|  | G |
SECTION G — PHYSICS

|  | G |
Note(s) 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). 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 Fulltext... Hierarchy... Expanded...G01 and "control" and "regulation" in class Fulltext... Hierarchy... Expanded...G05. 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 (Fulltext... Hierarchy... Expanded...G09), for enabling the result of a measurement to be known (Fulltext... Hierarchy... Expanded...G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...G01L) or about some other condition linked to the pressure (another subclass of class Fulltext... Hierarchy... Expanded...G01, e.g., Fulltext... Hierarchy... Expanded...G01K for temperature), to make a record of the pressure or of its occurrence (Fulltext... Hierarchy... Expanded...G07C), to give an alarm (Fulltext... Hierarchy... Expanded...G08B), or to control another apparatus (Fulltext... Hierarchy... Expanded...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 (specially adapted to a particular field of use, see the relevant place for that field, e.g. Fulltext... Hierarchy... Expanded...A62C 37/00, Fulltext... Hierarchy... Expanded...B03B 13/00, Fulltext... Hierarchy... Expanded...B23Q)

|  | G05 |
Note(s) This class covers methods, systems, and apparatus for controlling, in general. 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". 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 Fulltext... Hierarchy... Expanded...G01S; closed-loop systems for regulating non-electric variables by electric means Fulltext... Hierarchy... Expanded...G05D; regulating power supply of digital computers Fulltext... Hierarchy... Expanded...G06F 1/26; regulating electric power distribution networks Fulltext... Hierarchy... Expanded...H02J; regulating the charging of batteries Fulltext... Hierarchy... Expanded...H02J 7/00; regulating of the output of static converters, e.g. switching regulators, Fulltext... Hierarchy... Expanded...H02M; regulation of the output of electric generators Fulltext... Hierarchy... Expanded...H02N, Fulltext... Hierarchy... Expanded...H02P 9/00, Fulltext... Hierarchy... Expanded...H03L; controlling transformers, reactors or choke coils Fulltext... Hierarchy... Expanded...H02P 13/00; regulating frequency response, gain, maximum output, amplitude or bandwidth of amplifiers Fulltext... Hierarchy... Expanded...H03G; regulating tuning of resonant circuits Fulltext... Hierarchy... Expanded...H03J; regulating characteristics of transmission lines Fulltext... Hierarchy... Expanded...H04B; electric control of X-ray apparatus Fulltext... Hierarchy... Expanded...H05G 1/30) [4,5]

|  | G05F |
Note(s) 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] This subclass does not cover elements per se, which are covered by the relevant subclasses.

|  | 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 Fulltext... Hierarchy... Expanded...B23K 9/12; arrangements for feeding electrodes for electric heating or electric lighting Fulltext... Hierarchy... Expanded...H05B 7/109, Fulltext... Hierarchy... Expanded...H05B 31/18; automatic control of power for heating by discharge Fulltext... Hierarchy... Expanded...H05B 7/148) [2]

|  | G05F 1/04 |
· · | by means of saturable magnetic devices

|  | G05F 1/06 |
· · | by means of discharge tubes

|  | G05F 1/08 |
· · | by means of semiconductor devices

|  | G05F 1/10 |
· | Regulating voltage or current (Fulltext... Hierarchy... Expanded...G05F 1/02 takes precedence; for electric railways Fulltext... Hierarchy... Expanded...B60M 3/02)

|  | G05F 1/12 |
· · | wherein the variable is actually regulated by the final control device is ac (Fulltext... Hierarchy... Expanded...G05F 1/625 takes precedence) [4]

|  | G05F 1/13 |
· · · | using ferroresonant transformers as final control devices [4]

|  | G05F 1/14 |
· · · | using tap transformers or tap changing inductors as final control devices [4]

|  | G05F 1/147 |
· · · · | with motor driven tap switch [4]

|  | G05F 1/153 |
· · · · · | controlled by discharge tubes or semiconductor devices [4]

|  | G05F 1/16 |
· · · · | combined with discharge tubes or semiconductor devices

|  | G05F 1/20 |
· · · · · | semiconductor devices only

|  | G05F 1/22 |
· · · · | combined with separate magnetic control devices having a controllable degree of saturation

|  | G05F 1/24 |
· · · | using bucking or boosting transformers as final control devices

|  | G05F 1/247 |
· · · · | with motor in control circuit [4]

|  | G05F 1/253 |
· · · · | the transformers including plural windings in series between source and load (Fulltext... Hierarchy... Expanded...G05F 1/247 takes precedence) [4]

|  | G05F 1/26 |
· · · · | combined with discharge tubes or semiconductor devices

|  | G05F 1/30 |
· · · · · | semiconductor devices only

|  | G05F 1/32 |
· · · | using magnetic devices having a controllable degree of saturation as final control devices

|  | G05F 1/325 |
· · · · | with specific core structure, e.g. gap, aperture, slot, permanent magnet [4]

|  | G05F 1/33 |
· · · · | with plural windings through which current to be controlled is conducted [4]

|  | G05F 1/335 |
· · · · · | on different cores [4]

|  | G05F 1/34 |
· · · · | combined with discharge tubes or semiconductor devices

|  | G05F 1/38 |
· · · · · | semiconductor devices only

|  | G05F 1/40 |
· · · | using discharge tubes or semiconductor devices as final control devices

|  | G05F 1/42 |
· · · · | discharge tubes only

|  | G05F 1/44 |
· · · · | semiconductor devices only

|  | G05F 1/445 |
· · · · · | being transistors in series with the load [3]

|  | G05F 1/45 |
· · · · · | being controlled rectifiers in series with the load [3]

|  | G05F 1/455 |
· · · · · · | with phase control [3]

|  | G05F 1/46 |
· · | wherein the variable actually regulated by the final control device is dc (Fulltext... Hierarchy... Expanded...G05F 1/625 takes precedence) [4]

|  | G05F 1/52 |
· · · | using discharge tubes in series with the load as final control devices

|  | G05F 1/54 |
· · · · | additionally controlled by the unregulated supply

|  | G05F 1/56 |
· · · | using semiconductor devices in series with the load as final control devices

|  | G05F 1/563 |
· · · · | including two stages of regulation, at least one of which is output level responsive, e.g. coarse and fine regulation [4]

|  | G05F 1/565 |
· · · · | sensing a condition of the system or its load in addition to means responsive to deviations in the output of the system, e.g. current, voltage, power factor (Fulltext... Hierarchy... Expanded...G05F 1/563 takes precedence) [4]

|  | G05F 1/567 |
· · · · · | for temperature compensation [4]

|  | G05F 1/569 |
· · · · · | for protection [4]

|  | G05F 1/571 |
· · · · · · | with overvoltage detector [4]

|  | G05F 1/573 |
· · · · · · | with overcurrent detector [4]

|  | G05F 1/575 |
· · · · | characterised by the feedback circuit [4]

|  | G05F 1/577 |
· · · · | for plural loads [4]

|  | G05F 1/585 |
· · · · · | providing voltages of opposite polarities [4]

|  | G05F 1/59 |
· · · · | including plural semiconductor devices as final control devices for a single load [4]

|  | G05F 1/595 |
· · · · · | semiconductor devices connected in series [4]

|  | G05F 1/607 |
· · · | using discharge tubes in parallel with the load as final control devices [3]

|  | G05F 1/61 |
· · · · | including two stages of regulation, at least one of which is output level responsive [4]

|  | G05F 1/613 |
· · · | using semiconductor devices in parallel with the load as final control devices [3]

|  | G05F 1/614 |
· · · · | including two stages of regulation, at least one of which is output level responsive [4]

|  | G05F 1/618 |
· · · | using semiconductor devices in series and in parallel with the load as final control devices [4]

|  | G05F 1/62 |
· · · | using bucking or boosting dc sources

|  | G05F 1/625 |
· · | wherein it is irrelevant whether the variable actually regulated is ac or dc [4]

|  | G05F 1/63 |
· · · | using variable impedances in series with the load as final control devices [4]

|  | G05F 1/635 |
· · · · | being Hall effect devices, magnetoresistors or thermistors [4]

|  | G05F 1/644 |
· · · · | being pressure-sensitive resistors [4]

|  | G05F 1/648 |
· · · · | being plural resistors among which a selection is made [4]

|  | G05F 1/652 |
· · · | using variable impedances in parallel with the load as final control devices [4]

|  | G05F 1/656 |
· · · | using variable impedances in series and in parallel with the load as final control devices [4]

|  | G05F 1/66 |
· | Regulating electric power

|  | G05F 1/67 |
· · | to the maximum power available from a generator, e.g. from solar cell [4]

|  | G05F 1/70 |
· | Regulating power factor; Regulating reactive current or power [3]

|  | 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 3/06 |
· · · | using combinations of saturated and unsaturated inductive devices, e g. combined with resonant circuit

|  | G05F 3/08 |
· · | wherein the variable is dc

|  | G05F 3/10 |
· · · | using uncontrolled devices with non-linear characteristics [4]

|  | G05F 3/12 |
· · · · | being glow discharge tubes

|  | G05F 3/16 |
· · · · | being semiconductor devices [3]

|  | G05F 3/18 |
· · · · · | using Zener diodes [3]

|  | G05F 3/20 |
· · · · · | using diode-transistor combinations (Fulltext... Hierarchy... Expanded...G05F 3/18 takes precedence) [3]

|  | G05F 3/22 |
· · · · · · | wherein the transistors are of the bipolar type only (Fulltext... Hierarchy... Expanded...G05F 3/26, Fulltext... Hierarchy... Expanded...G05F 3/30 take precedence) [4]

|  | G05F 3/24 |
· · · · · · | wherein the transistors are of the field-effect type only (Fulltext... Hierarchy... Expanded...G05F 3/26, Fulltext... Hierarchy... Expanded...G05F 3/30 take precedence) [4]

|  | G05F 3/26 |
· · · · · · | Current mirrors [4]

|  | G05F 3/28 |
· · · · · · · | combined with a non-linear current amplifier [4]

|  | G05F 3/30 |
· · · · · · | Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities (Fulltext... Hierarchy... Expanded...G05F 3/26 takes precedence) [4]

|  | 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

|  | G05F 5/02 |
· | Phase controlled switching using electronic tubes or three or more terminal semiconductive devices [4]

|  | G05F 5/04 |
· | using a transformer or inductor as the final control device [4]

|  | G05F 5/06 |
· · | saturable [4]

|  | G05F 5/08 |
· | using a linearly acting final control device [4]

|  | G05F 7/00 |
Regulating magnetic variables (details of apparatus for measuring magnetic variables involving magnetic resonance Fulltext... Hierarchy... Expanded...G01R 33/28) [5]