FEATURES
• High precision
• All welded construction
• Molded thermosetting plastic
bobbin
• Wide ohmic range combined with
tight tolerance
• Excellent long-term stability
• Inherent low temperature coef-
ficient
• Extremely low Thermal EMF
• Low voltage coefficient
• Low noise
CONSTRUCTION
All Welded Construction:
The
combination of all welded con-
struction and compatible materials
provide the most reliable means of
interconnects possible.
Axial
Butt Weld of Tab to Terminal:
1.25" /
31.75mm
B
A
A tab material of 800 ohm alloy
min.
(the same as the resistance wire)
is butt welded to the terminal and
molded deep into the resistor
bobbin. This design parameter
Round Radial
Flat Radial
assures the least possible DC
transients due to thermal EMF.
C
A
Bobbin Design:
The ratio of the
SPECIFICATIONS
height of the Pi wall to the width
A
B
Minimum Values:
0.1Ω for ±1%
of the Pi and to the diameter of
and ±0.5%; 10Ω for ±0.1% and
the bobbin mandrel are critical to
Model
Dim. C
Dim. D
D
B
tighter
the basic stability of a wirewound
101P 0.150 /
3.81
0.110 /
2.79
resistor. These parameters are
Resistance Tolerance:
±0.005%,
102P 0.125 /
3.18
0.125 /
3.18
optimized for each wire size, watt-
±0.01%, ± 0.02%, ±0.05%,
203PC 0.150 /
3.81
—
age size and range of resistor
±0.1%, ±0.5%, and ±1%,
203PA 0.200 /
5.08
—
values.
depending on style and value
305PA 0.200 /
5.08
—
Temperature Coefficient (TCR):
505PA 0.300 /
7.62
—
Encapsulation Material:
Both the
±10ppm/°C standard for 10Ω
bobbin and the final encapsulation
and above. Higher TC’s on
material are thermoset-
low ohmic values. TC match
ting alkyd polyester. The
to ±1ppm/°C. High TC’s upto
resulting resistor is vir-
Power Rating
Overall Dimensions
+6000ppm/°C are available
tually a homogeneous
Max. @125°C Max.
(±.020 in./ ±.508
mm)
mass with an identical
Type
Ohms (Watts) Volts
A
B
AWG
Standard temperature range:
coefficient of expansion
–10°C to +80°C
123A
111k
0.05
150 0.100 /
2.54
0.230 /
5.84
24*
which is unaffected
Working temperature range:
118A
192k
0.05
150 0.130 /
3.30
0.180 /
4.57
26
by the most violent of
–60°C to +145°C
122A
199k
0.05
150 0.123 /
3.12
0.218 /
5.54
24
temperature cycling. All
102A
334k
0.10
150 0.110 /
2.79
0.250 /
6.35
24
types are unaffected by
application of solvents.
102AL
334k
0.10
150 0.130 /
3.30
0.313 /
7.95
24
101A
410k
0.10
300 0.130 /
3.30
0.375 /
9.53
22*
Terminal Materials:
The standard terminal
153A
435k
0.10
0.150 /
3.81
0.245 /
6.22
22
material is hot solder
103A
633k
0.10
150 0.150 /
3.81
0.300 /
7.62
22
dipped copper (C5N).
135A
750k
0.10
0.160 /
4.06
0.500 /
12.70
22
Other available materi-
105A
820k
0.125
0.150 /
3.81
0.310 /
7.87
22
als are bare nickel
184A
820k
0.125
300 0.187 /
4.75
0.375 /
9.53
22
(N1N) and gold plated
nickel (N2N).
185A*
961k
0.125
300 0.187 /
4.75
0.500 /
12.70
22
202A
968k
0.25
200 0.250 /
6.35
0.310 /
7.87
22
O R D E R I N G I N F O R M AT I O N
204A
1.42 M
0.25
0.250 /
6.35
0.375 /
9.53
20
203A
1.7 M
0.25
200 0.250 /
6.35
0.343 /
8.71
20
205A* 1.93 M
0.33
400 0.250 /
6.35
0.500 /
12.70
20*
207A* 3.0 M
0.50
800 0.250 /
6.35
0.750 /
19.05
20*
Format*
Tolerance
Type
Resistance
A, AL = axial
T = 0.01%
1R000 =
1
Ω
308A
3.0 M
0.60
800 0.312 /
7.93
0.810 /
20.57
20
P = flat radial
Q = 0.02%
10R00 = 10
Ω
PA, PC = round 100R0 = 100
Ω
A = 0.05%
210A* 4.10 M
0.50
800 0.250 /
6.35
1.00 /
25.40
20
radial 1K000 = 1000
Ω
B = 0.1%
307A
5.63 M
0.60
0.375 /
9.53
0.750 /
19.05
20
F = 1.0%
10K00 = 10 KΩ
*Not every format
100K0 = 100 KΩ
is available in
310A
7.68 M
1.00
800 0.375 /
9.53
1.00 /
25.40
20
1M700 = 1.7 MΩ
every wattage
505A
10 M
1.00
0.500 /
12.70
0.500 /
12.70
20
Check product availability at
www.ohmite.com
510A* 24 M
1.25
800 0.500 /
12.70
1.00 /
25.40
20
515A* 35 M
1.50
1200 0.500 /
12.70
1.50 /
38.10
20
517A
43 M
1.75
1200 0.500 /
12.70
1.75 /
44.45
20
520A* 43 M
2.00
1200 0.500 /
12.70
2.00 /
50.8
20
101P
453k
0.125
150 0.300 /
7.62
0.320 /
8.13
22
102P
821k
0.125
150 0.250 /
6.35
0.250 /
6.35
22*
203PC 1.59 M
0.25
150 0.250 /
7.92
0.312 /
7.93
22
203PA 1.48 M
0.25
150 0.270 /
6.86
0.320 /
8.13
22
305PA 3.3 M
0.50
0.375 /
9.53
0.500 /
12.70
20
505PA 9.5 M
1.00
0.500 /
12.70
0.500 /
12.70
20
*Available in hermetically sealed
High Precision Welded Axial and Radial
HPW Series
C
203A1M700T
Our friendly Customer
Service team can be
reached at 866-9-OHMITE
Lead Diam.
0.020 /
0.508
0.016 /
0.406
0.020 /
0.508
0.020 /
0.508
0.020 /
0.508
0.026 /
0.660
0.026 /
0.660
0.026 /
0.660
0.026 /
0.660
0.026 /
0.660
0.026 /
0.660
0.026 /
0.660
0.026 /
0.660
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.032 /
0.813
0.026 /
0.660
0.026 /
0.660
0.026 /
0.660
0.026 /
0.660
0.032 /
0.813
0.032 /
0.813
Ohmite Mfg. Co.
1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • info@ohmite.com
39
OHMITE [ OHMITE MFG. CO. ]
