Power measuring circuit

Abstract

The invention provides a power measuring circuit which comprises a differential amplification circuit, a filter circuit, a peak value retaining circuit, an analog-digital conversion circuit and a micro-control component. The differential amplification circuit differentially outputs electric heating signals at two ends of a pyroelectric detector, the filter circuit extracts effective signals from the signals output by the differential amplification circuit and restrains the noise overlaid on the signals of the differential amplification circuit to increase signal to noise ratio, the peak value retaining circuit extracts the amplitude information of the effective signals, the analog-digital conversion circuit converts the amplitude information of the effective signals into digital signals and transmits the digital singles to the micro-control component, and the micro-control component controls the analog-digital conversion circuit and adjusts the amplification times of the differential amplification circuit. The power measuring circuit has the advantages that strong signals can be detected while measuring accuracy of weak signals is guaranteed, and the dynamic measuring range of the system is increased.

Description

technical field [0001] The invention belongs to the field of electric calibration pyroelectric radiometers, in particular to a power measurement circuit of electric calibration pyroelectric radiometers. Background technique [0002] The electrical calibration pyroelectric radiometer is a high-precision absolute radiometer for measuring optical radiation power. The power measurement circuit is an important part of the radiometer, which is used to measure the electric heating power equivalent to the optical power. The electric heating signal applied to both ends of the pyroelectric detector is a set of alternating polarity voltage signals with equal amplitude and opposite phase. By measuring the voltage amplitude U at both ends of the pyroelectric detector, it can be obtained by Calculate the electric heating power value. [0003] Under normal circumstances, U first obtains the voltage difference between the two ends of the pyroelectric detector through a differential circui...

AI Technical Summary

Problems solved by technology

When the signal to be measured is strong, the electric heating signal automatically generated inside the electric calibration radiometer is also relatively strong, and the measurement accuracy is relatively high at this time; The electric heating signal is also relatively weak, and it is easily disturbed by noise, which will cause measurement errors and reduce the accuracy of measurement

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