Abstract: Isolated thermal resistance temperature conditioning module is suitable for complex industrial environment. The traditional isolation module is based on common digital isolation technology, and it needs to use integrated digital-to-analog conversion (DAC) chip, which is complex in principle and requires logic control by program. The module designed by this architecture has high cost, large volume and so on. An isolated thermal resistance temperature conditioning module based on pulse width modulation (PWM) technology was designed and adjusted the collected temperature into 4—20mA output current. The power supply, input channel and output channel of the module were isolated from each other. This module has the characteristics of configurable range, high precision and low cost, and can reduce the volume of the module by 40%. It is suitable for the temperature acquisition and adjustment of nuclear power digital control system (DCS).

Key words: thermal resistance; temperature conditioning; pulse width modulation (PWM); isolation