Power supply arrangement for applying direct current to subscriber circuits

• US 4,560,835 A
• Filed: 07/11/1983
• Issued: 12/24/1985
• Est. Priority Date: 07/12/1982
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Bourgonje, Wouter
• Primary Examiner(s): Dwyer, James L.
• Application Number:
  US06/512,501
• Time in Patent Office: 897 Days
• Field of Search: 179/70, 179/77, 179/34, 179/35, 179/36, 179/40, 179/17 R, 179/18 J, 179/18 HB, 179/16 AA, 178/66.1, 307/41, 307/32, 323/267
• US Class Current: 379/324
• CPC Class Codes: H04M 19/008 Using DC/DC converters DC/DC converters per se H02M3/28

Abstract

A power supply for supplying pulsed direct current from a central power source to a plurality of subscriber circuits in a telephone system. The variation of the terminal voltage of the central power supply due to the pulsating load is reduced by shifting the phases of the current pulses supplied to the various subscriber circuits so they are produced in different time intervals relative to each other.

Claims

1. A power supply arrangement for supplying direct current to a plurality N (N=2, 3, 4 . . . ) of subscriber circuits in a telephone system, comprising:

a controllable pulse generating arrangement comprising N controllable pulse sources for connecting the respective subscriber circuits to a central source of direct current;

a control arrangement connected to each of said pulse sources for applying control signals thereto which cause them to supply pulses of current from said central source to the respective subscriber circuits, the duration of the current pulses produced by each of said pulse sources being controlled by the control signals applied thereto;

and a plurality of smoothing circuits connected between the respective subscriber circuits and said pulse sources for converting the current pulses produced thereby into smoothed direct current;

said control arrangement comprising a phase control circuit for producing relative phase differences between the start of each the control signals applied to respective ones of said pulse sources, whereby relative phase differences are produced between the start of each current pulse produced by said pulse sources.

2. A power supply arrangement as claimed in claim 1, characterized in that the phase control circuit produces a phase difference of 2π

/N radians between the start of each current pulse produced by successive pulse sources in response to successive control signals.

3. A power supply arrangement as claimed in claim 1, characterized in that the control signals applied to said pulse sources have the same relative phase and frequency relationships as the current pulses produced in response thereto.

4. A power supply arrangement as claimed in claim 3, characterized in that the phase control arrangement comprises a first cyclic counter which is controlled by a central clock, and start signal circuits connected to this counter for producing control pulse starting signals under the control of the counting states occurring in the counter.

5. A power supply arrangement as claimed in claim 4, characterized in that control arrangement further comprises:

a second cyclic counter arranged in cascade with the first cyclic counter between it and the central clock,

pulse duration registers provided in a one-to-one relationship with the pulse sources,

comparison circuits provided in a one-to-one relationship with the pulse sources for comparing the content of the associated pulse duration register with the content of the cyclic counters, and

logic circuits provided in a one-to-one relationship with the comparison circuits for supplying the individual control pulse signals, an input of the respective logic circuits being connected to respective ones of the start signal circuits and a further input of the respective logic circuits being connected to the associated comparison circuit.