Abstract: Testing apparatus in accordance with the invention generates a composite video signal for a CRT which produces a scanning line raster on the video screen thereof clearly displaying the spot size and line focus of the scanning electron beam generating such raster. The display consists of a single scanning test line of high luminance, or white, within an intermediate low luminance or black portion of an otherwise white scanning line raster. The test line is segmented, with black gaps at several discrete locations thereon, each gap being approximately three times the width of the scanning beam spot. Centered within each such gap is a region of high luminance, or white, of a width approximately that of the beam spot. The line focus and spot size of the smallest possible picture element is thereby accurately displayed and so can be measured on the video screen, enabling adjustment of the focussing components for optimum focus.

Abstract: A motorized drawer is moved from a fully closed to a fully open position, or vice versa, in response to user activation of a single pole double throw switch. The motor moving the drawer is connected to the user activated control switch and to a limit switch. Whenever the drawer reaches one of the end positions, a limit switch opens the circuit through which the motor was energized to move the drawer to that position. At the same time, the limit switch partially completes the circuit for energizing the motor in the opposite direction. The latter circuit is completed when the user again activates the control switch, i.e. completes the circuit allowing current flow through the motor in the direction required to drive the drawer to the other end.