Abstract: A unique drive circuit for a fluorescent lamp, as well as a housing for such lamp and drive circuit, designed for mineral museum displays, are disclosed herein. The drive circuit comprises a ballast subcircuit, a separate filament transformer subcircuit for pre-heating the lamp cathodes, and a relay between the subcircuits. The separate filament transformer subcircuit obviates the need for a conventional starter circuit for the fluorescent lamp. This way of pre-heating the cathodes prolongs the useful life of the lamp by making it possible for the lamp to undergo thousands of “on-off” cycles without the heretofore usual deterioration of the cathodes. The relay prevents the high voltage of the ballast from “hitting” the lamp cathodes before the cathodes have been pre-heated by the transformer subcircuit. Also disclosed is a method for using such a lamp, drive circuit, and housing to irradiate fluorescent minerals in a display case.

Abstract: A unique drive circuit for a fluorescent lamp, as well as a housing for such lamp and drive circuit, are designed for mineral museum displays. The drive circuit comprises a ballast subcircuit, a separate filament transformer subcircuit for pre-heating the lamp cathodes, and a relay between the subcircuits. The separate filament transformer subcircuit obviates the need for a conventional starter circuit for the fluorescent lamp. This way of pre-heating the cathodes prolongs the useful life of the lamp by making it possible for the lamp to undergo thousands of “on-off” cycles without the heretofore usual deterioration of the cathodes. The relay prevents the high voltage of the ballast from “hitting” the lamp cathodes before the cathodes have been pre-heated by the transformer subcircuit. Also a method is designed for using such a lamp, drive circuit, and housing to irradiate fluorescent minerals in a display case.

Abstract: A pair of doctor blade assemblies extend from upper and lower ends of a housing. Seal assemblies having compressible seals, seal spacers and retaining plates are disposed at opposite ends of the housing and extend between the upper and lower doctor blade assemblies. The doctor blade assemblies, the seal assemblies, the inner surface of the housing and the outer surface of the transfer roll define a fully encapsulated applicator chamber. The upper blade assembly includes a doctor blade positioned as a trailing edge blade, a blade support for clamping the blade and for securing the blade to the housing, a blade seal positioned for sealing the ink chamber and a pneumatic assembly for adjusting the pressure of the trailing doctor blade against the transfer roll. The lower blade assembly includes a doctor blade positioned as a trailing edge blade and a blade support for clamping the blade and for securing the blade to the lower end of the housing.