CONTROL CIRCUIT FOR A SWITCHING DC-DC POWER CONVERTER INCLUDING A CONTROLLED MAGNETIC CORE FLUX RESETTING TECHNIQUE FOR OUTPUT REGULATION

摘要

A DC-DC power converter (10) having a power transformer primary winding (16a) and a secondary winding (16b) producing a regulated output using a control technique and circuit (30) to control the magnetic flux reset time of the core of the power transformer (16). The control circuit (30) for the power converter provides control of the on and off time of the power transformer (16) by controlling the magnetic flux reset voltage produced on the secondary winding (16b), thereby controlling the duty cycle of the power transformer (16), and thereby regulating the output of the power transformer (16). Because control of the power transformer (16) 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 (12) of the DC-DC converter (10) allows for a wide range of input voltages. Minor variations to the control circuit (30) configuration provide the capability for short-circuit protection and inrush current limitation.