A multifunctional analog signal acquisition circuit

Abstract

The invention relates to a multi-function analog signal acquisition circuit. With controlling of turning on and off of a switch, whether a voltage signal outputted by the analog signal acquisition circuit reaches a peak value of a fixed limit or a normal working voltage range is determined; when the switch is turned on and the voltage signal outputted by the analog signal acquisition circuit reaches the peak value of the fixed limit, measurement of a current analog quantity is determined to be needed by the circuit; and then the switch is turned off, the circuit outputs a voltage converted from a to-be-tested current. When the voltage signal outputted by the circuit is in a normal working range, measurement of a voltage analog quantity is determined to be needed by the circuit and the circuit outputs a voltage converted from a to-be-tested voltage directly. With one analog signal acquisition circuit, monitoring of a to-be-tested current and a to-be-tested voltage can be completed without adding another signal acquisition circuit, so that the circuit design cost can be saved. Meanwhile, the circuit having a simple structure is easy to product and debug; the loop sampling precision is high and stable; and the bias voltage and temperature drift voltage are low.

Description

technical field [0001] The invention belongs to the technical field of power system protection measurement and control, and in particular relates to a multifunctional analog signal acquisition circuit. Background technique [0002] The output of non-electricity sensors in traditional substations is generally 0-5V or 4-20mA, such as transformer temperature and gas in oil. It can be designed to be compatible. When in use, the current sampling can be directly converted into voltage sampling by connecting the current sampling resistor. However, with the advancement of smart substation technology, in the detection of equipment power supply, new energy level, primary equipment detection, lightning arrester, etc., the monitoring range of non-electricity has been greatly expanded, resulting in multiple levels of non-electricity analog signal levels. One level, such as 0~600VDC, 0~300VDC, 0~48VDC, 0~5V, -10~+10V, 4~20mA, -40~40mA. [0003] The analog signal acquisition circuits in ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a multifunctional analog signal acquisition circuit, which is used to solve the problem that the existing conversion circuit for collecting analog signals cannot be used to detect voltage signals and current signals at the same time, and the detection circuit needs to be designed separately to increase the detection cost.

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