Direct current (DC) bus voltage-sampling circuit of servo system converting voltage into frequency

Abstract

The invention relates to a direct current (DC) bus voltage-sampling circuit of a servo system converting a voltage to a frequency, comprising a resistance-sampling divider circuit, a V / F converting circuit and an isolation optocoupler circuit. The resistance-sampling divider circuit is connected with a DC bus to acquire an input voltage Vin which is about 10V on the bus by voltage division when the bus is in full voltage; the input end of the V / F converting circuit is connected with the resistance-sampling divider circuit and converts an input voltage value into a pulse frequency signal in a direct frequency and voltage proportion; the primary positive end of the isolation optocoupler circuit is connected with the output end of the V / F converting circuit; the secondary end of the isolation optocoupler circuit is connected with the I / O of a DSP; and pulse signals with the same frequency are input to the DSP to acquire corresponding digital quantities. The invention has the advantages of good input / output linearity and high reliability and accuracy.

Description

technical field [0001] The invention relates to a DC bus voltage sampling circuit of a servo system. Background technique [0002] On the servo system at present, the bus voltage sampling circuit of prior art (referring to figure 1 ) is mainly composed of a sampling voltage dividing resistor, a balancing resistor, a linear optocoupler, an operational amplifier circuit, and an analog-to-digital conversion circuit; the positive terminal of the linear optocoupler is connected to the sampling voltage dividing resistor, and the negative terminal of the linear optocoupler is connected to the balancing resistor , the secondary of the linear optocoupler is connected to the input terminal of the operational amplifier circuit; the output terminal of the analog-to-digital conversion circuit is connected to the control circuit, and the output digital signal is transmitted to the control circuit, so that the control circuit can detect the voltage change on the DC bus. [0003] The circu...

AI Technical Summary

Problems solved by technology

[0008] The present invention solves the problems of poor input and output linearity, low reliability and low precision in the existing DC bus voltage sampling circuit of the servo system, and provides a voltage-to-frequency converter with good input and output linearity, high reliability and high precision. Servo system DC bus voltage sampling circuit

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