Sequence Boundary The sequence boundary is an unconformity updip and a correlative conformity downdip. Where it is an unconformity, it is a surface of subaerial exposure and erosion; however, the expression of those features in an individual outcrop may or may not be obvious.
The brushless motor provides greater reliability and efficiency for its low weight and size as compared to the brushed motors. Efficiency for the brushless motor is typically between 85-90% while that of the brushed motor ranges between 75-80%.
Both DC brushless and induction drives use motors having similar stators. Both drives use 3-phase modulating inverters. The only differences are the rotors and the inverter controls. One of the main differences is that much less rotor heat is generated with the DC brushless drive.