Isolation-type voltage-current bidirectional conversion output circuit

Abstract

The invention discloses an isolation-type voltage-current bidirectional conversion output circuit. The circuit includes an input selection circuit, a current / voltage isolation conversion circuit, a voltage / current isolation conversion circuit and an output selection circuit, wherein the input terminal of the current / voltage isolation conversion circuit is connected with the input selection circuit while the output terminal is connected with the output selection circuit, the input terminal of the voltage / current isolation conversion circuit is connected with the input selection circuit while the output terminal is connected with the output selection circuit. The circuit provided by the invention supports conversion from voltage input to current output and also supports conversion from current input to voltage output, and is high in adaptability for different industrial equipment. According to the invention, voltage-current conversion isolation is realized and adaptability for severe industrial environment for circuit use is improved.

Description

technical field [0001] The invention is used in the industrial control field of field control systems, in particular an isolated voltage and current bidirectional conversion output circuit. Background technique [0002] In the composition of the industrial field control system, there are often many devices, such as instruments and meters, etc., and the current signals output by them are finally collected by the processing unit in the control system to realize the control process operation of the entire control system. However, the processing unit often collects voltage signals of 0-5V, so it is necessary to convert the voltage signal of the current signal of 4mA-20mA. Similarly, in the composition of industrial control field control systems, there are often many analog devices that need to be driven by 4mA-20mA current, such as motors, valves, mechanical instruments, etc. Such devices cannot be directly driven by voltage signals, and the output of the processing unit is ofte...

AI Technical Summary

Problems solved by technology

[0003] However, the conversion from voltage input to current output and the conversion from current input to voltage output currently used in the industry often achieve a single conversion, resulting in insufficient versatility in the selection of conversion equipment when building a control system. At the same time, 4mA-20mA and 0.8V The conversion between ~4V, the voltage range is not wide enough, and the electrical isolation function is rarely integrated. When the control system is constructed, it is often necessary to add corresponding circuits, resulting in relatively high cost and relatively complicated system.

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