Resistors
General Purpose Cement
General Purpose Cement
Welwyn Components
Coated Wirewound Resistors
Coated Wirewound Resistors
WA80 Series
WA80 Series
Cost effective
Features
Flameproof protection
Surface mount ZI-form option
Can replace carbon comp. in many applications
Flameproof protection
Resistance values down to 0.01 ohms
Can replace carbon comp. i n many applications
Ideal for pulse handling applications
Resistance values down to 0.01 ohms
Ideal for pulse handling app lications
All Pb-free parts comply with EU Directive 2011/65/EU (RoHS2)
Electrical Data
WA82 WA83 WA835 WA84 WA85
Power rating at 25c watts 1 2.0 2.5 3.0 5
Power rating at 70c watts .86 1.6 2.0 2.5 4.3
Resistance range ohms 0R068 to 430 0R05 to 900R 0R05 to 900R 0R01 to 2K2 0R015 to 6K8
Limiting element voltage volts 50 50 75 100 150
Isolation voltage volts 250 250 250 350 500
TCR ppm/C <1:350 >1:200
Resistance tolerance % <20R: 5, 10 20R: 1, 2, 5, 10
Values E24 preferred
Thermal impedance C/watt 140 110 90 82 54
Ambient temperature range C - 55 to 155
Physical Data
Dimensions (mm) and Weight (g)
PCB Min
mounting bend Wt
Type L max. D max. f min. d nom. centres radius nom.
WA82 6.2 2.8 21.20 0.6 10.20 0.6 0.22
WA83 9.0 3.6 19.80 0.8 12.70 1.2 0.50
d
WA835 12.5 4.5 17.80 0.8 18.40 1.2 0.50 D
L f
WA84 14.5 5.2 24.55 0.8 20.30 1.2 1.10
(Note 1)
WA85 16.5 7.0 23.55 0.8 22.86 1.2 1.75
(Note 2)
Note 1: 5.4 for values 0R1 Note 2: 7.2 for values 0R1
Construction Terminations
Material Hot tin dipped copper wire
A high quality ceramic substrate is assembled with
interference fit end caps to which are welded the termination
Strength The terminations meet requirements of
wires. The resistive element is wound on the substrate and
IEC 68.2.21.
welded to the caps. Cement protection is applied to the
resistor body before marking with indelible ink.
Solderability The terminations meet the requirements of IEC
115-1, Clause 4.17.3.2.
General Note
BI Technologies IRC Welwyn
General Note
TT Electronics reserves the right to make changes in product specification without notice or liability.
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to TT Electronics own data and is considered accurate at time of going to print.
A subsidiary of
All information is subject to Welwyns own data and is considered accurate at time of going to print.
www.ttelectronicsresistors.com
TT electronics plc
TT Electronics plc 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
07.11
06.16
General Purpose Cement
General Purpose Cement
Coated Wirewound Resistors
Coated Wirewound Resistors
WA80 Series
Welwyn Components
WA80 Series
Solvent Resistance
Marking
The body protection and marking are resistant to all normal
WA85 resistors are legend marked with type
industrial cleaning fluids suitable for printed circuits.
reference, resistance value and tolerance. In conformance
with IEC 62.
Flammability
The resistor coating will not burn under any condition of
WA82, 83, 835 and 84 resistors 0R1 and above are colour
applied temperature or component overload.
coded with 4 bands in conformance with IEC 62. Values
below 0R1 are 3 band marked, two digits and tolerance,
there is no multiplier band.
Performance Data
Maximum Typical
Load at rated power: 1000 hrs at 25 or 70c R% 5.0 + .001 3.0
Dry heat: 1000 hrs at 200c R% 5.0 + .001 3.0
Derating from rated power at 25c See derating curve
Short term overload R% 5.0 + .001 1.0
Climatic R% 5.0 + .001 2.0
Climatic category R% 55/200/56
Long term damp Heat: 56 days R% 5.0 + .001 1.0
T.R.C. & Vibration R% 5.0 + .001 1.0
Robustness & Solder Heat R% 5.0 + .001 1.0
Pulse Handling Data available by request
Application Notes
Care must be taken when determining clearance between the
resistor body and the P.C.B. or other components. Resistance
is measured 6mm from body.
Packaging
All resistors are supplied tape packed ready for loading onto
automatic sequencing and insertion machines. The critical
dimensions are shown in figure 2.
Component wires will not protrude beyond the outside edge
of the tapes.
Figure 2
All taped resistors will be supplied either on reels or in
ammopacks, depending upon quantities orderded.
c
These products are also available in a range of lead forming options.
In particular, WA83, 84 and 85 are available in ZI-form SMD format
packed in blister tape - see:
f f
1 2