Current and frequency sampling circuit for automatic power supply changeover system

Abstract

The invention relates to a current and frequency sampling circuit for an automatic power supply changeover system. The circuit is used for realizing sampling of the current and frequency of a detection load by the power supply changeover system. The circuit comprises a mutual inductor, a sampling module, a current detection module and a frequency detection module which are connected in sequence, wherein the frequency detection module is connected with an input capture port of an MCU. The circuit is characterized in that the frequency detection module comprises a voltage comparator unit and a gate circuit unit which are connected with each other, wherein the input end of the voltage comparator unit is separately connected with a voltage reference and the current detection module, and the output end of the voltage comparator unit is connected with the input capture port of the MCU through the gate circuit unit. Compared with the prior art, the circuit has the advantages of strong anti-interference capability, small frequency output ripple, high sampling precision and the like.

Description

technical field [0001] The invention relates to a sampling circuit, in particular to a current and frequency sampling circuit for an automatic power conversion system. Background technique [0002] With the development of the electric power industry, electrical equipment has higher and higher requirements for the continuity and reliability of the power supply. Good signal acquisition technology can minimize the misjudgment rate of the control system output and improve the reliability of the system at the same time. The controller can detect the situation of the electrical equipment in real time, and when it deviates from the set normal state, it can reflect and make adjustments in time. [0003] Such as figure 1 As shown, in the existing sampling circuit, the current is generally directly connected to the differential amplifier after passing through the transformer, and the frequency detection is generally output to the MCU directly only through a voltage comparator. This ...

AI Technical Summary

Problems solved by technology

[0004] 1) Poor anti-interference ability of current sampling waveform;

[0005] 2) It is easy to generate oscillation;

[0006] 3) The frequency output ripple is large, and it is easy to miss or over-check;

[0007] 4) The filtering ability is not strong, and the sampling accuracy is easily affected by power fluctuations;

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