US Patent 9219419 Switched mode power supplies

An example embodiment relates to a switched-mode power supply comprising a transformer with a first winding and a second winding. There is a transmitter configured to: detect a detectable variable (Vout) at the first winding, generate a transformer relayed signal in accordance with the detectable variable (Vout), and provide the transformer relayed signal to the first winding. A receiver is configured to: receive the transformer relayed signal from the second winding, and control a controllable variable at the second winding in response to the transformer relayed signal, wherein the transformer relayed signal is a symbol stream comprising a plurality of symbols.