The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Feb. 27, 2001

Filed:

Apr. 02, 1998
Applicant:
Inventors:

Anders Emericks, Solna, SE;

Henrik Hellberg, Solna, SE;

Mattias Israelsson, Stockholm, SE;

Carl-Henrik Malmgren, Stockholm, SE;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M 1/24 ; H03K 7/06 ;
U.S. Cl.
CPC ...
H04M 1/24 ; H03K 7/06 ;
Abstract

In a subscriber line interface circuit connected to a telephone line having a high potential wire and a low potential wire, an arrangement for generating a signal for determining the line voltage comprises means (,) for alternately charging a capacitor (,), by means of a first DC current, to a first voltage, and discharging the capacitor (,), by means of a second DC current, to a second voltage. Hereby, a sawtooth wave having an amplitude corresponding to the difference between the first and second voltages is produced. This sawtooth wave is converted to a pulse train related to the line voltage, from which the line voltage can be determined.


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