Abstract: A drill collar position verifier for use with a drill bit having a drilling depth control collar positioned coaxially thereon. The drill bit is inserted in a cylindrical opening in a plastic block to a depth determined by the position of the collar. Three optical beam sources are positioned at three different predetermined depths in the plastic block. Each optical beam source projects an optical beam across the cylindrical opening and onto a corresponding optical beam detector, unless the drill bit breaks such optical beam projections. The optical beam detectors are connected to logic circuitry which is further connected to LED indicators. If the drill bit protrudes far enough through the plastic block to break the first but not the second and third optical beams, an LED is lit to indicate that the collar is positioned too close to the tip of the drill bit.

Abstract: An ultraviolet exposure unit for exposing both sides of a printed circuit board to ultraviolet light to cause ultraviolet sensitive materials which have been applied to said printed circuit board to cure. A vertically positioned curing chamber and a printed circuit board carrier system provide vertical orientation and simultaneous application of ultraviolet light to both sides of the printed circuit board when such ultraviolet materials are applied to both sides of the printed circuit board.

Abstract: A drill collar position verifier is disclosed for use with a drill bit having a drilling depth control collar positioned coaxially thereon. The drill bit is inserted in a cylindrical opening in a plastic block to a depth determined by the position of the collar. A metallic foil and membrane switch are positioned below the plastic block of predetermined depth and are connected to logic circuitry which is further connected to LED indicators. If the drill bit does not protrude through the plastic block, an LED is lit to indicate that the collar is positioned too close to the tip of the drill bit. If the drill bit protrudes through the fixture and contacts the foil only, an LED is lit to indicate that the collar is positioned within tolerances. And, if the drill bit protrudes through the fixture and contacts both the foil and the membrane switch, an LED is lit to indicate that the collar is positioned too far away from the tip of the drill bit.