thick film Axial surge high energy TFS Series Surge Capable Thick Film Non Inductive • Appropriate for medical surge protection applications • Ideal to replace standard carbon composition resistors • Custom dimensions, values, tolerances and characteristics available The TFS Series has been specifically developed to absorb large amounts of energy by efficient use of its compact mass. Ideal for medical surge protection applications, these thick film resistors offer non-inductive performance in an axial package. Uses include power supply conversion, electron microscopes, X-ray systems, high-resolution CRT displays, and geophysical instrument related products. Type TFSA TFSB TFSC TFSD TFSE TFSF *Published energy rating is for 10ms pulse. For shorter pulses energy rating has to be derated according to Max. Individual Pulse Rating chart and Single Pulse Energy Rating considerations. Resistive Element Thick Film Encapsulation Screen Printed Glass • Momentary overload capability is 5 times rated power for 1 second or 2 times rated power for 5 seconds. Always verify designs with pulse and surge conditions through thorough testing of the design at maximum operating temperature and maximum pulse loading (or some margin above maximum pulse loading). Resistance Value 100Ω up to 100KΩ Temperature Coefficient 100ppm/°C Tolerance 1%, 2%, 5%, 10% • Damage to the resistor by excessive pulse loading is generally indicated by an increasing resistance of the resistor. • Energy ratings are based on single pulses (at least 1 minute between pulses). Test VDE 0750 (Pulse Duration 10 msec) • For multiple pulse applications the energy pulse rating should be reduced and the average power should not exceed the nominal power rating of the selected model. • See Single Pulse Energy section for more information 1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • [email protected]

thick film Axial Surge Capable Thick Film Non Inductive S i n g l e P u l s e E n e r g y R at i n g Although Ohmite’s TFS Series resistors have been specially designed and developed to absorb much more energy than standard resistors, pulses and transients require special consideration since they cause an instantaneous temperature rise in the resistor film. This application note can guide you through these considerations. For applications with transients, pulses or surges the following must be considV 2t V E = ––– ered: R 1. Do not exceed the normal rated operating voltage of the device. t 2....