All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
09. 11
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
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