Electricity: electrical systems and devices – Safety and protection of systems and devices – High voltage dissipation
Reexamination Certificate
2005-09-27
2005-09-27
Jackson, Stephen W. (Department: 2836)
Electricity: electrical systems and devices
Safety and protection of systems and devices
High voltage dissipation
Reexamination Certificate
active
06950295
ABSTRACT:
Metal oxide varistors (MOVs) are employed in surge protection devices, such as overvoltage protection devices, between a pair of signal lines and ground to reduce the capacitive imbalance introduced by the overvoltage protector, thereby improving higher frequency transmissions over twisted-pair telephone lines. The MOVs are sorted into subgroups having a capacitive tolerance of no more than about 1.0 picofarad. MOVs with asymmetrical electrodes can also be sorted to reduce both the capacitance and the capacitive tolerance of the MOVs. The sorted MOVs can then be electrically connected in parallel with a gas discharge tube on each signal line to produce an overvoltage protection device, for example a station protector for use at a customer premises, having a capacitive imbalance that does not exceed about 1.3 picofarads. The use of asymmetrical electrodes reduces the capacitance of the sorted MOVs to less than about 30 picofarads.
REFERENCES:
patent: 4802055 (1989-01-01), Beckerman
patent: 4931901 (1990-06-01), Heron, Jr.
patent: 5142430 (1992-08-01), Anthony
patent: 5557065 (1996-09-01), Brower et al.
patent: 5623388 (1997-04-01), Chaudhry
patent: 5854730 (1998-12-01), Mitchell et al.
patent: 5880919 (1999-03-01), Napiorkowski et al.
patent: 6188557 (2001-02-01), Chaudhry
patent: 6195245 (2001-02-01), Kobsa
patent: 6226166 (2001-05-01), Gumley et al.
patent: 6327129 (2001-12-01), Oertel et al.
patent: 6421218 (2002-07-01), Vo et al.
patent: 6421220 (2002-07-01), Kobsa
patent: 6680839 (2004-01-01), Napiorkowski
patent: 6785110 (2004-08-01), Bartel et al.
Napiorkowski John J.
Slotnick Barry G.
Vo Chanh C.
Corning Cable Systems LLC
Demakis James A.
Dremann Christopher C.
Jackson Stephen W.
LandOfFree
Method and apparatus for balancing capacitance in hybrid... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for balancing capacitance in hybrid..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for balancing capacitance in hybrid... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3448593