US1788152A - Electrical translating apparatus - Google Patents

Electrical translating apparatus Download PDF

Info

Publication number
US1788152A
US1788152A US377019A US37701929A US1788152A US 1788152 A US1788152 A US 1788152A US 377019 A US377019 A US 377019A US 37701929 A US37701929 A US 37701929A US 1788152 A US1788152 A US 1788152A
Authority
US
United States
Prior art keywords
current
winding
flux
windings
core
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 - Lifetime
Application number
US377019A
Inventor
Philip H Dowling
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Rail STS USA Inc
Original Assignee
Union Switch and Signal Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from US286984A external-priority patent/US1739579A/en
Application filed by Union Switch and Signal Inc filed Critical Union Switch and Signal Inc
Priority to US377019A priority Critical patent/US1788152A/en
Application granted granted Critical
Publication of US1788152A publication Critical patent/US1788152A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F29/00Variable transformers or inductances not covered by group H01F21/00
    • H01F29/14Variable transformers or inductances not covered by group H01F21/00 with variable magnetic bias
    • H01F29/146Constructional details
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F29/00Variable transformers or inductances not covered by group H01F21/00
    • H01F29/14Variable transformers or inductances not covered by group H01F21/00 with variable magnetic bias
    • H01F2029/143Variable transformers or inductances not covered by group H01F21/00 with variable magnetic bias with control winding for generating magnetic bias

Definitions

  • My invention relates to electrical translating apparatus of the amplifier type.
  • One object of my invention is the provision of ampli 'ng apparatus having no electron tubes an no moving parts.
  • the reference character A designates a transformer comprising a magnetizablecore 1 having a bridging member 2 provided with two windings 5 and 6.
  • One leg 3 of this core is provided with a winding 7, and the other leg 4 carries a winding 8.
  • Winding 6 is connected in an input circuit which also includes a source of direct current here shown as the secondary of a transformer T and a full wave rectifier R Alternating current is at times sup- 7 plied to the primary of transformer T and it will be seen that when current is supplied to this primary unidirectional current will be supplied to winding 6.
  • Windings 7 and 8 of transformer A are connected in series with a load L in an output circuit which is constantly sup lied with alternating current from any suita le source such as an alternator G.
  • This circuit may be tuned to resonance by a condenser 9.
  • the windings 7 and 8 are so disposed that the alternating fluxes produced in core by a1- ternating current supplied to these windings traverse member 2 in opposite directions at any instant so that these fluxes do not cause a magnetic potential diiierence between the extremities of member 2.
  • Winding 5 of transformer A has its terminals connected across a rectifier 10 which permits current to flow through this winding in one direction but not in the other. i 4 When the current in winding 6 is increased,
  • the unidirectional flux in member 2 is also increased, and as a result the permeability of legs 3 and 4: is correspondingly decreased. It follows that the impedances of windings 7 and 8 are thereby decreased, so that the current supplied by enerator G to the load L through windings and 8 is increased. Furthermore, the unidirectional flux created in member 2 has another effect which I will now describe. It will be seenthat a portion of the flux created in member 2 by current in winding 6 traverses a path including leg 3 and indicated in the drawing by arrows 12. Another portion of this flux traverses the path indicated by arrows 13 and including leg 4.
  • rectifier 10 is so arranged that the current which is permitted to flow in winding 10 creates a unidirectional flux in member 2 which aids the unidirectional flux created in this member by current in windin 6. It follows that the impedances of win ings 7 and 8 are still further decreased and the unbalance between the alternating flux in core 1 is still further increased with a consequent further. increase in the current in load L. This cycle of operation continues until a condition ofequilibrium is reached for which the current supplied to the load will have been increased tion 0 by an amount which depends upon the amount of increase in the current supplied to winding 6. When the current in winding 6 returns to its original value, the current supplied to the load L also returns to its original value, the apparatus operating 1n a manner which will be understood from the foregoing without further explanation.
  • the winding 5 with its associated rectifier 10 may be dispensed with, the function of these parts being performed by the input circuit including winding 6 and rectifier R
  • alternating current induced in winding 6 by the alternating flux in member 2 resulting from an unbalance of the alternating fluxes in core 1 due to direct current supplied towinding 6 can flow through the circuit including rectifier R in only one direction, and that this direction is such that the induced current thus created in winding 6 assists the unidirectional current supplied to the winding from transformer T.
  • the apparatus wil 0 rate regeneratively without the addiwinding 5 and rectifier 10.
  • the sensitivity of the apparatus depends,
  • the current in the output circuit is varied in accordance with the current supplied to the input circuit, and that the apparatus operates regenerativeiy in response to comparatively small changes in the input circuit to cause enormously larger changes in the output circuit. Furthermore, this operation is accomplished without the use ofmovin parts.
  • Apparatus embodying my inventlon is particularly suitable for, though in no way limited to, use in railway traflic controlling apparatus in which the train is supplied with a device such as a relay which is supplied with current in accordance with variations in the current flowing in a track rail.
  • the train carried relay could be substituted for the load L and'the track rail would corres nd to the primary of trans gized in accordance with the 'trackway current.
  • a magnetizable core comprising two magnetic paths both including a bridgin member, two windings one on each said pat a circuit including a source of alternating current and said two windings in series in such manner that the alternating fluxes in said two paths are in opposition in said bridging member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a unidirec tional flux in said member, means for at times varying the flux in said member to vary the impedance of said windings, and a load receiving energy from said circuit.
  • a magnetizable core comprisin two magnetic paths both including a bri ging member, two windings one on each said path, a circuit including a source of alternating current and said two windings in series in such manner that fluxes in said two aths are in opposition in said bridging mem ber, a permanent magnet having its poles adjacent the extremities of said bridging member to create a unidirectional flux in said member, a third winding on said bridging member, means for at times supplying said third winding with unidirectional current for creating in said member a unidirectional flux to vary the impedance of said two windings, and a load receiving energy from said circuit.
  • a magnetizable core comprising two ma etic paths both including a bridgin mem er, two windings one on each said pat an output circuit including a source of alternating current and said two windings in series in such manner that the alternating fluxes in said two paths are in opposition in said bridging'member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a unidirectional flux in said member, a third windin on said bridging member, a
  • each said path a circuit including a source of alternating current andsaid two windings in series in such manner that the alternating fluxes in said two paths are in opposition in said; bridging member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a unidirec- -tiona1 flux in said member, a third winding on said bridging member, means for at times supplying said third winding with unidirectional current for creating in said member a unidirectional flux to vary the impedance of said two windings, a rectifier, a fourth winding on said bridging member connected across theterminals of said rectifier for creating in said bridging member a unidirectional flux which aids the unidirectional flux created in said member by the current supplied to said third winding, and a load receiving energy from said circuit.
  • a magnetizable core comprising two magnetic paths both including a bridging member, two windings one on each said path, a circuit including a source of periodic current and said two windings in such manner that the fluxes created thereby in said two paths are in opposition in said bridging member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a biasing flux in said member, a third winding on said bridging member, means for at times supplying said third winding with current for creating in said member a flux to vary the impedances of said two windings, and a load receiving energy from said circuit.
  • a magnetizable core comprising two ma etic paths both including a bridging mem I er, two windings one on each said path,.a circuit including a source of periodic current and said two windings in such manner that the fluxes created thereby in said two pathscare in opposition in-said bridging member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a biasing flux in said member, a third winding on said bridging member, means for at times supplying in a permanent magnet for producing a unidirectional flux inat least a portion of said core, independent means for creating flux in said core to vary the impedance of said Winding, a load, and means for supplying said load with energy in accordance wlth the current in said circuit.
  • a ma 7 etizable core a winding on said core, a clrcuit including said winding and a source of current, a permanent magnet "for producing a unidirectional biasing flux in at least a'portion of said core, means for at times varying the flux in said core to vary the impedance of said winding, means responsive to such variation in the impedance of said winding to cause further additive variation in the flux in said core, and a load receiving energy from said circuit.
  • said third winding with current for creating in said member a flux to vary the impedances of said two windings, a load, and means for supplying said load with energy in accordance with 'the current in said circuit.

Description

Jan. 6, 1931. p, DQWLING 1,788,152
ELECTRICAL TRANSLATING APPARATUS Original Filed June 20. 1928 Permanent INVENTOR'.
Patented Jan. 6, 1931 UNITED STATES PATENT OFFICE PHILIP H. DOWLING, OF SWISSVALE, PENNSYLVANIA, ASSIGNOB .TO THE UNION SWITCH & SIGNAL COMPANY, 01 SWISSVALE, PENNSYLVANIA, A CORPORATION v PENNSYLVANIA ELECTRICAL TBANSLATING' APPARATUS Original application filed June 20, 1928, serial No; 286,884. Divided and this application filed July 9, 1929,
* Serial No. 877,019.
My invention relates to electrical translating apparatus of the amplifier type. One object of my invention is the provision of ampli 'ng apparatus having no electron tubes an no moving parts.
The present application is a division of my copending application, Serial ,No. 286,984, filed June 20, 1928, for Electrical translating apparatus. I will describe one form of electrical translating apparatusembodying my invention, and will then point out the novel features thereof in claims.
In the accompanying drawing, the single 16 figure is a diagrammatic view illustrating one form of translating apparatus embodying my invention.
Referring to the drawing, the reference character A designates a transformer comprising a magnetizablecore 1 having a bridging member 2 provided with two windings 5 and 6. One leg 3 of this core is provided with a winding 7, and the other leg 4 carries a winding 8. Winding 6 is connected in an input circuit which also includes a source of direct current here shown as the secondary of a transformer T and a full wave rectifier R Alternating current is at times sup- 7 plied to the primary of transformer T and it will be seen that when current is supplied to this primary unidirectional current will be supplied to winding 6.
Windings 7 and 8 of transformer Aare connected in series with a load L in an output circuit which is constantly sup lied with alternating current from any suita le source such as an alternator G. This circuit may be tuned to resonance by a condenser 9. The windings 7 and 8 are so disposed that the alternating fluxes produced in core by a1- ternating current supplied to these windings traverse member 2 in opposite directions at any instant so that these fluxes do not cause a magnetic potential diiierence between the extremities of member 2. Winding 5 of transformer A has its terminals connected across a rectifier 10 which permits current to flow through this winding in one direction but not in the other. i 4 When the current in winding 6 is increased,
the unidirectional flux in member 2 is also increased, and as a result the permeability of legs 3 and 4: is correspondingly decreased. It follows that the impedances of windings 7 and 8 are thereby decreased, so that the current supplied by enerator G to the load L through windings and 8 is increased. Furthermore, the unidirectional flux created in member 2 has another effect which I will now describe. It will be seenthat a portion of the flux created in member 2 by current in winding 6 traverses a path including leg 3 and indicated in the drawing by arrows 12. Another portion of this flux traverses the path indicated by arrows 13 and including leg 4. It will be seen that during one-half cycle of the alternating flux created incore 1 by current in windings 7 and 8, this alternating flux will aid the unidirectional flux in leg 3 and will oppose the unidirectional flux in leg t. During the other half cycle, however, this alternating flux will aid the unidirectional flux in leg 4 and will oppose the unidirectional flux in leg 3. Since the reluctances of paths 12 and 13 depend upon the density of the flux through these paths, it follows that these reluctances will be varied by different amounts during at least a portion of each cycle. The balance normally existing between the alternating fluxes created in core 1 by windings 7 and 8 is, therefore, destroyed so that an alternatingflux is created in member 2. This alternating-flux, of course, induces in winding 5 an alternating electromotive force. Due to the rectifier 10, however, current can flow in this winding,
only during alternate half cycles and the.
rectifier 10 is so arranged that the current which is permitted to flow in winding 10 creates a unidirectional flux in member 2 which aids the unidirectional flux created in this member by current in windin 6. It follows that the impedances of win ings 7 and 8 are still further decreased and the unbalance between the alternating flux in core 1 is still further increased with a consequent further. increase in the current in load L. This cycle of operation continues until a condition ofequilibrium is reached for which the current supplied to the load will have been increased tion 0 by an amount which depends upon the amount of increase in the current supplied to winding 6. When the current in winding 6 returns to its original value, the current supplied to the load L also returns to its original value, the apparatus operating 1n a manner which will be understood from the foregoing without further explanation.
It should be pointed out that the alternaing flux in member 2 induces an alternating electromotive force in winding 6, and in order to su press this induced electromotive force an impedance 11 is interposed in the input circuit. I
Under some conditions of operation, the winding 5 with its associated rectifier 10 may be dispensed with, the function of these parts being performed by the input circuit including winding 6 and rectifier R It will be noted that alternating current induced in winding 6 by the alternating flux in member 2 resulting from an unbalance of the alternating fluxes in core 1 due to direct current supplied towinding 6 can flow through the circuit including rectifier R in only one direction, and that this direction is such that the induced current thus created in winding 6 assists the unidirectional current supplied to the winding from transformer T. Underpro r conditions, therefore, the apparatus wil 0 rate regeneratively without the addiwinding 5 and rectifier 10.
The sensitivity of the apparatus depends,
of course, upon the initial permeability of core 1, and for the purpose of adjusting this permeability to its optimum value, I provide a permanent magnet M having its poles M and M adjacent the extremities of member 2. With this arrangement it will be apparent that the magnet M su lies a unidirectional flux to the core 1, an y properly constructing the rmanent magnet M the initial permeabiht of the core 1 may be adj usted to the desire value.
It should be pointed out that with apparatus embodying my invention, the current in the output circuit is varied in accordance with the current supplied to the input circuit, and that the apparatus operates regenerativeiy in response to comparatively small changes in the input circuit to cause enormously larger changes in the output circuit. Furthermore, this operation is accomplished without the use ofmovin parts. Apparatus embodying my inventlon is particularly suitable for, though in no way limited to, use in railway traflic controlling apparatus in which the train is supplied with a device such as a relay which is supplied with current in accordance with variations in the current flowing in a track rail. In my present invention the train carried relay could be substituted for the load L and'the track rail would corres nd to the primary of trans gized in accordance with the 'trackway current.
It should be distinctly understood, however, that my invention is not limited to use with input circuits su lied by an alternating current source. en the input energy is direct current, this current may be supplied directly to the control winding 6, the rectifier R and transformer T then being umiec: essary.
Although I have herein shown and described only one form of electrical translating a paratus embodying my invention, it is un erstood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.
Having thus described my invention, what I claim 1s:
1. In combination, a magnetizable core comprising two magnetic paths both including a bridgin member, two windings one on each said pat a circuit including a source of alternating current and said two windings in series in such manner that the alternating fluxes in said two paths are in opposition in said bridging member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a unidirec tional flux in said member, means for at times varying the flux in said member to vary the impedance of said windings, and a load receiving energy from said circuit.
2. In combination, a magnetizable core comprisin two magnetic paths both including a bri ging member, two windings one on each said path, a circuit including a source of alternating current and said two windings in series in such manner that fluxes in said two aths are in opposition in said bridging mem ber, a permanent magnet having its poles adjacent the extremities of said bridging member to create a unidirectional flux in said member, a third winding on said bridging member, means for at times supplying said third winding with unidirectional current for creating in said member a unidirectional flux to vary the impedance of said two windings, and a load receiving energy from said circuit.
3. In combination, a magnetizable core comprising two ma etic paths both including a bridgin mem er, two windings one on each said pat an output circuit including a source of alternating current and said two windings in series in such manner that the alternating fluxes in said two paths are in opposition in said bridging'member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a unidirectional flux in said member, a third windin on said bridging member, a
transformer t e primary of which is at times supplied with alternating current, a rectifier,
' each said path, a circuit including a source of alternating current andsaid two windings in series in such manner that the alternating fluxes in said two paths are in opposition in said; bridging member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a unidirec- -tiona1 flux in said member, a third winding on said bridging member, means for at times supplying said third winding with unidirectional current for creating in said member a unidirectional flux to vary the impedance of said two windings, a rectifier, a fourth winding on said bridging member connected across theterminals of said rectifier for creating in said bridging member a unidirectional flux which aids the unidirectional flux created in said member by the current supplied to said third winding, and a load receiving energy from said circuit.
5. In combination, a magnetizable core comprising two magnetic paths both including a bridging member, two windings one on each said path, a circuit including a source of periodic current and said two windings in such manner that the fluxes created thereby in said two paths are in opposition in said bridging member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a biasing flux in said member, a third winding on said bridging member, means for at times supplying said third winding with current for creating in said member a flux to vary the impedances of said two windings, and a load receiving energy from said circuit.
6, In combination, a magnetizable core comprising two ma etic paths both including a bridging mem I er, two windings one on each said path,.a circuit including a source of periodic current and said two windings in such manner that the fluxes created thereby in said two pathscare in opposition in-said bridging member, a permanent magnet having its poles adjacent the extremities of said bridging member to create a biasing flux in said member, a third winding on said bridging member, means for at times supplying in a permanent magnet for producing a unidirectional flux inat least a portion of said core, independent means for creating flux in said core to vary the impedance of said Winding, a load, and means for supplying said load with energy in accordance wlth the current in said circuit.
8. In combination, a ma 7 etizable core, a winding on said core, a clrcuit including said winding and a source of current, a permanent magnet "for producing a unidirectional biasing flux in at least a'portion of said core, means for at times varying the flux in said core to vary the impedance of said winding, means responsive to such variation in the impedance of said winding to cause further additive variation in the flux in said core, and a load receiving energy from said circuit.
In testimony whereof I afiix' my signature.
PHILIP H. DOWLING,
said third winding with current for creating in said member a flux to vary the impedances of said two windings, a load, and means for supplying said load with energy in accordance with 'the current in said circuit.
7. In combination, a magnetizable core, a winding on said core, a circuit including a sou r-( 'c of periodic current and said first wind-
US377019A 1928-06-20 1929-07-09 Electrical translating apparatus Expired - Lifetime US1788152A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US377019A US1788152A (en) 1928-06-20 1929-07-09 Electrical translating apparatus

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US286984A US1739579A (en) 1928-06-20 1928-06-20 Electrical translating apparatus
US377019A US1788152A (en) 1928-06-20 1929-07-09 Electrical translating apparatus

Publications (1)

Publication Number Publication Date
US1788152A true US1788152A (en) 1931-01-06

Family

ID=26964182

Family Applications (1)

Application Number Title Priority Date Filing Date
US377019A Expired - Lifetime US1788152A (en) 1928-06-20 1929-07-09 Electrical translating apparatus

Country Status (1)

Country Link
US (1) US1788152A (en)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2560284A (en) * 1945-10-26 1951-07-10 Automatic Elect Lab Voltage regulating system
US2615155A (en) * 1948-12-31 1952-10-21 Gen Electric Voltage regulator
US2696583A (en) * 1949-08-17 1954-12-07 Walter J Brown Saturable reactor using permanent magnets
US2719276A (en) * 1952-02-28 1955-09-27 Patent Man Inc Inductance device
DE949892C (en) * 1942-10-27 1956-09-27 Siemens Ag Arrangement for changing the inductivity of a coil provided with a ferromagnetic core
US2780772A (en) * 1953-04-21 1957-02-05 Vickers Inc Self-saturating reactor circuits
US2780771A (en) * 1953-04-21 1957-02-05 Vickers Inc Magnetic amplifier
US2856578A (en) * 1953-08-21 1958-10-14 Bendix Aviat Corp Magnetic amplifier with constant magnetic flux bias
US2948842A (en) * 1955-12-27 1960-08-09 Du Pont Transducer
US2964693A (en) * 1955-08-17 1960-12-13 Honeywell Regulator Co Current regulator
US2982947A (en) * 1954-11-26 1961-05-02 Nat Res Dev Magnetic systems and devices
US3088039A (en) * 1958-12-19 1963-04-30 Ford Motor Co Impedance gate
US3098962A (en) * 1961-03-28 1963-07-23 Charles B Berg Battery charging apparatus
DE1153469B (en) * 1956-12-03 1963-08-29 Honeywell Regulator Co Device for detecting the presence of objects with magnetic or electrically conductive properties
DE1257214B (en) * 1965-04-15 1967-12-28 Philips Patentverwaltung Magnetic amplifier with controllable shunt
US4031457A (en) * 1975-09-19 1977-06-21 The Charles Stark Draper Laboratory, Inc. Saturable reactor current limiter
US4122385A (en) * 1975-11-28 1978-10-24 The Charles Stark Draper Laboratory, Inc. Saturable reactor current limiter
EP0010502A1 (en) * 1978-10-20 1980-04-30 Hydro-Quebec Variable inductance
WO1994001814A1 (en) * 1992-07-06 1994-01-20 Robert Delain Enhanced transformer
CN103946934A (en) * 2012-11-08 2014-07-23 三菱电机株式会社 Noise filter

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE949892C (en) * 1942-10-27 1956-09-27 Siemens Ag Arrangement for changing the inductivity of a coil provided with a ferromagnetic core
US2560284A (en) * 1945-10-26 1951-07-10 Automatic Elect Lab Voltage regulating system
US2615155A (en) * 1948-12-31 1952-10-21 Gen Electric Voltage regulator
US2696583A (en) * 1949-08-17 1954-12-07 Walter J Brown Saturable reactor using permanent magnets
US2719276A (en) * 1952-02-28 1955-09-27 Patent Man Inc Inductance device
US2780771A (en) * 1953-04-21 1957-02-05 Vickers Inc Magnetic amplifier
US2780772A (en) * 1953-04-21 1957-02-05 Vickers Inc Self-saturating reactor circuits
US2856578A (en) * 1953-08-21 1958-10-14 Bendix Aviat Corp Magnetic amplifier with constant magnetic flux bias
US2982947A (en) * 1954-11-26 1961-05-02 Nat Res Dev Magnetic systems and devices
US2964693A (en) * 1955-08-17 1960-12-13 Honeywell Regulator Co Current regulator
US2948842A (en) * 1955-12-27 1960-08-09 Du Pont Transducer
DE1153469B (en) * 1956-12-03 1963-08-29 Honeywell Regulator Co Device for detecting the presence of objects with magnetic or electrically conductive properties
US3088039A (en) * 1958-12-19 1963-04-30 Ford Motor Co Impedance gate
US3098962A (en) * 1961-03-28 1963-07-23 Charles B Berg Battery charging apparatus
DE1257214B (en) * 1965-04-15 1967-12-28 Philips Patentverwaltung Magnetic amplifier with controllable shunt
US4031457A (en) * 1975-09-19 1977-06-21 The Charles Stark Draper Laboratory, Inc. Saturable reactor current limiter
US4122385A (en) * 1975-11-28 1978-10-24 The Charles Stark Draper Laboratory, Inc. Saturable reactor current limiter
EP0010502A1 (en) * 1978-10-20 1980-04-30 Hydro-Quebec Variable inductance
US4393157A (en) * 1978-10-20 1983-07-12 Hydro Quebec Variable inductor
WO1994001814A1 (en) * 1992-07-06 1994-01-20 Robert Delain Enhanced transformer
CN103946934A (en) * 2012-11-08 2014-07-23 三菱电机株式会社 Noise filter
US8810335B2 (en) 2012-11-08 2014-08-19 Mitsubishi Electric Corporation Noise filter
DE112012001304B4 (en) * 2012-11-08 2015-01-08 Mitsubishi Electric Corporation noise filter
CN103946934B (en) * 2012-11-08 2016-01-06 三菱电机株式会社 Noise filter

Similar Documents

Publication Publication Date Title
US1788152A (en) Electrical translating apparatus
US1739579A (en) Electrical translating apparatus
US2644109A (en) Variable current welding transformer
US1824577A (en) Electrical translating apparatus
US2322130A (en) Electrical regulating apparatus
US2678419A (en) Saturable transformer device
US2324634A (en) Electromagnetic inductance apparatus
US1812202A (en) Electrical translating apparatus
US2444715A (en) Voltage regulating transformer
US1793213A (en) Electrical translating apparatus
US2323441A (en) Electrical system
US2647253A (en) Electrical signaling system
US1758540A (en) Relay system
US1835209A (en) Electrical translating apparatus
US1878764A (en) Electrical translating apparatus
US1661651A (en) Electromagnetic apparatus
US1815516A (en) Electrical translating apparatus
US1862211A (en) Electrical translating apparatus
US2259711A (en) Alternating electric current control apparatus
US1797268A (en) Electrical translating apparatus
US1891044A (en) Electrical translating apparatus
US2283697A (en) Electroresponsive device
US2216631A (en) Railway traffic controlling apparatus
US2468878A (en) Frequency reducer
US2573255A (en) Means for reproducing a direct current