UAL-25

UAL Series Aluminum Housed Wirewound Resistors • • • • • • • UAL-25-4T UAL-25-4 UAL-25-4TR Power Rating 5 to 300Watts All Welded Construction Resistances from 0.005 to 250kOhms Tolerance to ±0.01% High Overload and Pulse Handling Low TCR: ± 20ppm/K Standard Four Terminal Versions Available SPECIFICATIONS Type UAL-5 UAL-10 UAL-25 UAL-50 UAL-100 UAL-180 UAL-250 UAL-300 MIL-R-39009 MIL-R-18546 Style Power Rating ( W @ 25°C ) Commercial 7.5 a 12.5 a 25 b 50 c 100 d 180 d 250 d 300 e 1 a MIL 5 a 10 a 20 b 30 c 75 d 120 d - Free Air 4.5 7.5 12 20 40 100 75 Resistance Range1 0.01 to 22K 0.01 to 47K 0.01 to 90K 0.01 to 250K 0.01 to 50K 0.01 to 50K 0.01 to 50K 0.005 to 100K RER-60 / RE-60 RER-65 / RE-65 RER-70 / RE-70 RER-75 / RE-75 RER-77 / RE-77 RER-80 / RE-80 - For non-inductive windings, divide maximum resistance by 2 Heatsink Required : 0.040 [1.0] Alum. Plate, 129 in2 [832 cm2] or equiv. b Heatsink Required : 0.040 [1.0] Alum. Plate, 167 in2 [1077 cm2] or equiv. c Heatsink Required : 0.059 [1.5] Alum. Plate, 291 in2 [1877 cm2] or equiv. d Heatsink Required : 0.125 [3.2] Alum. Plate, 294 in2 [1896 cm2] or equiv. e Heatsink Required : 0.125 [3.2] Alum. Plate, 895 in2 [5780 cm2] or equiv. Ordering Information For Non-Inductive Windings / insert the letter “N” ( i.e. UALN-25 ) Part Number - Resistance - Tolerance - TCR ( If not standard ) Example: UAL-25 10 Ohm 1% Willow Technologies Ltd. Shawlands Court, Newchapel Road, Lingfield, Surrey, RH7 6BL, United Kingdom. http://www.willow.co.uk + 44 (0) 1342 835234 + 44 (0) 1342 834306 info@willow.co.uk rev. 03/2006A UAL Series Aluminum Housed Wirewound Resistors SPECIFICATIONS (continued) Specification Tolerances Temperature Coefficient Value ±0.01% to ±10% ( 1% Standard ) >10W : ±20ppm/K 1W to10W : ±50ppm/K