|Publication number||US3654511 A|
|Publication date||Apr 4, 1972|
|Filing date||Sep 25, 1970|
|Priority date||Sep 25, 1970|
|Publication number||US 3654511 A, US 3654511A, US-A-3654511, US3654511 A, US3654511A|
|Original Assignee||Tdk Electronics Co Ltd|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (11), Classifications (12), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent Iwaya 72 Inventor:
Sholchi Iwaya, Akita, Japan TDK Electronics Company Ltd., Tokyo, Japan  Filed: Sept. 25, 1970  Appl.No.: 75,648
Related US. Application Data  Continuation-in-part of Ser. No. 717,602, Apr. 1,
 U.S.C| ..315/59,315/4l,3l7/67  Int. Cl. ..I*I0lj17/36  Field Of Search ..315/59, 41, 61, 1349;317/67; 313/325  References Cited UNITED STATES PATENTS 2,611,040 9/1952 Brunetti ..315/59 X 3,361,930 1/1968 Blank ..315/59 3,316,467 4/1967 Sperry ....3l7/256 3,322,995 5/1967 Hansen et al. ..3l3/325 [451 Apr. 4, 1972 Primary Examiner-Nathan Kaufman Attorney-Burgess, Ryan & Hicks [5 7] ABSTRACT A resistance-capacitor-discharge gap electric circuit component wherein the electrodes are respectively formed on both sides of a dielectric sheet and one of said electrodes in divided into two portions. The divided portions are symmetrical and provided on the respectively faced position with a space between them. The electrodes are printed on the dielectric sheet with electrically conductive material made of the mixture of 3 to 7 per cent, by weight, of the glass powder colloidal state having low melting point and fine silver powder, mixed with several per cent of organic solvent, such as toluol, tetraline, or cator oil.
A discharge gap, which is narrower than the above mentioned interval, is formed between said two divided portions of the electrode, and said two divided portions are bridged with a resistance. A sheet of electrode is provided on the rear side of the dielectric sheet at the corresponding position of the discharge gap and the electrodes on the front side of the sheet.
When a higher voltage than required is applied between the two divided portions, discharge is carried out through said resistance, but when such a high voltage as might break down the resistance or the electrodes is applied between said two divided portions, discharge is carried out through said discharge gap, and said resistance and the electrodes escape damage.
7 Claims, 8 Drawing Figures Patented April 4,' 1972 FIG. HB)
PRIOR ART P PRIOR ART FIG." 2(A) 6. 203) FIG. 3(A) FIG. 3(8) FIG. 4(A) FIG. 4(8) INVENTOR m WM m RC COMPOSITE TYPE CIRCUIT COMPONENT WITH DISCHARGE GAP This is a continuation-in-part of my earlier filed copending application Ser. N 0. 717,602 filed Apr. 1, 1968.
This invention relates to an RC (resistance capacitor) composite type circuit component and more in particular, this invention relates to an RC composite type circuit component with discharge gap provided between the electrodes, and a resistance bridging said electrodes and provided in such a manner that the electrodes are faced toward each other with said discharge gap between them.
Generally speaking, in a television receiver, a capacitor is wired in series into the antenna circuit as a filter and when the capacitor is thus used, it is necessary to provide a discharge gap for arresting lightning wired in parallel with said capacitor.
A conventional circuit component for the above mentioned purpose, is shown by (A) and (B) of FIG. 1, wherein the electrodes 8, 8a are respectively formed one on each side of the sheet of dielectrical material. The conductive portion is provided by using an appropriate material such as conductive paint, in connection with either of the electrodes, for example, the electrode 8. The conductive portion 10 extends as far as a part of the other side of the dielectrical material, and the discharge gap 7 is formed between the end of the conductive portion 10 and the electrode 8a. The lead wires 3, 3a are respectively fixed on the electrodes 8, 8a with a solder 5, 5a. The component is provided with insulating coating in such a manner that the portion of the discharge gap may not be coated. For example, the insulating coating is provided only on the upper part of [-1 ofFlG. 1.
In a capacitor of such a structure as described above, the form of the electrode is necessitated to be non-symmetrical, and, therefore, difficult to produce, and in addition to that, discharge is generated even at places outside of the discharge gap and this unstabilizes the action of the capacitor. On the other hand, because the conductive portion is formed on the peripheral portion of the dielectric 1, there are many inconveniences in production and another drawback is that the conductive portion can be easily peeled off.
Further a conventional circuit component is found on U.S. Pat. No. 3,316,467, in which a hole or a slit is provided through the dielectric sheet in order to prevent tracking when discharge occurred through discharge gap. This makes the manufacturing process complicated because the cutting hole or slit and the determination of relative positions of the hole or the slit with respect to the discharge gap are additional working procedures.
ln accordance with this invention, one of the electrodesprovided on both sides of the dielectric material is divided into two symmetrical portions, and a discharge gap is provided between the two divided portions which are bridged with a resistance.
According to this invention the electrodes are printed on the dielectric sheet with electrically conductive material prepared from the mixture of 3 to 7 per cent, by weight, of the glass powder of colloidal state having low melting point and fine silver powder, mixed with several per cent of organic solvent, such as toluol, tetraline, or castor oil.
In this novelty neither such hole nor such slit is required through the dielectric sheet for the prevention of tracking. In
Moreover, the capacity of the capacitor as a whole is simply and finely adjusted by changing of the area of the electrode on the reverse side of the dielectric.
The circuit components of this invention are made all symmetrically, and the structure of the tools for producing the circuit components of this invention can be simple, and can be easily operated to advantage, and stable discharge can be obtained when abnormally high voltage is applied.
An example of the results of the discharge tests of the circuit component of this invention is shown below.
Even after the discharge is repeated for 4,000 times, the fluctuations of the discharge initiating voltage is below 15 percent, and when compared with the conventional circuit component, the circuit component of this invention has remarkable excellent reliability.
One of the objects of this invention is to remove the drawbacks of the conventional circuit components as mentioned above.
Another object of this invention is to provide a capacitor which will not produce tracking.
Another object of this invention is to obtain the capacitor which can escape the break down of the electrodes and can operate in a stable manner.
Another object of this invention is to produce a capacitor which is relatively small and can withstand high voltage more than the conventional capacitor.
A further object of this invention is to improve the productivity of the component by simplifying the form of the electrodes.
The contents ofthis invention can be clarified by the following explanation in accordance with the attached drawings of which:
FIG. 1 shows the structure of the conventional circuit component with discharge gap before it is coated, and (A) is the front view thereof, and (B) is the rear view thereof;
FIG. 2 shows an embodiment of the RC composite type circuit component with discharge gap of this invention, and in the drawing, (A) is the front view thereof, and (B) is the rear view thereof;
FIG. 3 shows the circuit component of FIG. 2 having been coated, and in the drawing (A) is the front view thereof, and (B) is the side view thereof; and
FIG. 4 shows the electric equivalent circuit of the circuit component of this invention shown in FIG. 2 and FIG. 3, and in FIG. 4, (A) is an embodiment wherein two capacitors are serially connected, and (B) is an embodiment wherein two capacitors of (A) are made into one.
Referring to FIG. 2, the two symmetrical electrodes 2, 2a made of conductive material are fixed onto one of the surfaces of the sheet of ceramic dielectric l, and a space 4 is formed between the two electrodes. As a part of each of the respectively facing electrodes 2, 2a the projections 2b and 2c are respectively provided and the discharge gap 7 which is narrower than the interval between said electrodes 2, 2a is accordance with the RC composite type circuit component of this invention, two capacitors are serially formed with one dielectric between them, and it is possible to obtain a circuit component of twice as much withstand voltage as the conventional circuit component while the size of the circuit component of this invention is not so much different from that of the conventional circuit component.
According to the present invention the discharge gap is provided on the front side of the dielectric sheet at the corresponding position of the electrode sheet being provided on the rear side of the dielectric sheet.
formed. Carbon resin type resistive paint is coated on the portion of the wider interval 4 of the electrodes 2, 2a to form the resistance 9 and the two electrodes 2, 2a are bridged with said resistance 9. A circular electrode 11 is formed on a portion of the reverse side corresponding to said electrodes 2, 2a of the dielectric 1 in the same manner as in the electrodes 2, 2a.
On the dielectric sheet (1) neither hole nor slit, which is for the prevention of tracking in the conventional art, is provided adjacent to the discharge gap (7).
The electrodes 2, 2a, and 11 are printed on the dielectric sheet with electrically conductive material made of the mixture of 3 to 7 per cent, by weight, of glass powder of colloidal state having low melting point and fine silver powder, mixed with several per cent of organic solvents, such as toluol, tetraline, or castor oil. They are then baked at 600 C.
The resistive paint 9 is baked in the atmosphere of about 220 C. for 20 hours, after being printed on the dielectric sheet.
Further a portion of the sheet of undivided electrode 11 is so provided as to face the discharge gap 7, having the dielectric sheet therebetween. For this reason when discharge occurs between the discharging electrodes at the gap, the sheet of electrode will act as a shield for the components on the other side of the undivided electrode and will protect them from getting damaged.
On the surface of the electrodes 2, 2a, the lead wires 3, 3a are respectively fixed by the solder 5, 5a.
The place other than the discharge gap 7, such as the portion above line Il-ll of FIG. 2(A) is coated (6) with the insulating paint as is shown in FIG. 3.
ln the RC composite type circuit component having such a structure as described above, when abnormally high voltage is applied between the electrodes 2, 2a and if the voltage is below a certain level, the discharge is carried out through the resistance without being carried out at the discharge gap 7, and when a voltage higher than that is applied, discharge is carried out through the discharge gap 7.
FIG. 4 shows the electric equivalent circuit of the above explained embodiment.
FIG. 4 (A) shows the embodiment in which two capacitors are serially connected within the circuit component of the above mentioned embodiment. In accordance with said equivalent circuit, it will be more clearly understood that the circuit part of this embodiment can withstand a voltage twice as high as the voltage which the conventional circuit component can withstand at most.
FIG. 4 (B) shows an embodiment in which two capacitors are put together to make a one capacitor component.
At any rate, in the RC composite type circuit component of this invention the discharge gap and the discharge resistance are connected in parallel with the capacitor, and it will be more clearly understood from these circuits that it is possible to protect from abnormally high voltage, the instruments in which capacitors and the components of this invention are used.
What is claimed is:
l. A composite electrical circuit component comprising:
a planar dielectric sheet having first and second surfaces,
a common electrode formed on said first dielectric surface, first and second separated electrodes disposed on said second dielectric surface opposite said common electrode, v
a discharge gap on said second dielectric surface formed by a region of relatively narrow separation between said first and second electrodes, and
electrical lead wires connected to said first and second electrodes, characterized in that said planar dielectric sheet being circular shape without hole or slit for the prevention of tracking,
said electrodes being printed on said dielectric sheet surfaces with electrically conductive material prepared of the mixture of 3 to 7 per cent, by weight, of the glass powder of the colloidal state having low melting point and fine silver powder, mixed with several per cent of organic solvent, and then baked at about 600 C.,
said discharge gap being faced to said common electrode,
having the dielectric sheet therebetween.
2. A circuit component according to claim 1 wherein the two electrodes are bridged with a resistance formed substantially on the same surface as said electrodes.
3. A circuit component according to claim 1 wherein said resistance is formed at a place spaced from that of said discharge gap.
4. The resistance component according to claim 2, characterized in that the mixture of carbon powder and epoxy resin applied on to the surface of dielectric sheet, and baked in air at about 220 C. for 20 hours.
5. A circuit component according to claim 1, characterized in being formed symmetrically on the side of the two electrodes.
6. A circuit component according to claim 1 wherein said one electrode is shaped in a circular form, and said two electrodes are shaped approximately in the form of a bow, and said one electrode and said two electrodes are respectively symmetrical.
7. Circuit component according to claim 1 wherein insulating coating is provided on portions other than the discharge gap so that said discharge gap is exposed.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2611040 *||Jun 23, 1947||Sep 16, 1952||Brunetti Cledo||Nonplanar printed circuits and structural unit|
|US3316467 *||Aug 5, 1965||Apr 25, 1967||Globe Union Inc||Spark gap electronic component|
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|US3361930 *||Jun 27, 1966||Jan 2, 1968||Tobe Deutschmann Lab Inc||Discharge gap means including a spiral capacitor surrounding opposed electrodes|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3900767 *||Apr 26, 1973||Aug 19, 1975||Dale Electronics||Surge arrestor|
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|US4295174 *||May 29, 1979||Oct 13, 1981||Westinghouse Electric Corp.||Multi-series group capacitor bank protection equipment|
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|US4626957 *||Feb 14, 1985||Dec 2, 1986||Murata Manufacturing Co., Ltd.||Capacitor with discharge gap|
|US4945442 *||Nov 6, 1989||Jul 31, 1990||The Boeing Company||Protective circuitry for high-energy transients|
|DE2942192A1 *||Oct 18, 1979||Apr 30, 1980||Murata Manufacturing Co||Elektrisches verbundteil|
|EP0917264A1 *||Nov 12, 1998||May 19, 1999||Funai Electric Co., Ltd.||Discharge gap device|
|U.S. Classification||315/59, 361/118, 361/15, 315/41|
|International Classification||H01G2/00, H01T4/08, H01G2/14, H01T4/00|
|Cooperative Classification||H01G2/14, H01T4/08|
|European Classification||H01G2/14, H01T4/08|
|May 27, 1983||AS01||Change of name|
Owner name: TDK CORPORATION
Owner name: TDK ELECTRONICS CO., LTD.
Effective date: 19830301
|May 27, 1983||AS||Assignment|
Owner name: TDK CORPORATION
Free format text: CHANGE OF NAME;ASSIGNOR:TDK ELECTRONICS CO., LTD.;REEL/FRAME:004133/0509
Effective date: 19830301
Owner name: TDK CORPORATION, JAPAN