Parallel
Inductors |
|
|
|
Series
Inductors |
Ls
= L1 + L2 + ··· + Ln |
|
|
Straight
Wire |
Look
up wire diameter here.
|
|
W
= 1/2 Li2
XL = 2
p
f L
L
= inductance (H)
N = number of turns
a = inner radius
b = outer radius
x = length
v = voltage (V)
W = energy (J)
|
Coaxial
Cable |
|
|
Closely
Wound Toroid |
|
|
Single-Layer
Air Coil
|
L
(mH)
=
|
d2
* n2
18d
+ 40L |
Where: |
d
and L are in inches
n = number of turns |
Note: |
If
lead lengths are significant,
use the straight wire
calculation to add that
inductance. |
|
|
|
|
INDUCTANCE
CONVERSIONS
|
Standard
unit = Henry (H)
|
|
|
abhenry
|
henry
|
microhenry
|
millihenry
|
stathenry
|
1
abH =
|
1
|
10-9
|
0.001
|
10-6
|
1.113
* 10-21
|
1
H =
|
109
|
1
|
106
|
1000
|
1.113
* 10-12
|
1
µH =
|
1000
|
10-6
|
1
|
0.001
|
1.113
* 10-18
|
1
mH =
|
106
|
0.001
|
1000
|
1
|
1.113
* 10-15
|
1
statH =
|
8.987
* 1020 |
8.987
* 1011 |
8.987
* 1017 |
8.987
* 1014 |
1 |
|
|
|
TOROIDS
- POWDERED
IRON
|
Use the table
below to calculate inductance and number of turns per the
following formulas.
|
where:
|
L
= inductance in mH
AL = mH
per 100 turns
N = number of full turns |
|
AL
Values |
|
Mix
Type |
Size |
26 |
3 |
15 |
1 |
2 |
7 |
6 |
10 |
12 |
17 |
0 |
T-12 |
n/a |
60 |
50 |
48 |
20 |
18 |
17 |
12 |
7.5 |
7.5 |
3.0 |
T-16 |
145 |
61 |
55 |
44 |
22 |
n/a |
19 |
13 |
8.0 |
8.0 |
3.0 |
T-20 |
180 |
76 |
55 |
52 |
27 |
24 |
22 |
16 |
10 |
10 |
3.5 |
T-25 |
235 |
100 |
85 |
70 |
34 |
29 |
27 |
19 |
12 |
12 |
4.5 |
T-30 |
325 |
140 |
93 |
85 |
43 |
37 |
36 |
25 |
16 |
16 |
6.0 |
T-37 |
275 |
120 |
90 |
80 |
40 |
32 |
30 |
25 |
15 |
15 |
4.9 |
T-44 |
360 |
180 |
160 |
105 |
52 |
46 |
42 |
33 |
18.5 |
18.5 |
6.5 |
T-50 |
320 |
175 |
135 |
100 |
49 |
43 |
40 |
31 |
18 |
18 |
6.4 |
T-68 |
420 |
195 |
180 |
115 |
57 |
52 |
47 |
32 |
21 |
21 |
7.5 |
T-80 |
450 |
180 |
170 |
115 |
55 |
50 |
45 |
32 |
22 |
22 |
8.5 |
T-94 |
590 |
248 |
200 |
160 |
84 |
n/a |
70 |
58 |
32 |
n/a |
10.6 |
T-106 |
900 |
450 |
345 |
325 |
135 |
133 |
116 |
n/a |
n/a |
n/a |
19 |
T-130 |
785 |
3350 |
250 |
200 |
110 |
103 |
96 |
n/a |
n/a |
n/a |
15 |
T-157 |
870 |
420 |
360 |
320 |
140 |
n/a |
115 |
n/a |
n/a |
n/a |
n/a |
T-184 |
1640 |
720 |
n/a |
500 |
240 |
n/a |
195 |
n/a |
n/a |
n/a |
n/a |
T-200 |
895 |
425 |
n/a |
250 |
120 |
105 |
100 |
n/a |
n/a |
n/a |
n/a |
|
|
|
Iron
Powder Magnetic Core Properties |
Mix |
Color |
Material |
m |
Temp
Stability
(ppm/°C) |
f
(MHz) |
Uses |
26 |
Yellow/White |
Hydrogen
Reduced |
75 |
825 |
DC
-1 |
EMI
filters, DC chokes |
3 |
Gray |
Carbonyl
HP |
35 |
370 |
0.05
- 0.50 |
Exc.
stability, good Q at low freq. |
15 |
Red/White |
Carbonyl
GS6 |
25 |
190 |
0.10
- 2 |
Exc.
stability, good Q |
1 |
Blue |
Carbonyl
C |
20 |
280 |
0.50
- 5 |
Exc.
stability, good Q at low freq. |
2 |
Red |
Carbonyl
E |
10 |
95 |
2
-30 |
High
Q |
7 |
White |
Carbonyl
TH |
9 |
30 |
3
- 35 |
Similar
to mix 2 and mix 6, exc. temp stability |
6 |
Yellow |
Carbonyl
SF |
8 |
35 |
10
-50 |
Very
good Q and temp. stability for 20-50 MHz |
10 |
Black |
Powdered
Iron W |
6 |
150 |
30
- 100 |
Good
Q and stability for 40-100 MHz |
12 |
Green/White |
Synthetic
Oxide |
4 |
170 |
50
- 200 |
Good
Q, moderate temp. stability |
17 |
Blue/Yellow |
Carbonyl |
4 |
50 |
40
- 180 |
Similar
to mix 12, better temp. stability, Q drops about
10% above 50 MHz, 20% above 100 MHz |
0 |
Tan |
Phenolic |
1 |
0 |
100
- 300 |
L
varies greatly with winding technique |
|
|
Iron
Powder Magnetic Core Dimensions |
Size |
Color |
Dimensions
(in) |
O.D. |
I.D. |
Height |
T-200-2 |
Red |
2.00 |
1.25 |
0.55 |
T-94-2 |
Red |
0.94 |
0.56 |
0.31 |
T-80-2 |
Red |
0.80 |
0.50 |
0.25 |
T-68-2 |
Red |
0.68 |
0.37 |
0.19 |
T-50-2 |
Red |
0.50 |
0.30 |
0.19 |
T-37-2 |
Red |
0.37 |
0.21 |
0.12 |
T-25-2 |
Red |
0.25 |
0.12 |
0.09 |
T-12-2 |
Red |
0.125 |
0.06 |
0.05 |
T-50-10 |
Black |
0.50 |
0.30 |
0.19 |
T-37-10 |
Black |
0.37 |
0.21 |
0.12 |
T-25-10 |
Black |
0.25 |
0.12 |
0.09 |
T-12-10 |
Black |
0.125 |
0.06 |
0.05 |
T-94-9 |
Yellow |
0.94 |
0.56 |
0.31 |
T-80-6 |
Yellow |
0.80 |
0.50 |
0.25 |
T-68-6 |
Yellow |
0.68 |
0.37 |
0.19 |
T-50-6 |
Yellow |
0.50 |
0.30 |
0.19 |
T-26-6 |
Yellow |
0.25 |
0.12 |
0.09 |
T-12-6 |
Yellow |
0.125 |
0.06 |
0.05 |
|
|
|
|