Sunlight, Inc. - The Solar LED Solution Company Sunlight, Inc.
Himeji client office:
1-44, Sanjocho, Himeji City,
Hyogo-ken, JAPAN
zip code 670-0953
Tel: 81+ 079-222-8807
Fax: 81+ 079-222-8817
Tokushima factory:
574-2, Kawasaki tsutsumi-soto, Oasamachi,
Naruto City, Tokushima Ken, JAPAN
zip code 779-0223
Tel: 81+ 0886-83-5005
What's New | Product information | Company Profile | FAQ - Frequently Asked Question | Contact us | Top page | Japanese




Sunlight, Inc. - The Solar LED Solution Company
 Q1: The solar self-luminous products?
Answer Is storage electricity is taken out from the solar cell during the day, is called a system that automatically turns on the LED at night.
How long at a fraction of the power, it becomes relative merits and whether the products bright lights.
Also, because it is used in outdoor harsh environment, the durability is also important.


 Q2: What are the characteristics of the solar self-emission products of Sunlight?

Answer

  1. Has been adopted mainly capacitor (aka "electric double layer capacitor") to medium (storage medium) save electricity.
    Capacitor is extremely long life in terms of the number of times of charging and discharging, and does not include an environmental-depleting substances "lead" and "cadmium".

  2. is adopted to have solar cells, small mainly "amorphous silicon solar cells" in the self-emission products, also to those of medium / large size, has been mainly adopted the single crystal silicon solar cells.
    Amorphous silicon solar cells, the efficiency (conversion efficiency) which changes the light into electricity is slightly degraded, so that you can take out the electricity in the shade.
    Sunlight is by product of your environment, we have adopted in properly selected the solar cells.

  3. I have adopted a dedicated high efficiency circuit system of the capacitor for power storage (charging).

  4. LED drive circuit has high efficiency system including an optical system for bright and lit a long period of time at a fraction of the power is adopted.

  5. Especially for the "embedded self-luminous products", you have devised such as the following in waterproof structure.


    * To withstand a wide temperature range of outdoor, upper and lower cases mating part has adopted a high weather resistance of powerful elastic adhesive.
    * Rigidity of the case is high by special thick molding technology, and mating part has multiplied by mechanically locking also.
    * Receiving and emitting section (upper case) has adopted the weather resistance polycarbonate resin, and is suppressing sufficiently resin discoloration due to ultraviolet rays.

Technology

  1. Has been adopted mainly capacitor (aka "electric double layer capacitor") to medium (storage medium) save electricity.
    Capacitor is extremely long life in terms of the number of times of charging and discharging, and does not include an environmental-depleting substances "lead" and "cadmium".
    is adopted to have solar cells, small mainly "amorphous Si solar cells" in the self-emission products, also to those of medium / large size, has been mainly adopted the single crystal Si solar cells.
    Amorphous Si solar cells, the single-crystal Si solar cells both we and the proper use of the advantages.
    Comparison of amorphous and monocrystalline
    1. Light to power conversion efficiency
      (1000W / m2 => approximate conversion efficiency during a fine weather in a natural environment)
      Amorphous solar cells are at 6-7%, while single crystal solar cells are at 13-19% (Which is almost three times higher than amorphous)

    2. Linearity of changes in output due to illuminance level
      In case of amorphous solar cells the difference from highest to lowest level of illumination is about 5000 lux.
      (Conversion efficiency almost not suffering)
      In case of a single crystal solar cells the difference is astonishing 20000 lux.
      (Poor conversion efficiency at low illumination)

      There is a case of amorphous solar cells reversing the conversion efficiency under low illumination conditions.
      The output at low illumination can guarantee.

    3. Contrast of characteristics of a typical solar cell
    株式会社 サンライト - 説明図
    As illustrated by figure 1, output current varies greatly by illumination level.
    "Contrast linearity" has a great effect on the output current.
    株式会社 サンライト - 説明図
    figure 2: You might find amorphous cells more efficient in low light conditions.
    (AmorphousÅf curve is less inclined)
    • As single crystal solar cells are performing their best only during the clear weather, it is necessary to make use of the strong point of amorphous cells during the cloudy weather or other low illuminance conditions.
    • Speaking of voltage / illuminance ratio, amorphous have it at about 0.6V Pmax per cell in high illumination conditions and about 0.5V in low.
      The single-crystal cells are at about 0.5V Pmax per cell in high illumination conditions and about 0.3V in low. This leaves us with a good choice variety to suit.

  2. For storage (charge) to the capacitor I have adopted the high efficiency of the circuit system.
    Tricks to shorten charging time

    The charge time is shortened by using the following circuit configuration designed for the specific capacitor we use.

    Sunlight, Inc. - The Solar LED Solution Company
    • Figure 3: When the charging voltage is low, the capacitor will be charged with a parallel current.

  3. For storage (charge) to the capacitor I have adopted the high efficiency of the circuit system.

  4. Especially for the "embedded self-luminous products", you have devised such as the following in waterproof structure.

    * To withstand a wide temperature range of outdoor, upper and lower cases mating part has adopted a high weather resistance of powerful elastic adhesive.
    * Rigidity of the case is high by special thick molding technology, and mating part has multiplied by mechanically locking also.
    (About the case mating see Figure 6 for details )
    Waterproof structure used to protect our embedded self light emitting products
    Sunlight, Inc. - The Solar LED Solution Company

    Commentary:

    • Because of nature of the environment in which embedded lights are usually used, the materials of lower and upper cases are expected to expand, shrink and twist.
    • As shown on figure 6, elastic weather adhesive is used in our products to provide a buffering effect for the lateral movement of the upper and lower cases.
    • However, because during the sudden temperature changes materials of the cases will show different speed of physical reaction they will get cracks or break anyway by moving in different direction if they are not firmly fixed to each other.
      So, because mechanical locking is still important we also provide you with two ways to lock the device by screw to use in appropriate conditions.
    * Receiving and emitting section (upper case) has adopted the weather resistance polycarbonate resin, and is suppressing sufficiently resin discoloration due to ultraviolet rays.


 Q3: Do the lighting time and brightness is what in the determined? Actual values for lighting time described in the catalog is?

AnswerThe brightness of the lighting time and the LED is determined by the following conditions.

  1. Capacity of capacitor (unit: [F]) and the full-charge voltage (Unit: [V]) if have the same power consumption large storage energy is larger, respectively, it is possible to increase the lighting time.
    (10-fold in capacity, if the two-fold with full charge voltage, it becomes really 40 times the storage energy.)

  2. Determines the lighting time in power consumption of the magnitude of the LED.
    Sunlight of goods we have driven by circuit on, constant current by connecting the LED to each other in series. (Usually two to four from four series) LED is brightly lit in a certain range the greater power supply current.
    (Usually up to a few tens of mA)
    For example, it will be the power consumption at the time of 5mA energized blue LED in four series ... 70 (mW).
    Sunlight of the commodity, has adopted a "slight optical system and circuit system that emits bright power consumption." Naturally, the brighter the power consumption of the LED is large, but if storage energy is the same lighting time will be shorter.

  3. or the "lighting time" that has been described in the catalog, the ability basis there roughly about 1.2 times.For example, "lighting time 8 hours", you have ability to continue roughly lit 10 hours when fully charging.Sunlight of product may be devised of circuit system which brightly emitting an optical system and LED that make effective use of the LED light.
    (Sunlight made of irradiation lens, we are effective in its own technology, such as the light guide plate and LED drive circuit.)

Technology The brightness of the lighting time and the LED is determined by the following conditions.

  1. If storage medium is a capacitor, the capacity (unit: [F]): become the element that is better becomes large storage energy large respectively, to increase the lighting time when the constant power consumption and full charge voltage ([V] units) you.
    For example, it will be stored energy of ...... when capacity = 10F / full charge voltage 5V 113.75 (J) 32 (mwh).
    It will be stored energy of ...... when capacity = 100F / full charge voltage 10V 4550 (J) 1263 (mwh).
    (1/2)*C (F) *(Vcap (V) ) I have been estimated by the square of the official.
    10-fold in capacity, if the two-fold with full charge voltage, it becomes really 40 times the storage energy.

  2. Determines the lighting time in power consumption of the magnitude of the LED.
    Sunlight of the commodity on the circuit, connect the LED to a plurality series has been constant current drive. (Four series from the usual two)
    LED will brightly lit in a certain range the greater power supply current. (Usually up to a few tens of mA)
    For example, it will be the power consumption of ...... 70 (mW) when 5mA energized blue LED in the four series.
    (I have been estimated at LED forward voltage Vf = 3.5V constant.)
    In this case, (1) 10F / 5V is capacitor conditions and lighting time of that described in section ...... 0.457142857 (time)
    Next, I can see that there is only less than 2 hours lighting time. (Lighting time = the estimated at 32mWh / 70mW)
    Lighting time to about 8 hours, it must be reduced to the current 1/5 (ie 1mA).
    As described above, and the required capacitor stored energy and the LED current applied according to the lighting time and brightness are to have appropriately determined.

  3. It is also important to the elements of even lighting time emission efficiency of the entire system and brightness.
    Circuitry driven at maximum efficiency the optical system and the LED for irradiating the light emitted from the LED to the outside efficiently is important.
    Sunlight of product may be devised of circuit system which brightly emitting an optical system and LED that make effective use of the LED light.
    (Sunlight made of irradiation lens, we are effective in its own technology, such as the light guide plate and LED drive circuit.)
    Those who want to be sure the technical details contact Sunlight please.


 Q4: Do determined by what the charging time?

Answer

  1. If the charging medium of capacitor, its capacity and full charge voltage is better is larger one will take a long time to charge.
    In other words, charging time is larger the capacitor capacity, will long be elements charging time the higher the full charge voltage.
    In addition, it will be long become elements charging time as charging current is small.
    If you change the representation, it becomes output is large (generally large solar) shorter charging time about elements of the solar cells.
    On the other hand, the lower the charging voltage to be up to full charge voltage of the capacitor capacitance is small will be similar elements.

  2. Determines the lighting time in power consumption of the magnitude of the LED.
    Sunlight of the commodity on the circuit, connect the LED to a plurality series has been constant current drive. (Four series from the usual two)
    LED will brightly lit in a certain range the greater power supply current. (Usually up to a few tens of mA)
    For example, it will be the power consumption of ...... 70 (mW) when 5mA energized blue LED in the four series.
    (I have been estimated at LED forward voltage Vf = 3.5V constant.)
    In this case, (1) 10F / 5V is capacitor conditions and lighting time of that described in section ...... 0.457142857 (time)
    Next, I can see that there is only less than 2 hours lighting time. (Lighting time = the estimated at 32mWh ÅÄ 70mW)
    Lighting time to about 8 hours, it must be reduced to the current 1/5 (ie 1mA).
    As described above, and the required capacitor stored energy and the LED current applied according to the lighting time and brightness are to have appropriately determined.

Technology

  1. If the charging medium of capacitor, its capacity and full charge voltage is better is larger one will take a long time to charge.
    This Une be the same for secondary battery, but if the capacitor, the charge curve is very different from the secondary battery.


  2. In the case of capacitor, capacitor charging voltage charging time it will be the primary function of the charging current is I will consists in the following equation.
    T[sec]=C[F]*V[V] / I[A]
    In other words, charging time is larger the capacitor capacity, will long be elements charging time the higher the full charge voltage.
    In addition, it will be long become elements charging time as charging current is small.
    If you change the representation, it becomes output is large (generally large solar) shorter charging time about elements of the solar cells.
    On the other hand, the lower the charging voltage to be up to full charge voltage of the capacitor capacitance is small will be similar elements.

  3. The above (1), but I mentioned a little in the section, it is about charging time the output of the solar cell is large can be short, economic factors and space, the size of the solar cells to be selected by factors such as weight there is a limit .
    Also, is the sunshine conditions of a large most impact on the charging time.
    ...... Cloudy / rainy weather of problem solving is important.
    Typically, the characteristics at the time of cloudy weather as compared to the output characteristics at the time of fine weather in the single-crystal Si solar cell is extremely decreased.
    Especially of current output linearity (linearity of illumination / output current) is poor, it is not suitable for capacitor charge under cloudy weather.
    Sunlight of goods, so that it can be charged even at a relatively bad conditions sunshine conditions, following such ingenuity has been made.
    * Even in low light you have selected a rechargeable solar battery.
    (Low illumination linearity is adopted as good.)
    * The circuit configuration with an emphasis on charging in low light, and has realized the charging voltage ensure up to a certain level even under low illumination.
    Tricks to shorten charging time

    The charge time is shortened by using the following circuit configuration designed for the specific capacitor we use.

    Sunlight, Inc. - The Solar LED Solution Company

    When the charging voltage is low,
    The capacitor will be charged with a parallel current.

    Sunlight, Inc. - The Solar LED Solution Company


 Q5: lights, the mechanism of off?
Answer: The products Sunlight, and has adopted the "semiconductor photosensor" in order to detect the ambient brightness.
The photo-sensor does not have be false positives in such infrared you do not feel the human eye because it uses a sensor close to the (light wavelength sensitivity felt by the human eye) visibility. It also does not include the environmental destruction substances such as cadmium.

Characteristics of products' photosensor
Sunlight, Inc. - The Solar LED Solution Company

Figure 5: Sensitivity of photosensor we use is very close to that of human eye.

In addition, automatic lights in the following environment illuminance is about 10 lux (immediately after evening), it automatically turns off when it comes to about 50 lux (immediately after sunrise).


 Q6: Can I use immediately installed?
Answer: Usually from the date of the installed and operation, but a few days after installation it may take some time to charge.
Capacitor self leak will increase when a long period of time has been allowed to stand for a capacitor.
This phenomenon is overcome by repeating several times charging and discharging, then it becomes a stable operation.


 Q7: Can I use even during cloudy and rainy weather?
Answer: Night during cloudy weather we are also devised to be lit, but there is a limit on the performance.
In extremely dark conditions, even in the case of winter sunshine time is short and rainy weather, such as day there are times when it does not light up.
Sunlight of goods has become a generally following design so please refer to.
Fully rechargeable sunshine conditions: during the day 20,000 lux for 10 hours or more charge can be environment.
...... This corresponds to the time of the summer of cloudy weather.
In the following sunshine conditions above, or shorten the lighting time, in extreme cases may not light up.
Direct illumination of the time ...... fine weather as the reason is more than 100 000 lux, but why is that illuminance only obtained about one of the light energy of about 5 thousand lux and 20 minutes in the rain.


 Q8: About the safety of embedded products, do you have any kind of consideration?
Answer: The receiving and light emitting surface (upper case) full I am a projection provided with slip resistance (slip resistance more than 40).
In addition, since we have small corners taper of the exposed portion (1mm) step between the ground is small, it is safe.


 Q9: It should be noted at the time of construction it?
Answer: I think that may if you can observe the construction conditions notes of instruction manual.
Product groups of Sunlight has pursue "ease of construction."


 Q10: It should be noted after construction it?
Answer: Since receiving and light emitting surface sediment in (upper case) you will not be able to charge to ride leaves or accumulation, please remove.
After construction, you might when another installation products or growth branches of trees are located close to can not be charged as well.
Others, Please fully read the instruction manual.


 Q11: What is the useful life?
Answer: It is the right and left by installed is environment and construction conditions, expected life if you're the environment and conditions will be assumed about 10 years.


 Q12: Do you custom support possible?
Answer: As a general custom correspondence "LED color", "flashes, such as firefly lights lighting mode", because the OEM supply is also possible consideration of such correspondence and design changes and additional features such as "lighting time-brightness", what will and please consult.


 Q13: Do good if you contact to where such a variety of questions?
Please call from below telephone inquiries!
Tel: 81+ 079-222-8807

Click here for Email inquiries!!


 Q14: Other, beans knowledge that are related to the convenient "solar self-luminous products" to keep and know?
Answer:Sunlight product currently about capacity and the rated voltage of the capacitor, and a plurality adopted capacitor of 2.5V rating / capacity 22F - 4000F.
Also usually, two series-connected to 5V rated the capacitor, and four connected in series and is made up of 10V rating.
The relation between rated voltage and accumulator's capacity

Sunlight, Inc. - The Solar LED Solution Company

For calculation formula of storage energy, item 3 of Q & A Please check so are described in.

Answer: The Sunlight goods a bit more about the charging circuit, has the following method as a circuit means for charging from solar to a capacitor.

a. buck DC / DC converter system to charge the capacitor to be interposed solar output stage.
b. method of switching and capacitor charging voltage reaches a predetermined charge from parallel crowded connection of solar in series.
c. method to be charged by the solar and capacitor is interposed only rectifying device.

a. of method, but has the advantage that take increase the output current when capacitor charging voltage is low, since it is necessary to control the minimum operating voltage of the solar, circuit becomes complicated.
b. of method will be circuit is somewhat large, but you can No adjustment is a configuration is simple.
c. schemes charging efficiency is low, but the circuit is I can most simple and inexpensive.
(You have been suitably selected according the method of a - c the model grade.)

 



Sunlight, Inc. - The Solar LED Solution Company




Please call from below telephone inquiries!
Tel: 81+ 079-222-8807


Click here for Email inquiries!!






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Sunlight, Inc. - The Solar LED Solution Company
What's New | Product information | Company Profile | FAQ | Contact us | Top page | Japanese
Sunlight, Inc. - The Solar LED Solution Company
Sunlight, Inc. - The Solar LED Solution Company Sunlight, Inc. is developing solar self-powered light-emitting LED
Sunlight, Inc. Himeji client office: 1-44, Sanjo-cho, Himeji City, Hyogo-ken, JAPAN
zip code 670-0953
Tel: 81+ 079-222-8800   Fax: 81+ 079-222-8817
Copyright (c) SUNLIGHT, Inc. All Rights Reserved.
TECH CORPORATION