W20_08 Datasheet, PDF (1/3 Pages) Welwyn Components Limited – Vitreous Enamelled Wirewound Resistors

Vitreous Enamelled
Wirewound Resistors
Welwyn Components
W20 Series
• 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}
Electrical Data
Commercial
Power rating at 25°C
Resistance range at 1% tolerance
2% tolerance
5% tolerance
TCR (-55° to 200°C)
watts
ohms
ohms
ohms
pp/°C
W21
W215
W22
W23
W24
3.0
5.0
7.0
10.5
14.0
1R to 10K 1R to 15K 1R to 22K 1R to 60K 1R to 100K
0R5 to 10K 0R5 to 15K 0R5 to 22K 1R to 60K 1R to 100K
0R1 to 10K 0R1 to 15K 0R1 to 22K 0R15 to 60K 0R2 to 100K
Typically: <+-75
Maximum: +-200
BS 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)
Style
watts
watts
ohms
ohms
ohms
ppm/°C
JB
HB
KB
LB
MB
2.9
5.0
7.0
10.5
14.0
2.5
4.3
6.0
9.0
12.0
1R to 10K 1R to 15K 1R to 20K 1R to 56K 1R to 100K
0R5 to 10K 0R5 to 15K 0R5 to 20K 1R to 56K 1R to 100K
0R1 to 10K 0R1 to 15K 0R1 to 20K 0R15 to 56K 0R2 to 100K
≥5 ohms < 10 ohms: ±400
≥10 ohms: ±200
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
160
200
500
750
E24 preferred. Other values to special order
88
58
44
29
22
-55 to 200
Physical Data
Dimensions (mm) and Weight (g)
Type
L max
D max
W21
12.7
5.6
W215
22.0
7.0
W22
22.0
8.0
W23
38.0
8.0
W24
53.5
8.0
f min
22.75
23.1
23.1
-
-
d nom
0.8
0.8
0.8
0.8
0.8
Wt.nom
1
2
2
3.5
5
dD
L
f
400
W21 W215
W23 W24
W22
300
200
100
0
0
5 10 15 20
Dissipation – Watts
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.
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: [phone] · Facsimile: [phone] · Email: [e-mail] · Website: www.welwyn-tt.com
A subsidiary of
TT electronics plc