a subsidiary of tt electronics plc 05 . 08 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. ? welwyn components limited bedlington northumberland ne22 7aa, uk telephone: +44 (0) 1670 822181 facsimile: +44 (0) 1670 829465 email: info@welwyn-tt.com website: www.welwyn-tt.com radial ceramic case resistors wirewound / metal oxide 2 to 10 watts resistance 0r1 to 200k high overload capability flameproof case small pcb footprint rohs compliant sqm series electrical data sqm2 sqm3 sqm5 sqm7 SQM10 power rating at 70 c watts 2 3 5 7 10 resistance r ange ohms wirew ou nd 0r1 - 27r 0r1 - 39r 0r1 - 47r 0r1 - 68 0r 0r1 - 91 0r metal oxide 30r ? 33k 43r ? 56k 51r ? 100k 75 0r - 200k 1k0 - 20 0k limiting element voltage volts dc or ac rms 150 300 350 500 750 thermal impedance c /watt 50 45 30 28 23 isolation voltage volts 1000 tcr ppm/ c <20r: 400 , 20r: 35 0 resistance tolerance % 5 standard values e24 ambien t temperature range c - 55 to +155 o c physical data (all dimensions in mm, weights in g) type l 1.0 w 1.0 d 1.0 p 1.0 d 0.05 weight nom. sqm2 20 11.5 7.5 5 0.7 4.3 sqm3 25 12.5 8.5 5 0.7 5.6 sqm5 25 12.5 9 5 0.8 6.3 sqm7 38 12.5 9 5 0.8 10.7 SQM10 50 12.5 9 5 0.8 13.4 leads centered on sqm2, sqm3, sqm5 leads offset as shown on sqm7, SQM10 construction a high purity ceramic rod, with force fit end caps onto which is wound a wire element: or a deposited metal oxide film (depending on value). the element is fitted into a ceramic case with fireproof insulation cement. 5 1 d l p d w 5 1
radial ceramic case resistors wirewound / metal oxide 05 . 08 ? welwyn components limited bedlington northumberland ne22 7aa, uk telephone: +44 (0) 1670 822181 facsimile: +44 (0) 1670 829465 email: info@welwyn-tt.com website: www.welwyn-tt.com sqm series termination details: material the 100% sn finish copper lead wires are internally welded to the resistance element end caps. solderability the terminations meet the requirements of iec 115-1 clause 4.17.3.2 strength the terminations meet the requirements of iec 86.2.21 marking: type reference, resistance value and tolerance are legend marked onto the upper surface. flammability: the resistor will not burn under any condition of applied temperature or overload. solvent resistance: the body prote ction and marking are resistant to all normal industrial solvents suitable for printed circuits. performance data maximum load a t rated power ( 1000 hrs at 70 c) r <100k, 5%; 10 0k, 10% derating f rom rated power at 70 c see graph shor t term overl oa d * r 5% +0.05 ? damp heat st ea dy state (56 days, 40 c, 90 % r h) r 5% +0.05 ? temperature rapid c ha nge (5 cycles - 55 o c to +155 o c) r 2% +0.05 ? r esistance to solder he at r 1% +0 .05 ? volt ag e proo f (1kv for 60s) no evidence o f flashover, mec ha nical damage, arcing or insulation breakdown solderability min. 9 5% coverage * wirew ound : the lower of 5x rated power, or 2.5x lev for 5s metal oxide : the lower of 6.25x rated power, or 2.5x lev for 5s derating curve ordering procedure example: sqm3 at 1.2 kilohms and 5% tolerance bulk packed in a box of 3000 pieces ? s q m 3 ? 1 k 2 j b 3 type value (use iec62 code) tolerance (use iec62 code) j 5% packing b3 bulk sqm2, 3 300 0 / box sta nd ard b2 sqm5 200 0 / box b1 sqm7, 10 100 0 / box 0% 10 0% t ( c) 70 155 275 60% - 55 p/pr
|
