Vitreous Enamelled
Vitreous Enamelled
Wirewound Resistors
W20 Series
W20 Series
Features
Wirewound Resistors
•
IECQ-CECC approved
CECC approved
Suitable for harsh environments
Suitable for harsh environments
•
Impervious lead free vitreous enamel coating
•
Overload characteristics ideal for protection circuits
Impervious lead free vitreous enamel coating
•
High stability and reliability
ideal
Overload characteristics
for protection circuits
High power dissipation for size
•
High stability and reliability
Welwyn Components
•
High power dissipation for size
All parts are Pb-free and comply with EU Directive 2011/65/EU amended by (EU) 2015/863 (RoHS3)
Electrical Data
Commercial
Power rating at 25° C
Resistance range at 1% tolerance
2% tolerance
5% tolerance
TCR (-55° to 200° C)
BS IECQ-CECC 40-201-002 Requirements
CECC 40-201-002 Requirements
Power rating at 25° C
Power rating at 70° C
Resistance range at 1% tolerance
2% tolerance
5% tolerance
TCR (-55° to 200° C)
watts
ohms
ohms
ohms
ppm/ ° C
Style
watts
watts
ohms
ohms
ohms
ppm/° C
W21
W22
3.0
70
1R to 10K
1R to 22K
0R5 to 10K
0R5 to 22K
0R1 to 10K
0R1 to 22K
Typically: <+-75
JB
2.9
2.5
1R to 10K
0R5 to 10K
0R1 to 10K
≥5
ohms <
.
W23
W24
10.5
14.0
1R to 60K
1R to 100K
1R to 60K
1R to 100K
0R15 to 60K
0R2 to 100K
Maximum: +-200
LB
MB
10.5
14.0
9.0
12.0
1R to 56K
1R to 100K
1R to 56K
1R to 100K
0R15 to 56K
0R2 to 100K
≥10
ohms: ±200
KB
7.0
6.0
1R to 20K
0R5 to 20K
0R1 to 20K
10 ohms: ±400
This table indicates the CECC specification requirements, and these are met or exceeded by the corresponding W20 series products
Applicable to commercial and approved ranges
Limiting element voltage
Standard values
Thermal impedance
Ambient temperature range
volts
° C/watt
°C
100
88
200
500
750
E24 preferred. Other values to special order
44
29
22
-55 to 200
Physical Data
Dimensions
Type
W21
W22
W23
W24
400
(mm) and Weight (g)
L max
D max
12.7
5.6
22.0
8.0
38.0
8.0
53.5
8.0
f min
22.75
23.1
-
-
d nom
0.8
0.8
0.8
0.8
Wt.nom
1
2
3.5
5
d
D
L
f
Construction
W21
W23
W22
W24
300
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.
Temperature Rise
°C
Terminations
200
100
Material
Strength
Solderability
Length
Copper clad steel wire, nickel plated and solder-coated.
The terminations meet the requirements of IEC 68.2.21.
The terminations meet the requirements of IEC 115-1,– Clause 4.17.3.2.
W23’s and W24’s are not supplied on tape. Minimum lead length is 30 mm.
0
0
5
10
15
20
Dissipation – Watts
General Note
General Note
The resistors are legend marked with type reference, resistance value and tolerance. Values are
marked in accordance with IEC 62.
Marking
Welwyn Components reserves the right to make changes in product specification without notice or liability.
TT Electronics 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.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
BI Technologies IRC Welwyn
A subsidiary of
TT electronics plc
www.ttelectronics.com/resistors
01.22
© Welwyn Components Limited
· Bedlington, Northumberland NE22 7AA, UK
© TT Electronics plc
822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
Telephone: +44 (0) 1670
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Vitreous Enamelled
Wirewound Resistors
Vitreous Enamelled
W20 Series
Solvent Resistance
W20 Series
Wirewound Resistors
Welwyn Components
Flammability
The body protection and marking are resistant to all normal industrial cleaning solvents suitable for printed circuits
Solvent Resistance
Flammability
The body protection and marking are resistant to all normal
All materials used in the construction of ‘W’ series resistors
are inorganic and inherently non burning.
industrial cleaning solvents suitable for printed circuits.
All materials used in the construction of W20 series resistors are inorganic and inherently non-burning.
Performance Data
CECC 40201-002
IECQ-CECC 40201-002
Requirements
Load at commercial rating: 1000 hrs at 25°C
R%
Load at CECC rating: 1000 hours at 25°C
R%
5
Dry heat: 1000 hours at 200°C
R%
5
Shelf life: 12 months at room temperature
R%
not specified
Derating
Short term overload
R%
1
Climatic
R%
5
Climatic category
R%
55/200/56
R%
5
0.05
0.02
Long term damp heat
Temperature rapid change
R%
1
0.5
0.2
Resistance to solder heat
R%
1
0.25
0.03
R%
1
0.25
0.05
Vibration and bump
Noise (in decade of frequency)
µv/v
not specified
zero
zero
Robustness
R%
1
0.4
0.05
Insulation resistance
ohms
not specified
> 1G ohm
> 1G ohm
Voltage Proof
volts
not specified
500 min
500 min
Pulse handling
data available by request
Data available at: https://www.ttelectronics.com/TTElectronics/media/ProductFiles/Resistors/ApplicationNotes/Wirewound-Pulse-Overload-Resistors.pdf
Actual Performance
Maximum
Typical
5
3.5
5
3.5
2
1
0.03
0.02
see derating curve
1.0
0.2
0.5
0.2
Packaging
For W21 the standard method of packaging is
taped in Ammo Packs. For W22 the standard method of
packaging is taped and reeled. W23’s and W24’s are
available only as loose packed in boxes.
10
Type
W21
f
1
6
f
2
f
1
– f
2
b
1.4 mm
6
W22
b
63±2
73±2
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.
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.
BI Technologies IRC Welwyn
www.ttelectronics.com/resistors
© TT Electronics plc
01.22
Wirewound Resistors
W20 Series
W20 Series
Vitreous Enamelled
Vitreous Enamelled
Wirewound Resistors
Welwyn Components
Ordering Procedure
Example: W22 at 3.3 kilohms and 5%
Pb-free)
Example: W22-3K3JI
(W22, 3.3 kilohms ±5%,
tolerance on a reel of 700 pieces –
W
2
1
1
2
2
-
3
K
2
3
J
3
3
Tolerance
F = ±1%
G = ±2%
J = ±5%
I
4
4
Packing & Termination Finish
I = Standard packing & Pb-free
1000/box
W21
W22
700/reel
W23, W24
50/box
W22–3K3J
I
Type
Value (use IEC62 code)
Type
W21
Value
Tolerance (use IEC62 code)
W22
R = ohms
F
G
1%
2%
J
W23
W24
5%
kilohms
K=
E24 = 3/4 characters
For CECC released product follow the MPN with text indicating the relevant release and style.
Packing
(Note that
released product state on order the CECC number and style. Example:
W22-3K3JI CECC40201-002 KB
KB
text does not form part
1000/box
Example:
W22-3K3JI IECQ-CECC40201-002
of our MPN.)
Ammo
For CECC
this additional
W21, W215
I
Tape
Bulk
W22
W23, W24
700/reel
50/box
Standard
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
General Note
TT Electronics reserves the right to make changes in product specification without notice or liability.
© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA, UK
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
BI Technologies IRC Welwyn
07.11
www.ttelectronics.com/resistors
01.22
86
© TT Electronics plc
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