The determined frequency is then compared with {TAIL ~ a running average} of previous frequency determinations, and the drive frequency of {HEAD ~ the appliance} is adjusted if the difference between the compared frequencies is greater than a threshold value, e.g. 1 Hz 
The determined frequency is then compared with { TAIL ~ a running average } of previous frequency determinations , and the drive frequency of { HEAD ~ the appliance } is adjusted if the difference between the compared frequencies is greater than a threshold value , e.g. 1 Hz
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH