Abstract: A DC-DC power converter having a power transformer primary winding and a secondary winding producing a regulated output using a control technique and circuit to control the magnetic flux reset time of the core of the power transformer. The control circuit for the power converter provides control of the on and off time of the power transformer by controlling the magnetic flux reset voltage produced on the secondary winding, thereby controlling the duty cycle of the power transformer, and thereby regulating the output of the power transformer. Because control of the power transformer is accomplished by controlling the secondary winding reset voltage, input-to-output isolation and improved converter stability is provided. Minor variations to the input section of the DC-DC converter allows for a wide range of input voltages. Minor variations to the control circuit configuration provide the capability for short-circuit protection and inrush current limitation.