Welwyn Components Limited WFF
Fast Fusible Metal Film Resistors
| Part No. | WFF |
|---|---|
| Datasheet | WFF Download |
| Manufacturer |  Welwyn Components Limited |
| Description | Fast Fusible Metal Film Resistors |
| Buy | Stock & Price |
Fast Fusible Metal Film Resistors WFF Series Welwyn Components
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● Low power fusing Predictable fusing characteristics Flameproof protection Electrical Data WFF1/4 Power rating at 70˚ C Resistance range Limiting element voltage TCR Resistance tolerance Standard values Thermal impedance Ambient temperature range ˚ C/watt ˚C 150 watts ohms volts ppm/˚ C % 0.25 0R1 - 10K 250 WFF1/2 0.5 0R10 - 27K 350 250 5 E24 preferred 120 -55 to 155 100 WFF1 1 0R2 - 1K5 350 Physical Data Dimensions (mm) & Weight (g) Type L max 6.2 9.0 12.5 D max 2.3 2.5 3.4 4.2 f min 21.0 19.6 17.8 d nom 0.6 0.8 0.8 PCB mounting centres 10.2 12.7 18.4 Min. bend radius 0.6 1.2 1.2 Wt. nom 0.3 0.6 0.9 d D WFF1/4 WFF1/2 WFF1 L f Construction The metal film is deposited on a high purity ceramic rod. End caps are force fitted and termination wires welded to the caps. The resistive film is adjusted to the required value by a special helical cut. A fuse aid coating is then applied. Finally a cement protection is applied to the resistor body prior to marking with indelible ink.
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● Low power fusing Predictable fusing characteristics Flameproof protection Electrical Data WFF1/4 Power rating at 70˚ C Resistance range Limiting element voltage TCR Resistance tolerance Standard values Thermal impedance Ambient temperature range ˚ C/watt ˚C 150 watts ohms volts ppm/˚ C % 0.25 0R1 - 10K 250 WFF1/2 0.5 0R10 - 27K 350 250 5 E24 preferred 120 -55 to 155 100 WFF1 1 0R2 - 1K5 350 Physical Data Dimensions (mm) & Weight (g) Type L max 6.2 9.0 12.5 D max 2.3 2.5 3.4 4.2 f min 21.0 19.6 17.8 d nom 0.6 0.8 0.8 PCB mounting centres 10.2 12.7 18.4 Min. bend radius 0.6 1.2 1.2 Wt. nom 0.3 0.6 0.9 d D WFF1/4 WFF1/2 WFF1 L f Construction The metal film is deposited on a high purity ceramic rod. End caps are force fitted and termination wires welded to the caps. The resistive film is adjusted to the required value by a special helical cut. A fuse aid coating is then applied. Finally a cement protection is applied to the resistor body prior to marking with indelible ink.
