general purpose cement coated wirewound resistors wa80 series c flameproof cement coating c all welded construction c resistance values down to 0.01 ohms electrical data wa82 wa83 wa835 wa84 wa85 wa87 power rating at 25c watts 1 2.0 2.5 3.0 5 7 power rating at 70c watts .86 1.6 2.0 2.5 4.3 6 resistance range ohms 0.068 to 430 0.05 to 900 0.05 to 900 0.01 to 2k2 .05 to 4k5 0.15 to 10k limiting element voltage volts 50 50 75 100 150 150 isolation voltage volts 250 250 250 350 500 700 tcr ppm/c <1 :350 >1 :200 resistance tolerance % 5, 10 values e24 preferred thermal impedance c/watt 140 110 82 90 54 35 ambient temperature range c - 55 to 155 physical data dimensions (mm) and weight (g) pcb min mounting bend wt type l max. d max. f min. d nom. centres radius nom. wa82 6.2 2.8 21.20 0.6 10.20 0.6 0.22 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 construction 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. terminations material solder-coated copper wire on 82, 83, 835 and 84, copper weld on 85 and 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. ? welwyn components limited bedlington, northumberland ne22 7aa, england tel: 01670 822181 fax: 01670 829465 web: http://www.welwyn-tt.co.uk issue a 07/9 9 general note welwyn components 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. l d f d dia marking wa85 and 87 resistors are legend marked with type reference, resistance value and tolerance. in conformance with iec 62. wa82, 83, 835 and 84 resistors rio and above are colour coded with 4 bands in conformance with iec 62. values below rio are 3 band marked, two digits and tolerance, there is no multiplier band. solvent resistance 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.
b f 1 f 2 6 6 c body location f 1 ?f 2 1.4 mm performance data maximum typical load at rated power: 1000 hrs at 25 or 70c ? r% 5.0 + .001 3.0 dry heat: 1000 hrs at 200c ? r% 5.0 + .001 3.0 derating from rated power at 25c see derating curve short term overload ? r% 5.0 + .001 1.0 climatic ? r% 5.0 + .001 2.0 climatic category ? r% 55/200/56 long term damp heat: 56 days ? r% 5.0 + .001 1.0 t.r.c. & vibration ? r% 5.0 + .001 1.0 robustness & solder heat ? r% 5.0 + .001 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. component wires will not protrude beyond the outside edge of the tapes. all taped resistors will be supplied either on reels or in ammopacks, depending upon quantities orderded. wa series resistors can be supplied preformed. contact factory for details. general purpose cement coated wirewound resistors wa80 series standard quantities per package type wa82 wa83 wa835 wa84 wa85 wa87 reel 5000 2500 2500 1000 750 700 large ammopack 5000 2500 1500 1000 700 n/a ? welwyn components limited bedlington, northumberland ne22 7aa, england tel: 01670 822181 fax: 01670 829465 web: http://www.welwyn-tt.co.uk issue a 07/9 9 figure 2 type wa82 wa83 wa835 wa84 wa85 wa87 b 525252676385 c 5 5 5 10 10 10 20 40 60 80 100 120 140 160 180 200 220 240 260 280 130 120 110 100 90 80 70 60 50 40 30 20 10 0 temp wa80 series derating curve % of rated power at 70
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