Flameproof WHS-UL wirewound resistors have high surge tolerance
Inrush resistors from TT Electronics combines high surge tolerance with failsafe line voltage fusing. The WHS-UL inrush resistors are reliable and offer enhanced product safety, says the company and simplify UL approval for a variety of power supply and monitoring applications.
According to TT, they offer enhanced surge and pulse energy withstand capability. The WHS-UL series has been developed for inrush control applications, such as power supplies, UPS (uninterrupted power supplies), energy metering and motor drives.
Designers will be able to meet a range of surge requirements – either with a larger safety margin or in a smaller body size – due to the WHS-UL resistors’ specially-designed, high energy windings, comments Brian Stephenson, engineering director, TT Electronics. “At the same time, we are supporting our customers in the rapid achievement of their EMC and safety testing goals with this safety agency-accredited product,” he says.
The UL1412-recognised fusible resistors (UL file E234469) provide failsafe fusing at 120 / 240V rms with a UL94-V0 flameproof coating. The WHS-UL resistors are available in 2.0, 3.0 and 5.0W sizes and at E24 values from 10 to 100 Ohms. They offer up to 30J of surge energy capacity and 7kV peak 1.2/50 micro second performance. They also guarantee safe fusing in fault condition overloads from as low as 30W, notes TT.
The WHS-UL is available in a wide range of lead preforms, including vertical radial form in tape and ZI form for SMD processing.
TT Electronics provides engineered technologies for performance critical applications in high growth markets including healthcare, aerospace, defence, electrification and automation.
TT invests in R&D to create designed-in products where reliability is mission critical. Products designed and manufactured include sensors, power management and connectivity solutions. TT has design and manufacturing facilities in the UK, North America, Sweden, and Asia.
