general note w elwyn components r eserves the right to make changes in pr oduct specification without notice or liability . all information is subject to w elwyn? s own data and is consider ed accurate at time of going to print. ? w elwyn components limited bedlington, northumberland ne22 7aa, uk t elephone: +44 (0) 1670 822181 facsimile: +44 (0) 1670 829465 email: info@welwyn-tt.com w ebsite: www .welwyn-tt.com pr4 pr5 power rating at 70c watts 0.25 0.5 resistance range ohms 100r ? 1m limiting element voltage volts 250 350 tcr (20c to 70c) ppm/c 240k: 15, 25, 50 >240k: 25, 50 resistance tolerance % 500k: 0.1, 0.25, 0.5, 1 >500k: 0.25, 0.5, 1 standar d values e24, e96 thermal impedance c/watt 140 112 ambient temperatur e range c -55 to 155 electrical data physical data 07. 08 a subsidiary of tt electr onics plc w elwyn components 182 l d f d construction the r esistance element is a pr ecisely contr olled thin film of metal alloy sputter ed on to a high purity ceramic cor e, pr otected by a moistur e-r esistant, high dielectric str ength coating applied so that terminations r emain completely clear . this permits a well defined body length (clean lead to clean lead dimension l). t erminations material hot tin dipped copper wire str ength the terminations meet the r equir ements of iec 68.2.21 solderability the terminations meet the r equir ements of iec 115-1, clause 4.17.3.2 marking resistors ar e colour coded with 5 bands. iec 62 colours ar e used. solvent resistance the body pr otection and marking ar e r esistant to all normal industrial cleaning solvents suitable for printed cir cuits. p r ecision metal film resistors pr series ? low cost pr ecision r esistors ? t olerances down to 0.1% ? tcr down to 15ppm/c dimensions (mm) & w eight (g) pc min. wt. nom mounting bend t ype l max d max f min d nom centr es radius pr4 6.2 2.5 21 0.6 10.2 pr5 9.0 0.6 0.3 3.6 19.6 0.8 12.7 1.2 0.5
maximum load: 1000 hours at 70c ? 5 . 0 % r c 5 5 1 t a o r e z c 0 7 t a r e w o p d e t a r m o r f g n i t a r e d short term overload ? 5 2 . 0 % r climatic ? 5 . 0 % r climatic category 55/125/56 long term damp heat ? 5 . 0 % r t emperatur e rapid change ? 5 2 . 0 % r resistance to solder heat ? 5 2 . 0 % r v ibration and bump ? 1 . 0 % r g 1 > s m h o e c n a t s i s e r n o i t a l u s n i pr4: 500 min, pr5: 700 min s t l o v f o o r p e g a t l o v p r ecision metal film resistors pr series ? w elwyn components limited bedlington, northumberland ne22 7aa, uk t elephone: +44 (0) 1670 822181 facsimile: +44 (0) 1670 829465 email: info@welwyn-tt.com w ebsite: www .welwyn-tt.com 183 07. 08 w elwyn components performance data packaging all pr r esistors ar e supplied tape packed r eady for loading on to automatic sequencing and insertion machines. component wir es will not pr otrude beyond the outside edge of the tapes. alter native packaging available by r equest. lead formed resistors can also be supplied. standard options of lancet, radial and goalpost forming are available. 52 f 1 f 2 6 6 5 body location f 1 ? f 2 1.4 mm pr_c.qxd 1/5/03 8:58 am page 2 or d e r in g p r o ced u r e ex a m p l e : pr4 w i t h t cr o f 15pp m / c a t 10 ki l o h m s and 0 . 1% to l e rance i n an a mm o pack b o x o f 5000 p i e ce s - p r 4 y ? 1 0 k b i t ype t c r y 15 p p m / c 25 p p m / c 50 p p m / c va l ue (u s e iec62 code) t o l e rance (u s e iec62 co de) b 0 . 1 % d 0 . 5 % c 0 . 2 5 % f 1 % pa cki ng i a m m o p r 4 5000 / box s t anda r d p r 5 2500 / box c
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