LED dies are designed to perform optimally at 77˚F (25˚ Celsius) or lower, and by most measures, each 1.8˚F (1˚ C) rise above the level reduces the lumen output of a white LED by .5%. Over time, high heat levels also dramatically shorten an LED’s useful life. Each 30˚F (17˚C) rise in temperature halves the useful service life of most LEDs. Unlike traditional bulbs, LEDs generally do not fail catastrophically, but diminish in intensity over time. Hi-semicon Technology addresses this issue with every step of its luminaire fixture design process.
Fluorescent lamps require a ballast to stabilize the lamp and to provide the initial striking voltage required to start the arc discharge. This increases the cost of fluorescent luminaires, though often one ballast is shared between two or more lamps. Electromagnetic ballasts with a minor fault can produce an audible humming or buzzing noise.Conventional lamp ballasts do not operate on direct current. If a direct current supply with a high enough voltage to strike the arc is available, a resistor can be used to ballast the lamp but this leads to low efficiency because of the power lost in the resistor. Also, the mercury tends to migrate to one end of the tube leading to only one end of the lamp producing most of the light. Because of this effect, the lamps (or the polarity of the current) must be reversed at regular intervals.
Fluorescent fittings using a magnetic mains frequency ballast do not give out a steady light; instead, they flicker (fluctuate in intensity) at twice the supply frequency. While this is not easily discernible by the human eye, it can cause a strobe effect posing a safety hazard in a workshop for example, where something spinning at just the right speed may appear stationary if illuminated solely by a fluorescent lamp. It also causes problems for video recording as there can be a 'beat effect' between the periodic readings of a camera's sensor and the fluctuations in intensity of the fluorescent lamp.
Incandescent lamps, due to the thermal inertia of their element, fluctuate to a lesser extent. This is also less of a problem with compact fluorescents, since they multiply the line frequency to levels that are not visible. Installations can reduce the stroboscope effect by using lead-lag ballasts, by operating the lamps on different phases of a polyphase power supply, or by use of electronic ballasts.Electronic ballasts do not produce light flicker, since the phosphor persistence is longer than a half cycle of the higher operation frequency.
Questions about Solar LED street light
2010-01-11 22:56:26
Q:How to repair solar LED street light when it fails to work?
A: First, check whether the instruction lights of controller and battery are on. If not, check whether the connecting line is off. If there is no problem about the connecting line, then use the multimeter to test the voltage of battery whether it is normal. Otherwise, change the controller.
Secondly, check whether the controller load indicator is on by using the multimeter to test the output voltage. If there in no output voltage, change the controller.
The third, check whether the input voltage and fuse of LED driver are normal. If the fuse is ok, then use the multimeter to test the output voltage of LED driver is normal. If it is normal, please change the LED light fixture. Otherwise, change the LED driver.
Q: Should the PV panel face south?
A: It would be best for customers from the northern hemisphere to put the PV panel face south. In the meantime, to assure our PV panel could receive the sunshine light as much as possible, we will design the best lean degree according the sunshine situation in different districts.
Q: Is PV panel fragile?
A: The firm glass of solar panel has passed the hail testing under the mock condition of north pole and south pole.
Q: How much power the PV panel could offer?
A: The power of PV system is depending on the panel specification. We could recommend and design the exact PV system according to your requirement.
Q: How about the guarantee about Hi-semicon solar LED street light?
A: Ten years for PV panel system; three years for battery; ten years for LED light source; two years for control inverter and eight years for light pole.
Q: Would it be a problem when the PV panel is covered with ice?
A: The solar PV panel only could supply power when there is sunshine. When the PV panel is covered by ice of several inch thickness, PV panel couldn’t supply power even if it could receive a little sunshine. Most of the power has been stocked in the sunny day. W have consider this problem when we design our products.
Q: What about when the solar PV panel has been shading?
A: The solar PV panel should be installed in the places where could receive sunshine all day. Because even there is a little shading, it would greatly reduce the output power. We should avoid any shading when we design and install the solar PV panel.
Q: Do we need to clean the solar PV panel frequently?
A: Generally speaking, we don’t need to clean the PV panel frequently. In most of the areas, PV panel could be cleaned by the rain. But there is necessary for us to clean the panel when there is much dust every day. We could use soft tube to wash it. Of course we couldn’t stand or walk on the PV panel. Don’t use metal or other tough things to clean it and don’t use the water of high temperature.
Trouble one: all the led light source fail to work
Possibility: 1 The AC input line hasn’t been connected correctly;
2 The fuse has been damaged;
3 The DC input line hasn’t been connected correctly.
Solution: 1 Connect correctly the AC output of light fixture and AC input of power supply with waterproof connector;
2 Use the fuse of 5A/250V (glass tube). If the LED street light still doesn’t work, change the power supply;
3 Connect correctly the DC output of power supply and DC input of light fixture with waterproof connector.
Trouble two: LED lights flashing
Possibility: there is some problem with power supply
Solution: change the power supply
Trouble three: one group of LED light source is getting darker
Possibility: there is some problem with power supply
Solution: change the power supply
Trouble four: some LED doesn’t work or is very dark
Possibility: LED light source is damaged
Solution: change the LED light source of same type
Q:How to repair solar LED street light when it fails to work?
A: First, check whether the instruction lights of controller and battery are on. If not, check whether the connecting line is off. If there is no problem about the connecting line, then use the multimeter to test the voltage of battery whether it is normal. Otherwise, change the controller.
Secondly, check whether the controller load indicator is on by using the multimeter to test the output voltage. If there in no output voltage, change the controller.
The third, check whether the input voltage and fuse of LED driver are normal. If the fuse is ok, then use the multimeter to test the output voltage of LED driver is normal. If it is normal, please change the LED light fixture. Otherwise, change the LED driver.
Q: Should the PV panel face south?
A: It would be best for customers from the northern hemisphere to put the PV panel face south. In the meantime, to assure our PV panel could receive the sunshine light as much as possible, we will design the best lean degree according the sunshine situation in different districts.
Q: Is PV panel fragile?
A: The firm glass of solar panel has passed the hail testing under the mock condition of north pole and south pole.
Q: How much power the PV panel could offer?
A: The power of PV system is depending on the panel specification. We could recommend and design the exact PV system according to your requirement.
Q: How about the guarantee aboutJEGO’s solar LED street light?
A: Ten years for PV panel system; three years for battery; ten years for LED light source; two years for control inverter and eight years for light pole.
Q: Would it be a problem when the PV panel is covered with ice?
A: The solar PV panel only could supply power when there is sunshine. When the PV panel is covered by ice of several inch thickness, PV panel couldn’t supply power even if it could receive a little sunshine. Most of the power has been stocked in the sunny day. W have consider this problem when we design our products.
Q: What about when the solar PV panel has been shading?
A: The solar PV panel should be installed in the places where could receive sunshine all day. Because even there is a little shading, it would greatly reduce the output power. We should avoid any shading when we design and install the solar PV panel.
Q: Do we need to clean the solar PV panel frequently?
A: Generally speaking, we don’t need to clean the PV panel frequently. In most of the areas, PV panel could be cleaned by the rain. But there is necessary for us to clean the panel when there is much dust every day. We could use soft tube to wash it. Of course we couldn’t stand or walk on the PV panel. Don’t use metal or other tough things to clean it and don’t use the water of high temperature.
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