US3711747A - Power transformer primary winding fuse arrangement - Google Patents

Power transformer primary winding fuse arrangement Download PDF

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Publication number
US3711747A
US3711747A US3711747DA US3711747A US 3711747 A US3711747 A US 3711747A US 3711747D A US3711747D A US 3711747DA US 3711747 A US3711747 A US 3711747A
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Prior art keywords
primary windings
power supply
means
voltage
connected
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H Sahara
K Yamakawa
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Sony Corp
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Sony Corp
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    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F29/00Variable transformers or inductances not covered by group H01F21/00
    • H01F29/02Variable transformers or inductances not covered by group H01F21/00 with tappings on coil or winding; with provision for rearrangement or interconnection of windings
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/04Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS 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
    • H02M5/00Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T307/00Electrical transmission or interconnection systems
    • Y10T307/25Plural load circuit systems
    • Y10T307/297Transformer connections

Abstract

A power supply for use with different AC line voltages, which includes a power transformer having a plurality of separate primary windings and a corresponding plurality of fuses connected thereto. The primary windings are connected to each other in several different ways to change the turns ratio of the power transformer depending upon the value of the voltage supplied thereto. Thus, a predetermined voltage is produced in the secondary winding of the transformer irrespective of the value of the supplied AC line voltage and the current flowing through each of the fuses is held substantially constant, during normal operating conditions, regardless of the manner in which the separate primary windings are connected.

Description

United States Patent Sahara et a1.

POWER TRANSFORMER PRIMARY WINDING FUSE ARRANGEMENT Inventors: Hiroshi Sahara; Kiyoshi Yamakawa,

both of Tokyo, Japan Assignee: Sony Corporation, Tokyo, Japan Filed: Aug. 10, 1971 Appl. No.: 170,577

Foreign Application Priority Data Aug. 13,1970 j'a' an....1'...'i.." .."T..'..i'..;...4s'/so941 323/49 Int. Cl. ..H02h 7/04 Field of Search....323/48, 49, 43.5 R, 6; 307/17,

References Cited UNITED STATES PATENTS 11/1931 Ross ..323/49 ELECTRIC '1 APPARATUS 3,617,967 11/1971 Mitrach ..336/l47 3,084,308 4/1963 Porter ....3 17/14 R 1,291,078 l/l919 Moody ..323/49 Primary Examiner-Gerald Goldberg AttorneyLewis H. Eslinger et a1.

[57] ABSTRACT A power supply for use with different AC line voltages, which includes a power transformer having a plurality of separate primary windings and a corresponding plurality of fuses connected thereto. The primary windings are connected to each other in several different ways to change the turns ratio of the power transformer depending upon the value of the voltage supplied thereto. Thus, a predetermined voltage is produced in the secondary winding of the transformer irrespective of the value of the supplied AC line voltage and the current flowing through each of the fuses is held substantially constant, during normal operating conditions, regardless of the manner in which the separate primary windings are connected.

7 Claims, 8 Drawing Figures PATENTEDJAH 16 1915 SHEET 1 [IF 3 ELECTRIC APPARATUS p mvsmonfi A a W.0 M m m c v ml I S mm OW W M H L B PATENTEDJAN 16 1975 SHEET 2 OF 3 S CU mm R A ufm EA w A r w mmvlg AM M u WU.S

POWER TRANSFORMER PRIMARY WINDING FUSE ARRANGEMENT This invention relates generally to powersupply devices, and particularly to power supply devices for supplying a predetermined voltage to a load and which is designed to work with commercial AC power lines of differing voltage.

As is well known, different commercial AC line voltages, such as lOOV, 117V, 220V, 240V, and so on are employed in different countries, or in different localities in the same country. Accordingly, when radio receivers, television receivers, or the like, are used in localities where the commercial AC line voltages are different from one another, it is necessary to adjust the power supply in the device to correspond to the different line voltage so that a predetermined operating voltage is at all times obtained at the output of the power supply. For this purpose, a power transformer is usually employed to transform the voltage into said predetermined operating voltage and the transformation ratio of the transformer changed according to the value of the commercial line voltage. One method that has been used is to make the power transformer with a plurality of separate primary windings and to change the connections of these windings to alter the turns ratio between the primary and secondary of the transformer, in response to the line voltage supplied thereto, thereby obtaining a predetermined output voltage at the secondary winding. In this case, a fuse is interposed between the primary winding of the power transformer and the AC line for the protection of the apparatus and, when an abnormally high current flows therethrough, the fuse is broken to terminate the supply of power to the transformer. However, when the primary windings are interconnected to match the value of the line voltage, the impedance of the primary also varies, so that the current normally flowing in the fuse varies depend ing upon the voltage of the line. Accordingly, the value of the current which will blow the fuse also varies with the line voltage employed, and consequently the load connected to the power supply cannot be sufficiently protected by a single, common fuse. Therefore, in the prior art, the fuse must be replaced, in accordance with the voltage of the AC mains employed, and, if the replacement of the fuse is forgotten, the load is likely to be, damaged if a fault condition occurs which is insufficient to blow the fuse, but which is high enough to damage the load.

Accordingly, it is an object of the present invention to provide a power supply which supplies a predetermined operating voltage to a load, without fear of destruction thereof, irrespective of the AC line voltage used.

It is another object of the present invention to provide a power supply which has a power transformer whose turns ratio is capable of alteration in response to the line voltage supplied thereto, to thereby supply a predetermined operating voltage to a load, and which does not require replacement of the fuse supplied for the protection of the load, in accordance with the voltage employed.

It is still another object of the present invention to provide a power supply which has a power transformer whose turns ratio may be varied in response to the line voltage supplied thereto, to supply a predetermined operating voltage to a load, in which the current normally flowing in a fuse supplied for the protection of the load is held substantially constant, irrespective of the line voltage employed.

The above, and other objects, features and advantages of this invention will be apparent in the following detailed description of illustrative embodiments thereof which are to be read in connection with the accompanying drawings, wherein:

FIG. 1 is a diagram showing the construction of one example of a power supply according to this invention.

FIGS. 2 and 3 are connection diagrams, for explaining the operation of the device shown in FIG. 1.

FIG. 4 is a diagram showing the construction of a modified form of this invention, and

FIGS. 5, 6, 7, and 8 are connection diagrams, for explaining the operation of the device in FIG. 4.

In a first embodiment of the invention, the power supply includes a power transformer comprising a plurality of primary windings having substantially the same number of turns, each of which is connected, at one end, to a first terminal, and at the other end to a second terminal through a fuse, and these terminals are selectively connected to one another to place the primary windings in parallel or in series, to thereby change the turns ratio of the transformer. By this selective connection a constant voltage is obtained from the secondary winding of the transformer and a substantially constant current flows in the fuses, irrespective of the voltage of the AC mains connected to the transformer.

With reference to FIGS. 1, 2 and 3, a detailed description will be given of one example of a power supply according to this invention and which is capable of working with two different line voltages, for example, 1 10V and 220V AC.

In the Figures, reference numeral 1 indicates a load, such as a radio receiver, a television receiver, or the like, 2 a power transformer therefor, 3 a power switch, 5 a connecting plug to a commercial AC source and 6 some suitable means for selectively changing the interconnection of the primary windings of transformer 2. The primary winding 7 of the power transformer 2 is comprised of two independent primary windings 7a'and 7b, which are connected, at one end, to terminals t and t, of changing means 6, and at the other ends, to terminals t and t, of changing means 6 through a pair of fuses 9 and 10, respectively. The connecting plug 5 is connected to a terminal T and to a terminal T through the power switch 3. The number of turns on the secondary winding 8 of transformer 2 is suitably selected so that a predetermined output voltage is derived across the secondary winding 8 connected to the load 1.

In operation, if plug 5 is connected to a commercial AC voltage source of V, terminal T, is connected to terminals t and t and terminal T is connected to terminals t and t.,, as shown in FIG. 2, by operating changing means 6 to provide a parallel connection of the two primary windings 7a and 7b, by which connection the turns ratio of the transformer 2 is increased to establish a predetermined voltage across the secondary winding 8.

On the other hand, if plug 5 is connected to a commercial AC yoltage source of 220V, terminals T T and t, are respectively connected to terminals t t and i as shown in FIG. 3, by similarly operating changing means 6 to connect the two windings 7a and 7b in series, thereby lowering the turns ratio of the transformer 2 to obtain the same predetermined voltage across the secondary winding 8.

If the impedance of each of the windings 7a and 7b is taken as Z (the windings 7a and 7b are assumed to be identical with each other), and if the impedances of the fuses 9 and 10 are neglected because of their extremely small values, currents i, and i flowing in fuses 9 and 10, in the case where the line voltage is 110V, are given as follows:

While, when the line voltage is 220V, currents i and i flowing in the fuses 9 and 10, are given as follows:

Accordingly, i i i 11,, so that the currents flowing in fuses 9 and 10 are constant, irrespective of the voltage of the AC mains connected to the power supply.

Therefore, with this invention it is not necessary to replace the fuses in accordance with the line voltage employed, and, hence, the possibility of damage or destruction of the load which may occur if the user forgets to replace the fuse is completely avoided. FIG. 4 shows another embodiment of this invention, in which the power supply device is adapted to be operable with four different commercial AC voltages, for example, 100V, 117V, 220V, and 240V. In FIG. 4 similar elements to those shown in FIG. 1 are identified by the same reference numerals and no further detailed description will be given.

In the illustrated example, terminals t and z, are connected to taps on the windings 7a and 7b, respectively. When plug 5 is connected to a commercial AC supply of 100V, terminal T, is connected to terminals 1 and t and terminal T is connected to terminals t and t,, as shown in FIG. 5, by operating the changing means 6, to derive a predetermined voltage across the secondary winding 8 of power transformer 2. On the other hand, if plug 5 is connected to a power source of 117V, terminal T, is connected to terminals t, and t and terminal T is connected to terminals t and as shown in FIG. 6, to derive the same predetermined voltage from the secondary winding 8. Further, where plug 5 is connected to a power source of 220V, terminals T, and T are connected to terminals r, and t respectively, and terminal t is connected to terminal t,,, as shown in FIG. 7, to again derive the same predetermined voltage from the secondary winding 8. Further, when plug 5 is connected to a power supply of 240V, terminals T, and T are connected to terminals 1, and t,,, respectively and terminal t is connected to terminal as shown in FIG. 8, to derive the same predetermined voltage on the secondary winding 8. In the example shown in FIG. 4, the currents flowing in fuses 9 and 10 are substantially constant, irrespective of the line voltage supplied to plug 5, so that the same results obtained with the circuit of FIG. 1 can be obtained with the circuit of FIG. 4.

It should be noted that the foregoing examples are intended to be illustrative and do not limit the invention specifically thereto.

Although illustrative embodiments of this invention have been described in detail herein with reference to the accompanying drawings, it IS to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.

What I claim is:

l. A power supply for use with input voltages of differing magnitude, said power supply comprising; a power transformer having a secondary winding and a plurality of separate primary windings, said primary windings being interconnected to supply a predetermined operating voltage to an external load; means for supplying a source of AC voltage to said plurality of primary windings; means for selectively changing the interconnection of said primary windings, to maintain said predetermined operating voltage when said source of AC voltage is of differing magnitude; and a plurality of fuse means, a separate one of said fuse means being connected, in series, between each of said separate primary windings and said changing means.

2. A power supply according to claim 1, wherein said separate primary windings each have the same number of turns.

3. A power supply according to claim 2, wherein each of said separate primary windings is provided with at least one intermediate winding tap.

4. A power supply according to claim 1, wherein said changing means includes means for selectively changing the turns ratio of said power transformer to correspond to predetermined magnitudes of the AC voltage supplied to the primary windings, thereby providing a substantially constant voltage at the output of the power supply, irrespective of the magnitude of said AC voltage.

5. A power supply for use with any one of a plurality of different AC input voltages, said power supply comprising; a power transformer having a secondary winding and at least two separate primary windings each having the same number of turns; means for supplying a source of AC voltage to said two primary windings; means for changing the connecting relationship between said two primary windings; and at least two fuse means respectively connected in series between each of said two primary windings and said changing means.

6. A power supply according to claim 5, wherein each of said two primary windings has a terminal connecting to an intermediate tap on said winding.

7. A power supply according to claim 6, wherein the primary windings are supplied with AC voltage through said changing means.

Claims (7)

1. A power supply for use with input voltages of differing magnitude, said power supply comprising; a power transformer having a secondary winding and a plurality of separate primary windings, said primary windings being interconnected to supply a predetermined operating voltage to an external load; means for supplying a source of AC voltage to said plurality of primary windings; means for selectively changing the interconnection of said primary windings, to maintain said predetermined operating voltage when said source of AC voltage is of differing magnitude; and a plurality of fuse means, a separate one of said fuse means being connected, in series, between each of said separate primary windings and said changing means.
2. A power supply according to claim 1, wherein said separate primary windings each have the same number of turns.
3. A power supply according to claim 2, wherein each of said separate primary windings is provided with at least one intermediate winding tap.
4. A power supply according to claim 1, wherein said changing means includes means for selectively changing the turns ratio of said power transformer to correspond to predetermined magnitudes of the AC voltage supplied to the primary windings, thereby providing a substantially constant voltage at the output of the power supply, irrespective of the magnitude of said AC voltage.
5. A power supply for use with any one of a plurality of different AC input voltages, said power supply comprising; a power transformer having a secondary winding and at least two separate primary windings each having the same number of turns; means for supplying a source of AC voltage to said two primary windings; means for changing the connecting relationship between said two primary windings; and at least two fuse means respectively connected in series between each of said two primary windings and said changing means.
6. A power supply according to claim 5, wherein each of said two primary windings has a terminal connecting to an intermediate tap on said winding.
7. A power supply according to claim 6, wherein the primary windings are supplied with AC voltage through said changing means.
US3711747A 1970-08-13 1971-08-10 Power transformer primary winding fuse arrangement Expired - Lifetime US3711747A (en)

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JP8094170U JPS50497Y1 (en) 1970-08-13 1970-08-13

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JP (1) JPS50497Y1 (en)
CA (1) CA936231A (en)
DE (1) DE2140034A1 (en)
FR (1) FR2102247B1 (en)
GB (1) GB1351008A (en)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3855521A (en) * 1972-05-24 1974-12-17 Sony Corp Transformer having switch means for causing series or parallel connection between plural primary or secondary winding
US3938031A (en) * 1974-09-03 1976-02-10 Robicon Corporation Adjustable voltage power supply
US4151575A (en) * 1977-03-07 1979-04-24 Hogue Maurice A Motor protective device
US4249696A (en) * 1979-05-11 1981-02-10 Emerson Electric Co. Charging circuit for battery in thermostat with battery operated timer
US4678986A (en) * 1982-05-25 1987-07-07 Louis Barthelemy Electric transformer with selectively energized modular circuits
US5319854A (en) * 1991-05-28 1994-06-14 Pracht Guenther Scissors
US6212430B1 (en) 1999-05-03 2001-04-03 Abiomed, Inc. Electromagnetic field source with detection of position of secondary coil in relation to multiple primary coils
US6496563B1 (en) 1999-09-27 2002-12-17 Christopher M Bacon X-ray tube driver
US20050140336A1 (en) * 2003-12-26 2005-06-30 Fuji Jukogyo Kabushiki Kaisha Voltage equalizer for battery elements
CN102904456A (en) * 2011-07-29 2013-01-30 安奕极电源系统有限责任公司 Power supply assembly with means for increasing voltage
US8620447B2 (en) 2011-04-14 2013-12-31 Abiomed Inc. Transcutaneous energy transfer coil with integrated radio frequency antenna
US8766788B2 (en) 2010-12-20 2014-07-01 Abiomed, Inc. Transcutaneous energy transfer system with vibration inducing warning circuitry
JP2014123539A (en) * 2012-11-26 2014-07-03 Panasonic Corp Induction heating apparatus and rice cooker using the same
US20140285302A1 (en) * 2013-03-19 2014-09-25 Munsu SIN High voltage transformer
US9002469B2 (en) 2010-12-20 2015-04-07 Abiomed, Inc. Transcutaneous energy transfer system with multiple secondary coils
US9002468B2 (en) 2011-12-16 2015-04-07 Abiomed, Inc. Automatic power regulation for transcutaneous energy transfer charging system
US9220826B2 (en) 2010-12-20 2015-12-29 Abiomed, Inc. Method and apparatus for accurately tracking available charge in a transcutaneous energy transfer system
US20160307695A1 (en) * 2014-03-19 2016-10-20 Ionel Jitaru Magnetic structures for low leakage inductance and very high efficiency
US9673716B2 (en) * 2015-06-26 2017-06-06 Lite-On Technology Corp. Resonant converter with three switches

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2326608C2 (en) * 1973-05-24 1985-05-02 Sony Corp., Tokio/Tokyo, Jp Easily adjustable AC voltage adaptor - has rotary switch for selective tapping of transformer to give standard AC output

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1291078A (en) * 1915-02-27 1919-01-14 Gen Electric Method and means for the operation of electrical apparatus.
US1831886A (en) * 1929-11-11 1931-11-17 Julian J Ross Transformer
US3084308A (en) * 1960-01-05 1963-04-02 Hewlett Packard Co Electrical apparatus
US3617967A (en) * 1970-04-14 1971-11-02 Electromagnetic Ind Inc Current transformer having primary side switchable to different measuring ranges

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* Cited by examiner, † Cited by third party
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FR1447120A (en) * 1961-11-08 1966-07-29 Improvement made to voltage dividers

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1291078A (en) * 1915-02-27 1919-01-14 Gen Electric Method and means for the operation of electrical apparatus.
US1831886A (en) * 1929-11-11 1931-11-17 Julian J Ross Transformer
US3084308A (en) * 1960-01-05 1963-04-02 Hewlett Packard Co Electrical apparatus
US3617967A (en) * 1970-04-14 1971-11-02 Electromagnetic Ind Inc Current transformer having primary side switchable to different measuring ranges

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3855521A (en) * 1972-05-24 1974-12-17 Sony Corp Transformer having switch means for causing series or parallel connection between plural primary or secondary winding
US3938031A (en) * 1974-09-03 1976-02-10 Robicon Corporation Adjustable voltage power supply
US4151575A (en) * 1977-03-07 1979-04-24 Hogue Maurice A Motor protective device
US4249696A (en) * 1979-05-11 1981-02-10 Emerson Electric Co. Charging circuit for battery in thermostat with battery operated timer
US4678986A (en) * 1982-05-25 1987-07-07 Louis Barthelemy Electric transformer with selectively energized modular circuits
US5319854A (en) * 1991-05-28 1994-06-14 Pracht Guenther Scissors
US6212430B1 (en) 1999-05-03 2001-04-03 Abiomed, Inc. Electromagnetic field source with detection of position of secondary coil in relation to multiple primary coils
US6366817B1 (en) 1999-05-03 2002-04-02 Abiomed, Inc. Electromagnetic field source device with detection of position of secondary coil in relation to multiple primary coils
US6400991B1 (en) 1999-05-03 2002-06-04 Abiomed, Inc. Electromagnetic field source method with detection of position of secondary coil in relation to multiple primary coils
US6496563B1 (en) 1999-09-27 2002-12-17 Christopher M Bacon X-ray tube driver
US20050140336A1 (en) * 2003-12-26 2005-06-30 Fuji Jukogyo Kabushiki Kaisha Voltage equalizer for battery elements
US7400114B2 (en) * 2003-12-26 2008-07-15 Fuji Jukogyo Kabushiki Kaisha Voltage equalizer for battery elements
US9002469B2 (en) 2010-12-20 2015-04-07 Abiomed, Inc. Transcutaneous energy transfer system with multiple secondary coils
US9220826B2 (en) 2010-12-20 2015-12-29 Abiomed, Inc. Method and apparatus for accurately tracking available charge in a transcutaneous energy transfer system
US8766788B2 (en) 2010-12-20 2014-07-01 Abiomed, Inc. Transcutaneous energy transfer system with vibration inducing warning circuitry
US8620447B2 (en) 2011-04-14 2013-12-31 Abiomed Inc. Transcutaneous energy transfer coil with integrated radio frequency antenna
EP2551862A1 (en) * 2011-07-29 2013-01-30 AEG Power Solutions B.V. Power supply assembly with means for increasing voltage
CN102904456A (en) * 2011-07-29 2013-01-30 安奕极电源系统有限责任公司 Power supply assembly with means for increasing voltage
US9002468B2 (en) 2011-12-16 2015-04-07 Abiomed, Inc. Automatic power regulation for transcutaneous energy transfer charging system
JP2014123539A (en) * 2012-11-26 2014-07-03 Panasonic Corp Induction heating apparatus and rice cooker using the same
US20140285302A1 (en) * 2013-03-19 2014-09-25 Munsu SIN High voltage transformer
US20160307695A1 (en) * 2014-03-19 2016-10-20 Ionel Jitaru Magnetic structures for low leakage inductance and very high efficiency
US9673716B2 (en) * 2015-06-26 2017-06-06 Lite-On Technology Corp. Resonant converter with three switches

Also Published As

Publication number Publication date Type
FR2102247A1 (en) 1972-04-07 application
FR2102247B1 (en) 1976-05-28 grant
JPS50497Y1 (en) 1975-01-09 grant
DE2140034A1 (en) 1972-02-17 application
CA936231A1 (en) grant
GB1351008A (en) 1974-04-24 application
CA936231A (en) 1973-10-30 grant

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