| 摘要 |
A resistor composition comprises a glassy matrix, preferably a lead borosilicate glass, containing a mixture of a thallium oxide and rethenium oxide dispersed therein; there may also be included up to 20% by weight of metallic silver, gold, palladium or platinum, or their oxides, or up to 50% of a filler such as titania, magnesia, lime, strontia, baria, alumina or zirconia. Preferred proportions are thallium oxide 20-75%, ruthenium oxide 0.1 to 20%, silver, gold platinum, palladium or their oxides 0-10%, filler 0-30% and glass 20-75%. The resistor material may be in the form of a flat or cylindrical film coating on a dielectric base or in the form of a spiral coating or may form a solid volumetric resistor. The material may be applied to the base with the aid of a temporary binder subsequently burned off. Terminals may be provided in known manner, e.g. by printing with a noble metal powder suspension. The resistors are less noisy than resistors without the ruthenium oxide. The glass has the following composition in percentages by weight: PbO, 45-85; B2O3, 2-9; SiO2, 7-40; Al2O3, 0-3; Na2O, 0-5; ZnO, 0-10; metal earth oxides (Ca, Mg, Sr, Ba), 0-10. |
