Resistors General Purpose Cement General Purpose Cement Welwyn Components Coated Wirewound Resistors Coated Wirewound Resistors WA80 Series WA80 Series Cost effective Features Flameproof protection Surface mount ZI-form option Can replace carbon comp. in many applications Flameproof protection Resistance values down to 0.01 ohms Can replace carbon comp. i n many applications Ideal for pulse handling applications Resistance values down to 0.01 ohms Ideal for pulse handling app lications All Pb-free parts comply with EU Directive 2011/65/EU (RoHS2) Electrical Data WA82 WA83 WA835 WA84 WA85 Power rating at 25c watts 1 2.0 2.5 3.0 5 Power rating at 70c watts .86 1.6 2.0 2.5 4.3 Resistance range ohms 0R068 to 430 0R05 to 900R 0R05 to 900R 0R01 to 2K2 0R015 to 6K8 Limiting element voltage volts 50 50 75 100 150 Isolation voltage volts 250 250 250 350 500 TCR ppm/C <1:350 >1:200 Resistance tolerance % <20R: 5, 10 20R: 1, 2, 5, 10 Values E24 preferred Thermal impedance C/watt 140 110 90 82 54 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 d WA835 12.5 4.5 17.80 0.8 18.40 1.2 0.50 D L f WA84 14.5 5.2 24.55 0.8 20.30 1.2 1.10 (Note 1) WA85 16.5 7.0 23.55 0.8 22.86 1.2 1.75 (Note 2) Note 1: 5.4 for values 0R1 Note 2: 7.2 for values 0R1 Construction Terminations Material Hot tin dipped copper wire A high quality ceramic substrate is assembled with interference fit end caps to which are welded the termination Strength The terminations meet requirements of wires. The resistive element is wound on the substrate and IEC 68.2.21. welded to the caps. Cement protection is applied to the resistor body before marking with indelible ink. Solderability The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2. General Note BI Technologies IRC Welwyn General Note TT Electronics reserves the right to make changes in product specification without notice or liability. Welwyn Components reserves the right to make changes in product specification without notice or liability. All information is subject to TT Electronics own data and is considered accurate at time of going to print. A subsidiary of All information is subject to Welwyns own data and is considered accurate at time of going to print. General Purpose Cement General Purpose Cement Coated Wirewound Resistors Coated Wirewound Resistors WA80 Series Welwyn Components WA80 Series Solvent Resistance Marking The body protection and marking are resistant to all normal WA85 resistors are legend marked with type industrial cleaning fluids suitable for printed circuits. reference, resistance value and tolerance. In conformance with IEC 62. Flammability The resistor coating will not burn under any condition of WA82, 83, 835 and 84 resistors 0R1 and above are colour applied temperature or component overload. 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 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. Figure 2 All taped resistors will be supplied either on reels or in ammopacks, depending upon quantities orderded. c These products are also available in a range of lead forming options. In particular, WA83, 84 and 85 are available in ZI-form SMD format packed in blister tape f f 1 2 see