04196320 is referenced by 9 patents and cites 7 patents.

An essentially non-dissipative, strap-free, continuously adjustable power unit inherently impervious to shorts and open circuits for powering repeaters in a T1 or similar telephone span line is disclosed. The unit uses a pulse-width modulated inverter in the converter input circuit to produce a variable-voltage D.C. output to the span line. The pulse width or duty cycle of the inverter is controlled by a control logic which senses the span line current and maintains it at a selectable predetermined level without any apreciable power dissipation.

Title
Method and means for powering telephone span lines
Application Number
5/866696
Publication Number
4196320
Application Date
January 3, 1978
Publication Date
April 1, 1980
Inventor
Todd V Townsend
Reno
NV, US
Agent
Phillips Moore Weissenberger Lempio & Majestic
Assignee
Lynch Communication Systems
NV, US
IPC
H04B 3/44
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