Abstract: In a switched mode power supply wherein an integrated circuit (IC) controller monitors and regulates power supply operation, a self-adjusting circuit compensates for variations in controller operation and ensures stable power supply operation. The output voltage of the power supply's transformer is compared to a reference voltage in generating an error signal which is fed back to the controller IC for regulating its operation. The self-adjusting circuit is impedance-matched with and provides an extremely high DC control gain to the controller IC's control input pin so as to simulate a manual adjustment arrangement, the need for which is eliminated by the automatic, self-adjusting circuit which maintains the AC impedance defined to ensure stable operation of the switched mode system.