Abstract: The continuous flow of fresh water to and metal hydroxide contaminated water from a counter flow rinse tank in an electroplating apparatus is greatly reduced or eliminated by a parallel flow path provided to an adjacent ion exchange treatment unit and from the ion exchange unit back to the rinse tank. The rinse tank is fitted with a submerged pump to provide the rinse water to the ion exchange unit and through this unit back to the rinse tank.

Abstract: A holder for supporting a printed circuit board in a vertical plane for movement along a path for treatment of sides of the board. The holder comprises a rigid frame support an means for mounting the frame for movement along the path. The improvement comprises means for mounting an edge of the board at a first position on the frame and a moveable weight bar for mounting a second edge of the board at a second position on the frame below the first position. The weight bar acts to provide a stretching force to the board for aiding and maintaining the board substantially planar during processing of the board as mounted in the frame.

Abstract: A printed circuit board conveyor apparatus has a conveyor for moving a planar circuit board components mounted on frames, in a vertical plane, seriatim, along a first path through a spray treatment area. The components are then raised and returned toward a starting point along a second path with additional processing occurring during the return trip. The use of an overhead return along with positive positioning of the components provides substantial efficiency and allows precision and accuracy in treatment of printed circuit board components while minimizing floor space requirements.

Abstract: A printed circuit board conveyor apparatus has a conveyor for moving a planar circuit board components mounted on frames, in a vertical plane, seriatim, along a first path through a spray treatment area. The components are then raised and returned toward a starting point along a second path with additional processing occurring during the return trip. The use of an overhead return along with positive positioning of the components provides substantial efficiency and allows precision and accuracy in treatment of printed circuit board components while minimizing floor space requirements.

Abstract: Zinc oxide varistors having high resistance and exponent values are fabricated from a composition consisting essentially of the oxides of zinc, tin, bismuth, antimony, manganese, nickel, cobalt and boron. The composition does not contain barium oxide or silicon dioxide and still retains long term stability properties.

Abstract: A station arrester employing metal oxide varistors has varistors whose capacitances increase in a direction measured from the ground side of the arrester. An approximately uniform voltage distribution can be produced across the varistors when appropriately graded according to their positions in the varistor stack. In this configuration, the varistor disks located near the top or line end of the stack are not subjected to increased thermal stresses.

Abstract: A box completely enclosing an ultrafiltration unit forming part of a larger water purification system, has brackets for support of the unit and ports for the entrance and exit of wastewater conduits. A drain located a distance above the bottom of the box permits a moist atmosphere to be maintained in the box during normal operations and a second drain located flush with the bottom of the box permits quick and effective isolation of a unit so that the system operation may be continued in the event of failure of the unit.

Abstract: A metal oxide resistor of the type consisting essentially of zinc oxide and containing significant amounts of the impurities bismuth trioxide, cobalt trioxide, manganese dioxide, antimony oxide, chromic oxide, and silicon dioxide contains also significant amounts of the impurities barium oxide and boron oxide.