An apparatus, system and method for measuring alternating voltage with variable frequency

Abstract

The invention discloses a device, a system and a method for measuring a frequency-variable alternating current voltage. The method comprises the following steps: S1, an edge detection module polls whether a rising edge or a falling edge of a square wave signal having the same period as an alternating current is detected or not and outputs a period changing signal when the rising edge or the falling edge is found; S2, a central processing circuit receives the period changing signal, whether the central processing circuit is in the process of sampling voltage values of the alternating current or not is judged, if yes, a step S4 is executed, and otherwise a step S3 is executed; S3, the central processing circuit samples and stores the voltage values of the alternating current according to a sampling time interval, and then the step S1 is executed; and S4, the central processing circuit stops sampling and calculates an average value of all sampled voltage values, and then the step S1 is executed. The system comprises a comparison circuit and a measuring device of the alternating current voltage. The method has the advantages that the sampling time interval is kept unchanged, and the number of sampling points is changed according to the length of the period of the alternating current voltage, so that the frequency-variable alternating current voltage can be accurately measured.

Description

technical field [0001] The present invention relates to the measurement technology of alternating voltage, more specifically, relates to a device, system and method for measuring alternating voltage with variable frequency. Background technique [0002] In our daily life, the demand for electricity is indispensable. In order to let people understand the power supply voltage status of various electrical appliances more intuitively, it is necessary to monitor the voltage. figure 1 It is an existing system for detecting AC voltage, and the system includes a small generator, a transformer, a filter circuit, a voltage divider circuit, a single-chip microcomputer control board and a digital display device. The small generator outputs AC voltage, the AC voltage is transformed by the transformer, filtered by the filter circuit and divided by the voltage divider circuit, and then the voltage amplitude information is output to the single-chip control board, and the single-chip control...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the defect that the existing system for detecting AC voltage cannot accurately detect the variable-frequency AC voltage, a device, system and method capable of accurately measuring the variable-frequency AC voltage are provided

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