CN213632448U

CN213632448U - Compatible Pt temperature sensor sampling circuit

Info

Publication number: CN213632448U
Application number: CN202022819285.5U
Authority: CN
Inventors: 刘聪; 刘长来; 夏诗忠; 吴银龙; 骆淼
Original assignee: Zhongkeluorui New Energy Technology Co ltd
Current assignee: Zhongkeluorui New Energy Technology Co ltd
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2021-07-06
Anticipated expiration: 2030-11-30

Abstract

The utility model discloses a compatible Pt temperature sensor sampling circuit, which comprises a power supply, an isolation power supply module, a constant current source, a Pt temperature sensor, a zero line resistance error bias circuit, a low-pass filter circuit, a signal amplification circuit, an A/D conversion circuit, a digital isolation circuit, a low-pass filter and an MCU; the power supply supplies power to the isolation power module, the output end of the digital isolation circuit, the low-pass filter and the MCU respectively; the isolation power supply module provides isolation power supplies for the input ends of the constant current source, the low-pass filter circuit, the signal amplification circuit, the A/D conversion circuit and the digital isolation circuit respectively, and a signal line of the Pt temperature sensor is connected to the zero line resistance value error bias circuit and is powered by the constant current source; the zero line resistance value error bias circuit is sequentially connected in series with the low-pass filter circuit, the signal amplification circuit, the A/D conversion circuit, the digital isolation circuit, the low-pass filter and the MCU. The utility model discloses sampling circuit can satisfy multiple different temperature sensor's user demand.

Description

Compatible Pt temperature sensor sampling circuit

Technical Field

The utility model relates to a circuit design technical field, more specifically say, especially relate to a compatible Pt temperature sensor sampling circuit.

Background

The existing motor temperature sampling technology mostly adopts a single Pt100 or Pt1000 temperature sensor for sampling, and generally adopts a single 2-wire Pt100/Pt1000 or a single 3-wire Pt100/Pt1000 for sampling, a sampling circuit directly inputs a sampling signal into an A/DC module of an MCU through simple processing, and then the motor temperature is obtained through sampling. However, the temperature sampling circuit has weak anti-interference capability, influences temperature measurement accuracy, has no compatible design, and cannot be compatible with Pt100 and Pt1000 for use.

SUMMERY OF THE UTILITY MODEL

The utility model aims at the not enough of above-mentioned prior art, provide a compatible Pt temperature sensor sampling circuit, can satisfy multiple different temperature sensor's user demand, no matter 2 line system Pt100/Pt1000 or 3 line system Pt100/Pt1000 can all be general.

In order to achieve the above object, the utility model adopts the following technical scheme: a compatible Pt temperature sensor sampling circuit comprises a power supply, an isolation power supply module, a constant current source, a Pt temperature sensor, a zero line resistance error bias circuit, a low-pass filter circuit, a signal amplification circuit, an A/D conversion circuit, a digital isolation circuit, a low-pass filter and a Micro Control Unit (MCU); the power supply is respectively connected with the isolation power supply module, the output end of the digital isolation circuit, the low-pass filter and the micro control unit MCU, the power supply supplies power, and the output end of the digital isolation circuit, the low-pass filter and the micro control unit MCU are all connected with the ground; the isolation power supply module is respectively connected with the input ends of the constant current source, the low-pass filter circuit, the signal amplification circuit, the A/D conversion circuit and the digital isolation circuit, the isolation power supply module outputs an isolation power supply to supply power, a signal line of the Pt temperature sensor is connected to the zero line resistance value error bias circuit and is supplied with power by the constant current source, and the input ends of the Pt temperature sensor, the zero line resistance value error bias circuit, the low-pass filter circuit, the signal amplification circuit, the A/D conversion circuit and the digital isolation circuit are in isolated grounding connection; the zero line resistance value error bias circuit is sequentially connected in series with the low-pass filter circuit, the signal amplification circuit, the A/D conversion circuit, the digital isolation circuit, the low-pass filter and the micro control unit MCU.

When the utility model is used, the power supply current of the constant current source is adjusted according to the specific Pt temperature sensor, when the Pt1000 temperature sensor is connected, the constant current source current is 0.1mA, and when the Pt100 temperature sensor is connected, the constant current source current is 1 mA; and voltage signals at two ends of the Pt are filtered, amplified, isolated and filtered to the MCU through the sampling circuit, and the real-time temperature inside the motor is finally measured through processing and calculation of the MCU analog signal to digital signal conversion module.

The utility model discloses sampling circuit can satisfy multiple different temperature sensor's user demand, and no matter 2 line system Pt100 Pt1000 or 3 line system Pt100 Pt1000 can all be general, is applicable to the inside temperature sampling of equipment such as motor, engine.

Drawings

Fig. 1 is a block diagram of the circuit structure of the present invention.

In the figure: 1-a power supply; 2-isolating the power supply module; 3-a constant current source; 4-Pt temperature sensors; 5-zero line resistance error bias circuit; 6-a low-pass filter circuit; 7-a signal amplification circuit; 8-A/D conversion circuit; 9-digital isolation circuit; 10-a low-pass filter; 11-MCU.

Detailed Description

The present invention will be described in further detail with reference to the following examples, which are not intended to limit the invention.

As shown in fig. 1, the utility model provides a compatible Pt temperature sensor sampling circuit, including 5V power supply 1, isolation power module 2, constant current source 3, Pt temperature sensor 4, zero line resistance error bias circuit 5, low pass filter circuit 6, signal amplification circuit 7, AD converting circuit 8, digital isolation circuit 9, low pass filter 10 and little the control unit MCU 11; the power supply 1 is respectively connected with the isolation power supply module 2, the output end of the digital isolation circuit 9, the low-pass filter 10 and the micro control unit MCU11, the power supply 1 supplies power, and the output end of the digital isolation circuit 9, the low-pass filter 10 and the micro control unit MCU11 are all connected with the ground; the isolation power supply module 2 is respectively connected with the input ends of the constant current source 3, the low-pass filter circuit 6, the signal amplification circuit 7, the A/D conversion circuit 8 and the digital isolation circuit 9, the isolation power supply is output by the isolation power supply module 2 to supply power, a signal line of the Pt temperature sensor 4 is connected to the zero line resistance value error bias circuit 5 and is supplied with power by the constant current source 3, and the input ends of the Pt temperature sensor 4, the zero line resistance value error bias circuit 5, the low-pass filter circuit 6, the signal amplification circuit 7, the A/D conversion circuit 8 and the digital isolation circuit 9 are in isolated grounding connection; the zero line resistance value error bias circuit 5 is sequentially connected in series with the low-pass filter circuit 6, the signal amplification circuit 7, the A/D conversion circuit 8, the digital isolation circuit 9, the low-pass filter 10 and the micro control unit MCU 11.

The utility model discloses in being connected to zero line resistance error bias circuit 5 with the signal line of Pt temperature sensor 4, through the processing of this circuit, can compatible 2 line system Pt100 Pt1000 or 3 line system Pt100 Pt 1000's access, utilize the constant current source power supply, according to the concrete Pt temperature sensor who inserts, adjust the supply current of constant current source 3, when the access be Pt1000 temperature sensor, the constant current source current size is 0.1mA, when the access be Pt100 temperature sensor, the constant current source current size is 1 mA; the signal output by the zero line resistance value error bias circuit 5 is input into a low-pass filter circuit 6 for low-pass filter processing, the processed signal is input into a signal amplifying circuit 7 for signal amplification, the amplified signal is input into an A/D conversion circuit 8 for converting the input analog signal into a digital signal with high precision, the digital isolating circuit 9 is used for isolating the signal (isolating strong electric signal interference in a motor and weak electric signal to be input into an MCU), the isolated signal is filtered by a first-order active low-pass filter 10, the voltage signals collected by the MCU11 are processed and calculated by an A/D conversion module arranged on the MCU11, and obtaining the real-time temperature inside the motor through the temperature corresponding to the corresponding resistance value of the Pt temperature sensor 4.

Claims

1. The utility model provides a compatible Pt temperature sensor sampling circuit, includes power supply, keeps apart power module, constant current source, Pt temperature sensor, zero line resistance error biasing circuit, low pass filter circuit, signal amplification circuit, AD converting circuit, digital isolating circuit, low pass filter and little the control unit MCU, its characterized in that: the power supply is respectively connected with the isolation power supply module, the output end of the digital isolation circuit, the low-pass filter and the micro control unit MCU, the power supply supplies power, and the output end of the digital isolation circuit, the low-pass filter and the micro control unit MCU are all connected with the ground; the isolation power supply module is respectively connected with the input ends of the constant current source, the low-pass filter circuit, the signal amplification circuit, the A/D conversion circuit and the digital isolation circuit, the isolation power supply module outputs an isolation power supply to supply power, a signal line of the Pt temperature sensor is connected to the zero line resistance value error bias circuit and is supplied with power by the constant current source, and the input ends of the Pt temperature sensor, the zero line resistance value error bias circuit, the low-pass filter circuit, the signal amplification circuit, the A/D conversion circuit and the digital isolation circuit are in isolated grounding connection; the zero line resistance value error bias circuit is sequentially connected in series with the low-pass filter circuit, the signal amplification circuit, the A/D conversion circuit, the digital isolation circuit, the low-pass filter and the micro control unit MCU.

2. The compatible Pt temperature sensor sampling circuit of claim 1, wherein: the voltage of the power supply is 5V.

3. The compatible Pt temperature sensor sampling circuit of claim 1, wherein: when a Pt1000 temperature sensor is connected, the current of the constant current source is adjusted to be 0.1 mA; when a Pt100 temperature sensor is connected, the current of the constant current source is adjusted to be 1 mA.