DC-To-DC converter with secondary flyback core reset

Claim 1

In a single ended DC-to-DC forward converter of the type having a transformer and switched primary causing a magnetic flux excursion of a core of the transformer, and further comprising multiple single ended secondary outputs n (where n=1, 2, 3- - - nth), and wherein each said output has at least one diode as an output forward rectifier, said diodes having values of parasitic capacitance Csh 1 , Csh 2 , - - - Csh n that determine a total effective parasitic reset capacitance Cr that forms a transformer secondary flyback parasitic reset means including a resonant circuit of a secondary magnetizing inductance and said total effective parasitic reset capacitance Cr for resetting magnetic flux of the transformer core, where Csh 1 =the parasitic capacitance of the output forward rectifier diode of secondary output n=1, Csh 2 =the parasitic capacitance of the output forward rectifier diode of secondary output n=2, - - - and Csh n =the parasitic capacitance of the output forward rectifier diode of secondary output n, and further having additional parasitic capacitance factors of Cd of a primary diode clamp circuit, Cm of a primary switch, Cp of the primary winding, Cs 1 of a first secondary winding and Csn of an nth secondary winding wherein the total effective parasitic capacitance Cr is determined by the formula: Cr=(Cd+Cm+Cp)*(Np/Ns.sub.1).sup.2 +(Cs.sub.1 +Csh.sub.1)+(Cs.sub.2 +Csh.sub.2)*(Ns.sub.2 /Ns.sub.1).sup.2 + . . . +(Cs.sub.n +Csh.sub.n)*(Ns.sub.n /Ns.sub.1).sup.2 where Cd=the parasitic capacitance of the primary diode clamp circuit, Np=the number of secondary winding turns in secondary n=1, Ns 2 =the number of secondary winding turns in secondary n=2, and Ns n =the number of secondary winding turns in secondary n, Cm=the parasitic capacitance of the primary switch, and Cp=the parasitic capacitance of the primary winding.