Transcript Document

Design Example: Inductor
Design Specs
L=100 mH
IDC = 5 A
DI = 0.75 A p-p
Bmax = 0.25 T = 0.25 x 10-6 wb/mm2
Jmax = 6.0A/mm2
fs = 100kHz
kw = 0.5
4
ˆ
10
 5.375 5.005


LII rms
4
4
Ap 


3590mm

0.359cm
kw Bmax J max  0.5  0.25x10-6   6.0 
Catalog Link
Acore 
 F2
4

H2
4


11.3
4
2
 5.52   97.44 mm 2
Ae  93.9 mm2
C F 
2
AW   2 D  

5.5
18.0

11.3

36.85
mm




 2 
Ap 3900
Aw 

 41.5 mm2
Ae
93.9
Ap  Acore AW  97.4436.85  3950 mm4
LIˆ
5.375 x 104
N

 22 Turns
6
Bmax Acore  0.25x 10   97.44 
Acond 
I rms 5.0

 0.83 mm2
J max 6.0
N m0 Acore
lg 

L
2
This would be 18 gauge wire, which is
pretty stiff. The author suggests 5 strands
of 25 gauge (0.162 mm2)
 22  4 x 1010  97.44
2
10
4
 0.59 mm
Design Example: Transformer
Design Specs
v1 = v2 = v3 = 30 v
IRMS = 2.5 A
Bmax = 0.25 T = 0.25 x 10-6 wb/mm2
Jmax = 5.0A/mm2
fs = 100kHz
kw = 0.5
kc = 0.5
Ap 
kc Vy I rms , y
y
kw f s Bmax J max
 1800 mm4  0.18 cm4
Acore 
 F2
4

H2
 63.9 mm 2
4
CF 
2
AW   2 D  

29.2
mm

 2 




kc
0.5
  10 Turns
N1  N2  N3  V 
  30 
-6
5
  63.9   0.25 x 10 10  
 Acore Bmax f s 
Acond 
I rms 2.5

 0.5 mm2
J max 5.0
This would be 20 gauge wire. The author
suggests 3 strands of 25 gauge (0.162 mm2)
Design Example: Transformer
Design Specs
Primary : 28 v, Secondary A: 5 v @ 6 A, Secondary B: 12 v @ 2.75 A
Primary current: Ip = 6(5/28)+2.75(12/28) = 2.25A
Bmax = 0.25 T = 0.25 x 10-6 wb/mm2
Jmax = 6.0A/mm2
fs = 50kHz
kw = 0.6
kc = 0.5
Ap 
kc  Vy I rms , y
y
kw f s Bmax J max
E Core:

0.5  28  2.25    5  6   12  2.75  
 0.6   5 x 104  0.25 x 106   6 
 1400 mm 4  0.14 cm 4
Acore  Ae  45.5 mm
2
AW 
Ap

Ae
1500
 33 mm2
45.5




kc
0.5
  280.88  25 Turns
N p  Vp 
  28 
-6
4
  45.5  0.25 x 10 5 x10  
 Acore Bmax f s 
N A  4.4  5 Turns
N B  10.5  11 Turns
Wire Cross Section:
Acond
Check Fill Factor with actual turns
and Wire sizes:
I
 rms
J max
2.25
Apri 
 0.375 mm 2 21 Gauge
6.0
17 Gauge
AA  1.0 mm 2
AB  0.458 mm 2
20 Gauge
kw 
 25.410    51.04   11 0.518
 0.64
33