Power current isolation acquisition circuit

Abstract

The invention belongs to the technical field of airborne analog signal acquisition, in particular to a power current isolation acquisition circuit based on floating ground power supply. The circuit comprises an isolation power supply unit, a sampling resistor, a signal conditioning unit, an A / D conversion unit and an isolation optocoupler unit, wherein the sampling resistor is serially connected to the power circuit; the voltage at two ends of the sampling resistor is conditioned by the signal conditioning unit and is then sent to the A / D conversion unit; the conversion result of the A / D conversion unit is transmitted to an electromechanical management computer through the isolation optocoupler unit; power of one end of the isolation optocoupler unit is supplied by the isolation power supply unit and power of the other end is supplied by a digital power supply; power of the A / D conversion unit and the signal conditioning unit is supplied by the isolation power supply unit; and the positive end of the isolation power supply unit is connected with the current input end of the sampling resistor. According to the power current isolation acquisition circuit provided in the invention, high-precision power current isolation acquisition is realized.

Description

technical field [0001] The invention belongs to the technical field of airborne analog quantity acquisition, in particular to a power and current isolation acquisition circuit based on floating ground power supply. Background technique [0002] The aircraft electromechanical system contains a large number of needs to detect the power and current of the interface. The traditional method is to connect the sampling resistor in series before the power current of the interface is connected to the ground wire, and calculate the power and current of the interface by collecting the resistance voltage. When it is inside, it is necessary to set a separate power and current return line, which leads to a heavy cable design, and at the same time, due to the mutual interference and coupling of the ground plane, the accuracy of analog quantity acquisition is reduced and the complexity of signal processing is increased; another existing method The sampling resistor is connected in series be...

AI Technical Summary

Problems solved by technology

[0002] The aircraft electromechanical system contains a large number of needs to detect the power and current of the interface. The traditional method is to connect the sampling resistor in series before the power current of the interface is connected to the ground wire, and calculate the power and current of the interface by collecting the resistance voltage. When it is inside, it is necessary to set a separate power and current return line, which leads to a heavy cable design, and at the same time, due to the mutual interference and coupling of the ground plane, the accuracy of analog quantity acquisition is reduced and the complexity of signal processing is increased; another existing method The sampling resistor is connected in series before the power current flows into the interface, and the analog voltage is sent to the A / D conversion module after being transformed by the isolation op amp, but the isolation op amp will cause the A / D conversion module to lose 2 to 3 digits of acquisition accuracy. Reduced Accuracy of Power Current Acquisition

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