ULN series

ULN Downloads

Supporting Manufacturer Information


The ULN series by RARA sets a benchmark in resistor design, featuring a robust metal-clad, wirewound construction tailored for high-power industrial applications. Housed in an extruded aluminum casing, the ULN resistors not only ensure durable protection but also carry UL approval, attesting to their adherence to rigorous safety standards. This UL certification enhances the reliability of ULN resistors, making them a trusted choice for demanding industrial environments.

Delving into specific features, ULN resistors exhibit a compact, flat design that optimizes space utilization without compromising performance. This distinctive form factor facilitates excellent heat dissipation, a critical aspect in industrial settings. With a substantial power rating of up to 150W when mounted on a heat sink, these resistors cover a resistance range from 1Ω to 1.75kΩ. Users can customise their choice between cement or silicone filling materials based on specific application requirements. Operating effectively over a wide temperature range, from -55℃ to 200℃ for cement and -55℃ to 150℃ for silicone, ULN resistors maintain precise performance. The series showcases exceptional tolerances as low as ±0.5% and a maximum Temperature Coefficient of Resistance (TCR) of ±260ppm/℃, ensuring reliable and accurate operation in diverse industrial scenarios.

For those seeking a non-UL approved alternative with comparable precision and reliability, the IRN series offers a viable option within RARA’s resistor lineup. Although lacking UL approval, the IRN series shares outstanding features with its ULN counterpart, making it suitable for applications where this certification may not be a primary requirement.

RARA IRN/ULN/IRF/ULF Flat Type Metal Clad Wire Wound Resistors
  • RARA
  • Narrow and Flat type metal clad wire wound resistor
  • Resistance options from 1Ω up to 420Ω
  • Power rating of 50W (on a heat sink)
  • Tolerance options between ±0.5% and ±10.0%
  • TCR of +260 ppm/°C maximum
  • For Non UL Approval see the IRN Series
  • RARA
  • Narrow and Flat type metal clad wire wound resistor
  • Resistance options from 1Ω up to 1.1kΩ
  • Power rating of 100W (on a heat sink)
  • Tolerance options between ±0.5% and ±10.0%
  • TCR of +260 ppm/°C maximum
  • For Non UL Approval see the IRN Series
  • RARA
  • Narrow and Flat type metal clad wire wound resistor
  • Resistance options from 1Ω up to 1.75kΩ
  • Power rating of 150W (on a heat sink)
  • Tolerance options between ±0.5% and ±10.0%
  • TCR of +260 ppm/°C maximum
  • For Non UL Approval see the IRN Series
Please be advised that due to the ongoing supply issues with raw materials affecting the global electronics industry, as well as an increase in orders received by our manufacturing partners, a large number of products are facing increased lead times in recent months. For the latest lead time and stock availability, please contact one of our engineers who will be happy to discuss lead times further and the potential for alternative parts.