Wire-wound resistor
AssigneeU.S. Philips Corporation
InventorsHubertus J. J. Brech, deceased, by Friedrich J. de Haan, administrator
Life of this patent
Estimating the term…
Abstract
Wire-wound resistor covered with a layer of enamel on the basis of a zinc borosilicate having a composition: ______________________________________ SiO.sub.2 6-18 CaO 5-12 B.sub.2 O.sub.3 35-60 Al.sub.2 O.sub.3 5-15 Na.sub.2 O 2-12 ZrO.sub.2 5-10 ZnO 10-25 CoO 0,1-2 ______________________________________ wherein Al.sub.2 O.sub.3 +ZrO.sub.2 exceeds twice the Na.sub.2 O-content and some maxima for permissible contents of other oxides, including coloring oxides, are indicated. This enamel provides a proper solution of the problem of composing an enamel being adequately alkali-proof and being located in the proper range of coefficients of expansion for Ni-Cr and Ni-Cu-wire.
Claims2
A wire-wound resistor whose turns are covered with a layer of enamel on the basis of a zinc silicoborate, characterized in that the enamel has a composition in percent by weight within the following range of compositions:
- ______________________________________ SiO.sub.2 6-18 CaO 5-12 B.sub.2 O.sub.3 35-60 Al.sub.2 O.sub.3 5-15 Na.sub.2 O 2-12 ZrO.sub.2 5-10 ZnO 10-25 CoO 0,1-2 ______________________________________
- with the additional condition that Al.sub.2 O.sub.3 +ZrO.sub.2 >2 Na.sub.2 O, while,
- ______________________________________ BaO <
- 10 Fe.sub.2 O.sub.3 <
- 2 MgO <
- 3 Cr.sub.2 O.sub.3 <
- 2 TiO.sub.2 <
- 5 NiO <
- 2 MnO <
- 4 ______________________________________
Dependencies are inferred from the claim text.