For power electronics design engineers looking for high current devices capable of providing current-sense and surge protection functions in high temperature environments, TT electronics IRC offers a series of open-air current sense resistors. The OARS-3 Series surface mount metal alloy strip resistors feature a flameproof open-air design that elevates the device’s “hot spot” above the PC board, where heat can be dissipated to ambient air instead of to adjacent thermally-sensitive components. The unique design also gives the resistors desirable thermal temperature cycling performance. The resistors’ ability to operate reliably under elevated temperature conditions makes them appropriate for computer power supplies, high-reliability server equipment, and automotive underhood applications. The OARS-3 Series resistor performs at 3 W; however, testing conducted by IRC engineers demonstrate that the resistor is capable of handling higher power levels without forced air depending on system thermal design. Testing at 4 watts reveals that, although the “hot spot” temperature can reach in excess of 230°C when the resistor is running at full power, the solder joint remains at 110°C or below.

TT electronics IRC
361-992-7900, www.ttelectronics.com