Glenrothes, Scotland With power electronics design engineers in mind, TT electronics BI Technologies SMT Division has developed two series of non-inductive planar power resistors with power ratings from 3 W to 50 W at 70°C.
Designated as the BPC and BPR Series, the resistors are vertically-oriented, through-hole planar power devices with thick-film resistive elements on ceramic substrates that are designed to dissipate power above the circuit board. Their vertical orientation gives design engineers more flexibility in PC-board design and eliminates the need for high temperature soldering to the PC-board, said the company.
The BPC series resistors are available in 3 W, 5 W, 7 W and 10 W power ratings (at 70°C), with a resistance range from 0.1Ω to 200 KΩ, and standard tolerances of ±1%, ±2%, ±5% and ±10%. The temperature coefficient of resistance (TCR) rating is 100 ppm/° C, and the operating temperature range is -55°C to 125°C. The maximum operating voltage is 300 Vac/500 Vdc. They come with standard copper alloy through-hole leads. Click here for the BPC datasheet.
The BPR series resistors are available in 3 W, 5 W, 7.5 W, 10 W, 20 W, 30 W, 40 W and 50 W power ratings (at 70°C), with a resistance range from 0.1Ω to 200 KΩ, and standard tolerances of ±1%, ±2%, and ±5%. The TCR is 100 ppm/°C, and the operating temperature range is -55°C to 125°C. The maximum operating voltage is 500 Vdc with a dielectric strength of 750 V. Contact the company for power resistor networks with multiple resistors. Custom specifications are available. These devices feature heavy-duty phosphor-bronze double leads that make them suitable for withstanding shock- and/or vibration-prone environments. Click here for the BPR datasheet.
The company noted that the BPC resistors can handle up to 20 times rated current and the BPR series can handle up to 15 times rated current for up to 8 ms with no significant changes (±0.5%) in R values. The power ratings and construction of these devices enable excellent surge power characteristics for applications such as inrush current limiting applications, snubber circuits, power supply preloads and UPS systems. Both series are compliant to the European Union's Restriction of Hazardous Substances (RoHS).
Typical low volume pricing starts at $0.31 (0.24 Euro) for the BPC series and $1.03 (0.79 Euro ) for the BPR series. Delivery is from stock to six weeks. Samples are available for customer prototypes.
TT electronics BI Technologies SMT Division, +44-1-592-662200, www.bitechnologies.com