4BF1907-10RGI

Tubular Vitreous Enamelled Wirewound Resistors 1600/1900 Series Welwyn Components • • • • Impervious lead free vitreous enamel coating Can be supplied with fixed, adjustable, tapped or low inductance winding Seven termination styles with choice of mounting arrangements Manufactured RoHS compliant Pb-free terminations* * Check status of stock when ordering General Information Vitreous enamelled wirewound resistors are capable of withstanding a higher dissipation size for size, than any other protected type; this is attributable to the higher operating temperature which the wire and enamel can withstand. Vitreous enamel provides exceptionally good protection to the wire element and is essentially impervious to moisture. The resistors can safely be used in harsh environmental conditions. The Welwyn range is based on thirteen sizes of tube, each of which has a recommended maximum dissipation which limits operating surface temperature to a maximum of 375°C. The stability and high reliability of Welwyn tubular vitreous resistors is a direct result of the best quality materials being used in their construction. High purity ceramic tubes have been matched with nickel chromium resistance wires and specially formulated enamel to ensure that the resistors can withstand repeated heat cycling without damage. Connections between the resistance element and end terminations are welded; other connections are brazed. Mounting devices are available which permit resistors to be mounted by both ends or by one end. Single ended mounting is recommended for applications which do not subject the resistor to shock or vibration. Ferrules and the F type mounting plug are anchored into the tubes with high temperature adhesive. Special requirements, for types or styles not described in this brochure, will be considered for economic quantities. Electrical Data Power rating at 70°C Resistance range Limiting element voltage TCR (-55 to +200°C) Resistance tolerance Values Thermal impedance Operating temperature range watts ohms volts ppm/°C % °C/watt °C 1605 47 1601 11 1905 16 1602 1906 1603 1604 17 22 25 35 See Table 1 See Table 1 Typically: