A remote temperature detection circuit for textile machinery

Abstract

The application discloses a spinning machine equipment remote temperature detection circuit, which uses a platinum resistance temperature sensor as a temperature detection tool, one end of the platinum resistance temperature sensor is connected with two signal transmission wires A and B in parallel, the other end is connected with a wire C to ground to form a three-wire structure, the wire A is connected with input pins of first and third single-chip microcomputers in parallel, the wire B is connected with an input pin of a second single-chip microcomputer, three address switches and a gating switch of the three single-chip microcomputers are connected with a microcontroller through signal lines, and an output pin (OU) of the single-chip microcomputer is connected with an AD sampling port of the microcontroller through a compensation circuit mainly composed of a single power supply four-way operational amplifier. Signals transmitted by the two signal transmission wires A and B are compensated and arranged by the compensation circuit, the influence of the line resistance of the signal line on the platinum resistance temperature sensor signal is solved, and the accuracy of temperature detection is improved.

Description

Technical Field

[0001] This invention belongs to the field of textile machinery electrical control technology, and is particularly related to a remote temperature detection circuit for textile machinery equipment. Background Technology

[0002] To improve the safety and accuracy of automatic control in textile machinery, temperature detection at key locations is increasingly used in newer textile equipment such as twisting machines and spinning machines to provide real-time operational status information to the control system. Currently, platinum resistance temperature sensors (PTS) are commonly used, as they have relatively low resistance. However, since a textile machine consists of multiple sections connected in series, each with 1-2 temperature measurement points, and each section is over 2 meters long (some machines are 20-30 meters or even over 50 meters long), the signal cables are quite long. This results in significant line resistance, which greatly affects the temperature detection signal, thus impacting accuracy. Therefore, addressing the influence of the signal cable's line resistance on the PTS signal has become a critical requirement for temperature detection technology in textile machinery. Summary of the Invention

[0003] The purpose of this invention is to solve the problem that the resistance of the signal line itself affects the temperature detection accuracy when using a platinum resistance temperature sensor to detect temperature in textile machinery at a distance, and to provide a long-distance temperature detection circuit for textile machinery that can improve the temperature detection accuracy.

[0004] Therefore, the present invention adopts the following technical solution: a long-distance temperature detection circuit for textile machinery, using a platinum resistance temperature sensor as the temperature detection tool, characterized in that one end of the platinum resistance temperature sensor is connected in parallel to two wires, wire A and wire B, which serve as signal lines, and the other end is grounded through a wire C. The temperature detection circuit also includes a compensation circuit and a microcontroller (MCU). Wire A is connected in parallel to the input pins of the first and third MCUs respectively, and wire B is connected to the input pin of the second MCU. The first, second, and third MCUs are each equipped with a gating switch pin (NH), an output pin (OU), and three address switch pins, A, B, and C. The corresponding A address switch pins of the first, second, and third MCUs are connected to the microcontroller through signal lines, the corresponding B address switch pins are connected to the microcontroller through signal lines, the corresponding C address switch pins are connected to the microcontroller through signal lines, and the gating switch pins are all connected to the microcontroller through signal lines.

[0005] The compensation circuit includes a single-supply quad operational amplifier (U1). The non-inverting input of the first group of operational amplifiers is connected to a resistor (R14) and then to the output pin of the third microcontroller (U13). The signal output is connected to a resistor (R15) and then to the inverting input to form negative feedback. The signal output is connected to a resistor (R12) and then to the inverting input of the second group of operational amplifiers. The non-inverting input of the second group of operational amplifiers is connected to a resistor (R9) and then to the output pin of the second microcontroller (U12). The signal output is connected to a resistor (R11) and then to the inverting input to form negative feedback. The signal output is connected to a resistor (R10) and then to the AD sampling port of the microcontroller. The signal output, after passing through the resistor (R10), is also connected to the power supply terminal (VC) of the single-supply quad operational amplifier via a signal diode. C) Connections: The non-inverting input of the third operational amplifier is connected to a resistor (R3) and then to the output pin of the first microcontroller (U11). The signal output is connected to a resistor (R2) and then to the inverting input to form negative feedback. The signal output is also connected to a resistor (R1) and then to the output pin of the first microcontroller (U11). The inverting input is also connected to a resistor (R5) and then grounded. The non-inverting input of the fourth operational amplifier is connected to two capacitors in parallel, then to a capacitor in parallel and a signal diode, and then to the AD sampling port of the microcontroller. The non-inverting input is also connected to the power supply (VCC) of the single-supply four-channel operational amplifier through a resistor (R7). The inverting input is connected to a resistor (R6) and then to the signal output to form negative feedback. The signal output is also connected to a resistor (R4) and then to the non-inverting input of the third operational amplifier.

[0006] The power supply pin of the second microcontroller is connected to a resistor (R8), the power supply pin of the third microcontroller is connected to a resistor (R13), the power supply pin of the first microcontroller and the VCC power supply terminal of the single-supply quad operational amplifier are all connected to a 12V power supply; the GND terminal of the single-supply quad operational amplifier is grounded.

[0007] As a supplement and improvement to the above technical solution, the present invention also includes the following technical features.

[0008] The two capacitors connected in parallel are a general-purpose capacitor and a polarized capacitor.

[0009] The first, second, and third microcontrollers each have 8 input pins, which can correspond to the signal connections of up to 8 platinum resistance temperature sensors. Each microcontroller is controlled by an address switch pin to control the signal input of the platinum resistance temperature sensor corresponding to the address.

[0010] Each platinum resistance temperature sensor is connected to three microcontrollers: the first, second, and third. Each group of three microcontrollers forms a microcontroller combination, connecting up to eight platinum resistance temperature sensors. The third microcontroller output pin (OU) of each combination is connected to the resistor (R14) and then to the non-inverting input of the first operational amplifier group. The second microcontroller output pin (OU) of each combination is connected to the resistor (R9) and then to the non-inverting input of the second operational amplifier group. The first microcontroller output pin (OU) of each combination is connected to the resistor (R3) and then to the non-inverting input of the third operational amplifier group. The selector pins of the three microcontrollers in each combination are connected to the microcontroller via signal lines. The corresponding A address switch pins, B address switch pins, and C address switch pins of the first, second, and third microcontrollers are connected to the microcontroller via signal lines, allowing for expansion by grouping three microcontrollers together.

[0011] The present invention can achieve the following beneficial effects: by connecting a ground wire to one end of the platinum resistance temperature sensor and two signal transmission wires controlled by a microcontroller to the other end to form a three-wire structure, and by compensating and organizing the signals transmitted by the two signal transmission wires through a compensation circuit, the influence of the line resistance of the signal wires on the platinum resistance temperature sensor signal is solved, thereby improving the accuracy of temperature detection. Attached Figure Description

[0012] Figure 1 This is the circuit diagram of the basic model of the present invention.

[0013] Figure 2 This is a diagram illustrating the principle.

[0014] Figure 3 This is a diagram illustrating the principle.

[0015] Figure 4 This is a diagram illustrating the principle.

[0016] Figure 5 This is a circuit diagram for the extension of the present invention. Implementation

[0017] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The described embodiments are only for illustration and explanation of the present invention and do not constitute the only limitation of the present invention.

[0018] like Figure 1As shown, this invention is a basic long-distance temperature detection circuit for textile machinery. It uses a PT100 platinum resistance temperature sensor (RPT) as the temperature detection tool. One end of the RPT is connected in parallel to two wires, A and B, serving as signal lines, while the other end is grounded via a wire C. The temperature detection circuit also includes a compensation circuit, three microcontrollers (MCUs), and a CD4051 microcontroller. Wire A is connected in parallel to the input pins of the first microcontroller (U11) and the third microcontroller (U13), respectively. Wire B is connected to the input pin of the second microcontroller (U12). The first, second, and third microcontrollers each have a gating switch pin (NH), an output pin (OU), and three address switch pins A, B, and C. The corresponding A address switch pins of the first, second, and third microcontrollers are connected to the microcontroller via signal lines, the corresponding B address switch pins are connected to the microcontroller via signal lines, the corresponding C address switch pins are connected to the microcontroller via signal lines, and the strobe switch pins are all connected to the microcontroller via signal lines.

[0019] The compensation circuit includes an LM324 single-supply quad operational amplifier (U1). The non-inverting input of the first group of operational amplifiers is connected to a resistor (R14) and then to the output pin of the third microcontroller (U13). The signal output is connected to a resistor (R15) and then to the inverting input to form negative feedback. The signal output is connected to a resistor (R12) and then to the inverting input of the second group of operational amplifiers. The non-inverting input of the second group of operational amplifiers is connected to a resistor (R9) and then to the output pin of the second microcontroller (U12). The signal output is connected to a resistor (R11) and then to the inverting input to form negative feedback. The signal output is connected to a resistor (R10) and then to the AD sampling port of the microcontroller. The signal output is also connected to the power supply (VCC) of the single-supply quad operational amplifier via the resistor (R10) and a signal diode. The non-inverting input of the first operational amplifier is connected to a resistor (R3) and then to the output pin of the first microcontroller (U11). The signal output is connected to a resistor (R2) and then to the inverting input to form negative feedback. The signal output is also connected to a resistor (R1) and then to the output pin of the first microcontroller (U11). The inverting input is also connected to a resistor (R5) and then grounded. The non-inverting input of the fourth operational amplifier is connected to a parallel ordinary capacitor and a polarized capacitor, then to a parallel ordinary capacitor and an IN4148 signal diode, and then to the AD sampling port of the microcontroller. The non-inverting input is also connected to the power supply (VCC) of the single-supply four-channel operational amplifier through a resistor (R7). The inverting input is connected to a resistor (R6) and then to the signal output to form negative feedback. The signal output is also connected to a resistor (R4) and then to the non-inverting input of the third operational amplifier. Resistors (R14), (R9), (R6), and (R7) are 1 kΩ; resistors (R15), (R12), and (R11) are 10 kΩ; resistors (R2), (R3), (R4), and (R5) are 100 kΩ; resistors (R13) and (R8) are 205 kΩ; resistor (R10) is 3.3 kΩ; and resistor (R1) is 510 kΩ. According to the circuit of this invention, V3 = -(R11 / R12)*V1 + (1 + R11 / R12)*V2. Since R11 = R12, V3 = -V1 + 2V2.

[0020] The power supply pin (VC) of the second microcontroller is connected to a 12V power supply through a resistor (R8), the power supply pin (VC) of the third microcontroller is connected to a resistor (R13), and the power supply pin (VC) of the first microcontroller and the VCC power supply terminal of the single-supply quad operational amplifier are all connected to a 12V power supply; the GND terminal of the single-supply quad operational amplifier is grounded. The microcontroller is connected to the host computer via a data interface, and the host computer is connected to the display device. The display device is controlled to display the corresponding temperature based on the temperature signal sent by the microcontroller to the host computer.

[0021] The first, second, and third microcontrollers each have 8 input pins, which can correspond to the signal connections of up to 8 platinum resistance temperature sensors. Each microcontroller is controlled by an address switch pin to control the signal input of the platinum resistance temperature sensor corresponding to the address.

[0022] like Figures 2-4 The diagram shown is an equivalent representation of the principle of this invention. Let RX1, RX2, and RX3 be the resistances of wires A, B, and C, respectively. RX1 = RX2 = RX3, V1 = (RX1 + RPT + RX3) * I = (RPT + 2RX3) * I, V2 = (RPT + RX2) * I = (RPT + RX3) * I, V3 = RPT * I, -V1 + 2V2 = RPT * I, V3 = -V1 + 2V2. The V3 obtained after the circuit adjustment in this invention is equal to the V3 obtained from the equivalent diagram. Therefore, through the compensation circuit in this invention, regardless of the length of wires A and B, the V3 input to the microcontroller will not change and will always be equal to RPT * I. The resistance of the signal lines themselves will not affect the signal of the platinum resistance temperature sensor.

[0023] like Figure 5As shown, the circuit of this invention can be expanded for use. Each platinum resistance temperature sensor is connected to three microcontrollers: the first, second, and third. Each group of three microcontrollers forms a microcontroller combination that can connect up to eight platinum resistance temperature sensors. The third microcontroller output pin (OU) of each microcontroller combination is connected to the resistor (R14) and then to the non-inverting input of the first group of operational amplifiers. The second microcontroller output pin (OU) of each microcontroller combination is connected to the resistor (R9) and then to the non-inverting input of the second group of operational amplifiers. Each microcontroller's output pin (OU) is connected to the resistor (R3) and then to the non-inverting input of the third operational amplifier. The gating switch pins of the three microcontrollers in each microcontroller combination are connected to the microcontroller via signal lines. The corresponding A address switch pins of the first, second, and third microcontrollers are connected to the microcontroller via signal lines, the corresponding B address switch pins are connected to the microcontroller via signal lines, and the corresponding C address switch pins are connected to the microcontroller via signal lines. This allows for expansion by grouping three microcontrollers together.

Claims

1. A remote temperature sensing circuit for a textile machine, using a platinum resistance temperature sensor as a temperature sensing tool, characterized in that: The platinum resistance temperature sensor is connected in parallel with two wires A and B as signal lines at one end and grounded through a wire C at the other end, the temperature detection circuit further comprises a compensation circuit and a microcontroller (MCU), wire A is connected in parallel with the input pins of the first and third single-chip microcomputers, wire B is connected with the input pin of the second single-chip microcomputer, the first, second and third single-chip microcomputers are all provided with a gate switch pin (NH), an output pin (OU) and three address switch pins A, B and C, the corresponding A address switch pins of the first, second and third single-chip microcomputers are connected through signal lines and then connected with the microcontroller, the corresponding B address switch pins are connected through signal lines and then connected with the microcontroller, the corresponding C address switch pins are connected through signal lines and then connected with the microcontroller, and the gate switch pins are all connected through signal lines and then connected with the microcontroller; The compensation circuit comprises a single power supply four-channel operational amplifier (U1), the non-inverting input end of the first group of operational amplifiers of the single power supply four-channel operational amplifier is connected with a resistor (R14) and then connected with the output pin of the third single-chip microcomputer (U13), the signal output end is connected with a resistor (R15) and then connected with the inverting input end to form negative feedback, and the signal output end is connected with a resistor (R12) and then connected with the inverting input end of the second group of operational amplifiers; the non-inverting input end of the second group of operational amplifiers is connected with a resistor (R9) and then connected with the output pin of the second single-chip microcomputer (U12), the signal output end is connected with a resistor (R11) and then connected with the inverting input end to form negative feedback, the signal output end is connected with a resistor (R10) and then connected with the AD sampling port of the microcontroller, and the signal output end is further connected with the power supply end (VCC) of the single power supply four-channel operational amplifier through the resistor (R10) and a signal diode; the non-inverting input end of the third group of operational amplifiers is connected with a resistor (R3) and then connected with the output pin of the first single-chip microcomputer (U11), the signal output end is connected with a resistor (R2) and then connected with the inverting input end to form negative feedback, the signal output end is further connected with a resistor (R1) and then connected with the output pin of the first single-chip microcomputer (U11), and the inverting input end is further connected with a resistor (R5) and then grounded; the non-inverting input end of the fourth group of operational amplifiers is connected with two capacitors in parallel, then connected with a capacitor and a signal diode in parallel, and then connected with the AD sampling port of the microcontroller, the non-inverting input end is further connected with the power supply end (VCC) of the single power supply four-channel operational amplifier through a resistor (R7), the inverting input end is connected with a resistor (R6) and then connected with the signal output end to form negative feedback, and the signal output end is further connected with a resistor (R4) and then connected with the non-inverting input end of the third group of operational amplifiers; The power supply pins of the second single-chip microcomputer, the third single-chip microcomputer and the first single-chip microcomputer are all connected with a 12V power supply through a resistor (R8), a resistor (R13) and a resistor (R13) respectively, and the GND end of the single power supply four-channel operational amplifier is grounded.

2. The remote temperature sensing circuit for textile machinery according to claim 1, wherein: The two parallel capacitors are a common capacitor and a polar capacitor.

3. The remote temperature sensing circuit for textile machinery equipment as claimed in claim 2 wherein: The first, second and third single-chip microcomputers each have eight input pins, and can be connected to signals of up to eight platinum resistance temperature sensors; each single-chip microcomputer is controlled by address switch pins to input signals of platinum resistance temperature sensors corresponding to the respective addresses.

4. The remote temperature sensing circuit for textile machinery equipment according to claim 3, wherein: Each platinum resistance temperature sensor is connected to the first, second and third single-chip microcomputers; three single-chip microcomputers form a single-chip microcomputer combination to connect up to eight platinum resistance temperature sensors; the output pin (OU) of the third single-chip microcomputer of each single-chip microcomputer combination is connected to the resistor (R14) and then to the non-inverting input terminal of the first set of operational amplifiers; the output pin (OU) of the second single-chip microcomputer of each single-chip microcomputer combination is connected to the resistor (R9) and then to the non-inverting input terminal of the second set of operational amplifiers; the output pin (OU) of the first single-chip microcomputer of each single-chip microcomputer combination is connected to the resistor (R3) and then to the non-inverting input terminal of the third set of operational amplifiers; the gate switch pins of the three single-chip microcomputers of each single-chip microcomputer combination are connected to a microcontroller through signal lines; the A address switch pins of the first, second and third single-chip microcomputers are connected to a microcontroller through signal lines; the B address switch pins are connected to a microcontroller through signal lines; and the C address switch pins are connected to a microcontroller through signal lines.

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