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.
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".
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.
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
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]
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 3/06
· · ·
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]
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]
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
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]