WA80_D.qxd 8/6/04 10:58 AM Page 1 General Purpose Cement Coated Wirewound Resistors Welwyn Components WA80 Series • Cost effective • Flameproof protection • Can replace carbon comp. in many applications • Resistance values down to 0.01 ohms • Ideal for pulse handling applications Electrical Data WA82 WA83 WA835 WA84 WA85 WA87 Power rating at 25°c watts 1 2.0 2.5 3.0 5 7 Power rating at 70°c watts .86 1.6 2.0 2.5 4.3 6 Resistance range ohms 0R068 to 430 0R05 to 900R 0R05 to 900R 0R01 to 2K2 0R015 to 6K8 0R15 to 10K volts 50 50 75 100 150 150 volts 250 250 250 350 500 700 Limiting element voltage Isolation voltage TCR ppm/°C Resistance tolerance <1Ω:350 % >1Ω:200 <20R: 5, 10 Values ≥20R: 1, 2, 5, 10 E24 preferred Thermal impedance °C/watt Ambient temperature range 140 110 82 °C 90 54 35 - 55 to 155 Physical Data Dimensions (mm) and Weight (g) L max. D max. f min. d nom. PCB mounting centres WA82 6.2 2.8 21.20 0.6 10.20 0.6 WA83 9.0 3.6 19.80 0.8 12.70 1.2 0.50 WA835 12.5 4.5 17.80 0.8 18.40 1.2 0.50 WA84 14.5 5.2 24.55 0.8 20.30 1.2 1.10 WA85 16.5 7.0 23.55 0.8 22.86 1.2 1.75 WA87 25.0 8.8 28.30 0.8 31.40 1.2 4.40 Type Min bend radius Wt nom. 0.22 d D L f Construction Terminations A high quality 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. Cement protection is applied to the resistor body before marking with indelible ink. Material Solder-coated copper wire on 82, 83, 835, 84, and 85, solder coated cooper clad steel on 87. Strength The terminations meet requirements of IEC 68.2.21. Solderability The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2. 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. A subsidiary of TT electronics plc © Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com Issue D · 08.04 89 WA80_D.qxd 8/6/04 10:58 AM Page 2 General Purpose Cement Coated Wirewound Resistors Welwyn Components WA80 Series Marking Solvent Resistance WA85 and 87 resistors are legend marked with type reference, resistance value and tolerance. In conformance with IEC 62. The body protection and marking are resistant to all normal industrial cleaning fluids suitable for printed circuits. Flammability The resistor coating will not burn under any condition of applied temperature or component overload. WA82, 83, 835 and 84 resistors 0R1 and above are colour coded with 4 bands in conformance with IEC 62. Values below 0R1 are 3 band marked, two digits and tolerance, there is no multiplier band. Performance Data Maximum Typical 3.0 Load at rated power: 1000 hrs at 25 or 70°c ∆R% 5.0 + .001Ω Dry heat: 1000 hrs at 200°c ∆R% 5.0 + .001Ω Derating from rated power at 25°c 3.0 See derating curve Short term overload ∆R% 5.0 + .001Ω 1.0 Climatic ∆R% 5.0 + .001Ω 2.0 Climatic category ∆R% 55/200/56Ω Long term damp Heat: 56 days ∆R% 5.0 + .001Ω 1.0 T.R.C. & Vibration ∆R% 5.0 + .001Ω 1.0 Robustness & Solder Heat ∆R% 5.0 + .001Ω 1.0 Pulse Handling Data available by request Application Notes Care must be taken when determining clearance between the resistor body and the P.C.B. or other components. Resistance is measured 6mm from body. Packaging All resistors are supplied tape packed ready for loading onto automatic sequencing and insertion machines. The critical dimensions are shown in figure 2. % of Rated Power at 70°C WA80 Series Derating Curve 130 120 110 100 90 80 70 60 50 40 30 20 10 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 Temp°C Component wires will not protrude beyond the outside edge of the tapes. Figure 2 All taped resistors will be supplied either on reels or in ammopacks, depending upon quantities orderded. c WA series resistors can be supplied preformed. Contact factory for details. Type WA82 WA83 WA835 WA84 WA85 WA87 b 52 52 52 67 63 85 c 5 5 5 10 10 10 f1 6 f2 b 6 Body Location f1 – f2 ≤ 1.4 mm Standard Quantities Per Package Type WA82 WA83 WA835 WA84 WA85 WA87 Reel 5000 2500 2500 1000 750 700 Large ammo pack 5000 2500 1500 1000 700 n/a © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com 90 Issue D · 08.04 WA80_D.qxd 8/6/04 10:58 AM Page 3 General Purpose Cement Coated Wirewound Resistors Welwyn Components WA80 Series Ordering Procedure Specify type reference, value and tolerance as shown in this example of WA82 480R 5%: Type WA82 480R J Resistance value (IEC62 code) Tolerance (IEC62 code) F 1% G 2% J 5% © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com Issue D · 08.04