AUTOMATIC TESTING OF RELAY SWITCHING CIRCUITS 



1177 



TEST-TIME PER CIRCUIT 

 HANDLING-TIME PER CIRCUIT 



iv'AsSl SETUP-TIME PER CIRCUIT 



START-UP-TIME PER CIRCUIT 

 LOCATING-TIME PER DEFECT 



MANUAL TAPE 



MANUAL TAPE 



Fig. 16 — Comparison of manual and Tape-0-Matic test operation times. 



As might be expected the easy setup, automatic testing and superior 

 trouble indicating features of the Tape-0-Matic test set have materially 

 improved the quality and reduced the testing time and effort required 

 for wired relay units as compared to the older manually operated sets. 

 The aA'erage time per circuit for six representative units are shown 

 graphically in Fig. 16. One time consuming operation on manual testing 

 is the start up time allowance for reading and understanding the written 

 test instructions which has no counterpart in the Tape-0-Matic tests 

 and this alone represents a sizeable gain. The handling time of the unit 

 itself is the only operation which is not reduced in automatic testing. 



HISTORY 



The initial Card-0-Matic test set was installed in 1938 in the Western 

 Electric, Kearny, New Jersey plant. Post war and subsequent expansions 

 of production levels have necessitated construction of six more sets of 

 improved design of the type described earlier in this article. 



The first three Tape-0-Matic test sets were built in 1942 for the Wired 

 Relay Unit Shop and additional sets have since been constructed to 

 bring the number to twenty-six including six that are used in testing 

 trunk units in the Toll Crossbar Shop. They have performed admirably 

 with few changes from the initial design. They have been used to test 

 well over a million wired units with a minimum of maintenance. This 



