Magnetic structure assembly
There is illustrated the assembly of a dual inductor ( 1 ) on to a printed circuit board ( 2 ). A printed circuit board ( 2 ) has a through hole ( 3 ). Then the first winding ( 5 ), formed from a stamping, is mounted across the hole ( 3 ). Then, the first winding ( 5 ) is connected to the first face ( 7 ) of the PCB ( 2 ). Then, a core assembly ( 10 ) is inserted into the hole ( 3 ) from the direction of a second face ( 8 ) of the PCB ( 2 ). Then, at some stage, for example as shown, the second winding ( 6 ) is inserted into the core assembly ( 10 ) and affixed to the bottom face ( 8 ) of the PCB ( 2 ).
1. A dual inductor ( 1 ) comprising:
a core assembly ( 10 ) formed from a central plate ( 11 ) and a set of three parallel spaced-apart legs, namely an inner leg ( 12 ) and outer legs ( 13 ) on opposed faces ( 14 ) of the central plate ( 11 ) forming first and second cores ( 15 , 16 ); and
a first and second winding ( 5 , 6 and 25 , 26 ) on the inner leg ( 12 ) of each of the first and second cores ( 15 , 16 ), in which at least one of the windings ( 25 , 26 ) extends outside one of the outer legs ( 13 ) to provide additional inductance.
2. A dual inductor ( 1 ) as claimed in claim 1 , in which the input and output of each set of windings ( 5 , 6 and 25 , 26 ) are in close proximity.
3. A dual inductor ( 1 ) as claimed in claim 1 , comprising:
a separate inductive element ( 30 ) in close proximity to the windings ( 25 , 26 ); and
a capacitive element ( 47 ) connected to the inductive element ( 30 ), the output of the capacitive element ( 47 ) providing a ripple current cancelling signal.
4. A dual inductor ( 1 ) as claimed in claim 3 , in which the inductive element ( 30 ) is a length of insulated copper wire ( 31 ) close to the first and second windings ( 25 , 26 ).
5. A dual inductor ( 1 ) as claimed in claim 1 , in which at least one of the windings ( 5 , 6 and 25 , 26 ) is formed from a metal stamping.
6. A dual inductor ( 1 ) as claimed in claim 5 , in which the metal stamping ( 25 , 26 ) is recessed to receive a PCB section forming an inductive element ( 30 ).
7. A dual inductor ( 1 ) as claimed in claim 1 , in which each winding ( 5 , 6 and 25 , 26 ) is formed by a PCB section.
8. A dual inductor ( 1 ) as claimed in claim 7 , in which an inductive element ( 30 ) is formed by the PCB section.
9. A power converter ( 40 ) comprising the dual inductor ( 1 ) as claimed in claim 1 .
10. A PCB ( 2 ) comprising the dual inductor ( 1 ) as claimed in claim 1 .
11. A current doubler comprising the dual inductor ( 1 ) as claimed in claim 1 .