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HPW Series

HPW Series
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High Precision Welded Axial and Radial F e at u r e s • High precision • All welded construction • Molded thermosetting plastic bobbin • Wide ohmic range combined with tight tolerance • Excellent long-term stability • Inherent low temperature coefficient • Extremely low Thermal EMF • Low voltage coefficient • Low noise characteristics Minimum Values 0.1Ω for ±1% and ±0.5%; 10Ω for ±0.1% and tighter Resistance ±0.005%, ±0.01%, ± 0.02%, ±0.05%, ±0.1%, ±0.5%, Tolerance and ±1%, depending on style and value Temperature ±10ppm/°C standard for 10Ω and above. Higher TC’s Coefficient (TCR on low ohmic values. TC match to ±1ppm/°C. High TC’s upto +6000ppm/°C are available Working tempera- –60°C to +150°C ture range All Welded The combination of all welded construction and comConstruction patible materials provide the most reliable means of interconnects possible. Butt Weld of Tab to A tab material of 800 ohm alloy (the same as the Terminal resistance wire) is butt welded to the terminal and molded deep into the resistor bobbin. This design parameter assures the least possible DC transients due to thermal EMF. Bobbin Design The ratio of the height of the Pi wall to the width of the Pi and to the diameter of the bobbin mandrel are critical to the basic stability of a wirewound resistor. These parameters are optimized for each wire size, wattage size and range of resistor values. Encapsulation Both the bobbin and the final encapsulation material Material are thermosetting alkyd polyester. The resulting resistor is virtually a homogeneous mass with an identical coefficient of expansion which is unaffected by the most violent of temperature cycling. All types are unaffected by application of solvents. Terminal Materials The standard terminal material is hot solder dipped copper (C5N).

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High Precision Welded Axial and Radial Power Rating *Available in hermetically sealed Format* Resistance A = axial 1R000 = 1Ω PA = round radial 10R00 = 10 Ω 100R0 = 100 Ω *All formats and 1K000 = 1000 Ω tolerances not 10K00 = 10 KΩ available in all 100K0 = 100 KΩ values 1M700 = 1.7 MΩ 1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • info@ohmite.com

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