TT Electronics ULW Wirewound Resistors
TT Electronics / Welwyn ULW Wirewound Resistors provide a fusible resistor function for mains circuits requiring defined fusing and surge withstand capability. The ULW series uses a high-purity ceramic rod with a wirewound resistive element, welded terminations, and a flameproof fusible cement coating. These resistors cover 2W to 5W power ratings at 25°C, 1R0Ω to 100RΩ resistance, ±5% tolerance, ±200ppm/°C TCR, and an operating temperature range from -55°C to +200°C. It supports UL1412 recognition, inrush and surge withstand capability, UL94-V0 flameproof coating, and a surface mount ZI-form option. Typical applications include main inrush limiting and white goods.
Features
- cRUus certified
- Fusible protection for 120Vrms / 240Vrms mains
- Resistance to inrush and surge conditions
- UL1412 recognised fusible resistor design
- UL94-V0 rated flame resistant coating
- ZI-formed leads for surface mount assembly
Applications
- LED lighting application
- Main inrush limiting
- Transient overvoltage protection
- White goods
Technical Specifications
| Parameters | Values |
|---|---|
| Isolation Voltage | 250V, 350V, and 500V |
| Operating Temperature Range | -55°C to +200°C |
| Power Ratings at 25°C | 2W, 3W, 4W, and 5W |
| Resistance Range | 1R0Ω to 100RΩ |
| Resistance Tolerance | ±5% |
| Temperature Coefficient of Resistance (TCR) | ±200ppm/°C |
ULW Wirewound Resistors Pulse Performance Graph
