Moving head light set, electronic, mechanical, optical, high-tech products. Qualified moving head lights, must be stable and reliable, excellent luminous efficiency, accurate positioning and good heat dissipation, light body and the material structure in line with ergonomic requirements. Moving head lights from the use of power can be divided into the 250W, 575W, 1200W varieties. 1200W for the professional performance of the main lamp type of place. The article focuses on the analysis of the fundamentals of the structure that 1200W moving head light. In a nutshell, shaking his head scanner is composed by three major systems of the optical, mechanical, electrical and process control. The three systems are interrelated, organic combination, to meet the needs of light, color, speed, direction, effects, heat, noise, and positioning elements.
First, the optical system
The optical system design is most important to consider the utilization of light flux. Specific performance indicators, including light intensity, uniformity, and saturation, and spot size. Factor affecting these indicators has two sides, one light source, the structure of the optical system, material selection. At present, domestic and foreign manufacturers, the user basic recommended double-ended metal gas OSRAM or PHILIPS 1200W short arc discharge lamp. Its characteristics is a compact, high brightness, high color temperature, color and light source dimmed the process can maintain a relatively stable color temperature. The drawback is that the hierarchical lamp filler, the filler arc imaging appears ribbon or in the arc tube condense to form a shadow effect to a minimum required in the design of optical structure. Optical structure, in order to achieve a uniform mixing beam can be used parabolic mirror to collect the divergence or narrow beam, should choose a mirror scale processing or surface texture. Reflector made of specular materials than a refraction system. When several beam from a light source can be a prism or lens combination refraction system. At present, domestic and foreign 1200W moving head scanner optical design are the lens combination, consists of non-spherical (ie parabolic) quartz lens.
The most important features of the parabolic lens placed in the focus a point source, will be a parallel beam. In the optical path design, the need to take into account the correlation between the intensity distribution curve, shape and light source size, reflective lens aperture size and light shapes.
Second, the mechanical system
A wide range of mechanical systems, including materials, structure, mechanical properties of the shell requirements, cooling requirements. Lighting material selection considerations are: to meet the functional requirements of light, manufacturing ease and economy. At present, the international and domestic 1200W moving head light of the material of steel, plastic, aluminum. Consider the needs of the overall function of the lamp, the structural model of the design of the lamp, the different parts with different materials. Moving head light Aceda-spot1200III1200W light body shell plastic support frame of the lamp body, base, side panels, end plate aluminum alloy castings, stamping parts, car parts.
The lamp structure determines its mechanical properties, heat, intensity, noise, weight and other factors. International and domestic 1200W moving head light arms support structure, the level of the lamp body rotation up to 540 ° vertical rotation up to 255 °, the base part to be done to strengthen to meet the head light suspension Flip requirements.
The mechanical properties of the lamp body, mainly in the mechanical strength of the lamp body parts, lamp body in continuous work effectively within the time, no deformation, wear resistance, corrosion resistance, seismic compression; the shell of the lamp must be strict Waterproof, dustproof, anti-static, moisture requirements. Different divisions of the dust, water level of enclosure protection class requirements: grades typically IP20 protection requirements such as the indoor use of computer lights and outdoor protection of computer lights requirements of the grade is usually of IP44.
1200W high-power computer lights, mechanical structure, cooling requirements is essential, cooling system, if any defect, usually caused by electrical parameter drift, color film, film rupture, a plaque, generate crash, out of step, out of control and serious consequences .
Third, electrical and process control section
A moving head light electrical characteristics and circuit design
Former worldwide professional 1200W moving head scanner vast majority of rare gas discharge lamp light source. The start of the discharge lamp and stability depend on the choice of circuit type of design, power supply, ballast and other electrical components. Rare gas discharge lamp is started, does not require a stable, in order to ensure the stabilization of the entire AC cycle, the difference between the instantaneous voltage of the circuit to maintain voltage and the lamp should be sufficiently large.
The start of the light source, stability, off, restart, and should be designed according to the characteristics of the light source circuit. The rare gas discharge lamp starting voltage is very high, requiring the use of transformers, start the device, semi-resonant circuit, etc., to improve an instant turn-on voltage. Light after starting the stability depends on the ballast and circuit parameters match. The ballast's basic function is to prevent current runaway and make light work in its normal electrical characteristics. Manufacturers usually use two ballasts, one inductor rectifier, an electronic rectifier. Inductor rectifier has the advantage of good stability drawback is that the intensity of the lamp body, handling, loading and unloading have a high requirements; electronic rectifier is essentially a power conversion circuit, the input supply current frequency, waveform and amplitude changed. The advantage is light weight, convenient loading and unloading; drawback is that the structural design requirements and high maintenance costs.
Re-start of the light source, in the conventional circuit design, due to the high temperature gas-discharge bulbs work, saturated gas bubbles to form a vapor pressure resistance, and light to immediately trigger is difficult to achieve, light gas pressure down to the cold numerical can trigger a restart. At present, international, domestic producers of basic conventional circuit design.
2, the program control section
International and domestic computer lights DMX data format is commonly used to write program files. DMX512 the principle: the speed of the DMX data stream is 250K, and that each BIT standard of 4 microseconds. DMX data format is divided into the following sections: 1) IDLE (idle) or NO DMX situation (situation): when no DMX packets output, a high signal; 2) BREAK: DMX packet start a 88-microsecond low output forecast {head}; 3) the MARK an AFTER BREAK (MAB): the MAB is a BREAK is an 8-microsecond high or two pulses; 4) STARTCODE (SC) began Code: SC is the data stream of channel data, it has the same format and the channel data, generally for 11 pulses or 44 microseconds; 5) the MARK TIME BETWEEN FRAMES (MTBF): MTBF for 0-1 seconds, less than one second for each channel before the start bit can to MTBF, is high; 6) CHANNEL DATA (CDs): Channel data frames in the SC after the logical format of 1-512 or less than 512; 7) the MARK TIME BETWEEN PACKETS (MTBP): send valid data to send after high.
Computer generated light effect, the King film by varying the shape, color changes, a different perspective, horizontal, vertical light angle changes and the speed of the strobe speed, the overall performance of the changes in aperture size, focal length change. All the indicators of these attributes is achieved by the stepper motor drive, stepper motor electrical operating parameters to be defined programming, to complete computer control of the lights.
