The idea of using a PIC microcontroller as a replacement for the analog circuitry of a smps controller was originally suggested to me by SurJector over on the linear1.org forums.

Originally I felt the topic was over my head. I also dismissed it because I thought it added unnessecary complexity to an already difficult to understand process. However, as I read more about how switch mode power supplies and dc/dc converrts worked, I realized that using a PIC as the brain was indeed a good idea, and very cutting edge. ‘Digital’ switch mode power supplies are just now starting to ‘pop up’ in the industry, with all the current “all in one” controllers still relying completely on analog.

As I understand it, a digital controller offers the potentional for great efficiency, by adjusting the operating frequency of the switch dynamicly with the load. I’m not sure how that all works yet, but I have a few other things in mind, related to using these converters in the field of solid state lighting. Firstly, I like the idea of being able to digitally controll the output current to the load. Instead of having to dim a bulb using PWM, which is very non linear, I can instead dim a bulb using current mode control… using whatever interface suits me. Secondly, a digital controller could be integerated into a larger project, an illumination manager. For example, combine the dc/dc conversion routine with a routine reading a thermistor – monitor your bulb temp and dynamicly vary the current to keep it at a safe level. Another possibility – with a digital processor monitoring the current draw of the load, a faults such as shorted or open diode could be detected and an alarm condition set – in addition to reducing the current to compensate, a small indicator led could light up – “Check Lights”.

I have some pictures and schematics to share when I’m back home – more to come!