This document introduces the characteristics of Welwyn Components' WH series resistors, including power, resistance range, TCR, resistance range, low value limits, limiting voltage, standard values, and temperature range.
This data sheet describes the WH SERIES chassis mounting wirewound resistors, highlighting their high‑quality ceramic substrate, welded construction, and anodised aluminium case. It lists electrical data such as power rating, resistance range, TCR, tolerance, and thermal impedance, as well as mechanical dimensions and termination details.
Additional sections cover construction, solvent resistance, performance under various environmental conditions, recommended heatsink dimensions, and packaging information. The document also includes application notes and compliance references.
| Power rating at 25°C | 10 W (WH5), 15 W (WH10), 25 W (WH25), 50 W (WH50) |
|---|---|
| Resistance range | 0.01 Ω to 10 kΩ (WH5), 0.01 Ω to 20 kΩ (WH10), 0.01 Ω to 44 kΩ (WH25), 0.015 Ω to 120 kΩ (WH50) |
| Temperature coefficient (TCR) | <10 ppm/°C (-55°C to 200°C) |
| Resistance tolerance | ±1 % (1 Ω), ±2 % (10 Ω), ±5 % (100 Ω), ±10 % (≥1 kΩ) |
| Thermal impedance | 16 °C/W (WH5), 10 °C/W (WH10), 6 °C/W (WH25), 3.5 °C/W (WH50) |
| Operating temperature range | -55 °C to 200 °C |
| Insulation resistance | >1 GΩ (WH5), >20 TΩ (WH10), >100 GΩ (WH25) |
| Termination material | Solder‑dipped, copper‑clad steel wire |
The WH5 resistor is rated for 10 watts at 25 °C.
Mount the WH50 on a heatsink measuring 30.5 cm × 30.5 cm × 1.5 mm.
They can operate from –55 °C up to 200 °C.
The terminations are made of solder‑dipped, copper‑clad steel wire.