|  | 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 88 to 90 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.

|  | H03 |
BASIC ELECTRONIC CIRCUITRY

|  | H03F |
AMPLIFIERS (measuring, testing Fulltext... Hierarchy... Expanded...G01R; optical parametric amplifiers Fulltext... Hierarchy... Expanded...G02F; circuit arrangements with secondary emission tubes Fulltext... Hierarchy... Expanded...H01J 43/30; masers, lasers Fulltext... Hierarchy... Expanded...H01S; control of amplification Fulltext... Hierarchy... Expanded...H03G; coupling arrangements independent of the nature of the amplifier, voltage dividers Fulltext... Hierarchy... Expanded...H03H; amplifiers capable only of dealing with pulses Fulltext... Hierarchy... Expanded...H03K; repeater circuits in transmission lines Fulltext... Hierarchy... Expanded...H04B 3/36, Fulltext... Hierarchy... Expanded...H04B 3/58; application of speech amplifiers in telephonic communication Fulltext... Hierarchy... Expanded...H04M 1/60, Fulltext... Hierarchy... Expanded...H04M 3/40)

|  | H03F |
Note(s) This subclass covers: linear amplification, there being linear relationship between the amplitudes of input and output, and the output having substantially the same waveform as the input; dielectric amplifiers, magnetic amplifiers, and parametric amplifiers when used as oscillators or frequency-changers; constructions of active elements of dielectric amplifiers and parametric amplifiers if no provision exists elsewhere.

|  | H03F |
Subclass index
AMPLIFIERS USING TUBES OR SEMICONDUCTORS; DETAILS | 3/00, 5/00; 1/00
PARAMETRIC AMPLIFIERS | 7/00
MAGNETIC; DIELECTRIC AMPLIFIERS | 9/00; 11/00
AMPLIFIERS USING SPECIAL ELEMENTS |
Mechanical or acoustic; using Hall effect; electroluminescent; superconductive | 13/00; 15/00; 17/00; 19/00
OTHER AMPLIFIERS | 21/00

P:90 |  | H03F 1/00 |
Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements

|  | H03F 1/02 |
· | Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation

|  | H03F 1/04 |
· · | in discharge-tube amplifiers

|  | H03F 1/06 |
· · · | to raise the efficiency of amplifying modulated radio frequency waves; to raise the efficiency of amplifiers acting also as modulators [2]

|  | H03F 1/07 |
· · · · | Doherty-type amplifiers [2]

|  | H03F 1/08 |
· | Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements (wide-band amplifiers with inter-stage coupling networks incorporating these impedances Fulltext... Hierarchy... Expanded...H03F 1/42; eliminating transit-time effects in vacuum tubes Fulltext... Hierarchy... Expanded...H01J 21/34)

|  | H03F 1/10 |
· · | by use of amplifying elements with multiple electrode connections

|  | H03F 1/12 |
· · | by use of attenuating means

|  | H03F 1/13 |
· · · | in discharge-tube amplifiers [2]

|  | H03F 1/14 |
· · | by use of neutralising means

|  | H03F 1/16 |
· · · | in discharge-tube amplifiers

|  | H03F 1/18 |
· · | by use of distributed coupling

|  | H03F 1/20 |
· · · | in discharge-tube amplifiers

|  | H03F 1/22 |
· · | by use of cascode coupling, i.e. earthed cathode or emitter stage followed by earthed grid or base stage respectively

|  | H03F 1/24 |
· · · | in discharge-tube amplifiers

|  | H03F 1/26 |
· | Modifications of amplifiers to reduce influence of noise generated by amplifying elements

|  | H03F 1/28 |
· · | in discharge-tube amplifiers

|  | H03F 1/30 |
· | Modifications of amplifiers to reduce influence of variations of temperature or supply voltage

|  | H03F 1/32 |
· | Modifications of amplifiers to reduce non-linear distortion (by negative feedback Fulltext... Hierarchy... Expanded...H03F 1/34)

|  | H03F 1/33 |
· · | in discharge-tube amplifiers [2]

|  | H03F 1/34 |
· | Negative-feedback-circuit arrangements with or without positive feedback (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H03F 1/02-H03F 1/30, Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H03F 1/38-H03F 1/50, Fulltext... Hierarchy... Expanded...H03F 3/50 take precedence) [3]

|  | H03F 1/36 |
· · | in discharge-tube amplifiers

|  | H03F 1/38 |
· | Positive-feedback circuit arrangements without negative feedback

|  | H03F 1/40 |
· · | in discharge-tube amplifiers

|  | H03F 1/42 |
· | Modifications of amplifiers to extend the bandwidth

|  | H03F 1/44 |
· · | of tuned amplifiers

|  | H03F 1/46 |
· · · | with tubes only

|  | H03F 1/48 |
· · | of aperiodic amplifiers

|  | H03F 1/50 |
· · · | with tubes only

|  | H03F 1/52 |
· | Circuit arrangements for protecting such amplifiers [3]

|  | H03F 1/54 |
· · | with tubes only [3]

|  | H03F 1/56 |
· | Modifications of input or output impedances, not otherwise provided for [3]

P:80 |  | H03F 3/00 |
Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements

|  | H03F 3/02 - H03F 3/189 |
Note(s) Groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H03F 3/20-H03F 3/72 take precedence over groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H03F 3/02-H03F 3/189. [2]

|  | H03F 3/02 |
· | with tubes only (subsequent subgroups take precedence)

|  | H03F 3/04 |
· | with semiconductor devices only (subsequent subgroups take precedence)

|  | H03F 3/06 |
· · | using hole storage effect

|  | H03F 3/08 |
· · | controlled by light

|  | H03F 3/10 |
· · | with diodes

|  | H03F 3/12 |
· · · | with Esaki diodes

|  | H03F 3/14 |
· · | with amplifying devices having more than three electrodes or more than two PN junctions

|  | H03F 3/16 |
· · | with field-effect devices

|  | H03F 3/18 |
· | with semiconductor devices of complementary types (subsequent subgroups take precedence)

|  | H03F 3/181 |
· | Low-frequency amplifiers, e.g. audio preamplifiers [2]

|  | H03F 3/183 |
· · | with semiconductor devices only [2]

|  | H03F 3/185 |
· · · | with field-effect devices (Fulltext... Hierarchy... Expanded...H03F 3/187 takes precedence) [2]

|  | H03F 3/187 |
· · · | in integrated circuits [2]

|  | H03F 3/189 |
· | High-frequency amplifiers, e.g. radio frequency amplifiers [2]

|  | H03F 3/19 |
· · | with semiconductor devices only [2]

|  | H03F 3/191 |
· · · | Tuned amplifiers (Fulltext... Hierarchy... Expanded...H03F 3/193, Fulltext... Hierarchy... Expanded...H03F 3/195 take precedence) [2]

|  | H03F 3/193 |
· · · | with field-effect devices (Fulltext... Hierarchy... Expanded...H03F 3/195 takes precedence) [2]

|  | H03F 3/195 |
· · · | in integrated circuits [2]

|  | H03F 3/20 |
· | Power amplifiers, e.g. Class B amplifiers, Class C amplifiers (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H03F 3/26-H03F 3/30 take precedence)

|  | H03F 3/21 |
· · | with semiconductor devices only [2]

|  | H03F 3/213 |
· · · | in integrated circuits [2]

|  | H03F 3/217 |
· · · | Class D power amplifiers; Switching amplifiers [2]

|  | H03F 3/22 |
· · | with tubes only (Fulltext... Hierarchy... Expanded...H03F 3/24 takes precedence)

|  | H03F 3/24 |
· · | of transmitter output stages

|  | H03F 3/26 |
· | Push-pull amplifiers; Phase-splitters therefor (duplicated single-ended push-pull arrangements or phase-splitters therefor Fulltext... Hierarchy... Expanded...H03F 3/30)

|  | H03F 3/28 |
· · | with tubes only

|  | H03F 3/30 |
· | Single-ended push-pull amplifiers; Phase-splitters therefor

|  | H03F 3/32 |
· · | with tubes only

|  | H03F 3/34 |
· | Dc amplifiers in which all stages are dc-coupled (Fulltext... Hierarchy... Expanded...H03F 3/45 takes precedence) [3]

|  | H03F 3/343 |
· · | with semiconductor devices only [2]

|  | H03F 3/345 |
· · · | with field-effect devices (Fulltext... Hierarchy... Expanded...H03F 3/347 takes precedence) [2]

|  | H03F 3/347 |
· · · | in integrated circuits [2]

|  | H03F 3/36 |
· · | with tubes only

|  | H03F 3/38 |
· | Dc amplifiers with modulator at input and demodulator at output; Modulators or demodulators specially adapted for use in such amplifiers (modulators in general Fulltext... Hierarchy... Expanded...H03C; demodulators in general Fulltext... Hierarchy... Expanded...H03D; amplitude modulation of pulses in general Fulltext... Hierarchy... Expanded...H03K 7/02; amplitude demodulation of pulses in general Fulltext... Hierarchy... Expanded...H03K 9/02)

|  | H03F 3/387 |
· · | with semiconductor devices only [2]

|  | H03F 3/393 |
· · · | with field-effect devices [2]

|  | H03F 3/40 |
· · | with tubes only

|  | H03F 3/42 |
· | Amplifiers with two or more amplifying elements having their dc paths in series with the load, the control electrode of each element being excited by at least part of the input signal, e.g. so-called totem-pole amplifiers

|  | H03F 3/44 |
· · | with tubes only

|  | H03F 3/45 |
· | Differential amplifiers [2]

|  | H03F 3/46 |
· | Reflex amplifiers

|  | H03F 3/48 |
· · | with tubes only

|  | H03F 3/50 |
· | Amplifiers in which input is applied to, or output is derived from, an impedance common to input and output circuits of the amplifying element, e.g. cathode follower

|  | H03F 3/52 |
· · | with tubes only

|  | H03F 3/54 |
· | Amplifiers using transit-time effect in tubes or semiconductor devices (parametric amplifiers Fulltext... Hierarchy... Expanded...H03F 7/00; solid state travelling-wave devices Fulltext... Hierarchy... Expanded...H01L 45/02)

|  | H03F 3/55 |
· · | with semiconductor devices only [2]

|  | H03F 3/56 |
· · | using klystrons

|  | H03F 3/58 |
· · | using travelling-wave tubes

|  | H03F 3/60 |
· | Amplifiers in which coupling networks have distributed constants, e.g. with waveguide resonators (Fulltext... Hierarchy... Expanded...H03F 3/54 takes precedence)

|  | H03F 3/62 |
· | Two-way amplifiers

|  | H03F 3/64 |
· · | with tubes only

|  | H03F 3/66 |
· | Amplifiers simultaneously generating oscillations of one frequency and amplifying signals of another frequency

|  | H03F 3/68 |
· | Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics

|  | H03F 3/70 |
· | Charge amplifiers [2]

|  | H03F 3/72 |
· | Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal [2]

P:70 |  | H03F 5/00 |
Amplifiers with both discharge tubes and semiconductor devices as amplifying elements

P:20 |  | H03F 7/00 |
Parametric amplifiers (devices or arrangements for the parametric generation or amplification of light, infra-red or ultra-violet waves Fulltext... Hierarchy... Expanded...G02F 1/39)

|  | H03F 7/02 |
· | using variable-inductance element; using variable-permeability element

|  | H03F 7/04 |
· | using variable-capacitance element; using variable-permitivity element

|  | H03F 7/06 |
· | with electron beam tube

P:10 |  | H03F 9/00 |
Magnetic amplifiers

|  | H03F 9/02 |
· | current-controlled, i.e. the load current flowing in both directions through a main coil [2]

|  | H03F 9/04 |
· | voltage-controlled, i.e. the load current flowing in only one direction through a main coil, e.g. Logan circuits (Fulltext... Hierarchy... Expanded...H03F 9/06 takes precedence) [2]

|  | H03F 9/06 |
· | Control by voltage time integral, i.e. the load current flowing in only one direction through a main coil, whereby the main coil winding also can be used as a control winding, e.g. Ramey circuits [2]

P:0 |  | H03F 11/00 |
Dielectric amplifiers

P:60 |  | H03F 13/00 |
Amplifiers using amplifying element consisting of two mechanically- or acoustically-coupled transducers, e.g. telephone-microphone amplifier

P:50 |  | H03F 15/00 |
Amplifiers using galvano-magnetic effects not involving mechanical movement, e.g. using Hall effect

P:40 |  | H03F 17/00 |
Amplifiers using electroluminescent element or photocell

P:30 |  | H03F 19/00 |
Amplifiers using superconductivity effects

P:100 |  | H03F 21/00 |
Amplifiers not covered by groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H03F 3/00-H03F 19/00 (dynamo-electric amplifiers Fulltext... Hierarchy... Expanded...H02K)