* Contact factory for values below 0R005 ohms
Open Air
Sense Resistors
OAR Series
•1, 3 and 5 watts
•±1% or ±5% tolerance
•Resistance wire TCR ±20 ppm/°C
•Resistance values down to 0R005 ohms
Dimensions (mm)
Type A B C E F
OAR-1 11.43 +1.020/-0.508 5.08 ±2.54 3.18 ±0.762 1.65 +0.254/-0.127 1.02 ±0.051
OAR-3 15.24 +1.020/-0.50 25.4 max. 3.18 ±0.762 1.65 +0.254/0.127 1.02 ±0.051
OAR-5 20.32 +1.020/-0.50 25.4 max. 3.18 ±0.762 1.65 +0.254/-0.127 1.02 ±0.051
General Note
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to Welwyn’s own data and is considered accurate at time of going to print.
© Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
101
OAR-1 OAR-3 OAR-5
Power rating at 85°C watts 1 3 5
Resistance range ohms 0R005* to 0.10 0R005 to 0.10 0R005 to 0.05
Electrical Data
Physical Data
Issue D · 08.04
A subsidiary of
TT electronics plc
Welwyn Components
B
A
C
F
E
On lower ranges stand-off may be eliminated
NOTE:
Contact factory for:
1.Variations of ‘A’ dimension
2.Different lead diameter
Test Point (Kelvin connection)
OAR_D.qxd 8/9/04 4:15 PM Page 1
Performance Data
Open Air
Sense Resistors
OAR Series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
102
Issue D · 08.04
Welwyn Components
Maximum change
Load life: 1000 hrs at 25°C ∆1%R
Moisture No Load 100 hrs ∆1%R
Temperature Cycle at -40°C & +125°C (1000 cyc): ∆1%R
Features
•Welded Construction
•Flameproof
•Inductance less than 10 nanohenries
•Solderable copper leads
Applications
•Current Sensing
•Feedback
•Low inductance
•Surge and pulse
OAR-5
Resistance 0.005 0.010 0.015 0.020 0.025
Height 15.240 19.304 19.304 22.860 22.860
OAR-3
Resistance 0.005 0.010 0.015 0.020 0.025 0.030 0.040 0.050 0.070 0.080 0.10
Height 16.002 16.510 16.510 17.018 22.098 22.860 16.002 18.288 22.860 21.590 22.860
OAR-1
Resistance 0.005 - 0.100
Height 5.080
Height Standards
All Resistances are in ohms. All Tolerances are ±2.54. Dimensions (mm)
Ordering Procedure
OAR_D.qxd 8/9/04 4:15 PM Page 2
Example: OAR3 at 10 milliohms and 5% tolerance in bulk pack -
O A R 3 – R 0 1 J I
Type
Value (use IEC62 code)
Tolerance (use IEC62 code)
F
1%
J
5%
Packing
I
Bulk
Standard
