EP0452286A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Arrangement for reduced power supply to a subscriber line
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1991-02-11
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Granted: —
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Expires: 2011-02-11
Abstract
Abstract An arrangement for feeding the subscriber's lines (10) of a public exchange with reduced line current upon the occurrence of a power failure, when the temperature within the public exchange or the temperature of individual components, mounted on circuit boards on which line interface circuits are present, exceeds a predetermined reference value, when the length of a subscriber's line is less than a line length reference value, or when the conversation time on a subscriber's line exceeds a conversation time reference value. All subscriber's lines or individual subscriber's lines only are fed with the reduced line current for a restricted time (Figure 5B).
Inventors
- 👤 Juho Arras
- 👤 Mats Carlos Sixtensson Ohlstedt
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 13:38
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/001; Y; Y02; Y02D; Y02D30/00; Y02D30/70
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
444 words
An arrangement for reducing the line current (I AB ) delivered by a line circuit (10) of a telephone exchange to a subscriber line (12, 13), said line circuit (10) including - a line voltage measuring circuit (14-17) which functions to measure the line voltage of the subscriber line and to produce a corresponding line voltage signal, - a current control circuit (11) which has a plurality of line current/line voltage characteristics (21) stored therein and which has a first input for the line voltage signal, a second input for a selection signal for selection of a predetermined characteristic from among the stored characteristics, and an output for producing a control signal whose value corresponds to the line current prescribed by the selected characteristic and the prevailing line voltage, and - current supply means (24-28) having an input and output, said input being connected to the output of the control circuit in order to receive the control signal and the outputs of which are connected to the subscriber line for supplying to said line a line current which corresponds to the current prescribed by the control signal, said arrangement further including - a main control unit (3) which is connected to the line circuits via a bus line (30, 48) common to said circuits and which sends said selection signal to said other input of the control circuits of said line circuits, characterized by - at least one sensor (17, 37, 42, 57) for detecting an operation parameter and for sending a corresponding operation parameter signal (T AMB , N, L, t, T j , mains status) to the main control unit, - a processor included in the main control unit (3) and comprising: a) at least one memory region (50, 51, 54, 59, 58, 63, 64) for storing at least one reference value (T⁺ AMB , T⁻ AMB , N o , L o , T⁺ j , t o , T j , mains current is present) for the operation parameter, b) a program memory means (46) for comparing the operation parameter signal with the reference value for the purpose of producing a first selection signal over that time period when the operation parameter exceeds/ is below the reference value, depending on the nature of the operation parameter, and for producing a second selection signal when the operation parameter is below/ exceeds the reference value, wherein the first selection signal results in the selection of a characteristic (22) which corresponds to supplying the subscriber line with reduced power, and wherein the second selection signal results in the selection of a characteristic (21) which corresponds to supplying the subscriber lines with normal power.
Claim 2
Dependent Claim
70 words
An arrangement according to Claim 1, characterized in that the sensor is chosen from the group comprising temperature sensors, sensors for detecting the number of active line circuits on a line board, sensors for detecting the length of a subscriber line, sensors for detecting the length of a call or conversation, sensors for detecting a failure in the conventional power supply to the telephone exchange, and combinations of these sensors.
Claim 3
Dependent Claim
54 words
An arrangement according to Claim 2, wherein the line circuits (10) are mounted on line boards (2) which, in turn, are packed in close relationship in a telephone exchange module (1), which, in turn, is mounted in a cabinet, characterized in that the sensor is a first temperature sensor (42) mounted in said cabinet.
Claim 4
Dependent Claim
40 words
An arrangement according to Claim 3, characterized in that the program memory means (46) is intended to produce said second selection signal when the temperature falls beneath the reference temperature value to a predetermined extent (T⁺ AMB -T⁻ AMB ).
Claim 5
Dependent Claim
120 words
An arrangement according to Claim 4, characterized by a first additional sensor (37, 47) for detecting the number (N) of active line circuits on a line board, a first additional memory region (64) for storing a reference value (N o ) for the number of active line circuits on a line board, wherein the program memory means is intended to deliver the first selection signal to the active circuits on solely that line board on which the number of active line circuits exceeds the reference value (N o ) for the number of active line circuits when the reference temperature value (T⁺ AMB ) and the reference value (N o ) for the number of active line circuits are exceeded.
Claim 6
Dependent Claim
138 words
An arrangement according to Claim 5, characterized by a second additional sensor (17) for detecting the length (L) of a subscriber line, a second additional memory region (54) for storing a line length reference value (L o ), wherein the program memory means (46) is intended to deliver the first selection signal to those active line circuits whose lengths (L) are shorter than the line length reference value (L o ) on those line boards on which the number (N) of active line circuits exceeds the reference value (N o ) of the number of active line circuits when the reference temperature value (T⁺ AMB ) and the reference value (N o ) of the number of active line circuits are exceeded and the detected subscriber line length is shorter than the reference line-length value (L o ).
Claim 7
Dependent Claim
140 words
An arrangement according to Claim 5 or 6, characterized by an additional third sensor (37, 46) for detecting the length (t) of a call on an active line circuit on a line board, a third additional memory region (63) for storing a reference value (t o ) for the call length or duration, wherein the program memory means is intended to send the first selection signal to the active line circuits on a line board with which the call length (t) exceeds the line length reference value (t o ) when the reference temperature value (T⁺ AMB ) and the reference value (N o ) of the number of active line circuits is exceeded and, when the arrangement is dependent on Claim 6, when the length of the subscriber line is shorter than the reference line-length value (L o ).
Claim 8
Dependent Claim
71 words
An arrangement according to Claim 2, characterized by a second temperature sensor (57) for sensing the temperature (T j ) of an individual component, a fourth additional memory region (55) for storing a second temperature reference value (T⁺ j ), wherein the program memory means is intended to deliver the first signal to the line circuit when its temperature (T j ) exceeds the second temperature reference value (T⁺ j ).
Claim 9
Dependent Claim
83 words
An arrangement according to any one of the preceding Claims, characterized by a main sensor for sensing the occurrence of a failure in mains power to the conventional power supply and for sending the first selection signal to all line circuits; an additional memory region (53) for storing a status signal representing normal power supply and power failure, wherein the program memory means is intended to send the first selection signal to all line circuits when the status signal indicates a power failure.
Claim 10
Dependent Claim
61 words
An arrangement according to Claim 3 or Claim 8, characterized in that the temperature sensor is an oscillator (40) having a network of components which determine oscillator frequency, in that the network includes a temperature responsive element (42) arranged adjacent the line circuit; and in that the temperature reference value is a temperature value (T⁺ AMB ) related to oscillator frequency.
Claim 11
Dependent Claim
69 words
An arrangement according to Claim 9, characterized in that the sensor for detecting the number of active line circuits on a line board is a circuit (37) for monitoring the loop current in the subscriber line, and a circuit (46) for determining when the number (N) of subscriber lines on one and the same line board exceeds the reference value (N o ) for the number of active lines.
Claim 12
Dependent Claim
73 words
An arrangement according to Claim 6, characterized in that the sensor for detecting the length of a subscriber line includes the line voltage measuring circuit (14-17) which produces a value of the voltage across the two wires (12, 13) of the subscriber line, a value of the resistance of the subscriber line pre-stored in the program memory (46), and a line length (L) calculated in the program memory by means of Ohms law.
Claim 13
Dependent Claim
128 words
An arrangement according to Claim 7, in which each line circuit includes a monitoring circuit (37) for continuously monitoring the line current in the subscriber line, characterized in that the sensor for monitoring call length (t) includes said monitoring circuit (37), which produces an output signal having a first and a second logic level, said output signal having said first logic level being produced during the duration of said call or, alternatively, when an attempt is made to connect a call, and which produces the output signal having said second logic level when a subscriber replaces the receiver, and a time measuring circuit for measuring the time over which the monitoring signal has the first logic level and for delivering a corresponding signal to the main control unit.
References Cited (Backward Citations)
US4254305A
Cited
GB2064915A
Cited
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