lOGO THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1952 



release times and those for the AG relay with no sleeve shows the time 

 advantage obtained with the domed armature. 



The AJ relay, with its long and relati\'ely heavy armature, is suited 

 for the more critical marginal appUcations and is capable of operating 

 heavier contact loads than the AF relay. All relays with more than 

 eighteen contact pairs are pro\-ided only on the AJ structure. For ex- 

 ample, Fig. 30 shows an AJ relay with a full complement of 12 transfers. 



A measure of the power requirements for the AJ relay is given in 

 Fig. 31. This shows the power required to assure operation with various 

 nimibers of contact pairs for coils designed to consume minimum power 

 at 48 volts. The chart includes allowances for variations in load, mag- 

 netic structure and coil, Avith some margin for changes in these char- 

 acteristics. Comparison with Fig. 20 shows the power requirements to 

 be slightly lower than for the AF relay except for small numbers of 

 contacts where limitation of wire sizes of the coils is controlling. Under 

 limiting conditions the AJ relay will operate on as little as 0.025 watt. 



Other features which may be used to extend the use of the AJ relay 

 for special marginal applications include armatures with, various thick- 

 nesses of nonmagnetic separators, Avire spring assemblies with reduced 

 contact forces, core laminations (strips of iron placed inside the coil, 

 against the middle leg of the core to increase the effective cross-section) 

 and the buffer spring Avhich may be used to control the operated load 

 of the relav and therefore the hold and release currents. 



Fig. 30 — AJ relay with twelve transfer contacts. 



