General Purpose Wirewound Resistors Welwyn Components SPP Series • • • • 0R1 to 2K4 ohms Positive high TC’s upon request Weldable and solderable magnetic leads Lower ranges available - contact factory Electrical Data Type Resistance range ohms Standard Tolerance ±% Power Rating watts Load Life Stability watts SPP-1 SPP-2 SPP-3 0R1 - 1K2* 0R1 - 2K4 0R1 - 2K4 5, 10 5, 10 5, 10 1 @ 85°C 2 @ 85°C 3 @ 85°C 0.75 @ 105°C 1 @ 140°C 2 @ 145°C 1 @ 190°C 0.5 @ 125°C - Derating to 0 @ 160°C - - 1 @ 85°C ± 10% 2 @ 85°C ± 10% 3 @ 85°C ± 10% √PR Max. Continuous Working Voltage Min. Insulation Resistance - Dry 10,000 megohm Min. Insulation Resistance - Wet 100 megohm Min. Dielectric Withstanding Voltage 600 volts RMS Current Noise Negligible Temperature Rise at Rated Load, 25°C Ambient Approx. 150°C Approx. 200°C Approx. 225°C Note: Unless specified otherwise standard test centres are 13/4 inches. Physical Data Dimensions (inches) A max. Type A max B max C±0.002 SPP-1 0.400 0.148 0.032 SPP-2 0.570 0.170 0.032 SPP-3 0.570 0.170 B C 1.125 min 0.032 Fuse/Pulse Applications SPP resistors normally fuse in less than one minute with five to ten times rated wattage depending on the range. By modifying the windings, using a different wire size or type, they can be made to fuse much faster. On the other hand, by using larger wire diameters and higher melt temperature alloys they can handle from five to fifty times overloads of film resistors depending on the range. 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. A subsidiary of TT electronics plc © Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com Issue B · 03.02 97 General Purpose Wirewound Resistors Welwyn Components SPP Series Performance Data Maximum Limits Temperature Coefficient ±600/°C 0.10Ω-0.91Ω SPP-1 ±300/°C 1.0Ω-1200Ω ±600/°C 0.10Ω-0.91Ω SPP-2 ±300/°C 1.0Ω-2400Ω ±600/°C 0.10Ω-0.91Ω SPP-3 ±600/°C 1.0Ω-2400Ω Thermal Shock ±5% Low Shock ±5% Short Time Overload ±5% Commercial Short Time Overload ±5% Resistance to Solder Immersion ±3% Solderability 95% minimum coverage Moisture Resistance ±5% Life Test ±5% Test Method EIA Specification RS-344 Power Derating: Temperature Rise: Temperature Rise (°C) Percent Rated Power 100 SPP-3 80 60 SPP-1, 2 40 20 0 0 50 100 150 200 250 300 Ambient Temperature (°C) SPP-3 300 SPP-2 200 100 SPP-1 0 0 20 40 60 80 100 Percent Rated Power Packaging Resistors are supplied taped and reeled. 4,000 pcs per reel. Bulk pack available. © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com 98 Issue B · 03.02