Patent ID: 8760894
Filing Date: 2014-06-24
Classification: H02M

Abstract:
1. A power converter comprising: a control circuitry; an electronically controlled switch responsive to an output of said control circuitry; a power transformer exhibiting a primary winding and a secondary winding magnetically coupled to the primary winding of the power transformer, said power transformer arranged such that when said electronically controlled switch is closed a current flows through said primary winding, the amount of primary winding current changing over time; a sense transformer comprising a primary current sense winding, an error current sense winding and a feedback winding, each of the primary current sense winding and the error current sense winding of said sense transformer magnetically coupled to the feedback winding of said sense transformer, the primary current sense winding of said sense transformer and the primary winding of said power transformer coupled in series with said electronically controlled switch and with a source of electrical power; and a transconductance error amplifier coupled to an output of the secondary winding of said power transformer, said transconductance amplifier arranged to drive an error current through the error current sense winding of said sense transformer, wherein the amount of the error current reflects a difference between an electrical characteristic of the output of the secondary winding of said power transformer and a reference value, wherein the feedback winding of said sense transformer is coupled to a feedback input of the control circuitry, said feedback winding arranged to provide the feedback input of the control circuitry with a combined signal reflective of both the amount of current flowing through the primary current sense winding and the amount of the error current.