ESTIMATION AND ('()\TJ;()I. OF ( iI'1;H ATI", TIIMK OF m;r>AVS 



117 



100 

 90 

 80 

 70 



3 4 5 6 7 



NUMBER OF TURNS 



20 

 X 10- 



Fig. 1 — Chart showing typical mass and load controlled operation. 



into two classes called mass and load controlled, and furthermore 

 empirically establish which of the three stages of operate time pre- 

 dominates. This distinction corresponds to that made in Part I in the 

 discussion of equation (12). For the lower power cases the term involving 

 the spring load predominates, for the higher power cases the mass term 

 predominates. As this equation shows, there is necessarily a transition 

 range where the operation time merges from one class into the other. 

 Both types of charts are extended to include this range. A rule of thumb 

 for an estimate of whether a time under discussion is in the mass or load 

 controlled case is that if the time is less than 



U 



/ 



27m (xi — rcs) 



F. 



(1) 



it is mass controlled; otherwise it is load controlled. The derivation of 



this bound will be discussed when mass controlled operation is considered. 



The single relay design data are general enough to include resistors 



