Patent ID: 6896721

Claim:
In an oxygen concentrator having a source of compressed air, at least two sieve beds, at least one valve for alternately connecting each sieve bed to the source of compressed air or to a reduced pressure which is less than the pressure of the source of compressed air, and a controller for controlling the valve, the improvement wherein the controller executes a timing subroutine to automatically actuate the valve during a start-up period immediately following turning on the source of compressed air with a relatively shorter period to alternatively connect each sieve bed to the source of compressed air or to the reduced pressure so as to reduce a pressure build-up in each sieve bed and thereby reduce the start-up load on the source of compressed air during the start-up period, after which the controller automatically actuates the valve with a relatively longer period, which is longer than the relatively shorter period, to alternatively connect each sieve bed to the source of compressed air or to the reduced pressure at a slower rate than during the start-up period so as to alternately build and relieve pressure in each sieve bed during a steady state period of operation of the oxygen concentrator in which oxygen enriched air is produced by the sieve beds.