Electricity: electrical systems and devices – Electrostatic capacitors – Fixed capacitor
Patent
1994-02-24
1996-08-06
Ledynh, Bot L.
Electricity: electrical systems and devices
Electrostatic capacitors
Fixed capacitor
361330, H01G 435, H01G 438
Patent
active
055440029
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a high voltage capacitor and a magnetron using this high voltage capacitor as a filter.
BACKGROUND ART
The best known high voltage capacitor of this type to date is a two-ganged type high voltage capacitor as disclosed in, for instance, Japanese Utility Model Examined Publication No. 19388/1989 or 48112/1985. This high voltage capacitor comprises a through type capacitor having two spaced-apart through holes, independent electrodes formed on one of opposite surfaces, where the through holes open, and a common electrode provided on the other surface shared by the independent electrodes, the common electrode being bonded by means of soldering or the like to a raised portion of a grounding member. Conductors clad with insulating tubes pass through the respective through holes of the through type capacitor and a through hole of the grounding member, and they are soldered by electrode connectors to the independent electrodes of the through type capacitor. The grounding member has a central raised portion formed on one side. An insulating case is fitted on the outer circumference of the raised portion of the grounding member on one side thereof so as to surround the through type capacitor, and an insulating cover is fitted on the other side so as to surround the conductors. The insulating case is usually made of a thermoplastic resin such as polybuthylene telephthalate (PBT) to achieve cost reduction. A thermosetting insulating resin such as an epoxy resin is provided on the inner and outer sides of the through type capacitor, which is surrounded by the insulating case and cover, thus ensuring moisture resistance and electric insulation. The conductors have terminal sections, such as tab connectors formed on the side of the insulating case for connection to the outside.
Since this high voltage capacitor comprises a thermosetting resin such as an epoxy resin provided on the inner side of the through type capacitor, it is necessary to reduce thermal stress generated in withstand voltage tests or heat shock tests or in use or shrinkage stress generated at the time of hardening. Heretofore, this has been achieved by covering the conductors with insulating tubes of silicone rubber or the like. The silicone rubber insulating resin tubes are elastic and can thus prevent interface separation between a porcelain element constituting the through type capacitor and the epoxy resin.
However, since the prior art high voltage capacitor comprises a through type capacitor with insulating resin provided on the inner and outer sides of the capacitor, the contact interface between the through type capacitor and the insulating resin extends broadly along the inner and outer peripheries of the through type capacitor. Therefore, the likelihood of interface separation occurring is high, and voltage breakdown failure is liable to occur. In addition, since the capacitor uses a two-ganged through type capacitor with an insulating resin provided therearound, size reduction is limited. Furthermore, the use of the two-ganged through type capacitor leads to high cost. The above problems are also present in a magnetron which uses the before-mentioned high voltage capacitor. In order to solve the problems described above, independent capacitor type high voltage capacitors using two independent through type capacitors, which had been commonly used before the two-ganged type, were reconsidered. However, the independent capacitor type high voltage capacitor comprises independent through type capacitors, which results in insufficient mechanical strength when they are bonded to a grounding member. Furthermore, conductors are mounted in the respective through type capacitors, and external connectors are fitted on and removed from tab-type terminal sections of the conductors. Therefore, insufficient mechanical strength leads to looseness in the conductors to cause interface separation of the conductors, the dielectric body and the grounding member from the insulating resin. In such a case, the with
REFERENCES:
patent: 4370698 (1983-01-01), Sasaki
patent: 4811161 (1989-03-01), Sasaki et al.
patent: 5032949 (1991-07-01), Sasaki et al.
patent: 5113309 (1992-05-01), Sasaki et al.
Fujiwara Isao
Itou Shigeru
Iwaya Shouichi
Kudou Hitoshi
Morita Makoto
Ledynh Bot L.
TDK Corporation
LandOfFree
High voltage capacitor and magnetron does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High voltage capacitor and magnetron, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High voltage capacitor and magnetron will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2196013