Abstract: Color-changing apparatus, and an associated method, for a lighting assembly. One or more dichroic filters are selectably positioned in the path of a light beam generated by a light source. A positioner supportively positions the dichroic filter and effectuates its translation into and out of the path of the light beam. A set of dichroic filters, each separately supported by a separate actuating positioner permits a combination of dichroic filters to be combined to cause the light color of the light beam to be of any desired color.

Abstract: A gobo handling apparatus for use in a spotlight is disclosed. The spotlight has a housing supporting a light source producing a light beam and supporting at least one focusing lens. The spotlight includes an iris slot through the housing proximate the focal plane of the light beam. The apparatus of the invention comprises an elongated gobo housing removably inserted in the slot. The gobo housing has a central axis and an aperture therethrough for passage of the light beam in a direction normal to the gobo housing axis. The housing has a plurality of generally disk shaped gobo carriers each supporting a gobo, arranged side by side and movably contained within the housing. A drive mechanism contained within the housing operatively engages each of said plurality of gobo carriers for independently translating the gobo members along the housing axis into and out of the spotlight beam and rotating the gobo carrier in the spotlight beam in response to a remote control signal.

Abstract: A performer tracking system, and an associated method, for tracking movements of at least one performer upon a stage. A plurality of signal transmitters are positioned about the stage and transmit electromagnetic signals. Performers on the stage carry transponders which receive the electromagnetic signals and, responsive thereto, generate coded sound signals. Sound signal receivers positioned together with the signal transmitters receive the sound signals. A controller determines positions of the transponders and, hence, the performers carrying the transponders and causes spotlights to track the performers.

Abstract: A light frequency communications system and method of using the system is disclosed. The system includes a base station and a plurality of remote units wherein the base station and all the remote units communicate in a full duplex mode utilizing a single light wave carrier. Multiplexing between the units is accomplished by modulating an audio signal on at least one subcarrier frequency.

Abstract: A communication system includes a filter device for passing only a desired carrier frequency, and a circuit for splitting the passed carrier frequency into a pair of signals. A circuit for feeding back one of the signals to the filter device for causing an oscillation to occur at the desired carrier frequency for direct broadcast purposes.

Abstract: The battery charger includes a slope detector which responds to the battery voltage of the battery being charged, to generate a peak indicating signal, when the voltage decreases following the peak charging voltage of the battery. A peak hold device responds to the peak indicating signal to cause the charger to switch abruptly from a high charge mode to a low trickle charge mode.

Abstract: A battery charger for recharging nickel cadmium batteries includes trickle charge, fast charge and deep charge modes. A control circuit responsive to the terminal voltage of the battery includes a clock-driven mode control counter having counter states which condition power supply circuitry within the charger to the mode appropriate to the battery terminal voltage. The counter is conditioned to its deep discharge state by actuation of a user-accessible switch. When the terminal voltage falls below a first predetermined level, the counter automatically reverts from the discharge state to its fast charge state to establish the fast charge mode. When the terminal voltage rises above a second predetermined level, the counter automatically reverts to its trickle charge state to establish the trickle charge mode.

Abstract: A microphone which consists of a speaker having a base resonant frequency, a suppression circuit for reducing the frequency response of the speaker at the base resonant frequency, and a high pass filter for reducing the base frequency response of the speaker is disclosed. The speaker creates electrical signals in response to sound waves received and the suppression apparatus reduces the relative magnitude of the electrical signals having frequencies substantially equal to the base resonant frequency of the speaker. The high pass filter reduces the magnitude of all electrical signals having frequencies below a predetermined frequency, and thus a desired microphone frequency response is obtained.A communications system which uses a receiver to drive a speaker in one mode of operation and uses the speaker as a microphone followed by a compensation network and a transmitter in another mode of operation is also disclosed.