CN-224233681-U - Wheatstone resistance bridge signal amplifying circuit and servo press controller

CN224233681UCN 224233681 UCN224233681 UCN 224233681UCN-224233681-U

Abstract

The utility model discloses a Wheatstone resistor bridge signal amplifying circuit and a servo press controller, and belongs to the field of servo control. The Wheatstone resistance bridge signal amplifying circuit comprises an input filter circuit, a primary operational amplifier, a voltage follower, a positive reference voltage generator, a negative reference voltage generator and an amplifying circuit, wherein the input filter circuit is used for receiving and filtering an input signal from a pressure sensor, the primary operational amplifier is used for carrying out preliminary amplification on the input signal, the voltage follower is used for outputting a low-impedance signal, the positive reference voltage generator and the negative reference voltage generator provide a +/-2.5V voltage reference, and the amplifying circuit amplifies the input signal to a +/-2.5V range for being processed by an analog-to-digital converter.

Inventors

HUANG CHENG
XU FEI
XIAO JUNCAI

Assignees

儒拉玛特自动化技术(苏州)有限公司

Dates

Publication Date: 20260512
Application Date: 20250321

Claims (10)

1. A wheatstone resistor bridge signal amplification circuit, comprising: an input filter circuit for receiving and filtering an input signal from the pressure sensor; A primary operational amplifier configured to perform a primary amplification of an input signal and to employ a low noise design; The voltage follower is connected to the output end of the operational amplifier and is used for providing an output signal with the same amplitude as the input signal but low impedance; the positive and negative reference voltage generator is connected with the voltage follower and provides a voltage reference of +/-2.5V; And the amplifying circuit amplifies an input signal to a range of +/-2.5V through the cooperation of the operational amplifier and an external element, and the amplified signal is processed by the analog-to-digital converter.
2. The wheatstone-resistance-bridge signal amplification circuit of claim 1, wherein the primary operational amplifier is an AD620 instrumentation amplifier having a 199-fold amplification factor for amplifying an input ± 9mV signal to between-1.12V and +2.47V.
3. The wheatstone-resistance-bridge signal amplification circuit of claim 1, wherein the voltage follower is an OPA2376 operational amplifier for providing a stable output signal and sharing a positive and negative voltage reference with the operational amplifier.
4. The wheatstone-resistance bridge signal amplification circuit of claim 1, wherein the positive and negative reference voltage generator is comprised of a U7 positive and negative reference voltage generator and a U28 buck-type linear voltage regulator for generating voltage signals of-2.5V, +2.5v, and +5v.
5. The wheatstone-bridge signal amplification circuit of claim 1, wherein the amplification circuit cooperates with an external resistor R96 and capacitor C78 through an operational amplifier U30 for signal amplification, wherein the amplification factor is adjusted by R96 and R97.
6. A servo press controller comprising a wheatstone resistance bridge signal amplifying circuit as claimed in any one of claims 1 to 5, the servo press controller comprising: The Wheatstone resistance bridge signal amplifying circuit is connected to the pressure sensor and is used for amplifying millivolt-level signals from the pressure sensor to a range of +/-2.5V; The analog-to-digital converter is connected with the Wheatstone resistance bridge signal amplifying circuit and is used for converting the amplified analog signals into digital signals; the digital I/O interface is connected with the singlechip and is used for realizing input and output control with external equipment and supporting compatibility of multiple peripheral equipment; An uninterruptible power supply connected to the core board for providing power support in the event of an interruption of the main power supply; And the real-time clock is connected with the core board and is used for providing a time synchronization function.
7. The servo press controller of claim 6 wherein the wheatstone resistance bridge signal amplifying circuit includes an input filter circuit, a primary operational amplifier, a voltage follower, a positive and negative reference voltage generator and an amplifying circuit for amplifying the signal from the pressure sensor to a signal range that can be processed by the ADC.
8. The servo press controller of claim 6 wherein the digital I/O interface is comprised of an optocoupler, an output chip, a single chip microcomputer and a fuse for providing digital signal input and output functions.
9. The servo press controller of claim 6 wherein the uninterruptible power supply includes a super-capacitor management chip, super-capacitors, output electronic switches for providing temporary power to the core board in the event of a power interruption.
10. The servo press controller according to any one of claims 6 to 9, wherein the ethernet interface comprises a core board ethernet lead-out, PCIE ethernet and USB ethernet for high-speed data transmission supporting remote communication with external devices.

Description

Wheatstone resistance bridge signal amplifying circuit and servo press controller Technical Field The utility model relates to the field of servo control, in particular to a Wheatstone resistor bridge signal amplifying circuit and a servo press controller. Background The utility model relates to the field of instruments and meters and servo control, in particular to a controller for a servo press and a signal amplifying circuit thereof. The servo press is used as high-precision and high-speed automatic control equipment and is widely applied to the fields of press fitting, assembly and testing of various machines. The main function of the device is to ensure high precision and high consistency in the press fitting process through accurate force and displacement control. In the prior art, a servo press controller generally adopts a PLC (programmable logic controller) as a core control unit. And implementing the execution of control logic through PLC programming to complete the operation of the press system. However, the conventional PLC controller has the following disadvantages in facing increasingly complex customer demands. The traditional PLC is limited by hardware performance, and is difficult to meet the requirements of high-precision and high-speed dynamic control, particularly performance bottlenecks exist in the aspects of real-time signal acquisition and processing, a large-size hardware platform is usually required by a PLC control system, wiring is complex, the difficulty of installation, debugging and maintenance is increased, the flexibility of the system is reduced, the traditional PLC control scheme is usually dependent on fixed control logic, and the requirements of customers on customized control are difficult to quickly adapt, so that the difficulty of system upgrading and customized development is caused. Furthermore, with the widespread use of pressure sensors, wheatstone resistive bridges have become a core component of pressure sensors. The output signals of the wheatstone resistor bridge are usually voltage signals of microvolts, and the signals need to be amplified to be effectively processed by a control system. The existing signal amplifying circuit generally needs a plurality of elements to form, so that the circuit design is complex, the size is large, the cost is high, the debugging and maintenance difficulty of the system is increased, noise interference is a non-negligible factor in the signal amplifying process, particularly in high-precision application, noise can influence the stability and control precision of the system, the existing signal amplifying circuit and an analog-to-digital converter (ADC) cannot meet the acquisition requirement of high-frequency dynamic signals, and the real-time control and feedback capability of a servo press are influenced. Therefore, it is necessary to provide a new design scheme of a servo press controller, which can overcome the defects of the prior art, provide more efficient and stable signal amplifying and processing capability, and reduce the complexity and hardware volume of the system, so as to meet the requirements of the modern servo press on precision, speed and flexibility. Disclosure of utility model The utility model provides a Wheatstone resistor bridge signal amplifying circuit, which can overcome the defects of the prior art, provide more efficient and stable signal amplifying and processing capacity, and simultaneously reduce the complexity and the hardware volume of a system so as to meet the requirements of a modern servo press on precision, speed and flexibility. The technical scheme is as follows: The utility model provides a Wheatstone resistance bridge signal amplifying circuit, which comprises: an input filter circuit for receiving and filtering an input signal from the pressure sensor; A primary operational amplifier configured to perform a primary amplification of an input signal and to employ a low noise design; The voltage follower is connected to the output end of the operational amplifier and is used for providing an output signal with the same amplitude as the input signal but low impedance; the positive and negative reference voltage generator is connected with the voltage follower and provides a voltage reference of +/-2.5V; And the amplifying circuit amplifies an input signal to a range of +/-2.5V through the cooperation of the operational amplifier and an external element, and the amplified signal is processed by an analog-to-digital converter (ADC). Optionally, the primary operational amplifier is an AD620 instrumentation amplifier with 199 times amplification factor for amplifying the input ±9mv signal to between-1.12V and +2.47V. Optionally, the voltage follower is an OPA2376 operational amplifier for providing a stable output signal and sharing positive and negative voltage references with the operational amplifier to reduce the number of external components. Optionally, the positive and negative refe