Basically if I have a load that I switch on and off, then its power
dissipation is proportional to the time I have it on. Duty cycle
= Ton / (Ton + Toff ). So if I have a 100W light bulb, and I switch
it on and for equal times, then duty cycle = 50%, and the effective
power being consumed over time is 50%.
That concept is used in micros where they service a task, then go to sleep.
So overall power consumed is duty cycle X ( micro power + other loads that
get switched off) + loads that do not get switched off .
Regards, Dana.