Smd wirewound resistor from Ohmite handles more than 5W

摘要

By using a simple idea from its heat-sink designs, Ohmite reports it has developed SMD wire-wound resistors that meet 5W power ratings. The new design incorporates fins in the body of the resistor, creating an additional surface area within the same resistor footprint. The company offers the resistors in 5W and 7W versions, and because tests performed over 1000 hours of continuous operation demonstrated that the resistance drift was negligible (less than 1%), customers can specify very tight tolerances along with the new, higher power ratings. A couple of fins have been removed to allow for a flat zone on the top center of the resistor to enable its use on pick-and-place equipment.