Patent ID: 6469491
Filing Date: 2002-10-22
Classification: H02M

Abstract:
For use with a first transformer having a primary winding for receiving a switched input voltage and a secondary winding outputting a secondary winding output, an apparatus for sensing current of the secondary winding output, comprising:a second transformer having first and second windings, the first winding operatively coupled with the primary winding of the first transformer; a resistance in circuit with the second winding of the second transformer; at least two switching devices, each of the switching devices having a first input in circuit with the resistance and a control input for receiving a switching control signal; a control circuit in circuit with the control inputs of each of the at least two switching devices to alternately switch the switching devices between on and off states according to a predetermined switching sequence; and an averaging circuit in circuit with the at least two switching devices, the averaging circuit being configured to average a voltage across the resistance.