www.vishay.com 159 1248 vishay foil resistors document number: 63058 revision 06-aug-02 trimmers vishay foil ?france +33.4.93.37.28.24 fax: +33.4.93.37.27.31 ?germany +49.9287.710 fax: +49 9287.70435 ?israel +972.3.557.0945 fax: +972.3.558.9121 ?italy + 39.2.300.11919 fax: +39.2.300.11999 ?japan +81.42.729.0661 fax: +81.42.729.3400 ?singapore +65.788.6668 fax: +65.788.0988 ?sweden +46.8.594.70590 fax: +46.8.594.70581 ?uk +44 191 514 8237 fax: +44 1953 457 722 ?usa +1 610 407-4800 fax: +1 610 640-9081 additional specifications: contact resistance variation ?crv (noise): 10 ohms maximum 5 hop-off: 0.25% typical; 1.0% maximum operating temperature range: ?55 c to + 150 c adjustment turns: 21 2 mechanical stops: wiper idles ?no discontinuity notes: 1. maximum is 1.0% a.q.l. standard for all specifications except tcr. (for tcr information see notes 2 and 3). ?ypical is a designers reference which represents that 85% of the lots supplied, over a long period of time, will be at least the figure stated or better. 2. maximum tcr applies to the 3 (sigma) limit or 99.73% of a production lot. (measured end-to-end with wiper off the element.) 3. measurements of tcr through the wiper are influenced more by setting stability and the percentage of the total resistance in use (at the wiper) than by fundamental resistance change due to temperature alone. the parameter shown is a 2 distribution typifying the behavior of the device when used with 40% or more of the total resistance in use. 4. derated linearly from full power @ + 85 c to zero (0) watts @ + 150 c. see figure 2, next page. 5. independent of resistance value 3 ohms maximum available on special request. special available options: special marking burn-in and screening operations average standard resistance values standard power rating @ no. of model termination style weight (g) (in ? ) tolerances +85 c ambient turns 1248 w-edge mount, top adjust 20, 50, 100, 0.4 200, 500, 1k 10% 0.25 w 21 2 x-edge mount, side adjust 2k, 5k p-horizontal mount, side adjust table 1 - model selection* *see figure 1, next page. please specify vishay model 1248 precision trimming potentiometers as follows: example: model no. termination resistance tolerance style value 1248 w 10% 100r features temperature coefficient of resistance (tcr): 20ppm/ c max 2 . (?55 c to + 150 c ref. @ + 25 c); through the wiper 3 ; 50 ppm/ c load life stability: 1.0% maximum ? r under full rated power for 2,000 hours @ + 85 c settability: 0.1% setting stability: 0.1% typical 1 ; 0.5% maximum 1 , ? ss power rating 4 : 0.25 watts @ + 85 c resistance range: 20 ? to 5k ? resistance tolerance: 10% bulk metal foil technology precision trimming potentiometers 1/4 inch rectilinear, rj26 style - industrial trimmer see table 1 for details. see figure 1, next page for standard marking. table 2 - ordering information - 1248 series parts product may not be to scale
document number: 63058 revision 06-aug-02 www.vishay.com 160 1248 vishay foil resistors trimmers vishay foil ?france +33.4.93.37.28.24 fax: +33.4.93.37.27.31 ?germany +49.9287.710 fax: +49 9287.70435 ?israel +972.3.557.0945 fax: +972.3.558.9121 ?italy + 39.2.300.11919 fax: +39.2.300.11999 ?japan +81.42.729.0661 fax: +81.42.729.3400 ?singapore +65.788.6668 fax: +65.788.0988 ?sweden +46.8.594.70590 fax: +46.8.594.70581 ?uk +44 191 514 8237 fax: +44 1953 457 722 ?usa +1 610 407-4800 fax: +1 610 640-9081 0.050" (1.27mm) c 0.040" (1.02mm) c vishay 2 3 1 cw 0.250" (6.352mm) d 1 2 3 0.250" (6.35mm) d 0.100" (2.54mm) a 0.100" (2.54mm) a 0.050" (1.27mm) c 0.050" (1.27mm) c 0.175" (4.45mm) c 0.125" (3.18mm) c (bottom view) 3 1 2 0.050" (1.27mm) c vishay 2 31 cw 0.250" (6.352mm) d 0.250" (6.35mm) d 0.100" (2.54mm) a 0.100" (2.54mm) a 0.050" (1.27mm) c 0.050" (1.27mm) c 0.175" (4.45mm) c 0.125" (3.18mm) c 0.040" (1.02mm) c 0.010" (0.25mm) a (bottom view) note: 1. adjustment screw 0.080 inches (2.03mm) diameter with 0.025 inches (0.64mm) x 0.030 inches (0.76mm) slot. tolerances on screw dimensions is 0.005 inches (0.13mm). model 1248 has gold plated terminal pins 0.016 inches (0.41mm) 0.001 inches (0.03mm) diameter, 0.200 inches (5.08mm) length minimum. standard marking model no. date code resistance value tolerance tolerances a = 0.005 inches (0.13mm) c = 0.010 inches (0.25mm) d = 0.020 inches (0.51mm) *standard markings on this surface. 1248w 1248x resistance value tolerance 0.055" (1.40mm) c 0.050" (1.27mm) c vishay 3 1 cw 0.175" (4.45mm) c 1 2 3 0.250" (6.35mm) d 0.100" (2.54mm) a 0.100" (2.54mm) a 0.035" (0.89mm) c 0.250" (6.36mm) d 0.125" (3.18mm) c 0.125" (3.18mm) c model no. date code 0.016" (0.41mm) a 1248p -75 -50 -25 0 +25 +50 +75 +100 +125 +150 +175 ambient temperature c +85 c +100 +75 +50 +25 0 percent of rated power figure 1 - schematic and dimensions in inches (millimeters) figure 2 - power derating curve bulk metal foil technology precision trimming potentiometers
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