Duty ratio measurement circuit for IC engine signal having different phases - has first counter for repetitively counting through range and second counter for counting number of cycled ranges, and counts out end value of second counter when phase of signal changes to obtain final result

摘要

During a first phase, a first counter (110) with a defined count frequency (FT) repeatedly cycles through its count region. The number of count cycles is counted by a second counter (140). When the subsequent signal phase changes occur, the achieved end value of the second counter is repeatedly counted and the final value of this counting process is used as a measure of the duty cycle. USE/ADVANTAGE - Eg for determination of position mechanism actuation signals for power control. Simple arrangement enables duty cycle of signal with at least two phases to be measured with minimal delay.