AU759464B2

AU759464B2 - Line power arrangement for a telephone

Info

Publication number: AU759464B2
Application number: AU21192/99A
Authority: AU
Inventors: Bruce Orr
Original assignee: Alcatel SA; Nokia Inc
Current assignee: Alcatel Lucent SAS
Priority date: 1998-04-20
Filing date: 1999-03-16
Publication date: 2003-04-17
Anticipated expiration: 2019-03-16
Also published as: AU2119299A

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "LINE POWER ARRANGEMENT FOR A TELEPHONE" The following statement is a full description of this invention, including the best method of performing it known to us: 004336314 1 This invention relates to telephone subsets and other communication equipment having calling line identification (CLI) display means, and in particular to a line power arrangement for such equipment.

With the introduction of sophisticated public switching equipment that can provide services such as calling line identification, the on-hook power requirements of telephone subsets and other equipment connected to such public switching equipment has increased to a point where the current required to be bled from the exchange line to provide on-hook power, exceeds the limit, typically 50A, set by Telecom Authorities.

It is known to provide current to telephone subsets for on-hook functions by means of batteries or mains energized power-packs. A disadvantage in using batteries is that they require maintenance by the subscriber; another disadvantage is the environmental problem of disposing of used batteries. In the case of power-packs, a disadvantage is that an AC power outlet is required in the vicinity of the telephone; another disadvantage is the relatively high cost of power packs.

S 15 In accordance with a first aspect of the present invention, there is provided a caller identification arrangement comprising line terminal means for connection to an exchange via an exchange line; a receiver means for receiving caller identification signals; a display means; "a rectification means for rectifying AC ring signals generated at said exchange and applied to said line terminal means; and a switching regulator means coupled to said rectification means, whereby, in use, a controlled voltage is produced at an output of said switching regulator means from an AC ring signal, wherein said rectification means and switching regulator means are arranged, in use, such that sufficient power derived from said AC ring signal is applied to a power input terminal means of said display means for powering said display means while the AC ring signals are present.

25 In a preferred embodiment, said switching regulator means comprises a "buck" S• switching regulator. The arrangement preferably comprises ringer means responsive to the presence of ring signals to generate an alert signal, and control means to inhibit the flow of ring signal current to the ringer means during a first period when ring signals are present, and to enable the flow of ring signal current to the ringer means for the remainder of the duration of the ring signal.

In order that the invention may be readily carried into effect, an embodiment thereof will now be described with reference to the accompanying drawings, in which: A Figure 1 shows a schematic circuit of a converter arrangement incorporated in a Y t one; and Figure 2 shows a modification of the arrangement of Figure 1.

2 Referring to the figure, line connections L1, L2 of the telephone set are connected via a capacitor 1 to rectification means 2. The positive and negative outputs of the rectification means 2 are connected to capacitor 3. The positive output of the rectification means is also connected to switching means 4 and pulse width modulator (PWM) means 7. Switching means 4 is controlled by PWM means 7. The output of switching means 4 is connected to an inductor 6 and a diode means 5. The output of inductor 6 is connected to capacitor 8 and CLI demodulator and display means 9.

Switching means 4, diode means 5, inductor 6 and capacitor 8 form a switching "buck" converter. The PWM 7 samples the output voltage at node 13 and uses this voltage for feedback control of a pulse width control signal outputted at node 14. A controlled voltage for powering of the CLI display means 9 is produced at node 13.

oAt the input of the converter the voltage may be typically 9.0V, and at the S"0 15 output thereof the voltage may be typically 3.3V. This allows approximately three times more current to be delivered to the output compared to that consumed at the input.

CLI display means 9 also has line connections to L1 and L2 for the purpose 0of receiving the modulated VF CLI signal from the line.

000* Resistor 12 provides a bypass path for a small amount of DC current, that may be used for standby power for the PWM and/or CLI display module 9. This resistor would normally be of high ohmic value.

In this embodiment where the CLI display function is combined with a normal telephone function, a telephone interface circuit 10 and alerting (ringer) circuit 11 is added. In this case, capacitor 1 and rectifier means 2 are shared by alerting circuit 11 and the CLI display means.

In an alternative embodiment of the invention not incorporating a normal telephone function, block 10 and 11 are deleted.

In a further alternative embodiment where the CLI display function is combined with a normal telephone set function, the first ring burst may be muted by switching off alerting circuit 11. This makes more of the power contained in the first ring burst available to be stored in capacitor 8 for use by the CLI demodulator and display means 9.

004336314 3 In the embodiment shown in Figure 2, control means 17 associated with ringer 11 senses the onset of ring signal and inhibits current flow into the ringer until after the first burst of ring signal.

It will be appreciated by the person skilled in the art that numerous modifications and/or variations may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.

In the claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication the word "comprising" is used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.

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Claims

1. A caller identification arrangement comprising: line terminal means for connection to an exchange via an exchange line; a receiver means for receiving caller identification signals; a display means; a rectification means for rectifying AC ring signals generated at said exchange and applied to said line terminal means; and a switching regulator means coupled to said rectification means, whereby, in use, a controlled voltage is produced at an output of said switching regulator means from an AC ring signal, wherein said rectification means and switching regulator means are arranged, in use, such that sufficient power derived from said AC ring signal is applied to a power input terminal means of said display means for powering said display means while the AC ring signals are present. S".i 15

2. An arrangement as claimed in claim 1, wherein said switching regulator means comprises a "buck" switching regulator.

3. An arrangement as claimed in claim 1 or claim 2 comprising ringer means responsive to the presence of ring signals to generate an alert signal, and control means to inhibit the flow of ring signal current to the ringer means during a first period when ring signals are present, and to enable the flow of ring signal current to the ringer means for the remainder of the duration of the ring signal. S4. A caller identification arrangement substantially as herein described with reference to the figures of the accompanying drawings. •ee2 .eeo. •gee