Moving head light is a electronic, mechanical, optical high-tech products. Qualified moving head lights, must be stable and reliable, excellent light efficiency, positioning accuracy, good heat dissipation, light body and the material structure ergonomic requirements. Moving head light from the use of power sizes can be divided into 250W, 575W, 1200W and other varieties. 1200W of professional venues including the main lamp type. This article focuses on the fundamentals of the structure 1200W moving head light for analysis. Broadly speaking, shaking his head computer light from the optical, mechanical, electrical and process control system composed of the three. Three interrelated systems, organic mix to meet the light, color, speed, direction, effects, heat, noise, location and other factors need.
First, the optical system
The main light source optical system design considerations flux utilization. Specific performance indicators, including light intensity, uniformity, saturation, spot size. Factors affecting these indicators, there are two, one light source, and second optical system structure, material selection. At present, domestic and foreign manufacturers, the basic user recommended OSRAM PHILIPS 1200W short arc or double-ended metal gas discharge lamps. Its characteristics is a compact, high brightness, high color temperature, color is good and in the dim light sources in the process, to maintain a relatively stable color temperature. The disadvantage is that this tube within the filler layer, namely, filler arc image appears in the ribbon or condensation in the arc tube to form a shadow effect, the need to control the optical design to a minimum. In the optical structure, in order to obtain a uniform mixture of the beam can be used parabolic mirrors, narrow beam divergence or to collect, process, or should choose the scale of the mirror surface texture. Using specular reflector system made of material reflects the system than good. When you need to get a few beam from a light source, we can use a combination of refraction of the prism or lens system. At present, domestic and foreign 1200W moving head computer light optical design, lens combinations are used the way by non-spherical (ie parabolic) quartz lenses and other components.
Parabolic lens focus on the most important features in place a point source, will be a parallel beam. In optical design, the need to take into account the intensity distribution curve, shape and light source size, lens aperture reflector size and shape of the light source between the association.
Second, the mechanical system
A wide range of mechanical systems, including materials, structural, mechanical, housing requirements, cooling requirements, etc. Lighting the main considerations for material selection: to meet the functional requirements of light, ease of manufacturing and the economy. At present, the international and domestic 1200W moving head light materials are mainly steel, plastic, aluminum. In considering the overall capabilities to meet the light under the premise of the design model of the structure of light, divided into different parts, using different materials. If Aceda-spot1200III1200W head light, light body shell plastic parts, lamp supports, base, side panels, side panels made of aluminum alloy castings, stamping parts, car parts.
Light of the structure determines its mechanical properties, heat, intensity, noise, weight and other factors. International and domestic 1200W moving head light support structure arms are used, light body horizontal rotation of 540 °, vertical rotation of 255 °, the base part of the deal to be done to strengthen, to meet the requirements of moving lights hanging flip.
Light body mechanical properties, mainly in the light of the mechanical strength of body parts, so that light body to work effectively in a continuous period of time, deformation, abrasion, corrosion, earthquake, compression; light waterproof shell must have strict , dust, static discharge, moisture requirements. According to dust, water-resistant shell to varying degrees into different degrees of protection requirements: such as the interior lights using a computer is usually required level of protection IP20, outdoor fixtures are usually required level of protection IP44.
1200W high power computer light mechanical structure, cooling requirements is essential, if defective cooling system, usually resulting in electrical parameter drift, color film, film rupture, plaques appeared, resulting in crashes, out of step, out of control and other serious consequences .
Third, some electrical and process control
1, moving head lights electrical characteristics and circuit design
1200W professionals worldwide before shaking his head most of the computer use the rare gas discharge lamp light bulb. Gas discharge lamp starting and stability depend on the type of circuit design, power supply, ballast and other electrical components of choice. Rare gas discharge lamp is started, generally do not need a stable time in order to ensure stabilization of the entire communication cycle, the circuit to maintain voltage and transient voltage bulbs should be sufficiently large difference between.
Light start, stability, off, restart, should be based on the characteristics of light to design the circuit. Rare gas discharge lamp starting voltage is very high, requiring the use of transformers, starting devices, semi-resonant circuit, etc., to improve the instant start voltage. After starting the stability of the light, ballast and circuit parameters depending on the match. The basic function is to prevent the ballast control and the current source of electrical characteristics in its normal work. Currently manufacturers are usually in two ballasts, one is the inductance rectifier, an electronic rectifier. Inductor rectifier has the advantage of stability, the disadvantage is the weight of the lamp body strength, handling, loading and unloading have higher requirements; electronic ballast is essentially a power conversion circuit, the input supply current to frequency, waveform and amplitude in the change. The advantage is light weight, easy handling, transportation; drawback is that the structural design requirements of high, high maintenance costs.
Light re-start in the conventional circuit design, the gas discharge lamp generates heat when working, so that the gas bubble formation within the saturated vapor pressure resistance, light to immediately re-trigger is difficult to achieve, the gas pressure must be reduced to a light cold &#118alue before they can trigger a restart. At present, international, domestic producers of basic conventional circuit design.
2, program control section
Current international and domestic fixtures DMX data format widely used programming file. DMX512 principle: DMX data stream speed is 250K, a standard that each BIT 4 microseconds. DMX data format is divided into the following sections: 1) IDLE (idle) or NO DMX situation (case): when there is no DMX output when the packet will be a high signal; 2) BREAK: DMX packet begins 88 microseconds of a low output forecast {head}; 3) MARK AFTER BREAK (MAB): MAB is BREAK, after an 8 microsecond pulses of high or 2; 4) STARTCODE (SC) beginning Code: SC is the start of the channel data stream, it has the same format with channel data, usually 11 or 44 microseconds pulse; 5) MARK TIME BETWEEN FRAMES (MTBF): MTBF for 0-1 seconds, less than 1 second, before the start bit of each channel can be to have MTBF, is high; 6) CHANNEL DATA (CD): After channel data frame in a logical format for the SC or less 1-512 512; 7) MARK TIME BETWEEN PACKETS (MTBP): After sending the valid data to send high.
Computer light effects produced by different modeling scene piece, different color changes, a different perspective, horizontal, vertical angle changes and the speed of light speed, strobe speed, aperture size changes, and changes in focal length and overall performance. All of these attributes indicators by the stepper motor drive to achieve, the stepper motor's electrical operating parameters to define the program, completed the computer controlled lights.