Appeal No. 2006-2007
Application No. 09/996,225
BACKGROUND
Appellants’ invention relates to a circuit for detecting the polarity of a voltage
present across a set of telephone wires in both the on-hook and the off-hook states. An
understanding of the invention can be derived from a reading of exemplary independent
claim 1, which is reproduced below:
1. A circuit for detecting a reversal in polarity, comprising:
a differential amplifier;
a low pass filter connected in series with the amplifier; and
a Schmidt trigger connected in series with the low pass filter.
The Examiner relies on the following prior art references:
Albouy 4,540,853 Sep. 10, 1995
Hwang et al. (Hwang) 5,987,120 Nov. 16, 1999
Bijman et al. (Bijman) 6,590,973 Jul. 8, 2003
(filed Nov. 9, 2000)
Claims 1-6, 13, 17, 18, 20, 21 and 27-29 stand rejected
under 35 U.S.C. § 103(a) as being unpatentable over Hwang and
Albouy.
Claim 12 stands rejected under 35 U.S.C. § 103(a) as being
unpatentable over Hwang, Albouy and Bijman.
2
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