NEW MULTICONTAOT 1{KL.\Y 1123 



Replacement Type Relays 



Future replacements of flat spring multicontact relays in (existing 

 crossbar equiimients for maintenance reasons re((nire a slightly modified 

 form of the new relay, capable of complete interchangeal)ility. As these 

 relays are commonly used in connector circuits, operate and release times 

 must be comparable with okUn- type relays in order to avoid circuit 

 interference. This was accomjjlished in the new wire spring relay with 

 only minor changes in design and in the manufacturing process. 



As illustrated by Fig. 12, the interchangeable or replacement relay 

 consists essentially of two 3()-contact units assembled on a common 

 mounting bracket having the same vertical mounting centers as the 60- 

 contact flat spring relay. Since horizontal mounting space required by 

 the new relay has been reduced, the 60-contact wire spring unit may 

 also be used to replace 30-, 40- and 50-contact flat spring multicontact 

 relays. The model shown in Fig. 12 has terminals arranged for horizontal 

 multiple wiring. In another variation of the replacement relay all termi- 

 nals are arranged for cable wiring. 



Modifications necessarj^ to slow down the new relays for replacement 

 use are (1) longer armature travel, requiring a different card; (2) an 

 armature of larger mass ■ — although this is a different piece part it 

 has the same contour as the armature for the fast relay and may be 

 punched in the same tool setup; (3) a core of low carbon steel in place 

 of the one per cent silicon iron used in the high speed relay; (4) a leak- 

 age reluctance shunt element shown in Fig. 13 to by-pass a portion of 

 the total magnetic flux; and (5) coil windings having resistances of 120 

 and 275 ohms as required for circuit reasons, but having the number of 

 turns calculated for slower speed consistent with reliable operating 

 capability. ' 



Relay Performance 



Measurements have been made on laboratory-built models carefull}^ 

 prepared and adjusted to simulate extreme ranges of manufacturing 

 tolerances, and more recently, on representative samples of pre-produc- 

 tion relays. Although some of the performance characteristics studied 

 will be determined accurately only after long-term use in the field, it 

 has been possible by designed experiments and comparative tests, to 

 obtain a fair appraisal of relay capability. These tests and measure- 

 ments indicate that design objectives stated earlier in this paper have 

 been substantially achieved. 



