Features of using optoelectronic alignment amplifiers in industrial control systems

In the article, the authors substantiated the use of the optical isolation components in the circuits of industrial control systems. The options of using analog amplifiers in optoelectronic circuits were also analyzed, and the advantages and disadvantages of existing isolation systems were examined. As a result of the experimental research, a galvanic isolation circuit for the analog signal of a frequency converter was developed. The circuit is intended for interfacing a converter and a control system built on the basis of an industrial computer. The circuit for generating an the analog signal in a predetermined range based on the HCPL-7840 amplifier, which ensures the coordination of the industrial controller with the SPI serial port with the actuators with a proportional control was proposed by the authors in the article. The authors showed that on the strength of such criteria's as a linearity, a displacement and a temperature stability, it is shown that the analog optical isolation devices are very competitive and demonstrate the advantages over the alternative technical solutions for the analog voltage measurement.