A power converter constituted of: a control circuitry; an electronically controlled switch responsive to the control circuitry; a power transformer exhibiting a primary winding and a secondary winding; a sense transformer comprising a primary current sense winding, an error current sense winding and a feedback winding, the primary current sense winding of the sense transformer and the primary winding of the power transformer coupled in series with the electronically controlled switch; a transconductance error amplifier coupled to an output of the secondary winding of the power transformer, the transconductance amplifier arranged to drive a current through the error current sense winding of the sense transformer whose value reflects an electrical characteristic of the output of the secondary winding of the power transformer, wherein the feedback winding of the sense transformer is coupled to a feedback input of the control circuitry.