# US 10,320,305 B2 · Transformer

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- Number: US 10,320,305 B2
- Document ID: US10320305B2
- Status: Granted
- Kind: B2
- Application number: 14/912,568
- Filed: 2014-08-08
- Published: 2016-07-21
- Granted: 2019-06-11
- Earliest claimed: 2013-08-29
- Assignees: Sumitomo Electric Industries, Ltd.; National University Corporation Toyohashi of Technology
- Applicants: Sumitomo Electric Industries, Ltd.; National University Corporation Toyohashi University of Technology
- Inventors: Kenichi Hirotsu; Nobuo Shiga; Hideaki Nakahata; Takashi Ohira; Kyohei Yamada
- Web page: https://patentgrep.com/patent/US10320305B2

## CPC

- H02M 5/06: using impedances
- H02M 5/293: using semiconductor devices only
- H03H 7/38: Impedance-matching networks
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P)

## Abstract

A transformer is provided between a power supply, and a load with a resistance value R, and includes a two-terminal pair circuit composed of n-number of reactance elements that are mutually connected, where n is a natural number equal to or greater than 4. With respect to any value of the resistance value R of the load, an input impedance Zin of the two-terminal pair circuit has a real number component of k·R, where k is a constant, and an imaginary number component of 0. Such a transformer has a small size and a light weight, and does not need a coil, an iron core, and the like as used in a conventional transformer.

## Claims

### Claim 1

A transformer provided between a power supply, and a load with a resistance value R, the transformer comprising:
a two-terminal pair circuit composed of n-number of reactance elements that are mutually connected, where n is a natural number equal to or greater than 4,
wherein, with respect to any value of the resistance value R of the load, an input impedance Zin of the two-terminal pair circuit has a real number component of k·R, where k is a constant, and an imaginary number component of 0,
wherein, in the case where reactances of four reactance elements are X1, X2, X3, and X4, the two-terminal pair circuit is composed of, starting from an input side, X1 present on one line of the two-terminal pair circuit, X2 present between two lines thereof, X3 present on the one line, and X4 present between the two lines, and the following condition is satisfied:
(1/X1)+(1/X2)+(1/X3)=0∧X2+X3+X4=0.

### Claim 2

A transformer provided between a power supply, and a load with a resistance value R, the transformer comprising:
a two-terminal pair circuit composed of n-number of reactance elements that are mutually connected, where n is a natural number equal to or greater than 4,
wherein, with respect to any value of the resistance value R of the load, an input impedance Zin of the two-terminal pair circuit has a real number component of k·R, where k is a constant, and an imaginary number component of 0,
wherein, in the case where reactances of four reactance elements are X1, X2, X3, and X4, the two-terminal pair circuit is composed of, starting from an input side, X1 present between two lines of the two-terminal pair circuit, X2 present on one line thereof, X3 present between the two lines, and X4 present on the one line, and the following condition is satisfied:
X1+X2+X3=0∧(1/X2)+(1/X3)+(1/X4)=0.

### Claim 3

A transformer provided between a power supply, and a load with a resistance value R, the transformer comprising:
a two-terminal pair circuit composed of n-number of reactance elements that are mutually connected, where n is a natural number equal to or greater than 4,
wherein, with respect to any value of the resistance value R of the load, an input impedance Zin of the two-terminal pair circuit has a real number component of k·R, where k is a constant, and an imaginary number component of 0,
wherein, in the case where reactances of four reactance elements are X1, X2, X3, and X4, the two-terminal pair circuit is composed of: starting from an input side, a T-shaped circuit formed by X1 present on one line of the two-terminal pair circuit, X2 present between two lines thereof, and X3 present on the one line; and X4 present in parallel with a series unit of X1 and X3, and the following condition is satisfied:
X1+X3+X4=0∧(1/X1)+(1/X2)+(1/X3)=0.

### Claim 4

A transformer provided between a power supply, and a load with a resistance value R, the transformer comprising:
a two-terminal pair circuit composed of n-number of reactance elements that are mutually connected, where n is a natural number equal to or greater than 4,
wherein, with respect to any value of the resistance value R of the load, an input impedance Zin of the two-terminal pair circuit has a real number component of k·R, where k is a constant, and an imaginary number component of 0,
wherein, in the case where reactances of four reactance elements are X1, X2, X3, and X4, the two-terminal pair circuit is composed of, starting from an input side, a first series unit of X1 and X2 present between two lines of the two-terminal pair circuit, and a second series unit of X3 and X4 present between the two lines, such that a mutual connection point in the first series unit and a mutual connection point in the second series unit are output terminals, and the following condition is satisfied:
X1+X2+X3+X4=0∧(1/X1)+(1/X2)+(1/X3)+(1/X4)=0.

### Claim 5

A transformer provided between a power supply, and a load with a resistance value R, the transformer comprising:
a two-terminal pair circuit composed of n-number of reactance elements that are mutually connected, where n is a natural number equal to or greater than 4,
wherein, with respect to any value of the resistance value R of the load, an input impedance Zin of the two-terminal pair circuit has a real number component of k·R, where k is a constant, and an imaginary number component of 0,
wherein, in the case where reactances of five reactance elements are XA, XB, XC, XD, and XE, the two-terminal pair circuit is composed of, starting from an input side, XA present on one line of the two-terminal pair circuit, XB present between two lines thereof, XC present on the one line, XD present between the two lines, and XE present on the one line, and the following relationship is satisfied:
XA=−XB∧XE=−XD∧XC=XA+XE.

### Claim 6

A transformer provided between a power supply, and a load with a resistance value R, the transformer comprising:
a two-terminal pair circuit composed of n-number of reactance elements that are mutually connected, where n is a natural number equal to or greater than 4,
wherein, with respect to any value of the resistance value R of the load, an input impedance Zin of the two-terminal pair circuit has a real number component of k·R, where k is a constant, and an imaginary number component of 0,
wherein, in the case where reactances of five reactance elements are XA, XB, XC, XD, and XE, the two-terminal pair circuit is composed of, starting from an input side, XA present between two lines of the two-terminal pair circuit, XB present on one line thereof, XC present between the two lines, XD present on the one line, and XE present between the two lines, and the following relationship is satisfied:
XA=−XB∧XE=−XD∧XC=XA·XE/(XA+XE).

### Claim 7

A transformer provided between a power supply, and a load with a resistance value R, the transformer comprising:
a two-terminal pair circuit composed of n-number of reactance elements that are mutually connected, where n is a natural number equal to or greater than 4,
wherein, with respect to any value of the resistance value R of the load, an input impedance Zin of the two-terminal pair circuit has a real number component of k·R, where k is a constant, and an imaginary number component of 0,
wherein, in the case where reactances of six reactance elements are XA, XB, XC, XD, XE, and XF, the two-terminal pair circuit is composed of, starting from an input side, XA present on one line of the two-terminal pair circuit, XB present between two lines thereof, XC present on the one line, XD present between the two lines, XE present on the one line, and XF present between the two lines, and the following relationship is satisfied:
XA=XC=−XB∧XD=XF=−XE.

### Claim 8

A transformer provided between a power supply, and a load with a resistance value R, the transformer comprising:
a two-terminal pair circuit composed of n-number of reactance elements that are mutually connected, where n is a natural number equal to or greater than 4,
wherein, with respect to any value of the resistance value R of the load, an input impedance Zin of the two-terminal pair circuit has a real number component of k·R, where k is a constant, and an imaginary number component of 0,
wherein, in the case where reactances of six reactance elements are XA, XB, XC, XD, XE, and XF, the two-terminal pair circuit is composed of, starting from an input side, XA present between two lines of the two-terminal pair circuit, XB present on one line thereof, XC present between the two lines, XD present on the one line, XE present between the two lines, and XF present on the one line, and the following relationship is satisfied:
XA=XC=−XB∧XD=XF=−XE.