V700

Vitreous Enamelled Wirewound Resistors V700 (RB Style) Series Welwyn Components • BS/CECC approved • Stability for harsh environments • Overload characteristics ideal for protection circuits • • • High stability and reliability High power dissipation for size Impervious lead free vitreous enamel coating Electrical Data V757 (RB57) Power rating at 25°C Resistance range Limiting element voltage TCR Resistance tolerance watts ohms volts ppm/°C % 7 0R1 to 20K 200 5 V758 (RB58) 11.0 0R2 to 82K 400 Typically: +75 V759 (RB59) 3.0 0R1 to 10K 100 V760 (RB60) 8.0 0R1 to 56K 250 Maximum +120 V761 (RB61) 5.0 0R1 to 15K 160 Closer tolerances to special order Approved CECC 40201 - 001 Power rating at 25°C Power rating at 70°C Resistance range Limiting element voltage TCR Resistance tolerance Standard values Thermal impedance Ambient temperature range °C/watt °C 44 watts watts ohms volts ppm/°C % 5 32 6.5 5.6 0R1 to 20K 160 >20 ohms ±500 5 88 -55 to 200 3.0 2.6 0R1 to 10K 63 8.0 6.9 250 ≥20 ohms -50 +250 5 36 5 58 5.0 4.3 160 0R1 to 56K 0R15 to 15K E24 preferred. Other values to special order * See temperature rise in graph Application Notes Physical Data Maximum Dimensions (mm) and Weight (g) Type V757 (RB57) V758 (RB58) V759 (RB59) V760 (RB60) V761 (RB61) L max 22.2 47 12.7 36 23 D max 8 11 5.6 10.0 7.0 f min 30 30 30 30 30 d max 0.88 0.88 0.88 0.88 0.88 Wt. Nom 2 9 1 4 2 d D L f Construction A high purity ceramic substrate is assembled with force fit end caps to which are welded the termination wires. The resistive element is wound on the substrate and welded to the caps; the vitreous enamel protective coating is then applied. 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. A subsidiary of TT electronics plc Issue B · 03.02 © 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 87 Vitreous Enamelled Wirewound Resistors V700 (RB Style) Series Welwyn Components Terminations Material Copper clad steel wire, nickel plated and solder-coated. Strength The terminations meet requirements of IEC 68.2.21. Solderability The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2. Performance Data CECC 40201-001 Load at rated power: 1000 hrs Dry heat: 1000 hours at 200°c Shelf life: 12 mths at room temp Derating from rated power at 25°C Short term overload Climatic Climatic category Long term damp heat Temperature rapid change Resistance to solder heat Vibration Noise (µV/V in a decade of freqency) Shock Pulse handling ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% 5 5 Not specified Not specified 2 5 55/200/56 5 1 1 1 Not specified 1 0.2 Data available by request 1.5 0.5 55/200/56 0.05 0.5 0.25 0.25 zero 0.05 5 2 0.03 See derating curve 0.5 0.2 55/200/56 0.02 0.05 0.03 0.05 Actual Performance Maximum Typical 3.5 1 0.02 Application Notes The terminations should not be bent closer than 1.6mm from the body, and the recommended minimum bend radius is 1.2mm. If resistors are to dissipate full rated power, the terminations should not be soldered closer than 4mm from the body. When cold, vitreous enamel has excellent insulation resistance. In common with all insulants the specific resistance of the enamel decreases with increase in temperature. Therefore, resistors operated at near maximum temperature cannot be classed as insulated and should not be used in contact with any conducting material. Care must be taken when determining clearance distance between the resistor body and the printed circuit board or other components to ensure these are not over heated. Resistance is measured 6mm from the body. 116 Derating Curve % of Rated Power 100 54 0 25 70 200 315 Ambient temperature °C Packaging For RB59 and RB61 the standard method of packaging is taped and Ammo Packed. For RB57, the standard method of packaging is taped and reeled. RB58 and RB60 are loose packed in boxes. Alternative packaging available by request. Standard Quantities Per Box/Spool Type V759 V757 V761 L 63 73 73 6 f1 L f1 – f2 ≤ 1.4 mm f2 6 10 Type (style) Ammo pack Spool Box (Loose) V757 (RB57) – 700 – V758 (RB58) – – 25 V759 (RB59) 1000 – – V760 (RB60) – – 50 V761 (RB61) 1000 – – © 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 88 Issue B · 03.02