TD-2 MICROWAVE RADIO RELAY SYSTEM 



1075 



shown on Fig. 22, this battery serves as the lower section of the 250-volt 

 plate supply. Its capacity of 20 amperes is sufficient to supply the combined 

 130 and 250 volt loads. The regulated rectifiers normally float the plate 

 battery at a voltage of 136 =b 1%. Under a-c. power failure conditions emer- 

 gency limits of 116 to 140 volts are permissible. Due to the relatively high 

 voltage involved and in order to insure maximum service and personnel 

 protection, the rectifiers and their associated control and distribution equip- 

 ment are mounted in sheet metal enclosures as shown in Fig. 24. 



Fig. 24— 130V power plant. 



C. +250 Volt Supply . 



The 250-volt supply consists of duplicate 56 cell batteries in parallel 

 which are in turn connected in series with the 63-cell 130-volt battery. Regu- 

 lated thyratron rectifiers similar to those used in the 130-volt plate are 

 connected across the 56 cells to float the load. The normal limits are 254 to 

 259 volts and the emergency limits are 224 to 266 volts. Each section of the 

 250-volt battery is housed in its own cabinet and key interlocked to protect 

 maintenance personnel. 



