New direct water-cooled wirewound resistors save space and increase reliability

Vishay Intertechnology has a new series of direct water-cooled wirewound resistors that provide ultra-high power dissipation to 9000W with almost no external radiation. Available in six compact sizes ranging from 38mm x 178mm to 38mm x 410mm, Vishay MCB DCRF series devices are created to save space and increase reliability over standard wirewound resistors. These resistors handle 10 times the power of natural-cooled devices in the same size, and twice the power of indirect water-cooled devices. By substituting multiple components with one resistor, the DCRF series enables designers to simplify layouts, lower costs, and reduce the size of their end products. The devices' modular structure allows a multi-resistive element option. The series offers low inductance (<500nH for model DCRF 38 x 178 with resistance of 4.7Ohm) and provides a resistance range from 0.56Ohm to 27Ohm, with tolerances down to ±5%. The devices offer power ratings from 1500W to 9000W with a water inlet temperature of 65C and 8.33l/min flow rate (deionised water with conductivity <2µS/cm). RoHS-compliant and lead (Pb)-free, the resistors offer a typical temperature coefficient of 100 ppm/C and run over a temperature range of -55C to +120C.