Stackpole Electronics WWF: Wire-wound-fusible resistors allow failsafe operation under continuous overloads

Providing the surge-handling characteristics typical of wire-wound devices, the WWF (wire-wound-fusible) series of  conformal-coated devices also features a repeatable-fusing characteristic. This feature works well in applications subject to constant or sustained overload, which results in excessive heat buildup. The devices allow adjustments for quick fusing. Thus, they generate minimal heat and slow fusing for applications in which fusing resistors can open too quickly. The devices can withstand high-voltage surges and allow inherent increases or decreases in voltage. One device in the series survives 6-kV inrush pulses without failing; however, it fails at 120 or 240V-ac steady-state overloads without flame or excessive heat. Prices for the units range from 20 cents to $1.75 (250 to 2500).

Stackpole Electronics, www.seielect.com