MO-S C.qxd 7/22/04 2:19 PM Page 1 Power Metal Oxide Film Resistors Welwyn Components MO-S Series Small size for power rating Can replace carbon composition in many pulse handling applications Flameproof protection Electrical Data 1 MO /2S MO1S MO2S MO3S MO5S Power rating at 70C watts 0.5 1.0 2.0 3.0 5.0 Restance range ohms 10R - 50K 10R - 100K 10R - 100K Limiting element voltage volts 250 350 500 TCR ppm/C 350 Isolation voltage volts 350 500 700 Resistance tolerance % 5, 10 Standard values E24 preferred Thermal impedance C/watt 140 110 80 60 35 Ambient temperature range C -55 to +155 Physical Data Dimensions (mm) and Weight (g) pcb Min mounting bend Wt. Type L max. D max. f min. d nom. centres radius nom. 1 MO /2S 6.2 2.5 21.0 0.6 10.0 0.6 0.3 d MO1S 9.0 3.6 19.6 0.8 12.5 1.2 0.5 D L f MO2S 12.5 4.2 17.8 0.8 15.0 1.2 0.9 MO3S 14.5 5.3 23.8 0.8 20.0 1.2 1.1 MO5S 25.0 8.5 27.6 0.8 30.0 1.2 4.3 Construction Marking 1 The tin oxide resistance element is deposited onto a high MO /2S, MO1S, MO2S and MO3S resistors are colour coded purity ceramic rod. End caps are force fitted and termination with four bands. IEC 62 colours are used. For larger sizes type wires are welded to the end caps. The element is adjusted to reference, resistance value and tolerance are legend marked. the required resistance value by a helical cut finally a cement The resistance value marking conforms to lEC 62. protection is applied to the resistor body prior to marking with indelible ink. Solvent Resistance The body protection and marking are resistant to all normal Terminations industrial cleaning solvents suitable for printed circuits. Material Resistor sizes up to and including the MO3S use solder coated copper terminations. MO4S Flammability and MO5S use solder coated steel cored The resistor coating will not burn or emit incandescent terminations. particles under any condition of applied temperature or power overload. Strength The terminations meet the requirements of IEC 68.2.21. Solderability The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2. General Note Welwyn Components reserves the right to make changes in product specification without notice or liability. A subsidiary of All information is subject to Welwyns own data and is considered accurate at time of going to print. TT electronics plc 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 Issue C 07.04 149MO-S C.qxd 7/22/04 2:19 PM Page 2 Power Metal Oxide Film Resistors Welwyn Components MO-S Series Performance Data Maximum Load at rated power: 1000 hrs at 70c R% 5 Shelf life: 12 months at room temperature R% 2 Derating See derating curve Climatic R% 1 Climatic category 40/125/56 Temperature rapid change R% 0.5 Resistance to solder heat R% 0.5 Application Notes MO-S Series Derating Curve 100 1. If the resistors are to dissipate full rated power, it is 90 recommended that the terminations should not be 80 soldered closer than 4mm from the body. 70 60 50 2. Due to operating temperature limitations imposed by some 40 pcb materials, derating may be necessary. An estimate of 30 the temperature rise to be expected can be calculated 20 using the thermal impedance figures given under Electrical 10 Data. 0 60 80 100 120 140 160 180 200 220 240 Ambient Temp 3. MO-S resistors can also be supplied pre-formed. See lead form section for details. Figure 1 Packaging 1 Our standard packaging for MO /2S, MO1S, MO2S and MO3S is taped and ammo packed, MO5S is taped and reeled. The c critical dimensions are shown in Figure 1. The component wires will not protrude beyond the outside edge of the tapes. f f 1 2 6 b 6 Pre-formed resistors are supplied loose packed in plastic bags Body Location f f 1.4 mm 1 2 or boxes. Alternative packaging available by request. 1 Type MO /2S MO1S MO2S MO3S MO5S b52 52 52 67 85 c 5 5 5 10 10 Standard Quantities Per Package 1 Type MO /2S MO1S MO2S MO3S MO5S Reel 5000 2500 2500 1000 700 Ammo pack 5000 2500 1500 1000 n/a 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 Issue C 07.04 150 % of Rated Power at 70C