Computer moving head light is set electronic, mechanical, optical as one of the high-tech products. Eligible computer moving head light, must be stable and reliable, excellent light efficiency, accurate positioning, good heat dissipation, light body and conform to the requirements of the man-machine engineering material structure. Moving head light from using the power of the computer can be divided into 250 w, 575 w, 1200 w, and other varieties. 1200 w for professional performance places the main lamp type. This paper analyzes the structure principle of 1200 w moving head light. In a nutshell, shook his head amount is made up of optical, mechanical, electrical and process control of the three systems. Three systems connected to each other, and the organic combination, meet the light, color, speed, direction and effect, heat, noise, positioning elements such as need.
A, the optical system
Optical system design is the most main consideration lamp flux utilization. Specific performance indicators include light strength, evenness, saturation, and the size of the light spot. Influence the elements of the above indicators have two aspects, one is light, the second is the optical system structure, choice of materials. At present, the domestic and foreign manufacturers, users recommend basic OSRAM and PHILIPS 1200 w short arc duplex metal gas discharge tubes. Its features are compact, high brightness, high color temperature, good color rendering and in the process of dim light source, to maintain a relatively stable color temperature. Disadvantage is that this kind of lamp in layered problems of filler, the filler in the arc imaging ribbon or in the electric arc tube condenses, form the shadow effect, needs to be in control to a minimum when the optical structure design. In optical structure, to obtain uniform mixed beam, parabolic reflector, can be used to collect divergent or narrow beam, should choose to have scale processing or mirror surface texture. Use mirror material of reflector system is better than the refraction system. When you need a few of the beam of light from a light source, can be combined using prism or lens refraction system. At home and abroad at present, the optical design of 1200 w moving head amount, adopt lens combination way, by the aspheric (parabolic) quartz lens, etc.
Parabolic lens is the most important features in focus is placed on a point light source, will get a parallel beam. In the light path design, still need to consider to light intensity distribution curve, shape and size, reflection lens aperture size and the relationship between the shape of the light source.
Second, the mechanical system
Mechanical system range is very wide, including the material, structure, mechanical properties, shell demands, heat dissipation and so on. Material selection of lamps and lanterns main considerations are: to satisfy the functional requirement of the lamp, make ease and economy. At present, the 1200 w moving head light of international and domestic materials mainly include steel, plastic, aluminum alloy. Considering whole function under the premise of meet the lamp design structure model of lamp, different parts, with different materials. If Aceda - spot1200III1200W shook his head lamp, the lamp body die-casted shell plastic parts, lamp body supporting frame, base, side panel, end plate adopt aluminum alloy casting, stamping parts, car parts.
Light structure determines the mechanical properties, heat dissipation, strength, factors such as noise, and weight. 1200 w moving head light adopt international and domestic arms support structure, the lamp body level rotate 540 °, rotated 255 °, base part shall strengthen the treatment, can satisfy the demands of moving head light hanging inversion.
On the mechanical properties of the light body, mainly reflected in the lamp body parts of mechanical strength, make the light body within the continuous working time effectively, not deformation, wear resistance, corrosion resistance, seismic, compression; Lamp shell must have strict waterproof, dust-proof, antistatic, moisture-proof requirement. According to dustproof and waterproof shell divided into different levels of protection grade requirements: such as indoor use amount of protection level is usually IP20, the amount of outdoor protection level is usually IP44.
1200 w power amount of mechanical structure, the cooling requirements is critical, ventilation system, such as defective usually will cause the electrical parameters drift, color films, film rupture, plaque, crashing, out of step, uncontrolled and other serious consequences.
Part three, electrical and process control
1, computer and electrical characteristics of moving head light circuit design
Worldwide professional 1200 w shook his head before amount of the vast majority of the rare gas discharge light source. Gas discharge bubble of start-up and steady work depends on the type of circuit design, the choice of power supply, ballast and other electrical components. Rare gas discharge bubble starts, generally do not need stable time, in order to ensure the stabilization and in the communication cycle, to maintain the voltage of the circuit and the bulb of the difference between the instantaneous voltage ＆#118alue should be sufficiently large.
The start of the light source, stability, go out and start again, should according to the requirements of the light source characteristics of the design circuit. Rare gas discharge bubble of starting voltage is very high, require the use of transformer, start device, a resonance circuit, improve the instant on voltage. The stability of light source after starting, depending on the ballast and circuit parameters matching. The basic function of the ballast is out of control and prevent current make the light work under its normal electric property. The current production enterprises usually adopt two kinds of ballast, is a kind of inductive rectifier, one kind is electronic rectifier. Inductance rectifier has the advantage of good stability, the disadvantage is that, on the strength of the light body, handling, loading and unloading have high requirements; Electronic rectifier is essentially the power conversion circuit, the input power supply current in frequency, waveform and amplitude changes. Its advantage is light weight, convenient loading and unloading, handling, The disadvantage is that structure design demand is high, the maintenance cost is high.
Light to start again, in the conventional circuit design, because the gas discharge bubble produced in high temperature work, to form saturated gas inside the bubble vapor pressure resistance, light source will immediately trigger again it is difficult to realize, must reduce the gas pressure in the lamp to cold after numerical, can trigger a reboot. At present, the international and domestic production enterprise basic conventional circuit design.
Part 2, program control
The current international and domestic amount of generally used DMX data format program files. DMX512 principle: DMX data flow velocity is 250 k, namely every BIT as standard 4 microseconds. DMX data format is divided into the following parts: 1) the IDLE (IDLE) or NO DMX situation (situation) : when there is NO DMX, the output of the packet will be a high level signal; 2) BREAK: DMX the start of a packet is a low level of 88 microseconds output forecast} {head; 3) MARK AFTER BREAK (MAB) : MAB is AFTER the BREAK, is a high level of 8 microseconds or two pulse; 4) STARTCODE (SC) code: SC was started by the data flow channel data, it has the same format, and channel data for 11 general pulse or 44 microseconds; 5) MARK the TIME BETWEEN FRAMES (MTBF) : MTBF can 0-1 seconds, less than 1 second, in each channel at MTBF, prior to the start bit is high level; 6) CHANNEL DATA (CD) : CHANNEL DATA frame after SC logic format for 1-512 or less than 512; 7) MARK TIME BETWEEN PACKETS (MTBP) : send a high level after the valid data is sent.
Amount of effects, it is through the different modelling mural, different colour change, a different perspective, the change of horizontal and vertical angles and speed, stroboscopic speed, aperture size, focal length changes such as comprehensive performance. All these properties index of work are realized by stepper motor drive, the stepper motor electrical operation parameters defined programming, completes the amount of control.