This application claims priority date of Patent Application No. 0116365 filed 2001 Jul. 4 by the present inventor.
Not applicable
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1. Field of Invention
The invention relates to a buffer capacitor.
Capacitors are used to store electric charge and in doing so concentrates the charge at the ends of the positive plate and at the point of contact between the capacitor connector and the positive plate. These concentrated charges eventually build up and leak to the negative plate causing resistive heating and inducing inductance impairing the performance of the capacitor and can result in capacitor failure.
2. Prior Art
In attempts to reduce resistive heating and induced inductance various combinations of plate geometry and dielectric manipulations has been tried with limited success. One such attempt is by Charles C Rayburn U.S. Pat. No. 814,958. His capacitor is made from a plurality of plates, each plate being made of a thin film dielectric material, metallized on both sides and the plates and separating dielectric material are folded in a certain way and are laid in a staggered arrangement, whereby all the dielectric material is inside the electric field of the capacitor, after winding. This arrangement of plates and dielectric, improved the performance of the capacitor, but there is still the problem of the plate ends, where charge concentrates, leading to resistive heating and induced inductance, consequently like all current capacitors, it has limitations on its upper operational temperature usage, and the complex way in which the plates are folded, makes this capacitor more expensive manufacture.
Another attempt is the Slit-Foil Capacitor Application no. PCTGB/95/00213. This inventor simply made slits in the capacitor plate and the performance of the capacitor improved, but again, the ends of the plate still caused charge concentration, resulting in resistive heating and induce inductance, limiting the capacitor to an upper operational temperature limit. This capacitor requires the capacitor plates to be made with slits before it can be wound, thereby adding another element to manufacture, increasing manufacturing costs.
All currently available capacitors have upper operational temperature limitations due to resistive heating, showing clearly that resistive heating is still a significant problem in all capacitors in use in electronic and electrical applications. It is the view by experts in the capacitor industry, that resistive heating and induced inductance can be reduced, but cannot be eliminated completely.
This invention relates to a buffer capacitor having at least one pair of positive and negative plates. Each plate is in the form of a loop current or charge buffer, which comprises an electric conducting material, which may be rigid or flexible, arranged in parallel, electrically insulated from each other by a dielectric material and electrically joined to form a closed continuous electrical loop thereby eliminating the ends of the plates and subsequently charge concentration. The plates are arranged one on top the other in parallel and is electrically insulated from each other by alternate layers of a dielectric material or placed one inside the other and is electrically insulated from each other by dielectric material and can be tightly wound or laid flat. Each plate is provided with a conventional or a buffer connector, which comprises of a length of an electric conducting material which may be thin in cross-section over part or all of its length and electrically insulated over part of its thin length, the remaining length being of suitably sized and shaped cross-section, or either or each end provided with an eyelet for electrical connection. The thin cross-sectioned un-insulated part of the connector is electrically connected to the plate and the remaining length is folded back parallel and is insulated from the connected length or folded around the plate with the un-insulated length electrically connected to the plate and the remaining length insulated from the plate and the eyelet ends are electrically connected in each case to form a closed continuous electrical loop thereby reducing or eliminating charge concentration at the point of contact between the plate and the connector.
Or each positive and negative plate is comprised of a rigid or flexible electric conducting material formed into a current or charge buffers by providing each end of each plate with a conventional or buffer connector, or each end of each plate is provided with or formed into a current or charge buffer with a conventional or buffer connector electrically connected to each current or charge buffer. In each case at least one positive and one negative plate is arranged in parallel one on top of the other and is electrically insulated from each other by alternate layers of a dielectric material and the conventional or buffer connectors at the ends of the same plate is electrically connected after tightly winding or remaining rigid and is electrically connected in each case forming a closed continuous electrical loop and can be used for electrical connection.
The invention is explained with reference to the accompanying drawings
From the drawings
Or buffer capacitor as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 0116365.8 | Jul 2001 | GB | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/GB02/03091 | 7/4/2002 | WO | 00 | 1/3/2004 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO03/005386 | 1/16/2003 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5426561 | Yen et al. | Jun 1995 | A |
| 5555155 | Patel et al. | Sep 1996 | A |
| 5568353 | Bai et al. | Oct 1996 | A |
| 6137673 | Andou et al. | Oct 2000 | A |
| 6246569 | Strange et al. | Jun 2001 | B1 |
| 6275371 | Yoshio et al. | Aug 2001 | B1 |
| 6421227 | Nitoh et al. | Jul 2002 | B2 |
| 6507479 | Saito et al. | Jan 2003 | B2 |
| 6636417 | Sakata et al. | Oct 2003 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20040240145 A1 | Dec 2004 | US |