1 daylight and biological clock
From the very beginning, our biological clock has established some connection with the influence of the environment, most notably the connection with sunlight. Our inherent standard for light is daylight, so we strive to mimic sunlight.
But daylight has many unique features that artificial lighting can't replicate:
Artificial illumination is economically impossible to achieve with illumination of up to 100 000 lx.
Fully balanced, coordinated spectrum and excellent color reproduction, these colors can't be reproduced by artificial light sources, of course, and can't be obtained by cheap and widely used high-pressure nano lamps. The color rendering index of this lamp is much lower than that of daylight.
An exceptionally uniform light distribution and dynamic luminescence intensity caused by the sun, clouds and weather. In comparison, artificial lighting is very limited in terms of consistency, and the lighting performance is very monotonous and static.
The ratio of vertical illumination to horizontal illumination is 12, and most of the existing road lighting systems are almost impossible to achieve. Too low vertical illumination creates a tunneling effect that clearly makes us feel that this is not natural light illumination.
2 glare
The largest source of illumination interference Artificial lighting is often associated with glare. Glare is felt when the observer directly looks at a bright light source and an unoccluded mirror. The most common glare source is the headlight of a moving motor vehicle. Glare can also occur in road paving works or in poorly occluded luminaires. When the observer's eyes are adapted to low levels of illumination, they are particularly sensitive to direct glare, which is no longer sensitive to details in dark environments in order to accommodate high levels of illumination.
This effect, known as light curtain illumination, reduces contrast and makes it more difficult to identify pedestrians and targets on the street. The glare source increases the visual threshold and the minimum contrast required to identify the target (see 1).
This phenomenon can be seen as an increase in the threshold level, which is quantified in detail as a TI value, which has been defined by the DIN EN 13201 standard. This is a particularly dangerous phenomenon for motorists, as this glare interferes with the driver's field of view.
Standard method of avoiding glare
Based on the assumption that the luminaire used to illuminate the road has a certain angle of deployment for the driver's vision, in practice a visor is used. The function of the visor is to prevent the driver in a certain position from directly seeing the light source at a certain angle. The visor only provides the lowest glare control for pedestrians.
But the efficiency of glare control and lighting systems is contradictory.
In order to achieve the maximum spatial distance between street lighting poles, the luminaire must have the widest possible light distribution. Full light cuts and other various forms of shading devices limit the light distribution at a wider angle, which reduces the efficiency of the luminaire and increases the cost.
The Hess Faro luminaires in the plaza must be compromised, and the compromise scheme is usually worth the cost of glare control. The pedestrian or driver moves towards the luminaire and eventually enters the unoccluded area. If the luminaire is a direct lighting system, the person will suddenly face the glare from the unobstructed light source. As long as the illumination of such a luminaire is reduced, such as by using a perforated visor, the efficiency of the luminaire is greatly reduced. Therefore, it is impossible to obtain the best glare control.
3 indirect lighting
A large step forward with a secondary reflector system does have many advantages.
In the design of such a luminaire, the primary reflecting unit surrounds the light source and the secondary reflector blocks visual contact with the light source. The reflected image of the source can be seen in the secondary reflector. Although such luminaires produce less illumination than direct illumination systems, glare may still occur.
Beam Image Separation (LBIS) technology eliminates many of the same problems and can effectively reduce glare from secondary reflectors. How does this technique achieve this function? Beam image separation technology splits a single image into several smaller images, bringing together these lower individual illuminances to meet the requirements of traditional indirect lighting fixtures. Illumination. The result is that both glare is eliminated and no loss of light output is caused.
Close-up of a 3-beam image separation reflector showing multiple mirrors. Professor Christian Bartenbach proposed this beam image separation principle in the 1990s. Bartenbach Lichtlabor designed a new lighting system in the contracted lighting project at the Frankfurt airport apron. The new luminaire installation is mounted at a relatively low height (approximately 20m), but still provides very consistent illumination. In addition, glare is completely unacceptable because the pilot's eyes adapt to the darker environment when the aircraft is landing and are very susceptible to glare.
A reflector-transmitter system (now patented) that combines beam image separation technology is the best measure. An illumination system employing this technique can have one or more emitters. All of the emitted light from the emitter enters a reflector consisting of many small mirrors. These mirrors must achieve precise, specified geometries to meet the beam mirror separation principle and eliminate glare. Each mirror body must not exceed the determined maximum size, and the distance between each individual mirror body must be large enough so that they can be individually identified. As long as the dimensions of these mirrors conform to the required length, the illumination of the mirror can be increased to the extent required without glare. Because for an observer, only a very small number of mirrors are seen directly at the same time.
4 how to improve beam separation
Initially, such systems were used in applications where the installation height was relatively high and the power output was large (such as the apron of the airport).
Hess now uses this beam splitting technology for low-profile (typically 48 m) pole-mounted luminaires and relatively low power output (70 450 W). In addition, the quality of the light in such systems is optimized. A combination of a large number of mirrors and various mirror shapes to ensure a high degree of consistency and glare control. Accurate calculations and computer simulations will help design a variety of free-form mirrors.
Hess's mirror body also possesses another unique technique in which a metal coating made of pure aluminum is applied to the front surface of the mirror body. This metal coating will improve the optical performance of the luminaire and provide more precise lighting control than the back treatment. The mirror body precisely directs light according to pre-planning and computer calculations.
In addition to the rod-mounted Faro luminaire series, Hess has developed a modified version of the catenary suspension (Faro UE) and a slanted modified version with a secondary reflector (Faro AR) to increase the front and back. The light emitted. Another type of Devio luminaire for wall mounting with an asymmetric light distribution has the potential for further application. Wall-mounted luminaires are available in three different mirror systems: for road lighting, area lighting, and facade lighting.
It is also achievable to use a multiple transmitter system to increase the light output of the luminaire.
5 increase visual comfort
Thanks to the highly consistent illumination output and excellent glare control, the luminaire with secondary reflector beam splitting technology plays a positive role in the objective perception of night and night. Since the surface of the luminaire is black, it is difficult for the observer to see where the light is coming from. However, what the observer cares about is the comfortable atmosphere and the true embodiment of the surrounding environment, avoiding visual glare.
The complex mirror design and relatively large reflector plate make the reflector-emitter system with beam splitting technology more expensive to manufacture than conventional lighting fixtures. However, the value of such investments is that the quality of lighting plays an important role, both for increased security and privacy, or as a means of embodying aesthetic sensations in urban spaces and pedestrian areas.
Microwave PCB
microwave PCB`s is a type of PCB designed to operate on signals in the megahertz to gigahertz frequency ranges (medium frequency to extremely high frequency). These frequency ranges are used for communication signals in everything from cellphones to military radars. The materials used to construct these PCB`s are advanced composites with very specific characteristics for dielectric constant (Er), loss tangent, and CTE (co-efficient of thermal expansion).
High frequency circuit materials with a low stable Er and loss tangent allow for high speed signals to travel through the PCB with less impedance than standard FR-4 PCB materials. These materials can be mixed in the same Stack-Up for optimal performance and economics.
The advantages of using materials with a low X, Y and Z CTE is a resulting PCB structure that will remain extremely stable in high temperature environments while operating at up to 40 GHz in analog applications. This allows for the effective placement of very fine pitch components including, in some cases, bare die-attach. Additionally, the low CTE materials will facilitate the alignment of multiple layers and the features they represent in a complex PCB Layout.
Features
.CTEr = +40/+50 ppm per °C (low); Tg (glass transition temperature) is 280°C
.ER = 3.38/3.48 at 10.0 GHz
.ER is constant to 40.0 GHz
.ED (electro-deposited) copper only
.Layer-to-layer thickness control = +/- 0.001
.Fabrication costs are typical to slightly increased
Microwave PCB
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