Christie Digital Systems Inc. (Christie) has established a global reputation as the world’s single source manufacturer of a variety of display technologies and virtual reality. Christie’s broad range of technologies includes Digital Light Processing (DLP) Cinema™ projectors, networking solutions, and cutting edge projection technologies for 3D, virtual reality and simulation . All Christie projectors utilize ballasts; their primary function is to control the power levels sent to the projector lamps while maintaining a safe operating environment. Ballast control boxes (BCB’s), like the one shown in Figure 1, are used internally by Christie employees for testing the ballasts and lamps before assembly, allowing accurate information gathering by eliminating possible complications encountered from projector circuitry. The existing BCB design is over 10 years old and has served its purpose. This original BCB design has a limited ability to integrate air flow and temperature sensors and luminosity measuring devices. Additionally, the microprocessor used in the original design has reached the end of its service life. These problems, coupled with the diminishing supply of serviceable BCB’s, have led to the need for a redesigned BCB system. The project involves designing and testing of mechanical parts, the development of electronic circuitry, and software development.
Travis MacDonald, a co-op student from the University of Waterloo, was asked to investigate the electronic circuitry of the new BCB printed circuit board. The new design requires the consideration of space, cost, and technical limitations.
Christie’s current Ballast Control Box (BCB)
This case study develops, analyzes, and recommends a 5 volt power supply design solution. Three possible solutions are designed, evaluated, and then the most appropriate of these designs is recommended.