The 2mm high WDBR-UL series comes in nine values from 12R to 150R in five size options and the creepage, clearances and power ratings have been assessed in accordance with the requirements of UL508, easing the compliance burden for UL approved end users.
For circuit designers who need to design UL approved systems containing power resistors in highly compact enclosed assemblies with heatsink-based thermal management, the WDBR-UL series provides a far lower volume solution than competing encased wirewound products and a faster route to safety certification.
The thick-film on steel devies are aimed at industrial applications such as motor drive inverters, dynamic braking, inrush current limiting, snubber circuits, electronic assembly heater elements, and over-voltage protection in wind turbines. The high integrity dielectric layer is applied to a machined stainless steel substrate and the thick-film conductor and resistor patterns are printed and fired, then protected with a high temperature overglaze. This provides high isolation from a heatsink even after failsafe overload fusing and feature a very low inductance design and are available in continuous power ratings up to 1.4kW with up to 7kW continuous peak power dissipation, and they are able to handle single overload power levels up to 13kW.
A single fixing heatsink mountable resistors and choice of flying lead or solder terminations simplifies the manufacturing . The termination pads are tinned with solder and the optional leads are soldered on, and the devices are RoHS compliant.