G
SECTION G — PHYSICS
 G

Note(s)

  1. In this section, the following term is used with the meaning indicated:
    • "variable" (as a noun) means a feature or property (e.g., a dimension, a physical condition such as temperature, a quality such as density or colour) which, in respect of a particular entity (e.g., an object, a quantity of a substance, a beam of light) and at a particular instant, is capable of being measured; the variable may change, so that its numerical expression may assume different values at different times, in different conditions or in individual cases, but may be constant in respect of a particular entity in certain conditions or for practical purposes (e.g., the length of a bar may be regarded as constant for many purposes).
  2. Attention is drawn to the definitions of terms or expressions used, appearing in the notes of several of the classes in this section, in particular those of "measuring" in class G01 and "control" and "regulation" in class G05.
  3. Classification in this section may present more difficulty than in other sections, because the distinction between different fields of use rests to a considerable extent on differences in the intention of the user rather than on any constructional differences or differences in the manner of use, and because the subjects dealt with are often in effect systems or combinations, which have features or parts in common, rather than "things", which are readily distinguishable as a whole. For example, information (e.g., a set of figures) may be displayed for the purpose of education or advertising (G09), for enabling the result of a measurement to be known (G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (G08). The words used to describe the purpose depend on features that may be irrelevant to the form of the apparatus concerned, for example, such features as the desired effect on the person who sees the display, or whether the display is controlled from a remote point. Again, a device which responds to some change in a condition, e.g., in the pressure of a fluid, may be used, without modification of the device itself, to give information about the pressure (G01L) or about some other condition linked to the pressure (another subclass of class G01, e.g., G01K for temperature), to make a record of the pressure or of its occurrence (G07C), to give an alarm (G08B), or to control another apparatus (G05).

    The classification scheme is intended to enable things of a similar nature (as indicated above) to be classified together. It is therefore particularly necessary for the real nature of any technical subject to be decided before it can be properly classified.

  
INSTRUMENTS
 G05
CONTROLLING; REGULATING
 G05

Note(s)

  1. This class covers methods, systems, and apparatus for controlling, in general.
  2. In this class, the following terms or expressions are used with the meanings indicated:
    • "controlling" means influencing a variable in any way, e.g. changing its direction or its value (including changing it to or from zero), maintaining it constant, limiting its range of variation;
    • "regulation" means maintaining a variable automatically at a desired value or within a desired range of values. The desired value or range may be fixed, or manually varied, or may vary with time according to a predetermined "programme" or according to variation of another variable. Regulation is a form of control;
    • "automatic control" is often used in the art as a synonym for "regulation".
  3. Attention is drawn to the Notes following the title of section G, especially as regards the definition of the term "variable".
 G05F
SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES (regulating the timing or recurrence frequency of pulses in radar or radio navigation systems G01S; regulation of current or voltage, specially adapted for use in electronic time-pieces G04G 19/00; closed-loop systems for regulating non-electric variables by electric means G05D; regulating power supply of digital computers G06F 1/26; for obtaining desired operating characteristics of electromagnets with armatures H01F 7/08; regulating electric power distribution networks H02J; regulating the charging of batteries H02J 7/00; regulating of the output of static converters, e.g. switching regulators, H02M; regulation of the output of electric generators H02N, H02P 9/00; controlling transformers, reactors or choke coils H02P 13/00; regulating frequency response, gain, maximum output, amplitude or bandwidth of amplifiers H03G; regulating tuning of resonant circuits H03J; controlling generators of electronic oscillations or pulses H03L; regulating characteristics of transmission lines H04B; controlling electric light sources H05B 37/02, H05B 39/00, H05B 41/36; electric control of X-ray apparatus H05G 1/00)  [4,5]
 G05F

Note(s)

  1. This subclass covers:
    • systems only;
    • use of hydraulic, pneumatic, mechanical, and electrical motors for varying electric characteristics of devices which restore the quantity regulated;
    • the combination of static converters and current or voltage regulators, if the essential characteristic resides in the combination.  [4]
  2. This subclass does not cover elements per se, which are covered by the relevant subclasses.
P:20 G05F 1/00
Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
 G05F 1/02
·  Regulating electric characteristics of arcs (arrangements for feeding or moving of electrodes for spot or seam welding or cutting B23K 9/12; arrangements for feeding electrodes for electric heating or electric lighting H05B 7/00, H05B 31/00; automatic control of power for heating by discharge H05B 7/00)  [2]
 G05F 1/10
·  Regulating voltage or current (G05F 1/02 takes precedence; for electric railways B60M 3/00)
 G05F 1/66
·  Regulating electric power
 G05F 1/70
·  Regulating power factor; Regulating reactive current or power  [3]
P:30 G05F 3/00
Non-retroactive systems for regulating electric variables by using an uncontrolled element, or an uncontrolled combination of elements, such element or such combination having self-regulating properties
 G05F 3/02
·  Regulating voltage or current
 G05F 3/04
·  ·  wherein the variable is ac
 G05F 3/08
·  ·  wherein the variable is dc
P:10 G05F 5/00
Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output
P:0 G05F 7/00
Regulating magnetic variables (details of apparatus for measuring magnetic variables involving magnetic resonance G01R 33/28)  [5]