Research And Design Of Intelligent Beams Using Laser Based DMX512Protocol

The intelligent beams are a kind of illumination and effect light widely used intheatrical performances, they are an important part of the stage lighting system,responsible for rendering the atmosphere. The intelligent beams originated in theseventies and eighties of the last century, initially used in some foreign theater andopen-air stage. At first, the intelligent beam was just simple as a motor-driven lampcylinder. With the development of literature and art, intelligent beams as an importantpart of the lighting system has been developed by leaps and bounds.The intelligent beams at present are more complex, more feature-rich and easier touse than the earlier ones. The intelligent beams are no longer simply lamp cylinder,but a complex system including the advanced technology of optics, mechanicalscience and information science. They have the function of transforming the color,pattern transformation, chasing light, strobe and a variety of effects. The applicationof lighting console has dozens or even hundreds of intelligent beams ordered in asame lighting system, which makes the control of lights more automated.The lighting control can not fail to mention the DMX512protocol, the DMX512protocol is a lighting control protocol first proposed by USITT in1986. Its goal is toconnect multiple lights, dimmers and other lighting equipment with a pair of signallines. DMX512protocol is simple and clear and has good operability which madeDMX512protocol very popular with the world`s major manufacturers and users.After multiple revisions, DMX512protocol has become a mainstream lighting controlprotocol in the world. In the Internet age of today, there are several lighting controlprotocols based on network applications, but DMX512protocol still has incomparableadvantages on many occasions.Unlike traditional intelligent beams using metal halide light source, this paperdesigns a laser intelligent beams based on the DMX512protocol using RGB-laser asthe light source. Relative to the metal halide light source, laser lights have low power,less heat, no ultraviolet radiation, long life and less attenuation, which overcomesmany shortcomings of the metal halide light source. In addition, the monochrome of the laser gives stage light true color and strong performance.This system can be divided into three parts: the part of the circuit, the mechanicalparts and optical parts. Part of the circuit is the main object of study.Circuit part designs three circuit boards: DMX512signal decoding board, steppermotor driver board and the states display board. Drawing of the schematic and circuitboard are based on Altium Designer6.0software platform. DMX512signal decodingboard using microcontroller AT89S52as MCU, is mainly responsible for theDMX512signal receiving, decoding, control signal sending, the light sourcehigh-voltage switch controlling and the lamp motor driving, etc.. Lamp motor driveapplications NJU39610and NJM3772chip. Stepper motor driver board is designed tocomplete the motor driving of shutter, focal length, pattern plates, and other movingparts. Different with lamp motor, stepper motor driver board uses a L293DD as motordriving chip, AT89C2051microcontroller as MCU. States display board usesAT89S52as MCU, which drives four digital tubes to display system statusinformation. In addition, there are four buttons providing input.About the mechanical part, this paper analyzes the requirements of the motor`storque output with loads, then select the type of stepper motor. Considering the workmode of the stepper motor, format of the drive signal is analyzed, hence how togenerate such a signal through the driver chips.About the optical part, introducing and analyzing the laser light sources are focus.First the history of the development of the light source is introduced, with aconclusion that energy saving and environmental protection is a major trend of thelight source development. Comparing are made on the pros and cons of traditionalintelligent beams using metal halide light source and laser sourced ones in the energyconsumption and other aspects. Unlike traditional intelligent beams, color change ofthis system does not use a color wheel, but a laser beam mixing system based on theadditive color mixing method by RGB lasers.