870 



THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1953 



OTHER REGULATOR FUNCTIONS 



The regulators are also used for alarm and pilot indicator functions. 

 At line dynamic regulators the current flowing through the diode de- 

 tector load resistance is also passed through a relay to obtain an alarm 

 indication whenever the pilot level deviates from normal by more than 

 3 db. At offices similar arrangements operating on a 2 db error are pro- 

 vided both for alarm and switch initiation purposes. If any pilot deviates 

 by 2 db the service switches to the spare line. In addition fast switch 

 initiation is obtained from the 7,266-kc regulator by direct connection 

 to the detector output. This arrangement avoids the time delay of the 

 relay operation. For pilot level indication the diode load current is 

 read on appropriate meters. This avoids the necessity of providing 

 separate pilot level indicators and is possible because of the reliability 

 and stabihty of the regulator amplifiers. 



MECHANICAL FEATURES 



Figs. 30 and 31 are views of a regulator seen from the wiring side and 

 from the top respectively. The chasis consists of two steel end plates 

 riveted to steel angles, with a punched copper plate screwed to this 



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Fig. 30 — Lino dynamic regulator us seen fioin wiring side. 



