Adaptive Optocoupler Degradation Compensation in Isolated Feedback Loops

An optocoupler is an optoelectronic device, based on a light emitter and detector pair. Any degradation in the emitted light causes a change in the output of the component. This gain change is also known as CTR (current transfer ration) degradation,-although in some cases, the emitted light output actually increased over time. This phenomenon is inherent of the p-n junction electroluminescence and it is unpredictable. Excessive amount of degradation may cause a deviation from optimal operation or a catastrophic system failure. This paper puts forward a robust, microcontroller based solution for this problem.