t OM K = = OULQLMP = = NMWNV= ~ = = m~= N Resistors Vitreous Enamelled Vitreous Enamelled Welwyn Components Wirewound Resistors Wirewound Resistors W20 Series CECC approved W20 Series Suitable for harsh environments CECC approved Impervious lead free vitreous enamel coating Suitable for harsh environments Overload characteristics ideal Imper vious lead free vitreous enamel coating for protection circuits Overload characteristics ide al for protection circuits HighHigh s tstabilityability and and reliability reliability High p ower dissipation for size High power dissipation for size AllAll Pb-Pb-frfreeee partsparts ccomplyomply withwith EUEU DirDirectivectivee 2011/65/EU2011/65/EU amended amended b yb y(EU) (EU) 2015/863 2015/863 (R (RoHS3)oHS3) Electrical Data Commercial W21 W22 W23 W24 Power rating at 25 C watts 3.0 7 0 . 10.5 14.0 Resistance range at 1% tolerance ohms 1R to 10K 1R to 22K 1R to 60K 1R to 100K 2% tolerance ohms 0R5 to 10K 0 R5 to 22K 1R to 60K 1R to 100K 5% tolerance ohms 0R1 to 10K 0 R1 to 22K 0R15 to 60K 0R2 to 100K TCR (-55 to 200 C) ppm/ C Typically: <+-75 Maximum: +-200 BS CECC 40-201-002 Requirements Style JB KB LB MB Power rating at 25 C watts 2.9 7.0 10.5 14.0 Power rating at 70 C watts 2.5 6.0 9.0 12.0 Resistance range at 1% tolerance ohms 1R to 10K 1R to 20K 1R to 56K 1R to 100K 2% tolerance ohms 0R5 to 10K 0 R5 to 20K 1R to 56K 1R to 100K 5% tolerance ohms 0R1 to 10K 0 R1 to 20K 0R15 to 56K 0R2 to 100K TCR (-55 to 200 C) ppm/ C 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 volts 100 200 500 750 Standard values E24 preferred. Other values to special order Thermal impedance C/watt 88 44 29 22 Ambient temperature range C -55 to 200 Physical Data 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 d W22 22.0 8.0 23.1 0.8 2 D W23 38.0 8.0 - 0.8 3.5 L f W24 53.5 8.0 - 0.8 5 Construction 400 A high purity ceramic substrate is assembled with interference fit end caps to which are W21 W24 W23 welded the termination wires. The resistive element is wound on the substrate and welded to W22 the caps the vitreous enamel protective coating is then applied. 300 Terminations Material Copper clad steel wire, nickel plated and solder-coated. 200 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. 100 Length W23s and W24s are not supplied on tape. Minimum lead length is 30 mm. Marking 0 The resistors are legend marked with type reference, resistance value and tolerance. Values are 0 5 10 15 20 marked in accordance with IEC 62. Dissipation Watts General Note General Note BI Technologies IRC Welwyn 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 Welwyns own data and is considered accurate at time of going to print. A subsidiary of All information is subject to TT Electronics own data and is considered accurate at time of going to print. TT electronics plc www.ttelectronics.com/resistors Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK TT Electronics plc Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info welwyn-tt.com Website: www.welwyn-tt.com 06.20 Temperature Rise Ct OM K = = OULQLMP = = NMWNV= ~ = = m~= O Vitreous Enamelled Wirewound Resistors Vitreous Enamelled W20 Series Wirewound Resistors Welwyn Components W20 Series Solvent Resistance The body protection and marking are resistant to all normal industrial cleaning solvents suitable for printed circuits Flammability Solvent Resistance Flammability All materials used in the construction of W series resistors The body protection and marking are resistant to all normal are inorganic and inherently non burning. Allindustrial materials cleaning used in the solvents construction suitable of W20 for series printed resist orcisrcuits. are inorganic and inherently non-burning. Performance Data CECC 40201-002 Actual Performance Requirements Maximum Typical Load at commercial rating: 1000 hrs at 25C R% 5 3.5 Load at CECC rating: 1000 hours at 25C R% 5 5 3.5 Dry heat: 1000 hours at 200C R% 52 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 Noise (in decade of frequency) v/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: