A switched mode power converter is configured having predominate secondary side control. A primary side driving circuit is configured as a responsive state machine the output of which is input as the driving signal for a main switch. An output voltage, current or power is sensed and the secondary side controller compares the sensed output characteristic with a predefined reference. The comparison results in an error that signifies an amount that the output is out of regulation. The secondary side controller drives a secondary side switch to generate a voltage pulse across the secondary winding. The voltage pulse has a pulse width that represents the amount of error in the output characteristic. The voltage pulse is transmitted across the transformer and received by the primary side driving circuit, which generates a driving signal modulated according to the voltage pulse and drives the main switch to regulate the output characteristic.