An analog input circuit for engineering-machinery-dedicated controller

Abstract

The invention discloses an analog input circuit for engineering-machinery-dedicated controller. The analog input circuit comprises a voltage-current transformation circuit, which is a current series negative feedback amplifier circuit, and an analog voltage input circuit, which includes orderly connected a first RC filter circuit having an input thereof connected with a current output of said voltage-current transformation circuit, a noninverting amplifying circuit, and an isolating circuit having an output thereof connected with an A / D sampling port of a control unit. The analog resistor input circuit of the invention has the characteristics of strong anti-interference capability, high reliability, good compatibility, flexible applicability, and convenient operation, is also adaptable to wretched field environment and applied to the control circuit of engineering machinery equipment.

Description

technical field

[0001] The invention relates to an input circuit, in particular to an analog quantity input circuit of a special controller for engineering machinery. Background technique

[0002] At present, in the control equipment in the automation field of my country's construction machinery industry, in addition to the common analog voltage input signal and current input signal, the controller signal also has a resistance input analog input signal. The common problems in the analog input (sampling) circuit: 1) The design of the acquisition circuit for the analog signal is relatively simple, lack of isolation design, and the lack of channels is difficult to meet the needs of more acquisition points in the construction machinery control system; 2) Construction machinery site There is also large signal interference, which will cause large errors in analog signal acquisition and signal distortion, which will affect the overall control system and cannot meet the requirements...

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