分布式供电无法实现
  一种可行的解决方案是，尽量缩短低压直流传输导线的长度，将交流/直流电源设置在负载附近。 但这需要改变整个系统的供电方式，由“集中供电”改为“分布供电”，需要安排更多的交流“取电 点”，或者采用长距离的 230Vac 或 400Vac 交流传输线。在很多应用中，考虑到低压安全要求或系统 设计要求等，无法实行这种方案。

普通的直流/直流转换器方案
另一个可行的解决方案是在长距离低压直流导线末端串入一台直流/直流转换器，作为“电压补偿 器”，以补偿导线上的压降引起的电压波动。并不是所有的直流/直流转换器都适用于此类应用，非常 重要的是，
1) 直流/直流转换器要有较宽的输入电压范围，允许的输入低电压要很低。
2) 直流/直流转换器自身不能有过高的输入(起动) 电流需求。

PULS 普尔世的电压补偿器 CD5.241-L1
  PULS 普尔世在开发电压补偿器“CD5.241-L1 ”时，认真考虑了这些应用需求，设计了 14-35Vdc的宽输入电压范围，和主动式浪涌电流抑制以及“软”起动功能以避免普通直流/直流转换器起动时的 输入峰值电流。可以下述应用为例来说明它的特性。

Nortel M Series Handsets Ash
(2) Nortel Norstar Meridian M7100 -          
(2)Nortel Aastra M5312 Business Telephone Display Meridian Black Phones NT4X37JB
(25) Nortel M Series Handsets Ash for M2xxx, M5xxx, M7xxx Phones Brand         
(3) Nortel Meridian M3901 Norstar, Black - Core Base Unit Only
(3) NORTEL MERIDIAN NORSTAR PHONE SYSTEM 7310 PHONES NT8B20
(3)          Nortel Norstar Fast RAD's NT8B80AAAB (1) ATA2 NT8B09 Other Misc Norstar
(4)          NORTEL NORSTAR DIGITAL PHONE SYSTEMS LIT PACKS
(4) Nortel M Series Handsets Ash for M2xxx, M5xxx, M7xxx Phones - Brand         
(4) Nortel Meridian M3901 Norstar, Black - Replacement Base
(5) REF M7310 NORSTAR NORTEL NT8B20AB NT8B20AA NT8B40AF ONE YEAR WARRANTY
(LOT OF 5) Nortel Meridian Norstar NT8b41FA-03 Black (UNTESTED) | PH06DS
(Lot of 7) Nortel Networks Office Telephones 6x T713E 1x T7208
(Lot of Three) Nortel Meridian M7324 Receptionist Phones ((NT8B40)
(        ) NORTEL T7000 PLATINUM TELEPHONE (LOT OF 5)
(x2) Nortel, QMV1145AS5 (397)
(x3) Nortel Networks, Q1077B (401)
* NORTEL M2616 BLACK TELEPHONES / QTY AVAIL
* NORTEL NT6C18IE-61 48 VOLT BATTERY DISCONNECT PANEL W/ 120 AMP CIRCUIT BREAKER
** LOT OF 2 ** T7316E Nortel Norstar Networks T7316E
***Brand         *** Norstar M7208 Telephone (NT8B30AE-03)
**LOT OF 10** Nortel Meridian M3904 NTMN34 Professional Telephone
**LOT OF 2** Nortel Norstar Meridian M7208 NT8B30 Black UNTESTED
**LOT OF 5** Nortel Meridian M3904 NTMN34 Professional Telephone
**LOT OF 5** Nortel Networks NTMN35 M3905 Office Phones
**        ** Avaya Nortel NT7B09AAADE5 DSM 32 MBM Digital Station 90 Day Warranty
*        /OPEN* Nortel 9150 ISDN BRI Trunk I/F Module NTDR74AB [[[
*        /OPEN* Nortel M9216E Gray office display telephone [[[
*        /OPEN* Nortel Meridian M9216E Gray office display telephone NO HANDSET [[[
*        /POSSIBLY          * NORTEL NTDK23AA RLSE 13 Fiber Receiver Card [[[
*NORTEL MERIDIAN NT2K10WD MODULAR TELEPHONE POWER SUPPLY BOARD A97
*REFURB* Nortel 1110 NTYS02 IP Display Telephone phone system
*REFURB* Nortel 1120E NTYS03 office display telephone phone system
*REFURB* Nortel 1120E w/ Expansion NTYS03 NTYS08 office display phone system
*REFURB* Nortel 1535 IP Phone NTEX02AAE6 office display phone system
*REFURB* Nortel Norstar M7324 NT8B42 Charcoal Black office display telephone
*REFURB* Nortel Norstar T7316E NT8B27 Charcoal Black office display telephone
*REFURB* Nortel T7316 Display White Platinum Office Telephone
~ Nortel Norstar 48 Key Cap Module (NT8B41FA-03) ~
1 ATA NORTEL NETWORKS M3900 SERIES ANALOG TERMINAL ADAPTER MODULE NTMN685070
1          NORTEL 303979-A STACKING CASCADE CABLE NIP
1          NORTEL MERIDIAN 2616 NT2K16GH35 OFFICE DISPLAY PHONE ASH
1          NORTEL MERIDIAN M2616DIA DIGITAL TELEPHONE NIB
1          Nortel T24 KIM Moudule NT8B29AAAAE6 for T7316E
1 NORTEL NETWORKS NT8D02AB 32 PORT DIGITAL CONTROLLER BOARD
1 NORTEL NT8D14BB NETWORK UNIVERSAL TRUNK BOARD
1 Nortel Startalk Flash 2 to Flash 4 Expansion Cartridge NTAB2385
1 Nortel Startalk Flash 2 to Flash 4 Expansion Cartridge NTAB2385
1 Nortel Telephone Jazz Phone in Box Northern Telecom NTD9883
1 UNIT P/N: QMV104DQ1 Nortel Networks
1           NORTEL MERIDIAN NT2K08GL03 BLACK CORDED PHONE ***MAKE OFFER***
1           NORTEL MERIDIAN QPC441E PORT EXTENDER *MAKE OFFER*
1           NORTEL NT8B20AH-03 BUSINESS PHONE W/ NT8B91CA-03 BLF MODULE *MAKE OFFER*
1           NORTEL NT8D01AD RLSE 12 CONTROLLER 2 CARD *MAKE OFFER*
1           NORTEL NT8D04BA SUPERLOOP NETWORK CARD *MAKE OFFER*
1           NORTEL NT8D06AA PE POWER SUPPLY *MAKE OFFER*
1           NORTEL NT8D16AB MERIDIAN DIGITONE RECEIVER CARD *MAKE OFFER*
1           NORTEL NT8D17EA RLSE 01 CONTROLLER CARD *MAKE OFFER*
1           NORTEL NT8D29AB RLSE 03 POWER SUPPLY *MAKE OFFER*
1           NORTEL NT8D68AA SOFWARE LOADER CARD *MAKE OFFER*
1           NORTEL NTMN03DA70 BUSINESS PHONE
1           NORTEL QPC414C ANALOG MESSAGE WAITING CARD *MAKE OFFER*
10 Avaya Nortel Toshiba Cisco Polycom ESI 12' FT Phone Handset Cords Gray Black
10 Black Phone Handset Cords - Avaya Nortel Toshiba Cisco Polycom ESI
10          Button Lit Button for Nortel T7316E T7316 T7208
10 Nortel 1110 1120E 1140E 1165E 1210 1220 1230 IP Phone Handsets Charcoal         
10 Nortel Aastra Atlas Black Phone Handset Cords 9'         
10 Nortel Meridian M2317 M2616 M5008 Phone Replacement Handsets Black         
10 Nortel Meridian M5009 M5112 M5208 Phone Replacement Handsets Black         
10 Nortel Meridian M5209 M5212 M5216 Phone Replacement Handsets Black         
10 Nortel Meridian M5312 M5316 M8009 Phone Replacement Handsets Black         
10 Nortel Meridian M8314 M8417 M9216 Phone Replacement Handsets Black         
10 Nortel Meridian Norstar M7100 M7208 M7310 Replacement Handsets Black         
10 Nortel Networks M3903 NTMN33GA70 Charcoal Enhanced Business Phones
10 Nortel Norstar Meridian M7324 M7310 M7208 M7100 M2616 Phone Handsets Gray         
10 Nortel Norstar Meridian Vista M7324 M7310 M7208 M7100 Phone Handsets Black
10 Nortel Norstar T7100 T7208 T7316E Phone Handsets Black Charcoal Gray Grey         
10 Nortel Norstar T-Series T7000 M3900 Replacement Handsets Light Gray         
10 Nortel T-Series Handsets (Platinum) T7316 T7208 T7100 M3902 03 04 05
10 Qty GN Jabra 8800-01 Direct Connect Cord QD to Modular Plug for Avaya Nortel
10 x M9216 Nortel / Aastra Analog Telephone (A0402091)
10 x Nortel BCM IP i2004 NTDU82 Black 2004 Incl VAT/DEL
10 x Nortel i2001 NTDU90 IP Phones With Warranty Incl VAT & DEL Silver Bezel
10 x Nortel i2004 NTDU92 IP Phone 3 Month Warranty Inc VAT/DEL Silver Bezel
10 x Nortel i2004 NTDU92 IP Phone with Warranty inc VAT & FREE DELIVERY i 2004
10 X Nortel Meridian T7316E Phones with Warranty Incl VAT & FREE DELIVERY
10/units Nortel Meridian, Northern Telecom, NT9K08AC03 Business Phone Lot
100 Black Nortel Aastra Phone Handset Coil Curly Spiral Cords 9' FT Foot         
100 Nortel Norstar Phone Handsets Receivers T7316 T7208 T7100 Charcoal Gray         
10pc Nortel I2002 POE IP Phone NTDU91 NTDU91BD NTDU91BD70E6
10x          9ft 9' Nortel Standard Black Curly Phone Cord
10x Nortel Networks Char Digital Business Phone w/out Handset M3904 NTMN34GC70E6
10x Nortel Networks Charcoal Business Telephone W/out Handset M3904 NTMN34GA70
10x Nortel Networks Charcoal Enhanced Phone w/out Handset M3903 NTMN33GA70