US 2007/0176808 A1Published application

Switching power source device of multi-output type

AssigneeSanken Electric Co., Ltd.

InventorShohei Osaka

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Abstract

A switching power source device is provided which comprises a reactor 31 connected in a series circuit of a second secondary winding 2c of a transformer 2, a regulatory MOS-FET 18 and a second rectifying smoother 15; and an output controller 19 for controlling the on and off operation of regulatory MOS-FET 18 based on a voltage VO2 applied on a smoothing capacitor 14 of second rectifying smoother 15. Inductance in reactor 31 serves to restrict charging current flowing into smoothing capacitor 14 from second secondary winding 2c so as to clamp voltages induced on first and second secondary windings 2b and 2c of transformer 2 at voltage VO1 on smoothing capacitor 5 in first rectifying smoother 6. This allows first and second diode currents ID1 and ID2 to simultaneously flow respectively through first and second secondary windings 2b, 2c in order to reduce current concentration in either of first and second secondary windings 2b and 2c and reduce power loss incurred in each secondary output circuit.

Claims5

Dependent claims

A switching power source device of multi-output type comprising:

a primary winding of a transformer and a main switching element connected in series to a DC power source;
a first rectifying smoother connected to a first secondary winding of said transformer;
a second rectifying smoother connected to a second secondary winding of said transformer;
a main control circuit for controlling the on and off operation of said main switching element based on said first rectifying smoother;
a regulatory switching element connected between a smoothing capacitor provided in said second rectifying smoother and said second secondary winding;
a reactor connected in a series circuit of said second secondary winding, regulatory switching element and second rectifying smoother;
and
an output controller for controlling the on and off operation of said regulatory switching element based on a voltage applied on said smoothing capacitor of said second rectifying smoother to accumulate electric energy in said transformer during the on period of said main switching element and take out first and second DC outputs respectively from said first and second secondary windings through said first and second rectifying smoothers during the off period of said main switching element.

5 more elements

Dependencies are inferred from the claim text.