t OM K = = OULQLMP = = NMWNV= ~ = = m~= N Resistors Vitreous Enamelled Welwyn Components Wirewound Resistors Vitreous Enamelled Wirewound Resistors W20 Series W20 Series CECC approved 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 All Pb-free parts comply with EU Directive 2011/65/EU (RoHS2) Electrical Data Commercial W21 W215 W22 W23 W24 Power rating at 25C watts 3.0 5.0 7.0 10.5 14.0 Resistance range at 1% tolerance ohms 1R to 10K 1R to 15K 1R to 22K 1R to 60K 1R to 100K 2% tolerance ohms 0R5 to 10K 0R5 to 15K 0R5 to 22K 1R to 60K 1R to 100K 5% tolerance ohms 0R1 to 10K 0R1 to 15K 0R1 to 22K 0R15 to 60K 0R2 to 100K TCR (-55 to 200C) ppm/C Typically: <+-75 Maximum: +-200 BS CECC 40-201-002 Requirements Style JB HB KB LB MB Power rating at 25C watts 2.9 5.0 7.0 10.5 14.0 Power rating at 70C watts 2.5 4.3 6.0 9.0 12.0 Resistance range at 1% tolerance ohms 1R to 10K 1R to 15K 1R to 20K 1R to 56K 1R to 100K 2% tolerance ohms 0R5 to 10K 0R5 to 15K 0R5 to 20K 1R to 56K 1R to 100K 5% tolerance ohms 0R1 to 10K 0R1 to 15K 0R1 to 20K 0R15 to 56K 0R2 to 100K TCR (-55 to 200C) 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 100 160 200 500 750 Standard values E24 preferred. Other values to special order Thermal impedance C/watt 88 58 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 W215 22.0 7.0 23.1 0.8 2 d W22 22.0 8.0 23.1 0.8 2 D L f W23 38.0 8.0 - 0.8 3.5 W24 53.5 8.0 - 0.8 5 400 Construction W215 W21 W23 W24 A high purity ceramic substrate is assembled with interference fit end caps to which are W22 welded the termination wires. The resistive element is wound on the substrate and welded to 300 the caps the vitreous enamel protective coating is then applied. Terminations 200 Material Copper clad steel wire, nickel plated and solder-coated. Strength The terminations meet the requirements of IEC 68.2.21. 100 Solderability The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2. Length W23s and W24s are not supplied on tape. Minimum lead length is 30 mm. Marking 0 0 5 10 15 20 The resistors are legend marked with type reference, resistance value and tolerance. Values are 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 t 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. 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 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 at