|  | H |
SECTION H — ELECTRICITY

|  | H04 |
ELECTRIC COMMUNICATION TECHNIQUE

|  | H04Q |
SELECTING (switches, relays, selectors Fulltext... Hierarchy... Expanded...H01H; electronic switches Fulltext... Hierarchy... Expanded...H03K 17/00)

|  | H04Q |
Note(s) This sub-class deals with methods, circuits, or apparatus for establishing selectively a connection between a desired number of stations (normally two), or between a main station and a desired number of substations (normally one) for the purpose of transferring information via this connection after it has been established. The sub-class also deals with selective calling arrangements over connections already established. In either case, the connection may be by means of electric conductors or electromagnetic waves. In this sub-class: "Subscriber" is a general term for terminal equipment, e.g. telephone for public use. "Substation" means a subscriber or monitoring equipment which may connect a single subscriber to a line without choice as to subscriber. A "satellite" is a kind of exchange the operation of which depends upon control signals received from a supervisory exchange. "Switching centres" include exchanges and satellites.

|  | H04Q 1/00 |
Details of selecting apparatus or arrangements (details of selector switches Fulltext... Hierarchy... Expanded...H01H 63/00)

|  | H04Q 1/02 |
· | Constructional details

|  | H04Q 1/04 |
· · | Frames or mounting racks for selector switches; Accessories therefor, e.g. frame cover

|  | H04Q 1/06 |
· · | Cable ducts or mountings specially adapted for exchange installations (in general Fulltext... Hierarchy... Expanded...H02G)

|  | H04Q 1/08 |
· · | Frames or mounting racks for relays; Accessories therefor

|  | H04Q 1/10 |
· · | Exchange station construction

|  | H04Q 1/12 |
· · | Arrangements of multiple bars with or without pivotable frames

|  | H04Q 1/14 |
· · | Distribution frames

|  | H04Q 1/16 |
· · | Wiring arrangements for selector switches or relays in frames

|  | H04Q 1/18 |
· | Electrical details

|  | H04Q 1/20 |
· · | Testing circuits or apparatus; Circuits or apparatus for detecting, indicating, or signalling faults or troubles

|  | H04Q 1/22 |
· · · | Automatic arrangements

|  | H04Q 1/24 |
· · · · | for connection devices

|  | H04Q 1/26 |
· · · · | for signalling trouble in unoccupied sub-exchanges

|  | H04Q 1/28 |
· · | Current-supply circuits or arrangements for selection equipment at exchanges

|  | H04Q 1/30 |
· · | Signalling arrangements; Manipulation of signalling currents (multiplex systems providing for calling or supervisory signals Fulltext... Hierarchy... Expanded...H04J 1/14, Fulltext... Hierarchy... Expanded...H04J 3/12; telephone substation equipment Fulltext... Hierarchy... Expanded...H04M 1/00)

|  | H04Q 1/32 |
· · · | using trains of dc pulses (Fulltext... Hierarchy... Expanded...H04Q 1/39 takes precedence)

|  | H04Q 1/34 |
· · · · | Impulse regenerators with mechanical or other non-electrical marking arrangements

|  | H04Q 1/36 |
· · · · | Pulse-correcting arrangements, e.g. for reducing effects due to interference

|  | H04Q 1/38 |
· · · | using combinations of direct currents of different amplitudes or polarities over line conductors or combination of line conductors

|  | H04Q 1/39 |
· · · | using coded pulse groups [3]

|  | H04Q 1/40 |
· · · | whereby duration of pulse or interval between two pulses is variable

|  | H04Q 1/42 |
· · · · | involving the position of a pulse in a cycle

|  | H04Q 1/44 |
· · · | using ac (Fulltext... Hierarchy... Expanded...H04Q 1/50 takes precedence)

|  | H04Q 1/442 |
· · · · | with out-of-voice band signalling frequencies [3]

|  | H04Q 1/444 |
· · · · | with voice-band signalling frequencies [3]

|  | H04Q 1/446 |
· · · · · | using one signalling frequency (Fulltext... Hierarchy... Expanded...H04Q 1/46 take precedence) [3]

|  | H04Q 1/448 |
· · · · · · | with conversion of a single frequency signal into a digital signal) [3]

|  | H04Q 1/45 |
· · · · · | using multi-frequency signalling (Fulltext... Hierarchy... Expanded...H04Q 1/46 takes precedence)

|  | H04Q 1/453 |
· · · · · · | in which m-out-of-n signalling frequencies are transmitted [3]

|  | H04Q 1/457 |
· · · · · · | with conversion of multifrequency signals into digital signals [3]

|  | H04Q 1/46 |
· · · · · | comprising means for distinguishing between a signalling current of predetermined frequency and a complex current containing that frequency, e.g. speech current

|  | H04Q 1/48 |
· · · | Induced-current signalling arrangements

|  | H04Q 1/50 |
· · · | Conversion between different kinds of signals

|  | H04Q 1/52 |
( covered by Fulltext... Hierarchy... Expanded...H04Q 3/52 )

|  | H04Q 1/54 |
· · | Amplifier switched-on automatically in dependence on automatically selected lines

|  | H04Q 1/56 |
· · | Balancing circuitry switched-on automatically in dependence on automatically selected lines

|  | H04Q 3/00 |
Selecting arrangements (Fulltext... Hierarchy... Expanded...H04Q 5/00, Fulltext... Hierarchy... Expanded...H04Q 7/00, Fulltext... Hierarchy... Expanded...H04Q 9/00, Fulltext... Hierarchy... Expanded...H04Q 11/00 take precedence)

|  | H04Q 3/02 |
· | Circuit arrangements for selectors responsive to a permutation code

|  | H04Q 3/04 |
· | Circuit arrangements for receivers of routing digits

|  | H04Q 3/06 |
· · | for group or trunk group selectors

|  | H04Q 3/08 |
· · | for local or long-distance selectors

|  | H04Q 3/10 |
· · | for PBX selectors, i.e. private branche exchange selectors

|  | H04Q 3/12 |
· · | for line selectors providing transfer of routing digits

|  | H04Q 3/14 |
· · | for two-way operation selectors

|  | H04Q 3/16 |
· · | for marking-switches

|  | H04Q 3/18 |
· | Circuit arrangements for first stage of hunting switching

|  | H04Q 3/20 |
· · | for preselectors

|  | H04Q 3/22 |
· · · | comprising common calling and disconnecting circuit

|  | H04Q 3/24 |
· · | for line finders

|  | H04Q 3/26 |
· · · | comprising common calling and disconnecting circuit

|  | H04Q 3/28 |
· · · | comprising main groups and sub-groups

|  | H04Q 3/30 |
· · | Selector finders, i.e. allotters

|  | H04Q 3/32 |
· | Circuit arrangements for second or subsequent stages of hunting switching [2]

|  | H04Q 3/34 |
· · | for the second preselection stage

|  | H04Q 3/36 |
· · | for the second line-finder stage

|  | H04Q 3/38 |
· · | for stages after the group-selector stage

|  | H04Q 3/40 |
· · | for stages after the line selector, e.g. for extension selector

|  | H04Q 3/42 |
· | Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller marker

|  | H04Q 3/44 |
· · | using revertive control

|  | H04Q 3/46 |
· · | using signals other than revertive impulses

|  | H04Q 3/47 |
· · | using translators

|  | H04Q 3/48 |
· · | using markers

|  | H04Q 3/49 |
· · · | for end-to-end marking

|  | H04Q 3/495 |
· · · | for routing connecting paths

|  | H04Q 3/52 |
· · | using static devices in switching stages, e.g. electronic switching arrangements [2]

|  | H04Q 3/54 |
· · | in which the logic circuitry controlling the exchange is centralised, e.g. using a stored programme

|  | H04Q 3/56 |
· · | in which the control signals are multiplexed [2]

|  | H04Q 3/58 |
· | Arrangements providing connection between main exchange and sub-exchange or satellite

|  | H04Q 3/60 |
· · | for connecting to satellites or concentrators which connect one or more exchange lines with a group of local lines

|  | H04Q 3/62 |
· · | for connecting to private branch exchanges

|  | H04Q 3/64 |
· | Distributing or queueing

|  | H04Q 3/66 |
· · | Traffic distributors

|  | H04Q 3/68 |
· · | Grouping or interlacing selector groups or stages

|  | H04Q 3/70 |
· | Identification of class of calling subscriber

|  | H04Q 3/72 |
· | Finding out and indicating number of calling subscriber

|  | H04Q 3/74 |
· · | Identification of subscriber calling from a party-line

|  | H04Q 5/00 |
Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange

|  | H04Q 5/02 |
· | with direct connection for all subscribers, i.e. party-line system (Fulltext... Hierarchy... Expanded...H04Q 5/24 takes precedence)

|  | H04Q 5/04 |
· · | Signalling by currents in one or other or both line wires or additional wires

|  | H04Q 5/06 |
· · | Signalling by amplitude or polarity of dc

|  | H04Q 5/08 |
· · | Signalling by continuous ac

|  | H04Q 5/10 |
· · · | using single frequencies for different subscribers

|  | H04Q 5/12 |
· · · | using combinations of frequencies

|  | H04Q 5/14 |
· · | Signalling by pulses

|  | H04Q 5/16 |
· · · | by predetermined number of pulses

|  | H04Q 5/18 |
· | with indirect connection, i.e. through subordinate switching centre

|  | H04Q 5/20 |
· · | the subordinate centre permitting interconnection of subscribers connected thereto

|  | H04Q 5/22 |
· · | the subordinate centre not permitting interconnection of subscribers connected thereto

|  | H04Q 5/24 |
· | for two-party-line systems

|  | H04Q 7/00 |
Selecting arrangements to which subscribers are connected via radio links or inductive links

|  | H04Q 7/02 |
· | for subscribers using radio or inductive link only

|  | H04Q 7/04 |
· | with possibility of connection to and from line exchanges

|  | H04Q 9/00 |
Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

|  | H04Q 9/02 |
· | Automatically-operated arrangements

|  | H04Q 9/04 |
· | Arrangements for synchronous operation

|  | H04Q 9/06 |
· | Calling by using amplitude or polarity of dc

|  | H04Q 9/08 |
· | Calling by using continuous ac

|  | H04Q 9/10 |
· · | using single different frequencies

|  | H04Q 9/12 |
· · | using combinations of frequencies

|  | H04Q 9/14 |
· | Calling by using pulses

|  | H04Q 9/16 |
· · | by predetermined number of pulses

|  | H04Q 11/00 |
Selecting arrangements for multiplex systems (multiplex systems Fulltext... Hierarchy... Expanded...H04J)

|  | H04Q 11/02 |
· | for frequency-division multiplexing

|  | H04Q 11/04 |
· | for time-division multiplexing