System for synchronizing and phase shifting switching regulators

• US 4,034,232 A
• Filed: 06/01/1976
• Issued: 07/05/1977
• Est. Priority Date: 06/01/1976
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Burroughs Incorporated (Terreno Realty Corp.)
• Inventors: LaVenture, Orville W.
• Primary Examiner(s): Goldberg, Gerald
• Application Number:
  US05/691,867
• Time in Patent Office: 399 Days
• Field of Search: 321/2, 323/17, 323/23, 323/25, 307/11, 307/12, 307/31, 307/32, 307/33, 307/38, 307/39, 307/40, 307/41, 307/82
• US Class Current: 307/32
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 1/12 Arrangements for reducing harmonics from ac input or output
• CPC Class Codes: H02M 3/3378 in a push-pull configuration of the parallel type H02M3/3374 takes precedence

Abstract

A regulated power supply system, for a sensitive computer environment, having a plurality of switching regulators to provide highly regulated D.C. voltage to individual loads connected to each of the regulators. A centralized oscillator is used to supply the clock signal to the control circuit of each of the different switching regulators. Thus, any radio frequency interference problems will be associated with only one fundamental frequency and its related harmonics. A modified ring counter is used to stagger the turn-on point of each individual regulator so that the power demands on the source of power are not suddenly severe and instantaneous, which might generate transients disruptive of computer operations. Further, the modified ring counter is used to synchronize the frequency of each regulator to a common clock, in addition to its controlling the phase shifting of each regulator for a staggered turn-on.

Claims

1. A power supply system for supplying a plurality of constant D.C. voltages to a plurality of loads comprising:

(a) means for supplying an unregulated D.C. voltage across a first pair of lines;

(b) a plurality of switching regulators connected across said first pair of lines, each of said switching regulators providing a separate regulated voltage across a second pair of lines to a separate load;

(c) control means for operating said plurality of switching regulators at a common frequency while maintaining phase separation of power demand in each of said plurality of regulators wherein said control means includes;

(c-1) a plurality of individual gating means, at least one for each regulator, to determine the frequency of the switching cycle of that said switching regulator;

(c-2) enabling means for said gating means, said enabling means including;

common clocking means;

analog/digital conversion means for each regulator for providing digital signals having a duration inversely proportional to the deviation of the regulated output voltage of that regulator from its desired value;

(c-3) phasing signal means generated from said common clocking means for enabling each of said gating means at preselected moments in time.

2. The power supply system of claim 1 wherein said control means includes:

first means to enable the on-phase of each switching cycle of each switching regulator so that the on-phase of any one switching regulator will not overlap the on-phase of any other regulator.

3. The power supply system of claim 2 wherein each of said plurality of switching regulators include:

at least one transistor to operate in an on-off switching cycle;

isolation means to provide D.C. isolation of said first pair of lines from the plurality of each second pair of lines;

and wherein said control means includes a second means in each switching regulator to control the duration of the "on-time" of the said transistor in said each switching regulator.

4. In a regulated power supply system for supplying a plurality of separate unregulated D.C. voltages to a plurality of loads, the combination comprising:

(a) means for converting A.C. voltage to an unregulated D.C. voltage;

(b) a plurality of switching regulator means for controlling said unregulated D.C. voltage to provide a plurality of constant D.C. outputs for delivery to a plurality of loads;

(c) control means for determining a common frequency of switching for said plurality of switching regulator means and for determining the switch-on duration time of each cycle of each of said switching regulator means, said control means having individual subcontrol means responsive to the output voltage delivered to each of said loads in order to control the said switch-on duration time for each switching cycle of each of said switching regulators, wherein said control means includes;

common clock generation means;

phased signal generation means derived from said common clock means for generating a plurality of signals which are set to have a predetermined phase relationship, said plurality of signals being used to clock said plurality of switching regulator means;

and wherein said control means provides a subcontrol means for each switching regulator which subcontrol means includes;

(c-1) an operational amplifier;

(c-2) an integrator;

(c-3) a signal proportional to the output voltage of the individual switching regulator at its load;

(c-4) a reference voltage;

(c-5) a plurality of gates;

said operational amplifier receiving signals from said integrator and said proportional output voltage,

said integrator being clocked by a preselected phase signal from said phased signal generation means,

said gates being controlled by combined signals from said operational amplifier and from said preselected phase signals of said phased signal generation means.