|  | H |
SECTION H — ELECTRICITY

|  | H01 |
BASIC ELECTRIC ELEMENTS

|  | H01 |
Note(s) Processes involving only a single technical art, e.g. drying, coating, for which provision exists elsewhere are classified in the relevant class for that art.

|  | H01F |
MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES (selection of magnetostrictive materials Fulltext... Hierarchy... Expanded...H01V 9/02)

|  | H01F |
Note(s) Inductances and transformers are regarded in this sub-class as being "for power supply" if they are intended for this purpose even in systems operating at frequencies above 60 cycles/sec.

|  | H01F 1/00 |
Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties

|  | H01F 1/02 |
· | of hard-magnetic materials

|  | H01F 1/04 |
· · | metals or alloys

|  | H01F 1/06 |
· · · | in the form of particles, e.g. powder

|  | H01F 1/08 |
· · · · | pressed, sintered, or bound together

|  | H01F 1/09 |
· · | Mixtures of metallic and non-metallic particles; Metallic particles having oxide skin

|  | H01F 1/10 |
· · | non-metallic substances, e.g. ferrites

|  | H01F 1/11 |
· · · | in the form of particles

|  | H01F 1/113 |
· · · · | in a bonding agent

|  | H01F 1/117 |
· · · · · | Flexible bodies

|  | H01F 1/12 |
· | of soft-magnetic materials

|  | H01F 1/14 |
· · | metals or alloys

|  | H01F 1/16 |
· · · | in the form of sheets

|  | H01F 1/18 |
· · · · | with insulating coating

|  | H01F 1/20 |
· · · | in the form of particles, e.g. powder

|  | H01F 1/22 |
· · · · | pressed, sintered, or bound together

|  | H01F 1/24 |
· · · · · | the particles being insulated

|  | H01F 1/26 |
· · · · · · | by macromolecular organic substances

|  | H01F 1/28 |
· · · · | dispersed or suspended in a liquid or plastic medium

|  | H01F 1/30 |
· · · · | having specific size or shape (particles of different materials Fulltext... Hierarchy... Expanded...H01F 1/32)

|  | H01F 1/32 |
· · · · | the particles being of different materials

|  | H01F 1/33 |
· · | Mixtures of metallic and non-metallic particles; Metallic particles having oxide skin

|  | H01F 1/34 |
· · | non-metallic substances, e.g. ferrites

|  | H01F 1/36 |
· · · | in the form of particles

|  | H01F 1/37 |
· · · · | in a bonding agent

|  | H01F 1/375 |
· · · · · | Flexible bodies

|  | H01F 3/00 |
Cores, yokes, or armatures (magnetic materials Fulltext... Hierarchy... Expanded...H01F 1/00; permanent magnets Fulltext... Hierarchy... Expanded...H01F 7/02)

|  | H01F 3/02 |
· | made from sheet(s)

|  | H01F 3/04 |
· | made from strip(s) or ribbon(s)

|  | H01F 3/06 |
· | made from wire(s)

|  | H01F 3/08 |
· | made from powder (powder coatings on sheets Fulltext... Hierarchy... Expanded...H01F 3/02, on strips or ribbons Fulltext... Hierarchy... Expanded...H01F 3/04, on wires Fulltext... Hierarchy... Expanded...H01F 3/06)

|  | H01F 3/10 |
· | Composite arrangements of magnetic circuits

|  | H01F 3/12 |
· · | Magnetic shunt paths

|  | H01F 3/14 |
· · | Constrictions; Gaps, e.g. air-gaps (in magnetic shunt paths Fulltext... Hierarchy... Expanded...H01F 3/12)

|  | H01F 5/00 |
Coils (for transducers Fulltext... Hierarchy... Expanded...H04R)

|  | H01F 5/02 |
· | wound on non-magnetic supports, e.g. formers

|  | H01F 5/04 |
· | Arrangements of electric connections to coils, e.g. leads

|  | H01F 5/06 |
· | Insulation of windings

|  | H01F 7/00 |
Magnets (for purifying liquids, for separating ores Fulltext... Hierarchy... Expanded...B03C; for bench or like work-holders Fulltext... Hierarchy... Expanded...B23B 31/28, Fulltext... Hierarchy... Expanded...B23Q 3/00; work-holding devices Fulltext... Hierarchy... Expanded...B25B 11/00; lifting magnets Fulltext... Hierarchy... Expanded...B66C 1/00; for electric meters Fulltext... Hierarchy... Expanded...G01R; for relays Fulltext... Hierarchy... Expanded...H01H; for dynamo-electric machines Fulltext... Hierarchy... Expanded...H02K; for electroacoustic devices Fulltext... Hierarchy... Expanded...H04R)

|  | H01F 7/02 |
· | Permanent magnets

|  | H01F 7/04 |
· · | Means for releasing the attractive force

|  | H01F 7/06 |
· | Electromagnets

|  | H01F 7/08 |
· · | with armatures

|  | H01F 7/10 |
· · · | specially adapted for alternating current

|  | H01F 7/12 |
· · · · | having anti-chattering arrangements

|  | H01F 7/13 |
· · · | characterised by pulling-force characteristic

|  | H01F 7/14 |
· · · | Pivoting armatures

|  | H01F 7/16 |
· · · | Rectilinearly-movable armatures

|  | H01F 7/18 |
· · · | Circuit arrangements for obtaining desired operating characteristics, e.g. for slow operation, for sequential energisation of windings, for high-speed energisation of windings

|  | H01F 7/20 |
· · | without armature

|  | H01F 7/22 |
· · · | having a superconductive winding

|  | H01F 10/00 |
Thin magnetic films, e.g. of one-domain structure (magnetic record carriers Fulltext... Hierarchy... Expanded...G11B 5/00; thin-film magnetic stores Fulltext... Hierarchy... Expanded...G11C)

|  | H01F 10/02 |
· | characterised by the compositon of the magnetic layer

|  | H01F 10/04 |
· | characterised by the substrate, e.g. glass

|  | H01F 10/06 |
· | characterised by the coupling or physical contact with connecting or interacting conductors

|  | H01F 13/00 |
Apparatus or processes for magnetising or demagnetising (for degaussing ships Fulltext... Hierarchy... Expanded...B63G 9/06; for clocks or watches Fulltext... Hierarchy... Expanded...G04D 9/00)

|  | H01F 15/00 |
Details of inductances or transformers covered by groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H01F 17/00-H01F 21/00

|  | H01F 15/02 |
· | Mounting; Housing; Enclosing; Filling the housing or enclosure

|  | H01F 15/04 |
· | Electrostatic or electromagnetic shielding (movable for varying inductance Fulltext... Hierarchy... Expanded...H01F 21/10)

|  | H01F 15/06 |
· | Cooling; Heating; Ventilating

|  | H01F 15/08 |
· | Protection against corrosion

|  | H01F 15/10 |
· | Terminals; Tapping arrangements

|  | H01F 15/12 |
· | Arrangements for interchanging inductances, transformers, or coils thereof

|  | H01F 15/14 |
· | with special arrangement or spacing of turns of the winding(s), e.g. to produce desired self-resonance

|  | H01F 15/16 |
· | with temperature compensation

|  | H01F 15/18 |
· | Circuits for modifying, or compensating for, electric characteristics of inductances or transformers (impedance networks Fulltext... Hierarchy... Expanded...H03H)

|  | H01F 17/00 |
Inductances (coils in general Fulltext... Hierarchy... Expanded...H01F 5/00; variable inductances Fulltext... Hierarchy... Expanded...H01F 21/00; for power supply Fulltext... Hierarchy... Expanded...H01F 29/00, Fulltext... Hierarchy... Expanded...H01F 37/00, Fulltext... Hierarchy... Expanded...H01F 39/00)

|  | H01F 17/02 |
· | without magnetic core

|  | H01F 17/03 |
· · | with ceramic former

|  | H01F 17/04 |
· | with magnetic core

|  | H01F 17/06 |
· · | with core substantially closed in itself, e.g. toroid

|  | H01F 17/08 |
· · · | Loading coils for telecommunication circuits

|  | H01F 19/00 |
Transformers or mutual inductances (variable Fulltext... Hierarchy... Expanded...H01F 21/00; for power supply Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H01F 29/00-H01F 35/00, Fulltext... Hierarchy... Expanded...H01F 39/00)

|  | H01F 19/02 |
· | Audio-frequency transformers or mutual inductances, i.e. not suitable for handling frequencies considerably beyond the audio range

|  | H01F 19/04 |
· | Transformers or mutual inductances suitable for handling frequencies considerably beyond the audio range (resonant circuits Fulltext... Hierarchy... Expanded...H03H)

|  | H01F 19/06 |
· · | Broad-band transformers, e.g. suitable for handling frequencies well down into the audio range

|  | H01F 19/08 |
· · | Transformers having magnetic bias, e.g. for handling pulses

|  | H01F 21/00 |
Variable inductances or transformers, e.g. constructions for changing voltage ratio or frequency range (for power supply Fulltext... Hierarchy... Expanded...H01F 29/00, Fulltext... Hierarchy... Expanded...H01F 39/00)

|  | H01F 21/02 |
· | continuously variable, e.g. variometers

|  | H01F 21/04 |
· · | by relative movement of turns or parts of winding(s)

|  | H01F 21/06 |
· · | by movement of core or part of core relative to the winding(s) as a whole

|  | H01F 21/08 |
· · | by varying the permeability of the core, e.g. by varying magnetic bias

|  | H01F 21/10 |
· · | by means of a movable shield

|  | H01F 21/12 |
· | discontinuously variable, e.g. tapped

|  | H01F 27/00 |
Constructional details of transformers or inductances in general

|  | H01F 27/02 |
· | Casings

|  | H01F 27/04 |
· · | Leading of conductors or axles through casings, e.g. for tap-changing arrangements

|  | H01F 27/06 |
· | Mounting, supporting, or suspending transformers, reactors, or choke coils

|  | H01F 27/08 |
· | Cooling (heat-transfer elements Fulltext... Hierarchy... Expanded...F28F); Ventilating (structural details of casings Fulltext... Hierarchy... Expanded...H01F 27/02)

|  | H01F 27/10 |
· · | Liquid cooling

|  | H01F 27/12 |
· · · | Oil cooling

|  | H01F 27/14 |
· · · · | Expansion chambers; Oil conservators; Gas cushions; Arrangements for purifying, drying, or filling

|  | H01F 27/16 |
· · · | Water cooling

|  | H01F 27/18 |
· · · | by evaporating liquids

|  | H01F 27/20 |
· · | Cooling by special gases or non-ambient air

|  | H01F 27/22 |
· · | Cooling by heat conduction through solid or powdered fillings

|  | H01F 27/24 |
· | Magnetic cores

|  | H01F 27/26 |
· · | Fastening parts of the core together; Fastening or mounting the core on casing or support (on coil Fulltext... Hierarchy... Expanded...H01F 27/30)

|  | H01F 27/28 |
· | Coils; Windings; Conductive connections

|  | H01F 27/30 |
· · | Fastening or clamping coils, windings, or parts thereof together; Fastening or mounting coils or windings on core, casing, or other support

|  | H01F 27/32 |
· · | Insulating of coils, windings, or parts thereof

|  | H01F 27/33 |
· | Arrangements for noise damping

|  | H01F 27/34 |
· | Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields

|  | H01F 27/36 |
· · | Electric or magnetic shields or screens

|  | H01F 27/38 |
· · | Auxiliary core members; Auxiliary coils or windings

|  | H01F 27/40 |
· | Structural association with built-in electric component, e.g. fuse

|  | H01F 27/42 |
· | Circuits for modifying, or compensating for, electric characteristics of transformers, reactors, or choke coils (of instrument transformers Fulltext... Hierarchy... Expanded...H01F 40/14; impedance networks Fulltext... Hierarchy... Expanded...H03H)

|  | H01F 29/00 |
Variable transformers, reactors, or choke coils, for power supply or unspecified use

|  | H01F 29/02 |
· | with tappings on coil or winding; with provision for rearrangement or interconnection of windings

|  | H01F 29/04 |
· · | having provision for tap-changing without interrupting the load current

|  | H01F 29/06 |
· | with current collector gliding or rolling on or along winding

|  | H01F 29/08 |
· | with core, coil, winding, or shield movable to offset variation of voltage or phase shift, e.g. induction regulators

|  | H01F 29/10 |
· · | having movable part of magnetic circuit

|  | H01F 29/12 |
· · | having movable coil, winding, or part thereof; having movable shield

|  | H01F 29/14 |
· | with variable magnetic bias (magnetic amplifiers Fulltext... Hierarchy... Expanded...H03F)

|  | H01F 31/00 |
Single-phase transformers for power supply or unspecified use

|  | H01F 31/02 |
· | Auto-transformers

|  | H01F 31/04 |
· | having two or more secondary windings, each supplying a separate load, e.g. for power-supply units for radio sets

|  | H01F 31/06 |
· | High-leakage transformers, e.g. for arc welding

|  | H01F 31/08 |
· | Cascade transformers, e.g. for use with extra high tension

|  | H01F 33/00 |
Two-phase, three-phase, or polyphase transformers for power supply or unspecified use

|  | H01F 33/02 |
· | for changing the number of phases

|  | H01F 35/00 |
Transformers for operation with non-linear input/output characteristics for power supply or unspecified use, e.g. for generating harmonics, for changing wave shape (with variable characteristics Fulltext... Hierarchy... Expanded...H01F 29/14)

|  | H01F 37/00 |
Reactors or choke coils for power supply or unspecified use (Fulltext... Hierarchy... Expanded...H01F 29/00, Fulltext... Hierarchy... Expanded...H01F 39/00 take precedence)

|  | H01F 37/02 |
· | with non-linear characteristics (Fulltext... Hierarchy... Expanded...H01F 29/00, Fulltext... Hierarchy... Expanded...H01F 39/00 take precedence)

|  | H01F 39/00 |
Transformers, inductances, reactors or choke coils without magnetic cores, for power supply or unspecified use

|  | H01F 40/00 |
Instrument transformers

|  | H01F 40/02 |
· | for single-phase ac

|  | H01F 40/04 |
· · | Voltage transformers

|  | H01F 40/06 |
· · | Current transformers

|  | H01F 40/08 |
· · | Combined voltage and current transformers

|  | H01F 40/10 |
· | for polyphase ac

|  | H01F 40/12 |
· | for dc

|  | H01F 40/14 |
· | Circuit arrangements for modifying, or compensating for, electric characteristics

|  | H01F 41/00 |
Apparatus or processes specially adapted for manufacturing or assembling transformers, inductances, reactors or choke coils

|  | H01F 41/02 |
· | for manufacturing cores, coils, or magnets (for dynamo-electric machines Fulltext... Hierarchy... Expanded...H02K 15/00)

|  | H01F 41/04 |
· · | for manufacturing coils

|  | H01F 41/06 |
· · · | Winding (winding in general Fulltext... Hierarchy... Expanded...B65H, e.g. Fulltext... Hierarchy... Expanded...B65H 81/00)

|  | H01F 41/08 |
· · · · | Winding conductors on to or threading conductors through cores or formers which are closed in themselves, e.g. toroids

|  | H01F 41/10 |
· · · | Connecting leads to windings (making electric connections in general Fulltext... Hierarchy... Expanded...H01R 43/00)

|  | H01F 41/12 |
· · · | Insulating of windings (of conductors in general Fulltext... Hierarchy... Expanded...H01B 13/06)

|  | H01F 41/14 |
· · | for applying thin magnetic films to substrates (covering metals, or materials with metals, in general Fulltext... Hierarchy... Expanded...C23C)