High Voltage Precision Thick Film Resistors Welwyn Components T Series s Working voltage up to 100kV s Resistances up to 50G s TCR down to 25ppm s Termination variants s Sets of resistors with matched characteristics Electrical Data T43 T44 T48 Power rating at 20C watts 1.5 3.5 10 Resistance range ohms 10K to 10G 10K to 50G 33K to 50G volts 4K 14K 50K In air 8K 28K 100K In oil Limiting element voltage TCR ppm/C 100 * Values > 1G: TCR is 250ppm/C % 1, 2, 5 Closer tolerances over restricted range E24 preferred values Any value to special order Resistance tolerance Values Thermal impedance Notes C/watt Ambient temperature range 31 C 27 13 -55 to 150 * Contact factory for 25 or 50ppm/C Physical Data Dimensions (mm) & Weight (g) PCB Min Bend Radius Wt. nom Type L max D max f min d nom mounting centres T43D 25.4 8.4 32.0 0.8 31.8 1.2 3.1 T44D 50.8 8.4 32.0 0.8 57.2 1.2 5.6 T48D 150.0 8.4 32.0 0.8 156.4 1.2 18.5 T43KU 30.2 8.5 32.0 0.8 3.9 T44KU 53.2 8.5 32.0 0.8 7.4 T48KU 152.2 8.5 32.0 0.8 19.3 T43TU 32.6 8.5 T44TU 55.6 8.5 8.2 T48TU 154.8 8.5 20.2 T44D d D T44TU L L f T44KU L 5.8 General Note Welwyn Components reserves the right to make changes in product specification without notice or liability. All information is subject to Welwyn's own data and is considered accurate at time of going to print. (c) Welwyn Components Limited * Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 * Facsimile: +44 (0) 1670 829465 * Email: info@welwyn-tt.com * Website: www.welwyn-tt.com A subsidiary of TT electronics plc 07.11 High Voltage Precision Thick Film Resistors Welwyn Components T Series Construction Solderability: A ruthenium oxide based resistive film is fired onto the surface of a high quality former. Turned brass end caps are fitted. A Helical cut is made into the film to adjust its resistive value and finally a protective sleeve is fitted to provide mechanical protection and electrical insulation. Resistors for use in oil or SF6, can be supplied with a lacquer protection instead of the sleeve. The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2. Screw Terminations: Styles TU and KU. Material: Turned brass. Screw Thread: All caps are tapped UNF - 10 x 4.2 deep. UNF - 10 is 32 TPI, 60C thread angle, 4.720.07 mm outside diameter, 3.83 mm core diameter. Three styles of termination are available to permit resistors to be screwed together in a series chain, with the end members having axial wires for soldering. Wire Terminations: Styles D and KU. Non standard terminations available upon request. Coupling Stud: All KU & TU resistors are supplied with 8 mm long screwed brass studs. Material: Solder coated copper wire. Solvent Resistance Strength: The terminations meet the requirements of IEC 68.2.21 Terminations Marking Type reference, resistance value, tolerance and date code are legend marked. The resistance value conforms to IEC 62. The lacquer and the protective sleeve provide excellent resistance to all normal industrial cleaning solvents suitable for printed circuits. Performance Data Maximum Typical Load at rated power: 1000 hours at 20C R% IG:3, >IG:5 0.3 Shelf life: 12 months at room temperature R% 0.3 Derating from rated power at 20C 0.1 Zero at 150C Noise (in a decade of frequency) V/V Voltage coefficient of resistance ppm/V Matched Sets Matched sets can be supplied for use as precision voltage dividers. These may be screwed together to form sticks and, by selecting the KU type of termination, a wire connection can be provided at each end of the stick. Enquiries are welcomed for special resistors and sets when resistor length, operating voltage or resistance value are outside the catalogued range. Application Notes Due to the high voltage which can appear between the end cap and any adjacent metal part, resistors should be mounted at an adequate distance from other conductors. An appropriate number of resistors may be screwed together as a stick to provide an assembly which will be capable to withstanding any desired voltage, providing no individual resistor is subject to a greater stress or power dissipation than is recommended in this data sheet, and that appropriate anticorona devices are fitted. <2.5 <1 When resistors are required to be potted, the preferred encapsulant is a silicone compound. For voltage dividers with a low resistance section below the minimum available value of 1k, it is normal practice to use a Welwyn resistor, RC Series, obtainable down to 1 ohm. Oil Immersion For some high voltage applications it is required to immerse the components in oil or gas to reduce the effects of corona and surface tracking. A special lacquer protected version of the resistor is available, suitable for immersion in transformer oil or SF6. Packaging Resistors are supplied packed in boxes. Standard Quantities Per Box All Types 10 or 20 per box The axial termination should not be bent closer than twice the diameter of the terminal wire from the body of the resistor. (c) Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 * Facsimile: +44 (0) 1670 829465 * Email: info@welwyn-tt.com * Website: www.welwyn-tt.com 07.11 High Voltage Precision Thick Film Resistors Welwyn Components T Series Ordering Procedure Example: T44 wire-ended and sleeved at 4.7 gigohms and 5% tolerance T44D- 4G7JI Type Termination D KU TU Wire / wire Wire / screw Screw / screw Protection H Lacquered & Sleeved Lacquered only (for use in oil or SF6) Value (use IEC62 code) Tolerance (use IEC62 code) F G J 1% 2% 5% Packing I Box 10 or 20/box Standard Note: Standard TCR is 100ppm/C. Contact factory for 50 and 25ppm/C grades. (c) Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 * Facsimile: +44 (0) 1670 829465 * Email: info@welwyn-tt.com * Website: www.welwyn-tt.com 07.11