EMC Series Film Resistors

TT Electronics/Welwyn EMC series perform three circuit protection functions in a single component

Welwyn's EMC Series Film ResistorsTT Electronics/Welwyn EMC series is aimed at line (mains) input inrush limiting in power supply applications where UL approval is necessary. The EMC series has UL recognition, which is a component status indicating that a sample has been tested and verified by Underwriters Laboratories as suitable for use in a safety critical application. The relevant standard is UL1412, which covers fusing resistors designed to prevent fire by safely breaking a circuit under fault conditions. EMC parts perform three circuit protection functions in a single component:

  • The series provides protection against supply line voltage transients, often in conjunction with a shunt element such as a varistor or transient voltage suppressor (TVS). This enables the designer to achieve the required level of immunity to conducted lightning induced surges.
  • EMCs restrict the peak inrush current at switch-on to levels suitable for the rectifier bridge and consistent with good EMC design.
  • EMCs prevent fire by fusing safely under fault conditions such as rectifier or capacitor breakdown.

EMC Series Film Resistors

ImageManufacturer Part NumberDescriptionAvailable Quantity
EMC2-68RKI datasheet linkRES 68 OHM 2W 10% AXIALEMC2-68RKIRES 68 OHM 2W 10% AXIAL3824 - Immediate
EMC2-68RKI product page link
EMC2-33RKI datasheet linkRES 33 OHM 2W 10% AXIALEMC2-33RKIRES 33 OHM 2W 10% AXIAL915 - Immediate
EMC2-33RKI product page link
EMC2-22RKI datasheet linkRES 22 OHM 2W 10% AXIALEMC2-22RKIRES 22 OHM 2W 10% AXIAL408 - Immediate
EMC2-22RKI product page link
EMC2-47RKI datasheet linkRES 47 OHM 2W 10% AXIALEMC2-47RKIRES 47 OHM 2W 10% AXIAL0EMC2-47RKI product page link
Published: 2011-02-15