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Tuesday, October 25, 2016

Toroid Inductance/Reference Chart ~ by David Smith G4COE


Toroid Inductance Chart
                                                                           David Smith G4COE


To save a little time from calculating and experimenting when winding toroid cores here a chart of the most commonly used cores, simply pick the inductance required and read the required number of turns for the selected core. To keep things easy we’ll stick to three most common cores, T37, T50 and T68 and we’ll use the  -2 and 6 mix, these figures are for single layer windings only, and the windings should cover the entire core evenly.

Turns - Inductance in µH
                

Turns
Red T37-2
Yellow T37-6
Red
 T50-2
Yellow  T50-6
Red T68-2
Yellow   T68-6
1
.004
.003
.005
.004
.006
.005
2
.016
.012
.020
.016
.023
.019
3
.036
.027
.044
.036
.051
.042
4
.064
.048
.078
.064
.091
.075
5
.100
.075
.120
.100
.140
0.12
6
.140
.110
.180
.140
.210
0.17
7
.196
.150
.240
.196
.280
0.23
8
.256
.190
.310
.256
.360
0.30
9
.324
.240
.400
.324
.460
0.38
10
.400
.300
.490
.400
.750
0.47
11
.484
.360
.590
.484
.690
0.57
12
.576
.430
.710
.576
.820
0.68
13
.676
.500
.830
.676
.960
0.79
14
.784
.590
.960
.784
1.10
0.92
15
.900
.680
1.10
.900
1.30
1.10
16
1.02
.770
1.30
1.02
1.50
1.20
17
1.16
.870
1.40
1.16
1.60
1.40
18
1.30
.970
1.60
1.30
1.80
1.50
19
1.40
1.10
1.80
1.40
2.10
1.70
20
1.60
1.20
2.00
1.60
2.30
1.90
21
1.80
1.30
2.20
1.80
2.50
2.10
22
1.90
1.50
2.40
1.90
2.80
2.30
23
2.10
1.60
2.60
2.10
3.00
2.50
24
2.30
1.70
3.10
2.30
3.30
2.70
25
2.50
1.90
3.10
2.50
3.60
3.40
Turns
Red T37-2
Yellow T37-6
Red  T50-2
Yellow  T50-6
Red T68-2
Yellow   T68-6

26
2.70
2.00
3.30
2.70
3.90
3.20
27
2.90
2.20
3.60
2.90
4.20
3.40
28
3.10
2.40
3.80
3.10
4.50
3.70
29
3.40
2.50
4.10
3.40
4.80
4.00
30
3.60
2.70
4.40
3.60
5.10
4.20
31
3.80
2.90
4.70
3.80
5.50
4.50
32
4.10
3.10
5.00
4.10
5.80
4.80
33
4.40
3.30
5.30
4.40
6.20
5.10
34
4.60
3.50
5.70
4.60
6.60
5.40
35


6.00
4.90
7.00
5.80
36


6.40
5.20
7.40
6.10
37


6.70
5.50
7.80
6.40
38


7.10
5.80
8.20
6.80
39


7.50
6.10
8.70
7.10
40


7.80
6.40
9.10
7.50
41


8.20
6.70
9.60
7.90
42


8.60
7.10
10.0
8.30
43


9.10
7.40
11.0
8.70
44


9.50
7.70
11.0
9.10
45


9.90
7.90
12.0
9.50
46


10.0
8.50
12.0
9.90
47


11.0
8.80
13.0
10.0
48


11.0
9.20
13.0
11.0
49


12.0
9.60
14.0
11.0
50


12.0
10.0
14.0
12.0


For those interested in equations (√ L uH / AL value) x 100 will give us the turns required. To find the inductance of a pre-wound core, L uH  =  (turns/100)2  x AL value  of the core.  
 
This list could be expanded to cover many cores and greater winding ranges but would probably many pages of Sprat, this being pointless because many would not be used generally and any inductances greater than the range given above could be calculated with the above formula.   

Title:      Toroid Inductance Chart.                                                                          

Author:  David Smith G4COE
Page 1 of 2

GQRP Club
Datasheet


Inductance in µH - Turns
                

µH
Red
T37-2
Yellow T37-6
Red
 T50-2
Yellow 
T50-6
Red
T68-2
Yellow   T68-6
1
16
18
14
15
13
15
2
22
26
20
21
19
21
3
27
31
25
25
23
25
4
32
36
28
29
26
29
5
35
41
32
33
30
33
6
39
45
35
36
32
36
7
42
48
38
39
35
39
8
45
52
40
42
37
41
9
47
55
43
44
40
44
10
50
58
45
47
42
46
11
52
60
47
49
44
48
12
55
63
49
51
46
51
13
57
66
51
53
48
53
14
59
68
53
55
50
55
15
61
71
55
57
51
56
16
63
73
57
59
53
58
17
65
75
59
61
55
60
18
67
77
61
62
56
62
19
69
79
62
64
58
64
20
71
81
64
66
59
65
21


65
67
61
67
22


67
69
62
68
23


68
71
64
70
24


70
72
65
71
25


71
74
66
73

µH
Red T37-2
Yellow T37-6
Red  T50-2
Yellow  T50-6
Red T68-2
Yellow   T68-6
26


73
75
68
74
27


74
77
69
76
28


76
78
70
77
29


77
79
71
79
30


78
80
73
80
31


79
82
74
81
32


80
83
75
83
33


82
85
76
84
34


83
86
77
85
35


84
87
78
86
36


86
88
79
88
37


87
89
80
89
38


88
91
82
90
39


89
92
83
91
40


90
93
84
92
41


91
94
85
93
42


92
96
86
95
43


94
97
87
96
44


95
98
88
97
45


96
99
89
98
46


97
100
90
99
47


98
101
91
100
48


99
102
92
101
49


100
103
93
102
50


101
104
94
103


Title:      Toroid Inductance Chart.                                                                          

Author:  David Smith G4COE
Page 2 of 2

GQRP Club
Datasheet



Special thanks to G4COE David Smith and the GQRP Club for creating such a complete reference for us to use! I nore my page had anything to do with this reference other than converting it into a text format to make it searchable instead of just a PDF download.  IF you copy and paste it into a text file it should retain the correct format for your use.

The actual site can be found here www.gqrp.com/toroid_inductance_chart.pdf