Fusible Carbon Film Resistors Welwyn Components FC4 • Predictable fusing characteristics • Constant voltage fusing characteristics • Fuses at very low powers • Flame retardant lacquer Electrical Data FC4 Power rating at 70°C watts 0.33 Resistance range ohms 1R0-5K1 TCR ppm/°C 300 % 5, 10 Resistance tolerance Standard values E24 preferred Thermal impedance °C/watt Ambient temperature range 215 °C -55 to 125 Physical Data Dimensions (mm) & Weight (g) Type L Max D Max f min d nom PCB mounting centres FC4 6.2 2.5 21.0 0.6 10.2 Min. bend radius Wt.nom 0.6 0.3 d D L f Construction Marking The carbon film is deposited on a high purity ceramic rod. End caps are fitted and termination wires welded to the caps. The resistive film is adjusted to the required value by a special helical cut; finally the flame retardant lacquer protection is applied to the resistor body and marked with an indelible ink. Resistance value and tolerances are identified in accordance with IEC62.4 - band colour code. A fifth (yellow) band denotes that the product is fusible and suitable for use in constant voltage applications. Solvent Resistance Terminations Material Solder-coated copper wire. Strength The terminations meet the requirements of IEC 68.2.21 Solderability The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2 The body protection and marking are resistant to all normal industrial cleaning solvents suitable for printed circuits. Flammability The resistor coating will not burn or emit incandescent particles under any condition of applied temperature or power overload. 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 166 Issue B · 03.02 Fusible Carbon Film Resistor Welwyn Components FC4 Performance Data Maximum ∆ R% 1.0 - 1k Load 1000 hrs at 70°C 0.2 >1k to 5.1k 0.8 Derating from rated power at 70°C zero at 125°C ∆R% Climatic 0.5 Climatic category 40/125/56 Temperature rapid change ∆R% 0.25 Resistance to solder heat ∆R% 0.5 Vibration and bump ∆R% 0.1 Isolation resistance ohms >1G Graph 1 Fusing Characteristics (constant voltage) Graph 2 2 GRAPH GRAPH 1 FUSING CHARACTERISTICS (constant voltage) Maximum permissable applied voltage Fusing time (seconds) 100 50 40 30 20 10 5.0 2.0 1.0 0.5 0.1 3.5 5 10 15 Applied power (watts) Packaging All FC resistors are supplied tape packed ready for loading on to automatic sequencing and insertion machines. Maximum FusingVOLTAGE Voltage MAXIMUM FUSING 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0 1 10 100 Resistance value (ohms) 1k Standard Quantities Per Package Type FC4 Ammo pack 5000 Component wires will not protrude beyond the outside edge of the tapes. Lead formed resistors can also be supplied. Standard options of Lancet, Radial and Goalpost forming are shown in Lead Form Information section. 5 Alternative packaging available by request. f1 6 f2 52 6 Body location f1 – f2 ≤ 1.4 mm © 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 · 03.02 167