V1 port and the V2 port; one end of the voltage follower is electrically connected to the V2 port.

It should be noted that the utility model relates to a PWM temperature compensation circuit for wheatstone bridge, by customization little control chip (MCU), temperature sensor, filter circuit, voltage follower, integrated high resolution digital-to-analog conversion module, EEPROM data memory, external communication interface and wheatstone bridge constitute, add voltage + Vcc for wheatstone bridge both ends, can produce voltage at V1 and V2 end, V1 equals V2 of bridge under balanced state; when the environment temperature changes, the respective resistance values of four resistors R1, R2, R3 and R4 in the bridge change, and finally the bridge voltage is unbalanced, and V1 is not equal to V2; the ends V1 and V2 are connected with a digital-to-analog Converter (AD Converter) of a customized micro-control chip (MCU), the MCU acquires and reads the voltage difference between V1 and V2 through AD, a corresponding pulse width modulation signal (PWM) is generated through software calculation, the PWM signal is connected with the end V2 of the bridge through a filter circuit and a voltage follower, voltage compensation can be realized on V2, and the voltage of V2 is equal to the voltage of V1; the temperature sensor can record the ambient temperature and transmit the temperature value to the MCU, and the MCU stores the temperature value and the current PWM modulation parameter into the EEPROM data memory. MCU communicates with the outside through external communication interface, can realize that outside host computer program or computer carry out data transmission and software control to MCU, and is comparatively practical.

The basic principles and the main features of the invention and the advantages of the invention have been shown and described above. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the foregoing embodiments and descriptions are provided only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a PWM temperature compensation circuit for wheatstone bridge, includes customization little control chip (MCU), temperature sensor, filter circuit and voltage follower, its characterized in that: the input end of the customized micro control chip (MCU) is electrically connected with the output end of the temperature sensor, the output end of the customized micro control chip (MCU) is electrically connected with the input end of the filter circuit, and the input end of the voltage follower is electrically connected with the output end of the filter circuit.

2. A PWM temperature compensation circuit for a wheatstone bridge according to claim 1, wherein: the system comprises a customized micro control chip (MCU), an internal integration high resolution digital-to-analog conversion module, an EEPROM data memory and an external communication interface, wherein the output end of the external communication interface is electrically connected with the input end of the customized micro control chip (MCU), the customized micro control chip (MCU) is electrically connected with the EEPROM data memory, and the output end of the high resolution digital-to-analog conversion module is electrically connected with the input end of the customized micro control chip (MCU).

3. A PWM temperature compensation circuit for a wheatstone bridge according to claim 2, wherein: one end of the high-resolution digital-to-analog conversion module is provided with a Wheatstone bridge, a V1 port and a V2 port are arranged outside the Wheatstone bridge, and an R1 resistor, an R2 resistor, an R3 resistor and an R4 resistor are arranged inside the Wheatstone bridge.

4. A PWM temperature compensation circuit for a wheatstone bridge according to claim 3, wherein: the high-resolution digital-to-analog conversion module is electrically connected with the V1 port and the V2 port.

5. The PWM temperature compensation circuit for a Wheatstone bridge according to claim 4, wherein: one end of the voltage follower is electrically connected with the V2 port.