FEATURES
• WHM, UltraHigh ohmic value
precision series,
• WNM, Aryton Perry winding Non-
Inductive available.
Inductance <1nH at 1MHZ test,
• Designed to meet the most strin-
gent MIL-R-26F, MIL-STD-202
standard requirements
• Miniaturized Better power to
dimension ratios
• Use of the highest quality stan-
dard (96% Alumina) ceramic
core
• Manufacturing process -Wire
winding/ Spot Welding- by
Computer Numerical Control
(CNC) machine tools to ensure
consistency of product quality.
• Encapsulated by epoxy molding
compound
• Advanced IC encapsulation
mold/die technologies
SPECIFICATIONS
Material
Ceramic Core:
CeramTec
Rubalit
®
96% alumina
End Caps:
Stainless steel, preci-
sion formed
Leads:
Copper wire,100% Sn
(lead free) coated
ISAOHM
alloy resistance wire
TC+/-20ppm/°C
Encapsulation:
SUMICON 1100/
1200 Epoxy molding compound
for IC encapsulation
Electrical
Standard Tolerance:
F (1.0%),
J (5.0%)
Temperature Coefficient
(ppm/°C):
±90 for 0.100Ω
±20 for >0.100Ω
Maximum Working Voltage:
(PxR)1/2
Derating:
Linearly from
100% @ +70°C to
0% @ +150°C.
Operating Temp:
-55°C to
+150°C
WH/WN Series
Miniature Molded Wirewound
L
D
d
0.984 /
25
�½
�½
Power Resistance
Rating
Range
Type (watts)
(Ω)
WHA
0.5
0.100 - 1.0K
WNA
0.100 - 250
WHB
1
0.100 - 4.0K
WNB
0.100 - 1.0K
WHC
2
0.10 - 8.0K
WNC
0.10 - 2.0K
Dim. L
(mm/in)
5.08 / 0.200
7.00 / 0.276
11.4 / 0.450
Dim. D
(mm/in)
2.54 / 0.100
3.00 / 0.120
6.86 / 0.270
Dim. d
(mm/in)
0.60 / 0.024
0.60 / 0.024
0.80 / 0.031
PERFORMANCE CHARACTERISTICS
Conditions of Test
Rated power applied until thermal stability,
-55°C +0°C,-5°C,15min.
Short-time Overload 5 times rated wattage for 5 seconds
Solderability
Method 208 of MIL-STD-202
Terminal Strength
Pull test:10 pounds, 5 to10 seconds, Twist
test: 1080°,5 second/rotation
Dielectric
500Volts rms for 1W, 2W 1000Volts rms.
Withstanding Voltage 1 minute
High Temperature
Exposed to an ambient temperature of 275
Exposure
+5/-0°C for 250 ±8 hours,
Moisture Resistance MIL-STD-202 Method 106, 7b not applicable
Low Temperature
Cold chamber at a temperature of -65 ±2°C
Storage
for 24+/-4 hours
Vibration, High
Frequency varied 10 to 2000Hz, 200G peak,
Frequency
2 directions 6 hours each
Load Life
1000/2000 hours at rated power, +25°C, 1.5
hours “On”, 0.5 hours “Off”
Test
Thermal Shock
Performance
±0.2%
±0.2%
±0.2%
±0.1%
±0.1%
±0.5%
±0.2%
±0.2%
±0.1%
±0.5%
O R D E R I N G I N F O R M AT I O N
H
= Inductive
N
= Non Inductive
RoHS compliant
�½�½�½�½�½�½�½�½�½�½
Series Power
A = 0.5
B=1
C=2
Ohms Tolerance Package
T = Tape
F = 1%
J = 5%
blank = 25pc Pack
KEY TO FIVE-BAND CODE
�½�½�½�½ �½
Band
Color
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Grey
White
Gold
Silver
1
0
1
2
3
4
5
6
7
8
9
2
Digit
0
1
2
3
4
5
6
7
8
9
3
0
1
2
3
4
5
6
7
8
9
x
x
x
x
x
x
x
x
x
4
Multiplier
1Ω
10Ω
100Ω
1KΩ
10KΩ
±
±
5
Tolerance
1% (F)
2% (G)
S TA N D A R D PA RT N U M B E R S F O R W H / W N S E R I E S
Wattage:
0.5
Series:
WHA
Ohms
0.1
0.25
0.50
0.75
1
2
4
5
10
15
25
51
75
100
150
200
250
330
470
560
750
1K
2.5K
WHAR10FE
WHAR25FE
WHAR50FE
WHAR75FE
WHA1R0FE
WHA2R0FE
WHA4R0FE
WHA5R0FE
WHA10RFE
WHA15RFE
WHA25RFE
WHA51RFE
WHA75RFE
WHA100FE
WHA150FE
WHA200FE
WHA250FE
WHA330FE
WHA470FE
WHA560FE
WHA750FE
WHA1K0FE
WNAR10FE
WNAR25FE
WNAR50FE
WNAR75FE
WNA1R0FE
WNA2R0FE
WNA4R0FE
WNA5R0FE
WNA10RFE
WNA15RFE
WNA25RFE
WNA51RFE
WNA75RFE
WNA100FE
WNA150FE
WNA200FE
WNA250FE
WHBR10FE
WHBR25FE
WHBR50FE
WHBR75FE
WHB1R0FE
WHB2R0FE
WHB4R0FE
WHB5R0FE
WHB10RFE
WHB15RFE
WHB25RFE
WHB51RFE
WHB75RFE
WHB100FE
WHB150FE
WHB200FE
WHB250FE
WHB330FE
WHB470FE
WHB560FE
WHB750FE
WHB1K0FE
WHB2K5FE
WNBR10FE
WNBR25FE
WNBR50FE
WNBR75FE
WNB1R0FE
WNB2R0FE
WNB4R0FE
WNB5R0FE
WNB10RFE
WNB15RFE
WNB25RFE
WNB51RFE
WNB75RFE
WNB100FE
WNB150FE
WNB200FE
WNB250FE
WNB330FE
WNB470FE
WNB560FE
WNB750FE
WNB1K0FE
WHCR10FE
WHCR25FE
WHCR50FE
WHCR75FE
WHC1R0FE
WHC2R0FE
WHC4R0FE
WHC5R0FE
WHC10RFE
WHC15RFE
WHC25RFE
WHC51RFE
WHC75RFE
WHC100FE
WHC150FE
WHC200FE
WHC250FE
WHC330FE
WHC470FE
WHC560FE
WHC750FE
WHC1K0FE
WHC2K5FE
WNCR10FE
WNCR25FE
WNCR50FE
WNCR75FE
WNC1R0FE
WNC2R0FE
WNC4R0FE
WNC5R0FE
WNC10RFE
WNC15RFE
WNC25RFE
WNC51RFE
WNC75RFE
WNC100FE
WNC150FE
WNC200FE
WNC250FE
WNC330FE
WNC470FE
WNC560FE
WNC750FE
WNC1K0FE
0.5
WNA
1.0
WHB
1.0
WNB
2.0
WHC
2.0
WNC
x 100KΩ
1MΩ
10MΩ
± 0.5% (D)
± 0.25% (C)
± 0.10% (B)
± 0.05%
0.1Ω
0.01Ω
±
±
5% (J)
10% (K)
Check product availability at
www.ohmite.com
Ohmite Mfg. Co.
1600 Golf Rd., Rolling Meadows, IL 60008 • 1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • info@ohmite.com
15
OHMITE [ OHMITE MFG. CO. ]
