Boone, N.C. Using an innovative "Z" lead configuration to enable high power axial resistors to be surface mountable, TT electronics' Welwyn Components Division touts that it has developed the highest power surface-mount resistor that can handle the harsh temperatures found in automotive environments.
Designated the WA80Z Series, these flameproof resistors are touted as an economical replacement of costly molded power devices. The resistors feature high power ratings, excellent overload capabilities, and safe fusing operation, making them suitable for automotive applications such as water pump control and advanced braking systems, said the company.
The WA80Z is available in 2 W, 3 W and 5 W ratings, with values from 10MΩ to 6.8kΩ and tolerances to 1%. Meeting the automotive temperature range of -55°C to 155°C, the WA80Z Series can be customized for specific fusing or pulse handling characteristics.
A key advantage for the designer is that the WA80Z series resolves thermal management problems where other high power SMT resistors fail, said the company. The cement-coated wirewound resistor uses a unique SMD lead forming technique, pioneered by TT electronics, to convert axial power resistors into an SMD format.
"The WA80Z Series resistors offer engineers a 5W-rated device that will fuse safely under fault conditions, and its cement coated construction produces a rugged device that is inherently flameproof without requiring flame retardant material," said Keith Chipman, IRC product manager, in a statement.
"And, because the resistor's lead configuration raises it up off the PC-board, the devices have superior radiated and convective heat dissipation without relying on the PCB traces as a heat sink like some flat chip resistors," he said.
Developed under full approval to the TS16949: 2002 standard, the WA80Z resistors can replace molded parts and traditional through-hole devices. Supplied in blister pack tape and compatible with vacuum pick and place systems, these devices are typically priced $0.35 in quantities of 1,000. Delivery is from stock to 6 weeks.
Welwyn products are available from IRC's Wirewound & Film Technologies Division in North America.
Call (828) 264-8861