US 4,734,844 A · Master/slave current sharing, PWM power supply

Abstract

Each power supply of a number of power supplies equally shares the current load supplied by the respective parallel voltage outputs of the supplies. Each power supply is identical to the others and each has the capability to operate as a stand-alone power supply, a master of a master/slave combination, or a slave of a master/slave combination. The determining factor of whether a unit is a master or a slave of a master/slave(s) combination is a single two conductor cable which has the master connection at one end and the slave connector(s) at the remaining end(s). Whichever of the otherwise identical units that the master connection is connected to will be the master unit and whichever of the units are connected to the slave connection(s) will be the slave unit(s). Thus a simple, inexpensive, interchangeable master or slave capability is provided with units which are controlled by the master to equally share the current load.

Claims7

Dependent claims

An apparatus for causing a plurality of switching power supplies of the PWM type to share a current output load by synchronizing the PWM switching control signals thereof, comprising:

a first switching power supply having a PWM control circuit;
at least one additional switching power supply having a PWM control circuit substantially identical to said first switching power supply;
output interconnecting means for paralleling an output of said first power switching supply with a corresponding output of each additional switching power supply;
means connecting said first switching power supply to each additional switching power supply for synchronizing each PWM control circuit in each additional switching power supply to said PWM control circuit of said first switching power supply;
and
means for reproducing at an output of each additional switching power supply PWM control circuit, a control signal substantially identical to an external output of said first switching power supply PWM control circuit;
whereby each of the plurality of switching power supplies supplies a substantially equal share of the output current load.

4 more elements

A master/slave switching power supply combination comprising:

a first switching power supply;
a second switching power supply substantially identical to said first switching power supply;
a first PWM control circuit having an output and an output signal controlling a current output of said first switching power supply;
a second PWM control circuit having an output and an output signal controlling a current output of said second switching power supply;
a first external input connected to said first PWM control circuit;
a second external input connected to said second PWM control circuit;
a power output of said first switching power supply connected electrically in parallel with a corresponding power output of said second switching power supply;
and
a two-wire cable connecting the PWM control circuit output of one of said switching power supplies to the PWM control current external input of the other switching power supply forming a master/slave switching power supply which shares the current load supplied by said paralleled outputs.

6 more elements

Dependencies are inferred from the claim text.

Master/slave current sharing, PWM power supply

Life of this patent

Master/slave current sharing, PWM power supply

Life of this patent

Abstract

Claims7