Vitreous Enamelled
Wirewound Resistors
W20 Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics 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.
© TT electronics plc
09. 11
· CECC approved
· Suitable for harsh environments
· Impervious lead free vitreous enamel coating
· Overload characteristics ideal for protection circuits
· High stability and reliability
· High power dissipation for size
Vitreous Enamelled
Wirewound Resistors
W20 Series
sCECC approved
sSuitable for harsh environments
sImpervious lead free vitreous enamel coating
sOverload characteristics ideal
for protection circuits
sHigh stability and reliability
sHigh power dissipation for size
Dimensions (mm) and Weight (g)
Type L max D max f min d nom Wt.nom
W21 12.7 5.6 22.75 0.8 1
W215 22.0 7.0 23.1 0.8 2
W22 22.0 8.0 23.1 0.8 2
W23 38.0 8.0 - 0.8 3.5
W24 53.5 8.0 - 0.8 5
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
This table indicates the CECC specification requirements, and these are met or exceeded by the corresponding W20 series products
42W32W22W512W12WlaicremmoC
0.415.010.70.50.3sttawC°52 ta gnitar rewoP
K001 ot R1K06 ot R1K22 ot R1K51 ot R1K01 ot R1smhoecnarelot %1ta egnar ecnatsiseR
K001 ot R1K06 ot R1K22 ot 5R0K51 ot 5R0K01 ot 5R0smhoecnarelot %2
K001 ot 2R0K06 ot 51R0K22 ot 1R0K51 ot 1R0K01 ot 1R0smhoecnarelot %5
+< :yllacipyTC°/pp)C°002 ot°55-( RCT -75 Maximum: +-200
BS CECC 40-201-002 Requirements Style JB HB KB LB MB
0.415.010.70.59.2sttawC°52 ta gnitar rewoP
0.210.90.63.45.2sttawC°07 ta gnitar rewoP
K001 ot R1K65 ot R1K02 ot R1K51 ot R1K01 ot R1smhoecnarelot %1ta egnar ecnatsiseR
K001 ot R1K65 ot R1K02 ot 5R0K51 ot 5R0K01 ot 5R0smhoecnarelot %2
K001 ot 2R0K65 ot 51R0K02 ot 1R0K51 ot 1R0K01 ot 1R0smhoecnarelot %5
C°/mpp)C°002 ot°55-( RCT ≥5 ohms < 10 ohms: ±400 ≥10 ohms: ±200
Applicable to commercial and approved ranges
057005002061001stlovegatlov tnemele gnitimiL
redro laiceps ot seulav rehtO .derreferp 42Eseulav dradnatS
2292448588ttaw/C°ecnadepmi lamrehT
002 ot 55-C°egnar erutarepmet tneibmA
Electrical Data
Physical Data
A subsidiary of
TT electronics plc
Welwyn Components
L
Df
d
Construction
A high purity ceramic substrate is assembled with interference fit end caps to which are
welded the termination wires. The resistive element is wound on the substrate and welded to
the caps; the vitreous enamel protective coating is then applied.
Terminations
Material Copper clad steel wire, nickel plated and solder-coated.
Strength The terminations meet the requirements of IEC 68.2.21.
Solderability The terminations meet the requirements of IEC 115-1,– Clause 4.17.3.2.
Length W23’s and W24’s are not supplied on tape. Minimum lead length is 30 mm.
Marking
The resistors are legend marked with type reference, resistance value and tolerance. Values are
marked in accordance with IEC 62.
0 5 10 15 20
W21 W215
W22
W24
W23
400
300
200
100
0
Dissipation – Watts
Temperature Rise °C
W20_C.qxd 28/4/03 10:19 am Page 1
Vitreous Enamelled
Wirewound Resistors
W20 Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics 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.
© TT electronics plc
09. 11
Vitreous Enamelled
Wirewound Resistors
W20 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
Welwyn Components
CECC 40201-002 Actual Performance
Requirements Maximum Typical
Load at commercial rating: 1000 hrs at 25°c 5.35%R
Load at CECC rating: 1000 hours at 25°c R% 5 5 3.5
Dry heat: 1000 hours at 200°c R% 5 2 1
Shelf life: 12 months at room temperature R% not specified 0.03 0.02
Derating see derating curve
Short term overload R% 1 1.0 0.2
Climatic R% 5 0.5 0.2
Climatic category R% 55/200/56
Long term damp heat R% 5 0.05 0.02
Temperature rapid change R% 1 0.5 0.2
Resistance to solder heat R% 1 0.25 0.03
Vibration and bump R% 1 0.25 0.05
orezorezdeificeps tonv/vµ)ycneuqerf fo edaced ni( esioN
Robustness R% 1 0.4 0.05
mho G1.>mho G1.>deificeps tonsmhoecnatsiser noitalusnI
nim 005nim 005deificeps tonstlovfoorP egatloV
Pulse handling data available by request
Performance Data
Flammability
All materials used in the construction of ‘W’ series resistors
are inorganic and inherently non burning.
b
f1f2
6
6
10
f1– f2 1.4 mm
Application Notes
The termination should not be bent closer than 1.6mm from
the body, and the recommended minimum bend radius is
1.2mm. The terminations are solderable to within 4mm from
the body. When cold, vitreous enamel has excellent insulation
resistance. In common with all insulants the specific resistance
of the enamel decreases with increase in temperature.
Therefore, resistors operated at near maximum temperature
cannot be classed as insulated and should not be used in
contact with any conducting material. Care must be taken
when determining clearance distance between the resistor
body and the printed circuit board or other components to
ensure these are not over heated. Resistance is measured
6mm from body.
25 70 200 315
116
100
54
0
Ambient temperature °C
Derating Curve
% of Rated Power
Type b
W21 63±2
W215 73±2
W22 73±2
Packaging
For W21 and W215 the standard method of packaging is
taped in Ammo Packs. For W22 the standard method of
packaging is taped and reeled. Alternatives available by
special request are detailed in the table below. W23’s and
W24’s are available only as loose packed in boxes. W series
resistors can be supplied preformed. Contact factory for
details.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuits.
W20_C.qxd 28/4/03 10:19 am Page 2
Vitreous Enamelled
Wirewound Resistors
W20 Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics 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.
© TT electronics plc
09. 11
Vitreous Enamelled
Wirewound Resistors
W20 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
86
07.11
Welwyn Components
W20_C.qxd 28/4/03 10:19 am Page 2
Ordering Procedure
Example: W22 at 3.3 kilohms and 5% tolerance on a reel of 700 pieces –
W 2 2 – 3 K 3 J I
Type
Value (use IEC62 code)
Tolerance (use IEC62 code)
F
1%
J
G
2%
Packing
I
Ammo
W21, W215
1000/box
Standard
Tape
W22
700/reel
Bulk
W23, W24
50/box
For CECC released product state on order the CECC number and style. Example: W22-3K3JI CECC40201-002 KB
For SnPb finish instead of Pb-free replace the packing suffix with PB. Example: W22-3K3JPB