Specifically, what are the nature of ideal pulses. Voltage, current, duration, duty and polarity? What precautions/limits need to be observed?

I'm thinking of designing a microcontroller version. Difficult for me to answer the above questions just by looking at existing designs.

 

We had a discussion here http://forum.allaboutcircuits.com/showthread.php?t=32666 not so lang ago. This site give some explination on how it works http://forum.allaboutcircuits.com/showthread.php?t=32666