High-power, precision wirewound resistors enable surface-mount assembly

July 19, 2013 // By Graham Prophet
Resistor technology specialists Arcol has designed the RWS range of compact precision power wirewound SMD resistors, the highest power SMD resistor design currently commercially available.

To meet rising power requirements for surface mount components, an optimised thermal design is targeted to give greater efficiency and improved surge capacity of up to 5 times for 5 seconds, whilst reducing surface temperature rise compared with other resistors. The RWS range provides excellent overload characteristics, good stability, low standard TCR and low inductance and custom versions are available if required. The resistors are wirewound, constructed on an alumina core with steel end caps. The body is an encapsulated epoxy moulded compound with thermo conductivity contours.

The ARCOL RWS resistor series offers an ohmic range from R005 to 50KΩ at power ratings from 0.05 to 50KΩ at 5W, R1 to 5KΩ at 7W and up to 10K at 10W. Typical applications include shunt resistors, power supply current sense, capacitor discharge and bleeder resistors. The enable, the company says, previously unavailable SMD assembly of these components.

The RWS series offers high reliability and has been engineered to reduce long term thermal damage to printed circuit boards and surrounding components. The resistors are RoHS compliant and available in low inductance format and with close TCR and standard tolerance of 0.5%, 1% and 5%. The operating temperature range is - 55°C to +155°C or + 275°C depending on model.

Arcol; www.arcolresistors.com