When research the basic characteristics of any kind of solar road stud, the following aspects should be considered.
If the solar road stud cannot work under a certain extent of pressure, it will be out of work after several times crush or crash. So the compression resistance should be the most basic condition for the solar road stud. For the solar road stud is a electronic product, it is not that easy to make the road stud has strong pressure resistance. Thus the pressure resistance of the solar road stud is lower than the ordinary road stud.
There are several methods to increase the pressure resistance of solar road stud: 1. Use the PC bullet resistant material to make the solar panel outside to increase the pressure resistance of the electronic part of the road stud; 2. Use the IC control to decrease the volume of electronic circuit; 3. Put the reinforcing ribs on the shell to share the pressure on the electronic part.
The water will permeate into the solar road stud if it is not sealed tightly, which will cause short circuit, so the sealing property of the solar road stud should be good.
Several methods are provided to increase the sealing property of the solar road stud:
Separation design. Adopted separation design of the led lampshade and the circuit board inside the road stud, and even the led lampshade is out of work, there will be no water permeating inside the solar road stud.
Using the strong neutral adhesive to ensure that the solar panel, led lampshade and the shell of road stud can bond tightly, and there is no gap between them.
Solar road stud has one special characteristic when compared with common road stud, and that is, it must auto luminescence. The transportation sector has relative standard for this index, which is 2,000MCD.
Life span of the battery: Another factor that influences the life span of the solar road stud is the using time of battery, so it is quite important to choose a battery with good performance. Now there are two kinds of batteries to choose, and one battery whose capacity would reduce to 50% after 500 times charge-and-discharge and the other is the battery whose capacity would reduce to 79% after 1,000 times charge-and-discharge.
The using life of a battery should be long enough, and it must be working effectively in a wide range of temperature interval. The material inside a battery is chemical substances, and it cannot work in the environment which is too hot or too cold. So, the working temperature range should be abided with requirements of actual using environment. The requirement of related standard made by transportation sector for this index is that the solar road stud should work in the temperature between -10°C to 50°C. Actually, the working temperature of solar road stud may out of this range, so the battery with reliable quality and excellent performance need to be chosen to make the solar road stud.
Electronic circuit: The design principle of simple and effective should be followed. One more circuit will increase the possibility of malfunction. The electronic components should also be chosen strictly, for the whole system will be out of work if one electronic component is broken.
Welding: The welding of the solar road stud should be firm. For it is crashed or shocked everyday, a little loose of the welding spot will cause the loose of break off of the circuit, the high-quality welding gun and soldering should be chosen to ensure that the wielding spot is firm and can work long enough in severe environment.
Solar panel: The solar panel can absorb solar energy and transform it into electric energy, and this can be the first link of the whole working system of the solar road stud. The efficiency of the solar panel determines the efficiency of the solar road stud. The single crystal silicon solar panel is widely used nowadays, for it has high photoelectric conversion efficiency, which can be about 14%, to ensure the energy providing when the solar road stud is working. In addition, the solar panel must be high hardness and wear-resisting. For the solar road stud will resist crash and shock everyday, if it is not hard enough, the solar panel will be destroyed and influence the conversion efficiency of the solar panel.
Matching Performance of Battery
The rated capacity of the battery should meet the needs of 72 hours’ illuminating, if the battery is put in the standard testing condition for 8 hours. Even if the solar illumination is less than 1,000LX, the rated capacity of the battery should make road stud work normally for 12 hours after 8 hours’ charge. One thing should be noted, if the matching performance of battery is not that good, it will be lack of power in wet weather, which may cause the un-illuminate of solar road stud. If this condition happens, the solar road stud will out of particle value. This is also the limitation of capacitive solar road stud. If being put under the standard testing condition for 8 hours, the rated capacity capacitor can only make the solar road stud work for 12 to 14 hours, that is to say, the capacitive solar road stud is strict with its actual working environment, which should not only have enough sunshine, but should not work in continuous rainy weathers.