Moving head lamp is a collection of electronics, machinery, optics as one of the high-tech products. Qualified moving head light, must be stable and reliable, excellent luminous efficiency, accurate positioning, good heat dissipation, light body and material structure in line with ergonomic requirements. Moving head light from the use of power can be divided into size 250W, 575W, 1200W and other varieties. 1200W is the main type of lighting for professional performances. This article focuses on 1200W moving head lamp structure principle analysis. In a nutshell, the headlight is composed of three systems of optical, mechanical, electrical and process control. Three systems are interrelated, organic combination, to meet the needs of light, color, speed, direction, effect, cooling, noise, positioning and other factors.

    First, the optical system

    Optical system design is the most important factor to consider the luminous flux utilization. Specific performance indicators include light intensity, uniformity, saturation, spot size. Affect the above indicators of the elements have two aspects, one light source, the second is the optical system structure, material selection. At present, domestic and foreign manufacturers, users basically recommend OSRAM or PHILIPS 1200W short arc double-ended metal gas discharge lamp. Its characteristics are compact, high brightness, high color temperature, good color rendering and light source in the process of dimming, to maintain a relatively stable color temperature. The disadvantage is that the lamp tube filler layering problems, that is, fillers in the arc imaging of the ribbon or in the arc tube condensation, the formation of the shadow effect, the need to control the optical structure in the minimum design. In the optical structure, in order to obtain a uniform mixed beam, parabolic mirror can be used to collect the divergence or narrow beam, you should choose the scale processing or surface texture of the mirror. Reflector systems made of specular material are better than refraction systems. When you need to get several beams from a light source, you can use a prism or lens combination of the refractive system. At present, the optical design of domestically and internationally 1200W Moving Head Light adopts the combination of lenses and consists of aspherical (ie parabolic) quartz lenses.

    Parabolic lens of the most important features in the focus on a point light source, will be a parallel beam. In the light path design, the relationship between the light intensity distribution curve, the shape and the size of the light source, the size of the diameter of the reflective lens, and the shape of the light source needs to be considered.

    Second, the mechanical system

    A wide range of mechanical systems, including materials, structure, mechanical properties, shell requirements, cooling requirements and so on. Lighting material selection main considerations are: to meet the functional requirements of the lamp, manufacturing ease and economy. At present, the materials of the international and domestic 1200W moving head lights mainly include steel, plastic and aluminum alloy. In considering the overall function to meet the lamp under the premise of the design of the lamp structure model, divided into different parts, using different materials. Such as Aceda-spot1200III1200W moving head light, light body shell with plastic parts, light body support frame, base, side panels, end plates made of aluminum alloy castings, stampings, car parts.

    The structure of the lamp determines its mechanical properties, heat dissipation, strength, noise, weight and other elements. International and domestic 1200W moving head lights are used dual-arm support structure, lamp body horizontal rotation of 540 °, vertical rotation of 255 °, the base part to be done to strengthen the processing to meet the moving head lamp hanging flip requirements.

    The mechanical properties of the lamp body are mainly reflected in the mechanical strength of the lamp body parts, so that the lamp body in the continuous effective working time, no deformation, wear resistance, corrosion resistance, shock resistance, compression; lamp housing must have strict Waterproof, dustproof, anti-static, moisture-proof requirements. According to the different degree of dustproof and waterproofing, the protection requirements for different enclosures are as follows: For indoor use, the protection level of the fixtures is usually IP20, and the protection level of the outdoor fixtures is usually IP44.

    1200W high-power computer lamp mechanical structure, cooling requirements are crucial, cooling system, if any defects, usually cause electrical parameters drift, color film, film rupture, plaque, resulting in crashes, out of step, uncontrolled and other serious consequences .

    Third, the electrical and process control section

    1, Moving head lamp electrical characteristics and circuit design

    Before the world-wide professional 1200W moving head light most of the rare gas discharge bulb. Gas discharge bubble start and stability work depends on the type of circuit design, power supply, ballast and other electrical components of choice. Rare gas discharge bubble start, the general do not need a stable time, in order to ensure the stability of the entire exchange cycle, the circuit voltage and the instantaneous voltage of the lamp to maintain the difference between the large enough.

    Light source of the start, stability, off, restart, should be based on the characteristics of light source design circuit. Rare gas discharge bubble start voltage is very high, requiring the use of transformers, start devices, semi-resonant circuit, etc., to improve the instant start-up voltage. The stability of the light source after starting depends on the matching of the ballast and the circuit parameters. The basic function of the ballast is to prevent current loss and to operate the light source under its normal electrical characteristics. Currently manufacturers usually use two ballasts, one is the inductor rectifier, one is the electronic rectifier. Inductance rectifier has the advantage of good stability, the disadvantage is heavy, the strength of the lamp body, handling, loading and unloading have higher requirements; electronic rectifier is essentially a power conversion circuit, the input power supply current frequency, waveform and amplitude change. Its advantages are light weight, easy loading and unloading, handling; disadvantage is the structural design requirements, high maintenance costs.

    Light source restart, in the conventional circuit design, because the gas discharge bubble work produces high temperature, the saturated gas bubbles to form vapor pressure resistance, the light source to trigger again immediately difficult to achieve, the gas pressure must be reduced to a cold light ＆#118alue After the trigger to restart. At present, the international and domestic manufacturers basically adopt the conventional circuit design.

    2, the program control section

    At present, the international and domestic computer lights generally use the DMX data format to write program files. The principle of DMX512: The speed of DMX data stream is 250K, that is, each BIT is standard 4 microseconds. The DMX data format is divided into the following sections: 1) IDLE or NO DMX situation: will be a high level signal when no DMX packet is being output; 2) BREAK: DMX packet start is A 88 microsecond low output prediction {head}; 3) MARK AFTER BREAK (MAB): MAB is a 8 microsecond high or 2 pulses after BREAK; 4) STARTCODE Code: SC is the beginning of the data stream channel data, it has the same format with the channel data, typically 11 pulses or 44 microseconds; 5) MARK TIME BETWEEN FRAMES (MTBF): MTBF can be 0-1 seconds, less than 1 Second, the MTBF is high before the start bit of each channel; 6) CHANNEL DATA (CD): the channel data frame is logical format 1-512 or less after SC; 7) MARK TIME BETWEEN PACKETS (MTBP): Sends a high level after valid data has been sent.

    Computer lights produced by different shapes, different color changes, different perspectives, horizontal, vertical angle of light changes and speed, strobe speed, the size of the aperture change, the focal length changes and other comprehensive performance. All these indicators of the work is done through the stepper motor drive, the stepper motor electrical parameters to be defined to define programming, to complete the control of the scanner.