Design of an Independent and Controllable Isolated 4～20 mA Current Output System

With the continuous in-depth application of independent and controllable devices in the power industry, the development of independent and controllable technologies in this sector has entered a critical stage of transition from "import substitution" to "leading innovation". Against this background and considering the application characteristics of the power industry, this paper presents a design scheme for an independent and controllable isolated 4～20 mA current output circuit. Designed with isolation devices and DAC (digital-to-analog converter) as the core, the scheme achieves electrical isolation of the output circuit, improves the accuracy of current output, and enhances the circuit's anti-interference capability. The circuit is constructed using fully independent and controllable devices, and features advantages such as a simple structure, high isolation degree, high precision, and strong anti-interference capability.