NEW GENERAL I'UUl'OJ^E lUOIAY 



1019 



Typical ivlea.sc times for the AF ;mi(1 T relays are shown in Fig. J9, 

 with time plotted as a function of the iiinnl)er of contact pairs for relays 

 equipped with standard O.OOG-ini-h thick nonmagnetic separators. In 

 this case the improvement is greater than two to one, due principally to 

 the lighter moving parts of the AF relaj'' and lower eddy current effects 

 of the rectangular silicon iron core. 



Poiver Requirements 



The nominal jjower retiuii'cd to assure operation, with souk; margin, 

 of rela3^s with windings designed for minimum power consumi)tion is 

 shown in Fig. 20. Included is an allowance for adverse variations in 

 magnetic structure, winding and loads. Since least power will be used 

 by the largest coil wound with the finest wire consistent with meeting 

 the ampere-turn requirements for the various contact loads, the curves 

 are discontinuous and have steps as the wire sizes are shifted from one 

 size to the next to meet the ampere turns needed for increasing loads. 

 Again, the corresponding U relay power is shown for comparison. For 

 corresponding numbers of contact pairs, the AF relay rec|uires about 

 half the poAver of the U relay, except with fewer contact pairs where the 

 power in each case depends upon the use of No. 41 gauge wire. This 

 comparison applies only when coils of optimum design for minimum 

 power are used on both relays. In practice, the coils are selected for the 

 best economic balance between power consumption, cost of the coils and 

 value of speed of operation. Coils designed for minimum power are rela- 



0.018 



(/) < 

 < 5 



HJ 2 



0.016 

 0.014 

 0.012 

 0.010 

 0.008 

 0.006 

 0.004 

 0.002 



6 8 10 12 14 



NUMBER OF CONTACT PAIRS 



Fig. 19 — Topical rcloasc times of AF and U relaj's. 



