|  | G |
SECTION G — PHYSICS

INSTRUMENTS

|  | G05 |
CONTROLLING; REGULATING (specially adapted to a particular field of use, see the relevant sub-class, e.g. Fulltext... Hierarchy... Expanded...B23Q)

|  | G05 |
Note(s) Attention is drawn to the notes (particularly the definition of the term "variable") on page 1 of this elaboration. This class covers methods, systems, and apparatus for controlling in general. In this class, the following terms 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; the term "automatic control" is often used in the art as a synonym for "regulation". "Proportional band" means that range of values of deviation which corresponds to the full operating range of output signal of the controlling unit resulting from proportional action only.

|  | G05B |
CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (fluid-pressure actuators or systems acting by means of fluids in general Fulltext... Hierarchy... Expanded...F15B; valves in general Fulltext... Hierarchy... Expanded...F16K; characterised by mechanical features only Fulltext... Hierarchy... Expanded...G05G; sensitive elements, see the appropriate sub-classes, e.g. Fulltext... Hierarchy... Expanded...G12B, sub-classes of Fulltext... Hierarchy... Expanded...G01, Fulltext... Hierarchy... Expanded...H01; correcting units, see the appropriate sub-classes, e.g. Fulltext... Hierarchy... Expanded...H02K)

|  | G05B |
Note(s) Applications of control systems or elements for regulating specific variables are covered by sub-classes Fulltext... Hierarchy... Expanded...G05D, Fulltext... Hierarchy... Expanded...G05F, and not by this sub-class. However, features of such systems or elements which are clearly more generally applicable are classified in this sub-class. In this sub-class: The term "automatic controller" means a system, circuit, or device in which a signal from the detecting element is compared with a signal representing the desired value and which operates in such a way as to reduce the deviation. The automatic controller generally does not include the sensitive element, i.e. that element which measures the value of the condition to be corrected, or the correcting element, i.e. that element which adjusts the condition to be corrected. The term "electric" is intended to include "electromechanical", "electrohydraulic", and "electropneumatic". Details of specific control systems are classified in the group relevant to the system, if not otherwise provided for.

|  | G05D |
SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES (valves in general Fulltext... Hierarchy... Expanded...F16K; sensing non-electric variables, see the relevant sub-classes of Fulltext... Hierarchy... Expanded...G01; for regulating electric or magnetic variables Fulltext... Hierarchy... Expanded...G05F)

|  | G05D |
Note(s) This sub-class comprises only (a) systems for regulation of non-electric variables and (b) systems for control of non-electric variables and involving comparison between the actual and desired values of the variables to be controlled. The term "systems" in this sub-class includes self-contained devices such as speed governors, pressure regulators. Features of general applicability to regulating systems, e.g. anti-hunting arrangements, are classified in sub-class Fulltext... Hierarchy... Expanded...G05B. Control systems designed specifically for particular apparatus, machines, or processes are normally classified in the sub-classes for the apparatus, machines, or processes.

|  | 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 current supply in networks Fulltext... Hierarchy... Expanded...H02J; regulating the charging of batteries Fulltext... Hierarchy... Expanded...H02J 7/00; regulating motor current Fulltext... Hierarchy... Expanded...H02N, Fulltext... Hierarchy... Expanded...H02P; 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; regulating operating characteristics of X-ray tubes Fulltext... Hierarchy... Expanded...H05G 1/28)

|  | G05F |
Note(s) This sub-class includes the use of hydraulic, pneumatic, mechanical, and electrical motors for varying electric characteristics of devices which restore the quantity regulated. This sub-class is restricted to systems, the elements per se being in the relevant sub-classes. The regulation of the output of generators, converters, or transformers is dealt with in Fulltext... Hierarchy... Expanded...H02N, Fulltext... Hierarchy... Expanded...H02P, Fulltext... Hierarchy... Expanded...H03B, Fulltext... Hierarchy... Expanded...H03K.

|  | G05G |
CONTROL DEVICES OR SYSTEMS INSOFAR AS CHARACTERISED BY MECHANICAL FEATURES ONLY ("Bowden" or like mechanisms Fulltext... Hierarchy... Expanded...F16C 1/10; gearings or mechanisms not peculiar to this purpose Fulltext... Hierarchy... Expanded...F16H; systems peculiar to the control of particular machines or apparatus classified in a single other class, see the class for such machines or apparatus)

|  | G05G |
Note(s) This sub-class covers members of general applicability for mechanical control, and mechanical systems for moving members to one or more definite settings.