Telephone System and PBX System
Home Up Fire Protection Systems Telephone System and PBX System Security Systems Building Management System

 

phonesection01.jpg (195342 bytes)

Sectional View of an Old Western Electric Telephone Instrument

 

pluse02.jpg (33523 bytes)

Dial Pulsing

 

hlfreque01.jpg (49810 bytes)

Multifrequency Dialing

 

no1to0.jpg (34178 bytes)

 

phonedline02.jpg (44568 bytes)

Direct Telephone Connection (1)

 

phonedline01.jpg (51126 bytes)

Direct Telephone Connection (2)

 

phonedline03.jpg (191158 bytes)

Direct Telephone Connection (2)

 

sxs01.jpg (44744 bytes)

Step-by- Step Switching (1)

 

sxs02.jpg (49667 bytes)

Step-by- Step Switching (2)

 

sxs03.jpg (115487 bytes)

Step-by- Step Switching (3)

 

sxsphoto.jpg (184130 bytes)

Step-by- Step Switching (4)

 

sxsphoto02.jpg (230021 bytes)

Step-by- Step Switching (5)

 

cbar01.jpg (48575 bytes)

Cross-bar switching (1)

 

cbar02.jpg (256853 bytes)

Cross-bar switching (2)

 

cam02.jpg (262047 bytes)

Diesel Engine

 

cam01.jpg (79856 bytes)

Cam shaft

 

encswitch01.jpg (52660 bytes)

Electronic Switching

 

pbx01.jpg (62797 bytes)

PBX Interface with the Central Office

 

multiplex01.jpg (15251 bytes)

Multiplexing (1)

 

carrier01.jpg (13291 bytes)

Multiplexing (2)

 

optfibre01.jpg (14968 bytes)

Optical Fiber (1)

 

optfibre02.jpg (18744 bytes)

Optical Fiber (2)