Resistors Ultra Low Profile Power Resistors WDBR Series Ultra low profile thick-film o n steel 500W to 7kW peak power Single fixing heatsink mountable Ideal for dynamic braking , inrush limit and snubber circuits Choic e of flying lead, push- on or solder terminations Low inductance design High i solation, even aerft failsafe overload fusing RoHS compliant, non-flammable construction AllAll Pb-Pb-frfreeee partsparts ccomplyomply withwith EUEU DirDirectivectivee 2011/65/EU2011/65/EU amended amended b yb y(EU) (EU) 2015/863 2015/863 (R (RoHS3)oHS3) Electrical Data WDBR1/2 WDBR1 WDBR2 WDBR3 WDBR5 WDBR7 12, 15, 20, 22, 25, Resistance range ohms 12, 15, 20, 22, 25, 47, 50, 100, 150 33, 47, 50, 100 Resistance tolerance % 10 1 Pulse power rating kW 0.5 1.5 2.0 3.5 5.0 7.0 2 Power rating on heatsink W 160 180 200 260 270 280 3 Power rating on fan-cooled heatsink W 300 700 780 900 1000 1490 TCR ppm/C < +600 Maximum element temperature C 365 Ambient temperature range (heatsink) C -55 to +200 4 Dielectric withstand V (dc/ac peak) 2500 Inductance (typical) H <3 <4 <5 <6 Notes: 1. For details of pulse condition see Fig. 1 in Performance Data. 2. Mounted on a 0.53C/W heatsink with no forced air cooling , air temperature 25C. 3. Mounted on a 0.53C/W heatsink with 5m/s forced air cooling , air temperature 25C. 4. Based on 100% production test, duration 2s minimum Physical Data Dimensions in mm, weight without terminations in g D c Fixing hole is located cen- a trally except on WDBR1/2 L 0.1 W 0.1 t 0.1 D nom a nom b nom c nom Wt. nom where the dimension from the edge by the terminations WDBR1/2 31.9 28.1 2.2 7.5 3.1 4.3 6.5 to the mounting hole centre is W b 16.68mm. WDBR1 49.3 35.9 3.2 3.2 11.2 6.2 12.6 In addition to the central fixing WDBR2 61 40.6 0.9 4.7 13.0 5.8 17.1 hole, WDBR7 has two corner L WDBR3 101.6 70 13.5 22.0 10.2 50.8 holes. These are present for 5.3 manufacturing purposes only Substratethickness =t WDBR5 122 70 14.0 23.8 7.4 60.7 and should not be used as fix - ing holes. WDBR7 152.4 101.6 1.5 15.0 51.3 9.2 181.8 Construction A high integrity dielectric layer is applied to a machined stainless steel substrate. Thick-film conductor and resistor paernstt are printed and fired, then protected with a high temperature overglaze. The termination pads are tinned with solder and optional terminals or leads are soldered on. General Note BI Technologies IRC Welwyn TT Electronics reserves the right to make changes in product specification without notice or liability. All information is subject to TT Electronics own data and is considered accurate at time of going to print. www.ttelectronics.com/resistors TT Electronics plc 03.21Ultra Low Profile Power Resistors WDBR Series Terminations The following termination options are available Option Code Nominal Dimensions (mm) PL WDBR Size 1, 2, 3, 5 & 7 1 Solder pad only I Pad Length, PL 7.5 9.0 PW Pad Width, PW 4.5 9.0 250mm Flying leads UL3134/5 L 3mm 40A , 600V TW TT WDBR Size 1, 2, 3, 5 & 7 Terminal Height, TH 7.5 12 TH Push-on connectors T Terminal Width, TW 2.8 6.3 Terminal Thickness, TT 0.8 0.8 Notes: 1. Two options exist for solder type. The standard is SnAg (96SC) which is Pb-free and the second (HT) is high temperature HMP alloy which is Pb-bearing. Both are RoHS compliant, but the second relies on the RoHS exemption for high temperature solders and is targeted at specialist high temperature applications. Thermal Performance Maximum Pulsed load at full pulse power rating 50,000 cycles (see Fig 1) 5 R% Mounted on a 0.53C/W heatsink with 5m/s forced air cooling , air temperature 25C. Derating at heatsink temperatures >160C See Fig. 2 Fig.2: TemperatureDerating Fig. 1: Duty CycleWaveform 120 1ms 100 Ppk 80 60 40 20 0 8s 1ms 050100 150200 250 2s Heatsink Temperature(C) General Note BI Technologies IRC Welwyn TT Electronics reserves the right to make changes in product specification without notice or liability. All information is subject to TT Electronics own data and is considered accurate at time of going to print. www.ttelectronics.com/resistors TT Electronics plc 03.21 % of Rated Power