VISHAY Intertechnology, represented in Australia by Braemac , has released 30W, 50W and 100W thick-film power resistors in industry-standard TO220 and TO247 packages. They use a ceramic package design (with no metal tab) for direct-mounting on heatsinks.
They offer an inductance of less than 0.1H, suiting them for use in power conversion and control applications in a wide variety of industries.
The Sfernice devices are available in resistance values from 0.01Ω to 550kΩ for the LTO 30 and LTO 50 families, and from 0.015Ω to 1MΩ for the LTO 100. All of the devices have a temperature coefficient of 150ppm/°C for values above 0.5Ω. Their direct-mounting package design improves heat dissipation and reduces space on printed circuit boards.
The LTO resistors are designed for use in pulse-loading applications, as snubber or bleeder resistors, and in high-power equipment such as uninterruptible power supplies (UPS), power conversion for traction and industrial drives, and in medical, automotive, and industrial control environments. The resistors use an optimised process of printed thick-film technology on an alumina substrate to achieve tolerances as low as 1% and up to 10%.
All of the resistors are compatible with tin/lead and lead-free soldering processes, allowing use by all assemblers changing to lead-free processes to meet incoming legislation and voluntary environmental manufacturing codes. All devices comply with EU directives on vehicle end of life, including 2000/53/EC End of Vehicle Life Directive (ELV) and 2000/53/EC Annex II to End of Vehicle Life Directive (ELV II). All devices also meet 2002/95/EC Restriction of the use of Hazardous Substances Directive (RoHS) and 2002/96/EC Waste Electrical and Electronic Equipment Directive (WEEE).