Abstract: A motion picture projector is provided with a high intensity projection arrangement for improved image projection that also provides a projection lamp having a longer operating life. The projector is interconnected to a power supply unit by a multiconductor umbilical cable to supply all voltage and power requirements of the projector.The power supply unit is enabled to supply a high voltage starting pulse to the high intensity projection lamp only upon the occurrence of predetermined conditions to prevent shock hazards. The enabling control of the power supply is accomplished by the use of a standard projector control switch and a housing interlock switch on the projection lamp arrangement. Further, the power supply unit is enabled only when the umbilical cable is properly connected between the projector and the power supply unit by means of a return path continuity detector.

Abstract: Disclosed is a blower assembly for use in dispersing heat from an image projector with minimum air flow noise by interposing a constant torque clutch formed of a dual wound spring between the blower and a motor output drive to permit the rate of rotation of the blower to vary in response to variations in air weight due to changes in temperature, atmospheric pressure, and moisture content.