GB1574197A - Variable capacitors - Google Patents
Variable capacitors Download PDFInfo
- Publication number
- GB1574197A GB1574197A GB189378A GB189378A GB1574197A GB 1574197 A GB1574197 A GB 1574197A GB 189378 A GB189378 A GB 189378A GB 189378 A GB189378 A GB 189378A GB 1574197 A GB1574197 A GB 1574197A
- Authority
- GB
- United Kingdom
- Prior art keywords
- capacitor
- lead screw
- sealed chamber
- electrodes
- nut
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000003990 capacitor Substances 0.000 title claims description 50
- 239000000696 magnetic material Substances 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 4
- 229910001209 Low-carbon steel Inorganic materials 0.000 claims description 4
- 229910000792 Monel Inorganic materials 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 229910001369 Brass Inorganic materials 0.000 claims description 3
- 239000010951 brass Substances 0.000 claims description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- POIUWJQBRNEFGX-XAMSXPGMSA-N cathelicidin Chemical compound C([C@@H](C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCC(O)=O)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H]([C@@H](C)CC)C(=O)NCC(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCC(O)=O)C(=O)N[C@@H](CC=1C=CC=CC=1)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H]([C@@H](C)CC)C(=O)N[C@@H](C(C)C)C(=O)N[C@@H](CCC(N)=O)C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H]([C@@H](C)CC)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(O)=O)C(=O)N[C@@H](CC=1C=CC=CC=1)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H](CC(N)=O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C(C)C)C(=O)N1[C@@H](CCC1)C(=O)N[C@@H](CCCNC(N)=N)C(=O)N[C@@H]([C@@H](C)O)C(=O)N[C@@H](CCC(O)=O)C(=O)N[C@@H](CO)C(O)=O)NC(=O)[C@H](CC=1C=CC=CC=1)NC(=O)[C@H](CC(O)=O)NC(=O)CNC(=O)[C@H](CC(C)C)NC(=O)[C@@H](N)CC(C)C)C1=CC=CC=C1 POIUWJQBRNEFGX-XAMSXPGMSA-N 0.000 claims description 2
- 239000000919 ceramic Substances 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 239000010949 copper Substances 0.000 claims description 2
- 230000001419 dependent effect Effects 0.000 claims description 2
- 238000000034 method Methods 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G5/00—Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaft; Processes of their manufacture
- H01G5/04—Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaft; Processes of their manufacture using variation of effective area of electrode
- H01G5/14—Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaft; Processes of their manufacture using variation of effective area of electrode due to longitudinal movement of electrodes
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
Description
(54) IMPROVEMENTS IN OR RELATING TO VARIABLE CAPACITORS
(71) We, ENGLISH ELECTRIC VALVE
COMPANY LIMITED, a British Company, of 106, Waterhouse Lane, Chelmsford, Essex, CMl 2QU, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to variable capacitors and in particular to variable vacuum capacitors in which the moving plates of the capacitor are mounted within a sealed evacuated chamber.
In a typically known construction of variable vacuum capacitor the mechanical movement required to vary the capacitance is transmitted directly to one set of capacitor electrodes, giving movement along the axis of the assembly. The chamber within which the capacitor electrodes are mounted is completed by bellows through which the axial movement is transmitted.
The use of bellows involves a - number of disadvantages. A compromise has to be made between a bellows which is flexible enough to be distorted by convenient forces but robust enough to form a reliable envelope component having regard to the high degree of vacuum commonly involved.
Typically the bellows are constructed of thin metal with the above criteria in mind and this itself leads to a problem in that the bellows material tends to soften in the heat processes used in assembly. In addition the use of such bellows tends to impose undesired restrictions upon the lengths of stroke which may be employed.
The present invention seeks to provide an improved variable capacitor and in particular an improved variable vacuum capacitor in which the use of bellows as above mentioned is avoided.
According to this invention a variable capacitor is provided wherein within a sealed chamber at least one- capacitor electrode is connected to be moved linearly with respect to at least one other capacitor electrode by a lead screw and nut arrangement, said lead screw arrangement being magnetically coupled to a rotatable member outside of said chamber whereby rotary movement may be imparted to said lead screw and nut arrangement without the intermediary of a driving member extending from without to within said sealed chamber.
Preferably said capacitor is formed, as known per Se, of two sets of interleaved electrodes of which one set is mounted on a carrier arranged to be driven axially by the nut of said lead screw and nut arrangement and preferably again the electrodes are cylindrical.
Preferably the lead screw of said lead screw and nut arrangement is connected to rotate with a member of magnetic material, within said sealed chamber, and said rotatable member outside of said sealed chamber is a permanent magnet provided to act upon said member of magnetic material within said sealed chamber.
Preferably again said member of magnetic material within said sealed chamber is a disc and said rotatable permanent magnet outside of said sealed chamber is a horse-shoe magnet.
Preferably said horse-shoe magnet is mouonted within a cap of non-magnetic material, such as brass, and driven by a spindle passing through said cap, said cap being mounted upon one electrical conduo tive end closure for said sealed chamber and said end closure being arranged to provide an electrical termination for the moving electrode or electrodes of the capacitor within said sealed chamber.
Preferably the other electrode or electrodes of said capacitor is or are mounted on an opposite end closure of said sealed chamber which is also arranged to provide an electrical termination for said fixed electrode or electrodes.
Normally said sealed container will be evacuated
The invention is illustrated in and further described with reference to the drawing accompanying - the Provisional Specification which is a cross-section through one high vacuum variable capacitor in accordance with the present invention.
Referring to the drawing, the two plates of the capacitor consist of interleaving cylindrical electrodes of which those represented at 1 are fixed and those represented at 2 are movable in an axial direction as represented by the arrow 3 in order to vary the capacitance between the sets of electrodes 1 and 2. The fixed eletcrodes 1 are mounted on a metal end plate 4 which also forms a base for the capacitor which may be fixed to a chassis or other mounting by means of a mounting ring 5 having six circumferentially spaced tapped holes 5'.
The moving electrodes 2 are mounted on a carrier plate 6, which itself is mounted on the end of a carrier 7 for a lead screw nut 71 which, together with a monel lead screw 8 forms a lead screw arrangement.
Lead screw nut 71 is of carbon. Support for the carrier 7, at the end adjacent moving carrier plate 6 is afforded by a carbon guide liner 9 carried within a monel guide 10.
The end of the lead screw 8 remote from the moving plate carrier 6 carries a copper plated mild steel disc 11, which is fixed to the lead screw 8 so as to rotate therewith.
A conductive end plate 12, together with cylindrical metal wall 13, cylindrical ceramic wall 14 and the base plate 4 forming the outer walls of a sealed chamber enclosing the capacitor plates 1 and 2 and the lead screw and nut arrangement 7 and 8, together with the supports therefore. The moving plates 2 are electrically connected to the end plate 12 via the carrier plate 6 and a conductive compressible electric current carrier 15.
The interior of the sealed chamber is evacuated to a high vacuum by means of the sealed cliff tails 16.
Electrical connection may be made to the end plate 12 and thus the moving plates 2 by means of a mounting plate 17 which, like mounting plate 5, has six årcumfcren tially spaced holes referenced 171.
Mounted on the side of the end plate 12, outside of the vacuum is a brass cap 18, which carries a spindle 19 connected to a horse-shoe magnet 20, which is rotatable by means of the spindle 19 as represented by the arrow 21.
The horse-shoe magnet 20 is magnetically coupled to the mild steel disc 11 so that as the magnet 20 is rotated so rotates the disc 11 which causes the lead screw 8 to drive the nut 71 and thus move the moving electrodes 2 in an axial direction dependent upon the direction of rotation of the spindle 19.
Thus the electrodes 2 may be adjusted to vary the capacitance provided from outside of the vacuum without relying upon thin metal bellows or the like to maintain the integrity of the vacuum envelope whilst at the same time the operating torque may be relatively low and the variable stroke is not limited by restrictions imposed by restrictions imposed by bellows.
WHAT WE CLAIM IS:
1. A variable capacitor wherein within a sealed chamber at least one capacitor electrode is connected to be moved linearly with respect to at least one other capacitor electrode by a lead screw and nut arrangement, said lead screw arrangement being magnetically coupled to a rotatable member outside of said chamber whereby rotary movement may be imparted to said lead screw and nut arrangement without the intermediary of a driving member extending from without to within said sealed chamber.
2. A capacitor as claimed in claim 1 and formed, as known per se, of two sets of interleaved electrodes of which one set is mounted on a carrier arranged to be driven axially by the nut of said lead screw and nut arrangement.
3. A capacitor as claimed in claim 1 or 2 and wherein said capacitor electrodes are cylindrical.
4. A capacitor as claimed in any of the above claims and wherein the lead screw of said lead screw and nut arrangement is connected to rotate with a member of magnetic material, within said sealed chamber, and said rotatable member outside of said sealed chamber is a permanent magnet provided to act upon said member of magnetic material within said sealed chamber.
5. A capacitor as claimed in claim 4 and wherein said member of magnetic material within said sealed chamber is a disc and said rotatable permanent magnet outside of said sealed chamber is a horseshoe magnet.
6. A capacitor as claimed in claim 5 and wherein said horse-shoe magnet is mounted within a cap of non-magnetic material and driven by a spindle passing through said cap, said cap being mounted upon one electrical conductive end closure for said sealed chamber and said end closure being arranged to provide an electrical termination for the moving electrode or electrodes of the capacitor within said sealed chamber.
7. A capacitor as claimed in claim 6 and wherein the other electrode or electrodes of said capacitor is or are mounted on an opposite end closure of said sealed chamber which is also arranged to provide an electrical termination for said fixed electrode or electrodes.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (9)
1. A variable capacitor wherein within a sealed chamber at least one capacitor electrode is connected to be moved linearly with respect to at least one other capacitor electrode by a lead screw and nut arrangement, said lead screw arrangement being magnetically coupled to a rotatable member outside of said chamber whereby rotary movement may be imparted to said lead screw and nut arrangement without the intermediary of a driving member extending from without to within said sealed chamber.
2. A capacitor as claimed in claim 1 and formed, as known per se, of two sets of interleaved electrodes of which one set is mounted on a carrier arranged to be driven axially by the nut of said lead screw and nut arrangement.
3. A capacitor as claimed in claim 1 or 2 and wherein said capacitor electrodes are cylindrical.
4. A capacitor as claimed in any of the above claims and wherein the lead screw of said lead screw and nut arrangement is connected to rotate with a member of magnetic material, within said sealed chamber, and said rotatable member outside of said sealed chamber is a permanent magnet provided to act upon said member of magnetic material within said sealed chamber.
5. A capacitor as claimed in claim 4 and wherein said member of magnetic material within said sealed chamber is a disc and said rotatable permanent magnet outside of said sealed chamber is a horseshoe magnet.
6. A capacitor as claimed in claim 5 and wherein said horse-shoe magnet is mounted within a cap of non-magnetic material and driven by a spindle passing through said cap, said cap being mounted upon one electrical conductive end closure for said sealed chamber and said end closure being arranged to provide an electrical termination for the moving electrode or electrodes of the capacitor within said sealed chamber.
7. A capacitor as claimed in claim 6 and wherein the other electrode or electrodes of said capacitor is or are mounted on an opposite end closure of said sealed chamber which is also arranged to provide an electrical termination for said fixed electrode or electrodes.
8. A capacitor as claimed in any of the
above claims and wherein said sealed container is evacuated.
9. A variable capacitor substantially as herein described with reference to the drawing accompanying the Provisional Specification.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB189378A GB1574197A (en) | 1978-03-22 | 1978-03-22 | Variable capacitors |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB189378A GB1574197A (en) | 1978-03-22 | 1978-03-22 | Variable capacitors |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1574197A true GB1574197A (en) | 1980-09-03 |
Family
ID=9729899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB189378A Expired GB1574197A (en) | 1978-03-22 | 1978-03-22 | Variable capacitors |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB1574197A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1204124A3 (en) * | 2000-11-02 | 2006-05-31 | Thermo Finnigan Llc | Combined detector capacitor and vacuum feed through |
| WO2014191510A1 (en) * | 2013-05-30 | 2014-12-04 | Comet Ag | Vacuum variable capacitor |
-
1978
- 1978-03-22 GB GB189378A patent/GB1574197A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1204124A3 (en) * | 2000-11-02 | 2006-05-31 | Thermo Finnigan Llc | Combined detector capacitor and vacuum feed through |
| WO2014191510A1 (en) * | 2013-05-30 | 2014-12-04 | Comet Ag | Vacuum variable capacitor |
| US9721729B2 (en) | 2013-05-30 | 2017-08-01 | Comet Ag | Vacuum variable capacitor |
| US9805873B2 (en) | 2013-05-30 | 2017-10-31 | Comet Ag | Vacuum variable capacitor |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |