Ferrite and Iron Toroid Information

Iron powder: turns = 100 ((desired L/AL) 0.5) (where L in uH)
Ferrite: turns = 1000 ((desired L/AL) 0.5) (where L in mH)
Note: doubling the turns produces four times the inductance.

IRON POWDER TOROIDS – AL Values **

 

Core Size 26 3 15 1 2 6 10 12/17 0
T-12-( ) * 60 50 48 20 17 12 7.5 2.4
T-16-( ) 145 61 55 44 22 19 13 8 3
T-20-( ) 185 76 65 52 25 22 16 10 3.5
T-25-( ) 245 100 85 70 34 27 19 12 4.5
T-30-( ) 335 140 93 85 43 36 25 16 6
T-37-( ) 285 120 90 80 40 30 25 15 4.9
T-44-( ) 370 180 160 105 52 42 33 18.5 6.5
T-50-( ) 330 175 135 100 49 40 31 18 6.4
T-68-( ) 435 195 180 115 57 47 32 21 7.5
T-80-( ) 460 180 170 115 55 45 32 22 8.5
T-94-( ) 600 248 200 160 84 70 58 * 10.6
T-106-( ) 930 450 345 325 135 116 * * 19
T-130-( ) 810 350 250 200 110 96 * * 15
T-157-( ) 1000 420 * 320 140 115 * * *
T-184-( ) 1690 720 * 500 240 195 * * *
T-200-( ) 920 425 * 250 120 100 * * *
T-200A-( ) 1600 * * * 218 * * * *

* size not available in this material
** AL= µH/100 turns

FERRITE TOROIDS – ALValues **

Material ( )

 

Core Size 43 61 63 67 68 75 77 F J
FT-23-( ) 188 248 * 7.8 4.0 990 356 * *
FT-37-( ) 420 55.3 * 19.7 8.8 2110 884 * *
FT-50-( ) 523 68.0 * 22.0 11.0 * 990 * 2750
FT-50A-( ) 570 75.0 * 24.0 12.0 * 1080 * 2990
FT-50B-( ) 1140 150.0 * 48.0 24.0 * 2160 * *
FT-82-( ) 557 73.3 * 22.4 11.7 * 1060 * *
FT-87-( ) * * * * * * * * 3020
FT-87A-( ) * * * * * * * 3700 6040
FT-114-( ) 603 79.3 * 25.4 12.7 * 1270 1902 3170
FT-114A-( ) * 146.0 * * * * 2340 * *
FT-140-( ) 952 140.0 * 45.0 * * 2340 * *
FT-140A-( ) * * * * * * * * 6736
FT-150-( ) * * * * * * * 2640 4400
FT-150A-( ) * * * * * * * 5020 8370
FT-193-( ) * * * * * * * 3640 6065
FT-193A-( ) * * * * * * * 4460 7435
FT-240-( ) 1240 173.0 53.0 53.0 * * 3130 * 6845

* size not available in this material
** AL = mH/1000 turns
IRON POWDER MATERIAL PROPERTIES

 

Material Colour Permeability
i)
Temp. Coeff. 1
(+ppm/C)
Range for Best Q
(MHz)
#262 yellow/white 75 822 0 – 1.0
#3 gray/clear 35 370 0.02 – 1.0
#15 red/white 25 190 0.15 – 3.0
#1 blue/clear 20 280 0.15 – 3.0
#2 red/clear 10 95 0.25 – 10
#6 yellow/clear 8.5 35 3 – 40
#10 black/clear 6.0 150 15 – 100
#12 green/white 4.0 1703 30 – 250
#17 blue/yellow 4.0 50 20 – 200
#0 tan/tan 1.0 0 50 – 350

 

  1. Value averaged from -55 to +125°C.

 

  1. Mainly used for dc chokes, differential-mode chokes, power factor correction inductors, continuous-mode flyback inductors, light dimmer chokes and other EMI/RFI applications.

 

  1. Non-linear. #17 has stable temp coeff., but provides about 10% lower Q than #12.

FERRITE MATERIAL PROPERTIES

Material

 

43 61 64 67 68 73 77 F J/75
Initial Perm. 850 125 250 40 20 2500 2000 3000 5000
Max. Perm. 3000 450 375 125 40 4000 6000 4300 9500
Max. Flux Density
@ 10oer. (gauss)
2750 2350 2200 3000 2000 4000 4600 4700 4300
Residual Flux
Density (gauss)
1200 1200 1100 1000 1000 1000 1150 900 500
Vol. Resistivity
(ohms/cm)
1×105 1×108 1×108 1×107 1×107 1×102 1×102 1×102 1×102
Temp. Coeff. (%/C)
-20 to 70 °C
1 0.15 0.15 0.13 0.06 0.8 0.25 0.25 0.4
Loss Factor
(x 10-6)
120@
1MHz
32@
2.5MHz
100@
2.5MHz
150@
50MHz
400@
100MHz
7.0@
0.1MHz
4.5@
0.1MHz
4.0@
0.1MHz
15@
0.1MHz
Coercive Force
(Oersteds)
0.3 1.6 1.4 3 10 0.18 0.22 0.2 0.1
Curie Temp. (°C) 130 350 210 500 500 160 200 250 140
Resonant Circ.
Freq. (MHz)
.01-1 .2-10 0.05-4 10-80 80-180 .001-1 .001-2 .001-1 .001-1
Wideband Circ.
Freq. (MHz) *
1-50 10-200 50-500 50-500 200-1000 .2-15 .5-30 .5-30 1-15
Noise Attenuation
MHz
20-400 >200 >200 >1000 >10000 1-40 1-40 1-20 0.5-10

 

* Based on low power, small core applications. Listed frequencies will be lower with high power.
IRON POWDER CORE SIZE vs WIRE SIZE/TURNS ( Single layer winding )

Core Size Wire Gauge (Awg)

 

14 16 18 20 22 24 26 28 30 32 34 36
T-12 0 1 1 1 2 4 5 8 11 15 21 29
T-16 1 1 1 3 3 5 8 11 16 21 29 38
T-25 1 3 4 5 7 11 15 21 28 37 48 62
T-37 5 7 9 12 17 23 31 41 53 67 87 110
T-50 8 11 16 21 28 37 49 63 81 103 131 166
T-68 12 15 21 28 36 47 61 79 101 127 162 205
T-80 17 23 30 39 51 66 84 108 137 172 219 276
T-94 20 27 35 45 58 75 96 123 156 195 248 313
T-106 20 27 35 45 58 75 96 123 156 195 248 313
T-130 30 40 51 66 83 107 137 173 220 275 348 439
T-157 38 50 64 82 104 132 168 213 270 336 426 536
T-184 38 50 64 82 104 132 168 213 270 336 426 536
T-200 53 68 86 109 139 176 223 282 357 445 562 707

FERRITE CORE SIZE vs WIRE SIZE/TURNS ( Single layer winding)

Core Size Wire Gauge (Awg)

 

14 16 18 20 22 24 26 28 30 32 34 36
FT-23 0 0 2 4 7 11 15 21 28 37 48 62
FT-37 2 4 7 11 15 21 28 36 48 61 79 100
FT-50 7 10 14 19 26 34 45 58 75 95 121 154
FT-50A 8 13 19 22 30 39 51 66 84 106 135 171
FT-50B 8 13 19 22 30 39 51 65 84 106 135 171
FT-82 18 22 32 41 53 69 88 112 143 180 228 288
FT-87 19 25 34 43 56 72 92 118 150 188 239 239
FT-114 29 38 49 63 80 100 131 166 211 263 334 334
FT-140 36 42 60 77 97 125 158 201 255 318 403 403
FT-150 29 38 49 63 80 100 131 166 211 263 334 334
FT-193 53 68 86 109 139 176 223 282 357 445 562 562
FT-240 60 77 98 123 156 198 250 317 400 499 631 631

IRON POWDER TOROIDS – PHYSICAL DIMENSIONS

 

Core Number O.D.
(inches)
I.D.
(inches)
Hgt
(inches)
T-12-( ) .125 .062 .050
T-16-( ) .160 .078 .060
T-20-( ) .200 .088 .070
T-25-( ) .255 .120 .096
T-30-( ) .307 .151 .128
T-37-( ) .375 .205 .128
T-44-( ) .440 .229 .159
T-50-( ) .500 .303 .190
T-68-( ) .690 .370 .190
T-80-( ) .795 .495 .250
T-94-( ) .942 .560 .312
T-106-( ) 1.060 .570 .437
T-130-( ) 1.300 .780 .437
T-157-( ) 1.570 .950 .570
T-184-( ) 1.840 .950 .710
T-200-( ) 2.000 1.250 .550
T-200A-( ) 2.000 1.250 1.000

 

FERRITE TOROIDS – PHYSICAL DIMENSIONS

 

Core Number O.D.
(inches)
I.D.
(inches)
Hgt
(inches)
FT-23-( ) .230 .120 .060
FT-37-( ) .375 .187 .125
FT-50-( ) .500 .281 .188
FT-50A-( ) .500 .312 .250
FT-50B-( ) .500 .312 .500
FT-82-( ) .825 .516 .250
FT-87-( ) .870 .540 .250
FT-87A-( ) .870 .540 .500
FT-114-( ) 1.142 .750 .295
FT-114A-( ) 1.142 .750 .545
FT-140-( ) 1.400 .900 .500
FT-140A-( ) 1.400 .900 .590
FT-150-( ) 1.500 .750 .250
FT-150A-( ) 1.500 .750 .500
FT-193-( ) 1.932 1.250 .625
FT-193A-( ) 1.932 1.250 .750
FT-240-( ) 2.400 1.400 .500