|  | H |
SECTION H — ELECTRICITY

|  | H |
Note(s) These Notes cover the basic principles and general instructions for use of section H. Section H covers: basic electric elements, which cover all electric units and the general mechanical structure of apparatus and circuits, including the assembly of various basic elements into what are called printed circuits and also cover to a certain extent the manufacture of these elements (when not covered elsewhere); generation of electricity, which covers the generation, conversion and distribution of electricity together with the controlling of the corresponding gear; applied electricity, which covers: general utilisation techniques, viz. those of electric heating and electric lighting circuits; some special utilisation techniques, either electric or electronic in the strict sense, which are not covered by other sections of the Classification, including: electric light sources, including lasers; electric X-ray technique; electric plasma technique and the generation and acceleration of electrically charged particles or neutrons; basic electronic circuits and their control; radio or electric communication technique; the use of a specified material for the manufacture of the article or element described. In this connection, paragraphs 57 to 59 of the Guide should be referred to. In this section, the following general rules apply: Subject to the exceptions stated in I(c), above, any electric aspect or part peculiar to a particular operation, process, apparatus, object or article, classified in one of the sections of the Classification other than section H, is always classified in the subclass for that operation, process, apparatus, object or article. Where common characteristics concerning technical subjects of similar nature have been brought out at class level, the electric aspect or part is classified, in conjunction with the operation, process, apparatus, object or article, in a subclass which covers entirely the general electrical applications for the technical subject in question; The electrical applications referred to under (a), above, either general or particular, include: the therapeutic processes and apparatus, in class Fulltext... Hierarchy... Expanded...A61; the electric processes and apparatus used in various laboratory or industrial operations, in classes Fulltext... Hierarchy... Expanded...B01 and Fulltext... Hierarchy... Expanded...B03 and in subclass Fulltext... Hierarchy... Expanded...B23K; the electricity supply, electric propulsion and electric lighting of vehicles in general and of particular vehicles, in the subsection "Transporting" of section B; the electric ignition systems of internal-combustion engines, in subclass Fulltext... Hierarchy... Expanded...F02P, and of combustion apparatus in general, in subclass Fulltext... Hierarchy... Expanded...F23Q; the whole electrical part of section G, i.e. measuring devices including apparatus for measuring electric variables, checking, signalling and calculating. Electricity in that section is generally dealt with as a means and not as an end in itself; All electrical applications, both general and particular, presuppose that the "basic electricity" aspect appears in section H (see I(a), above) as regards the electric "basic elements" which they comprise. This rule is also valid for applied electricity, referred to in I(c), above, which appears in section H itself. In this section, the following special cases occur: Among the general applications covered by sections other than section H, it is worth noting that electric heating in general is covered by subclasses Fulltext... Hierarchy... Expanded...F24D or Fulltext... Hierarchy... Expanded...F24H or class Fulltext... Hierarchy... Expanded...F27, and that electric lighting in general is partly covered by class Fulltext... Hierarchy... Expanded...F21, since in section H (see I(c), above) there are places in Fulltext... Hierarchy... Expanded...H05B which cover the same technical subjects; In the two cases referred to under (a), above, the subclasses of section F, which deal with the respective subjects, essentially cover in the first place the whole mechanical aspect of the apparatus or devices, whereas the electrical aspect, as such, is covered by subclass Fulltext... Hierarchy... Expanded...H05B; In the case of lighting, this mechanical aspect should be taken to cover the material arrangement of the various electric elements, i.e., their geometrical or physical position in relation to one another; this aspect is covered by subclass Fulltext... Hierarchy... Expanded...F21V, the elements themselves and the primary circuits remaining in section H. The same applies to electric light sources, when combined with light sources of a different kind. These are covered by subclass Fulltext... Hierarchy... Expanded...H05B, whereas the physical arrangement which their combination constitutes is covered by the various subclasses of class Fulltext... Hierarchy... Expanded...F21; As regards heating, not only the electric elements and circuitry designs, as such, are covered by subclass Fulltext... Hierarchy... Expanded...H05B, but also the electric aspects of their arrangement, where these concern cases of general application; electric furnaces being considered as such. The physical disposition of the electric elements in furnaces is covered by section F. If a comparison is made with electric welding circuits, which are covered by subclass Fulltext... Hierarchy... Expanded...B23K in connection with welding, it can be seen that electric heating is not covered by the general rule stated in II, above.

|  | H04 |
ELECTRIC COMMUNICATION TECHNIQUE

|  | H04 |
Note(s) This class covers electrical communication systems with propagation paths employing light (optical communication), infra-red, ultrasonic, sonic, or infrasonic waves. [4]

|  | H04B |
TRANSMISSION (transmission systems for measured values, control or similar signals Fulltext... Hierarchy... Expanded...G08C; coding, decoding or code conversion, in general Fulltext... Hierarchy... Expanded...H03M; broadcast communication Fulltext... Hierarchy... Expanded...H04H; multiplex systems Fulltext... Hierarchy... Expanded...H04J; secret communication Fulltext... Hierarchy... Expanded...H04K; transmission of digital information Fulltext... Hierarchy... Expanded...H04L) [4]

|  | H04B |
Note(s) This subclass covers the transmission of information-carrying signals, the transmission being independent of the nature of the information, and includes monitoring and testing arrangements and the suppression and limitation of noise and interference.

|  | H04B |
Subclass index
DETAILS | 1/00
SYSTEMS CHARACTERISED BY THE MEDIUM USED FOR TRANSMISSION |
Using conductors | 3/00
Using free-space propagation | 5/00 - 11/00
Others | 13/00
SYSTEMS NOT CHARACTERISED BY THE MEDIUM USED FOR TRANSMISSION | 14/00
SUPPRESSION OR LIMITATION OF NOISE OR INTERFERENCE | 15/00
MONITORING, TESTING | 17/00

|  | H04B 1/00 |
Details of transmission systems, not covered by a single one of groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H04B 3/00-H04B 13/00; Details of transmission systems not characterised by the medium used for transmission (tuning resonant circuits Fulltext... Hierarchy... Expanded...H03J) [4]

|  | H04B 1/02 |
· | Transmitters (spatial arrangements of component circuits in radio pills for living beings Fulltext... Hierarchy... Expanded...A61B 5/07)

|  | H04B 1/03 |
· · | Constructional details, e.g. casings, housings [2]

|  | H04B 1/034 |
· · · | Portable transmitters [2]

|  | H04B 1/036 |
· · · | Cooling arrangements (cooling transformers Fulltext... Hierarchy... Expanded...H01F 27/08; cooling discharge tubes Fulltext... Hierarchy... Expanded...H01J 7/24, Fulltext... Hierarchy... Expanded...H01J 19/74) [2]

|  | H04B 1/04 |
· · | Circuits (of television transmitters Fulltext... Hierarchy... Expanded...H04N 5/38)

|  | H04B 1/06 |
· | Receivers (control of amplification Fulltext... Hierarchy... Expanded...H03G; television receivers Fulltext... Hierarchy... Expanded...H04N 5/44, Fulltext... Hierarchy... Expanded...H04N 5/64)

|  | H04B 1/08 |
· · | Constructional details, e.g. cabinet

|  | H04B 1/10 |
· · | Means associated with receiver for limiting or suppressing noise or interference

|  | H04B 1/12 |
· · · | Neutralising, balancing, or compensation arrangements

|  | H04B 1/14 |
· · · | Automatic detuning arrangements

|  | H04B 1/16 |
· · | Circuits

|  | H04B 1/18 |
· · · | Input circuits, e.g. for coupling to an aerial or a transmission line (input circuits for amplifiers in general Fulltext... Hierarchy... Expanded...H03F; coupling networks between aerials or lines and receivers independent of the nature of the receiver Fulltext... Hierarchy... Expanded...H03H)

|  | H04B 1/20 |
· · · | for coupling gramophone pick-up, recorder output, or microphone to receiver

|  | H04B 1/22 |
· · · | for receivers in which no local oscillation is generated

|  | H04B 1/24 |
· · · · | the receiver comprising at least one semiconductor device having three or more electrodes

|  | H04B 1/26 |
· · · | for superheterodyne receivers (multiple frequency-changing Fulltext... Hierarchy... Expanded...H03D 7/16)

|  | H04B 1/28 |
· · · · | the receiver comprising at least one semiconductor device having three or more electrodes

|  | H04B 1/30 |
· · · | for homodyne or synchrodyne receivers (demodulator circuits Fulltext... Hierarchy... Expanded...H03D 1/22)

|  | H04B 1/38 |
· | Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving

|  | H04B 1/40 |
· · | Circuits

|  | H04B 1/44 |
· · · | Transmit/receive switching (tubes therefor Fulltext... Hierarchy... Expanded...H01J 17/64; waveguide switches Fulltext... Hierarchy... Expanded...H01P 1/10) [2]

|  | H04B 1/46 |
· · · · | by voice-frequency signals; by pilot signals

|  | H04B 1/48 |
· · · · | in circuit for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter (in radar systems Fulltext... Hierarchy... Expanded...G01S)

|  | H04B 1/50 |
· · · | using different frequencies for the two directions of communication

|  | H04B 1/52 |
· · · · | Hybrid arrangements, i.e. for transition from single-path two-way transmission to single transmission on each of two paths, or vice versa

|  | H04B 1/54 |
· · · | using the same frequency for both directions of communication (Fulltext... Hierarchy... Expanded...H04B 1/44 takes precedence)

|  | H04B 1/56 |
· · · · | with provision for simultaneous communication in both directions

|  | H04B 1/58 |
· · · · | Hybrid arrangements, i.e. for transition from single-path two-way transmission to single transmission on each of two paths, or vice versa

|  | H04B 1/59 |
· | Responders; Transponders (relay systems Fulltext... Hierarchy... Expanded...H04B 7/14)

|  | H04B 1/60 |
· | Supervising unattended repeaters

|  | H04B 1/62 |
· | for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio

|  | H04B 1/64 |
· · | Volume compression or expansion arrangements

|  | H04B 1/66 |
· | for reducing bandwidth of signals (in pictorial communication systems Fulltext... Hierarchy... Expanded...H04N); for improving efficiency of transmission (Fulltext... Hierarchy... Expanded...H04B 1/68 takes precedence)

|  | H04B 1/68 |
· | for wholly or partially suppressing the carrier or one side band [4]

|  | H04B 1/69 |
· | Spread spectrum techniques in general (for code multiplex systems Fulltext... Hierarchy... Expanded...H04J 13/02) [6]

|  | H04B 1/707 |
· · | using direct sequence modulation [6]

|  | H04B 1/713 |
· · | using frequency hopping [6]

|  | H04B 1/72 |
· | Circuits or components for simulating aerials, e.g. dummy aerial (dissipative waveguide terminations Fulltext... Hierarchy... Expanded...H01P 1/26)

|  | H04B 1/74 |
· | for increasing reliability, e.g. using redundant or spare channels or apparatus [3]

|  | H04B 1/76 |
· | Pilot transmitters or receivers for control of transmission or for equalising [3]

|  | H04B 3/00 |
Line transmission systems (combined with near-field transmission systems Fulltext... Hierarchy... Expanded...H04B 5/00; constructional features of cables Fulltext... Hierarchy... Expanded...H01B 11/00)

|  | H04B 3/02 |
· | Details

|  | H04B 3/03 |
· · | Hybrid circuits (for transceivers Fulltext... Hierarchy... Expanded...H04B 1/52, Fulltext... Hierarchy... Expanded...H04B 1/58; hybrid junctions of the waveguide type Fulltext... Hierarchy... Expanded...H01P 5/16) [3]

|  | H04B 3/04 |
· · | Control of transmission; Equalising (control of amplification in general Fulltext... Hierarchy... Expanded...H03G)

|  | H04B 3/06 |
· · · | by the transmitted signal

|  | H04B 3/08 |
· · · · | in negative-feedback path of line amplifier

|  | H04B 3/10 |
· · · | by pilot signal

|  | H04B 3/11 |
· · · · | using pilot wire (Fulltext... Hierarchy... Expanded...H04B 3/12 take precedence) [3]

|  | H04B 3/12 |
· · · · | in negative-feedback path of line amplifier

|  | H04B 3/14 |
· · · | characterised by the equalising network used

|  | H04B 3/16 |
· · · | characterised by the negative-impedance network used

|  | H04B 3/18 |
· · · · | wherein the network comprises semiconductor devices

|  | H04B 3/20 |
· · | Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other

|  | H04B 3/21 |
· · · | using a set of bandfilters [3]

|  | H04B 3/23 |
· · · | using a replica of transmitted signal in the time domain, e.g. echo cancellers [3]

|  | H04B 3/26 |
· · | Improving frequency characteristic by the use of loading coils (loading coils per se Fulltext... Hierarchy... Expanded...H01F 17/08)

|  | H04B 3/28 |
· · | Reducing interference caused by currents induced in cable sheathing or armouring

|  | H04B 3/30 |
· · | Reducing interference caused by unbalance current in a normally balanced line

|  | H04B 3/32 |
· · | Reducing cross-talk, e.g. by compensating

|  | H04B 3/34 |
· · · | by systematic interconnection of lengths of cable during laying; by addition of balancing components to cable during laying

|  | H04B 3/36 |
· · | Repeater circuits (Fulltext... Hierarchy... Expanded...H04B 3/58 takes precedence; amplifiers therefor Fulltext... Hierarchy... Expanded...H03F)

|  | H04B 3/38 |
· · · | for signals in two different frequency ranges transmitted in opposite directions over the same transmission path

|  | H04B 3/40 |
· · | Artificial lines; Networks simulating a line of certain length

|  | H04B 3/42 |
· · | Circuits for by-passing of ringing signals

|  | H04B 3/44 |
· · | Arrangements for feeding power to a repeater along the transmission line

|  | H04B 3/46 |
· · | Monitoring; Testing

|  | H04B 3/48 |
· · · | Testing attenuation

|  | H04B 3/50 |
· | Systems for transmission between fixed stations via two-conductor transmission lines (Fulltext... Hierarchy... Expanded...H04B 3/54 takes precedence)

|  | H04B 3/52 |
· | Systems for transmission between fixed stations via waveguides

|  | H04B 3/54 |
· | Systems for transmission via power distribution lines (in alarm signalling systems Fulltext... Hierarchy... Expanded...G08B 25/06; remote indication of power network conditions, remote control of switching means in a power distribution network Fulltext... Hierarchy... Expanded...H02J 13/00)

|  | H04B 3/56 |
· · | Circuits for coupling, blocking, or by-passing of signals

|  | H04B 3/58 |
· · | Repeater circuits (amplifiers therefor Fulltext... Hierarchy... Expanded...H03F)

|  | H04B 3/60 |
· | Systems for communication between relatively movable stations, e.g. for communication with lift (Fulltext... Hierarchy... Expanded...H04B 3/54 takes precedence)

|  | H04B 5/00 |
Near-field transmission systems, e.g. inductive loop type

|  | H04B 5/02 |
· | using transceiver

|  | H04B 5/04 |
· | Calling systems, e.g. paging system

|  | H04B 5/06 |
· | using a portable transmitter associated with a microphone

|  | H04B 7/00 |
Radio transmission systems, i.e. using radiation field (Fulltext... Hierarchy... Expanded...H04B 10/00, Fulltext... Hierarchy... Expanded...H04B 15/00 take precedence)

|  | H04B 7/005 |
· | Control of transmission; Equalising [3]

|  | H04B 7/01 |
· | Reducing phase shift [3]

|  | H04B 7/015 |
· | Reducing echo effects [3]

|  | H04B 7/02 |
· | Diversity systems (for direction finding Fulltext... Hierarchy... Expanded...G01S 3/72; aerial arrays or systems Fulltext... Hierarchy... Expanded...H01Q)

|  | H04B 7/04 |
· · | using a plurality of spaced independent aerials

|  | H04B 7/06 |
· · · | at transmitting station

|  | H04B 7/08 |
· · · | at receiving station

|  | H04B 7/10 |
· · | using a single aerial system characterised by its polarisation or directive properties, e.g. polarisation diversity, direction diversity

|  | H04B 7/12 |
· · | Frequency-diversity systems

|  | H04B 7/14 |
· | Relay systems (interrogator-responder radar systems Fulltext... Hierarchy... Expanded...G01S 13/74) [2]

|  | H04B 7/145 |
· · | Passive relay systems [2]

|  | H04B 7/15 |
· · | Active relay systems [2]

|  | H04B 7/155 |
· · · | Ground-based stations (Fulltext... Hierarchy... Expanded...H04B 7/204 takes precedence) [2,5]

|  | H04B 7/165 |
· · · · | employing angle modulation [2]

|  | H04B 7/17 |
· · · · | employing pulse modulation, e.g. pulse code modulation [2]

|  | H04B 7/185 |
· · · | Space-based or airborne stations (Fulltext... Hierarchy... Expanded...H04B 7/204 takes precedence) [2,5]

|  | H04B 7/19 |
· · · · | Earth-synchronous stations [2]

|  | H04B 7/195 |
· · · · | Non-synchronous stations [2]

|  | H04B 7/204 |
· · · | Multiple access [5]

|  | H04B 7/208 |
· · · · | Frequency-division multiple access [5]

|  | H04B 7/212 |
· · · · | Time-division multiple access [5]

|  | H04B 7/216 |
· · · · | Code-division or spread-spectrum multiple access (spread spectrum techniques in general Fulltext... Hierarchy... Expanded...H04B 1/69) [5]

|  | H04B 7/22 |
· | Scatter propagation systems

|  | H04B 7/24 |
· | for communication between two or more posts (for selecting Fulltext... Hierarchy... Expanded...H04Q 7/00) [2]

|  | H04B 7/26 |
· · | at least one of which is mobile [2]

|  | H04B 10/00 |
Transmission systems employing electromagnetic waves other than radio waves, e.g. light, infra-red (optical coupling, mixing or splitting Fulltext... Hierarchy... Expanded...G02B; light guides Fulltext... Hierarchy... Expanded...G02B 6/00; switching, modulation, demodulation of light beams Fulltext... Hierarchy... Expanded...G02B, Fulltext... Hierarchy... Expanded...G02F; devices or arrangements for the control, e.g. modulation, of light beams Fulltext... Hierarchy... Expanded...G02F 1/00; devices or arrangements for demodulating light, transferring the modulation or changing the frequency of light Fulltext... Hierarchy... Expanded...G02F 2/00; optical multiplex systems Fulltext... Hierarchy... Expanded...H04J 14/00) [5]

|  | H04B 10/02 |
· | Details [5]

|  | H04B 10/04 |
· · | Transmitters [5]

|  | H04B 10/06 |
· · | Receivers [5]

|  | H04B 10/08 |
· · | Equipment for monitoring, testing or fault measuring [5]

|  | H04B 10/10 |
· | Transmission through free space, e.g. through the atmosphere (Fulltext... Hierarchy... Expanded...H04B 10/22, Fulltext... Hierarchy... Expanded...H04B 10/24 take precedence) [5]

|  | H04B 10/105 |
· · | specially adapted for satellite links [6]

|  | H04B 10/12 |
· | Transmission through light guides, e.g. optical fibres (Fulltext... Hierarchy... Expanded...H04B 10/22, Fulltext... Hierarchy... Expanded...H04B 10/24 take precedence) [5]

|  | H04B 10/13 |
· · | using multimodal transmission [6]

|  | H04B 10/135 |
· · | using single mode transmission [6]

|  | H04B 10/14 |
· · | Terminal stations [5]

|  | H04B 10/142 |
· · · | Coherent homodyne or heterodyne systems [6]

|  | H04B 10/145 |
· · · · | Transmitters [6]

|  | H04B 10/148 |
· · · · | Receivers [6]

|  | H04B 10/152 |
· · · | Non-coherent direct-detection systems [6]

|  | H04B 10/155 |
· · · · | Transmitters [6]

|  | H04B 10/158 |
· · · · | Receivers [6]

|  | H04B 10/16 |
· · | Repeaters [5]

|  | H04B 10/17 |
· · · | in which processing or amplification is carried out without conversion of the signal from optical form [6]

|  | H04B 10/18 |
· · | Arrangements for reducing or eliminating distortion or dispersion, e.g. equalisers [5]

|  | H04B 10/20 |
· · | Arrangements for networking, e.g. bus or star coupling [5]

|  | H04B 10/207 |
· · · | using a star-type coupler [6]

|  | H04B 10/213 |
· · · | using a T-type coupler [6]

|  | H04B 10/22 |
· | Transmission between two stations which are mobile relative to each other [5]

|  | H04B 10/24 |
· | Bidirectional transmission (Fulltext... Hierarchy... Expanded...H04B 10/22 takes precedence) [5]

|  | H04B 10/26 |
· · | using a single light source for both stations involved [6]

|  | H04B 10/28 |
· · | using a single device as a light source or a light receiver [6]

|  | H04B 11/00 |
Transmission systems employing ultranosic, sonic or infrasonic waves

|  | H04B 13/00 |
Transmission systems characterised by the medium used for transmission, not provided for in groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H04B 3/00-H04B 11/00

|  | H04B 13/02 |
· | Transmission systems in which the medium consists of the earth or a large mass of water thereon, e.g. earth telegraphy (line transmission systems with earth or water return Fulltext... Hierarchy... Expanded...H04B 3/00)

|  | H04B 14/00 |
Transmission systems not characterised by the medium used for transmission (details thereof Fulltext... Hierarchy... Expanded...H04B 1/00) [4]

|  | H04B 14/02 |
· | characterised by the use of pulse modulation (in radio transmission relays Fulltext... Hierarchy... Expanded...H04B 7/17) [4]

|  | H04B 14/04 |
· · | using pulse code modulation (analogue/digital or digital/analogue conversion Fulltext... Hierarchy... Expanded...H03M 1/00) [4]

|  | H04B 14/06 |
· · | using differential modulation, e.g. delta modulation (conversion of analogue values to or from differential modulation Fulltext... Hierarchy... Expanded...H03M 3/00) [4]

|  | H04B 14/08 |
· | characterised by the use of a sub-carrier [4]

|  | H04B 15/00 |
Suppression or limitation of noise or interference (by means associated with receiver Fulltext... Hierarchy... Expanded...H04B 1/10)

|  | H04B 15/02 |
· | Reducing interference from electric apparatus by means located at or near the interfering apparatus (structural association with dynamo-electric machines Fulltext... Hierarchy... Expanded...H02K 11/00)

|  | H04B 15/04 |
· · | the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver, in a tape-recorder (reducing parasitic oscillations Fulltext... Hierarchy... Expanded...H03B, Fulltext... Hierarchy... Expanded...H03F; screening Fulltext... Hierarchy... Expanded...H05K 9/00)

|  | H04B 15/06 |
· · · | by local oscillators of receivers

|  | H04B 17/00 |
Monitoring; Testing [2]

|  | H04B 17/02 |
· | of relay systems [2]