Resistors Cement Coated Cement Coated Welwyn Components Wirewound Resistors Wirewound Resistors W30 Series W30 Series Values down to 10m ohms Values down to 10m ohms Tolerance to 1% Tolerance to 1% Flameproof protection Flameproof protection Custom built to meet pulse requirements Custom built to meet pulse requirements Surface mount ZI-form option 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 W31 Notes Power rating at 25 C watts 3.0 Power rating at 70 C watts 2.5 Resistance range ohms 0R01 to 10K TCR (-55 to 155 C) ppm/ C See below Resistance tolerance % <R10: 5 >=R10: 1, 2, 5 Standard values E24 series preferred Other values to special order Thermal impedance C/watt 83 Ambient temperature range C -55 to 155 Limiting element voltage volts 100 TCR ppm/ C R01: 1000 >R01 - R033: 500 >R033 - R091: 200 >R091 - 10R: 150 >10R: 100 Physical Data Maximum Dimensions (mm) and Weight (g) Type L max. D max. f min. d nom. Wt.nom. d D L f W31 13 5.6 (note 1) 22.75 0.8 1.0 < Note 1: 5.8 for values 0R1 Construction Marking A high quality ceramic substrate is assembled with W31 resistors are legend marked with type reference, interference fit end caps to which are welded the element resistance value and tolerance. Values are marked in accordance with IEC 62. winding and termination wires. The protection is then applied to the body, providing an effective seal which is impervious to moisture, shock, vibration, fungus and salt spray. Solvent Resistance The body and marking are resistant to all normal industrial Terminations cleaning solvents suitable for printed circuits. Material Solder coated copper. Strength The terminations meet the requirements of Flammability IEC 68.2.21. The resistor coating will not burn under any condition of Solderability The terminations meet the requirements of applied temperature or component overload. IEC 115-1, Clause 4.17.3.2. General Note General Note Welwyn Components reserves the right to make changes in product specification without notice or liability. BI Technologies IRC Welwyn 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 Issue D 07.06 Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info welwyn-tt.com Website: www.welwyn-tt.com TT Electronics plc 12.19 99Cement Coated WirCement Coated ewound Resistors Cement Coated Wirewound Resistors Welwyn Components W30 Series Wirewound Resistors W30 Series Welwyn Components W30 Series Performance Data Performance Data Maximum Typical Load: 1000 hrs 3 watts 25C R% 5.0 + .001 3.5 Maximum Typical 1000 hrs 2.5 watts 70C R% 5.0 + .001 3.5 Load: 1000 hrs 3 watts 25C R% 5.0 + .001 3.5 Dry heat: 1000 hrs at 200C R% 5.0 + .001 3.5 1000 hrs 2.5 watts 70C R% 5.0 + .001 3.5 Derating from room temperature see derating curve Dry heat: 1000 hrs at 200C R% 5.0 + .001 3.5 Short term overload 10 x rated power for 5 seconds R% 5.0 + .001 1.0 Derating from room temperature see derating curve Climatic R% 5.0 + .001 3.5 Short term overload 10 x rated power for 5 seconds R% 5.0 + .001 1.0 Climatic category 55/200/56 Climatic R% 5.0 + .001 3.5 Long term damp heat: 56 days R% 3.0 + .001 1.0 Climatic category 55/200/56 Temperature rapid change R% 2.0 + .001 1.5 Long term damp heat: 56 days R% 3.0 + .001 1.0 Resistance to solder heat R% 5.0 + .001 2.0 Temperature rapid change R% 2.0 + .001 1.5 Vibration and bump R% 5.0 + .001 2.0 Resistance to solder heat R% 5.0 + .001 2.0 Voltage proof volts 500 min Vibration and bump R% 5.0 + .001 2.0 Pulse handling Data available by request Voltage proof volts 500 min Pulse handling Data available by request W31 Series Derating Curve 130 120 Application Notes W31 Series Derating Curve 110 130 100 The terminations should not be bent closer than 1.6mm from Application Notes 120 90 110 the body, and the recommended minimum bend radius is 80 100 The terminations should not be bent closer than 1.6mm from 1.2mm. 70 90 the body, and the recommended minimum bend radius is 60 80 1.2mm. 50 70 Care must be taken when determining clearance between the 40 60 resistor body and the P.C.B. or other components. Resistance 30 50 Care must be taken when determining clearance between the 20 40 is measured 6mm from body. 10 resistor body and the P.C.B. or other components. Resistance 30 0 20 is measured 6mm from body. 20 40 60 80 100 120 140 160 180 200 220 240 260 280 10 Temp 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 10 Packaging Temp The standard method of packaging is taped in ammo packs. 10 Packaging Can be provided on reels by request. The standard method of packaging is taped in ammo packs. These products are also available in a range of lead forming options. W31 can be supplied with radial, goalpost or lancet pre-formed leads - see Can be provided on reels by request. f f 1 2 In particular, it is available in ZI-form SMD format packed in blister tape