High-surge resistors qualified by a global manufacturer of smart energy meters

TT Electronics' WHS series wirewound high-surge resistors are now available from Farnell alament14. The resistors have been successfully qualified by a global manufacturer of smart energy meters in stringent surge tests designed to simulate the effect of lightning strikes on power lines. Such exceptionally high reliability in turn ensures many years of trouble-free operation despite being located at the electrically exposed point of entry of a line supply, says the company. WHS series resisters offer industry-leading surge energy ratings and answer the needs of power supply designers who require a line input resistor that will withstand the surge conditions associated with switch-on and external surge events, while avoiding multiple component solutions. They are available in 2W, 3W, 5W, 7W and 10W ratings, with values from 1R0 to 330R and energy ratings from 1 to 230J. A UL94-V0 flameproof coating provides up to 1kV of isolation. Power ratings of 5W and below are available with ZI-form surface mount format, allowing high voltage traces to be restricted to just one side of the PCB, says the company.