Due to increasing energy regulations, most people are familiar by now with the long life spans and energy savings associated with LEDs, or light-emitting diodes. However, many are not aware that these innovative light sources use specialized devices called LED drivers to operate. LED drivers (also known as LED power supplies) are similar to ballasts for fluorescent lamps or transformers for low-voltage bulbs: they provide LEDs with the correct power supply to function and perform at their best. Below, we discuss when you need an LED driver, why you need an LED driver, and what type of driver you may need.
When Do I Need an LED Driver?
Always. Every LED light source requires a driver led lights in china. The question should be whether or not you need to purchase one separately, as some LEDs already include an integrated driver within the bulb. LEDs designed for household use (bulbs with E26 / E27 or GU24 / GU10 bases and that run on 120V) typically already include a driver. However, low voltage LED light sources, such as some MR- bulbs (MR GU5.3s, MR8s, and MR11s) and tape light, as well as certain fixtures, panels, or outdoor-rated lights, usually require a separate driver. Always check your product data sheet to see if your LED light source requires a separate driver. Why Do I Need an LED Driver?
LEDs are designed to run on low voltage (12-24V), direct current electricity. However, most places supply higher voltage (120-277V), alternating current electricity. An LED driver’s main purpose is to rectify higher voltage, alternating current to low voltage, direct current.
LED drivers also protect LEDs from voltage or current fluctuations. A change in voltage could cause a change in the current being supplied to the LEDs. LED light output is proportional to its current supply, and LEDs are rated to operate within a certain current range (measured in amps). Too much or too little current can therefore cause light output to vary or degrade faster due to higher temperatures within the LED.
In sum, LED drivers serve two purposes: to convert higher voltage, alternating current to low voltage, direct current, and to keep the voltage or current flowing through the circuit at its rated level.
What Type of LED Driver Do I Need?
There are two main types of LED drivers, constant-current and constant-voltage. Often, you can simply check the datasheet of an LED light source to find out if it requires a constant-current or constant-voltage driver warm LED spot lights gu10. For example, if an LED datasheet says that your light source requires a 350mA output, you need a constant-current driver. If a datasheet says that your LED requires a 12-volt output, you need a constant-voltage driver. Below, we’ll review the differences between each technology.
Constant-Current
FLX-3528WW1203Since LEDs are forward-current driven light sources, LED light mini spot lights all LEDs require a constant-current driver to work. They only require one separately if they do not already include an integrated one inside the bulb. Constant-current LED drivers are available with a variety of different attributes depending on application and required electrical output. Constant-current drivers keep the current flowing through each LED at the rated current to maximize the light output and life span of each diode. Constant-current LEDs and drivers are more widely used, as well as more efficient, than constant-voltage technologies. Examples of constant-current LEDs include tape light, signage/channel letters, under-cabinet fixtures, and pathway lighting.
Keep in mind that when constant-current LEDs are connected in a series, the voltage supply will drop with each new diode. Be sure to choose a driver with a suitable voltage to meet the current requirements. For example, if you put 15 LEDs in a series, and each LED has a voltage drop of 3 volts (at its nominal current), you will need to provide a voltage source of 45 volts (15 x 3V = 45V).
If your LEDs already include a constant-current driver as part of the assembly, an external constant-voltage driver is required. Low-cost LED circuits that control the current flowing through the LED with a simple resistor also require a constant-voltage power source. Constant-voltage configurations are typically used when a constant-current array would require a very high voltage due to a high number of diodes connected in series. Constant-voltage technology is used in applications such as LED fixtures, panels, and strip lights, as well as backlit ad signs, traffic information signs, and large-screen high definition LED displays.
When selecting a constant-voltage driver, make sure that the output current range is higher than the estimated current draw of your LEDs. The feeding current may vary according to the load. The higher the load is, the bigger the current draw becomes, which can affect light output.
Tuesday, June 10, 2014
Friday, June 6, 2014
Differences emerge in AAP's top rung
Differences in the top rung of Aam Aadmi Party have come to the fore with Manish Sisodia accusing Yogendra Yadav of targeting party chief Arvind Kejriwal and making internal matters public.
In a letter written in response to Yadav's email, Sisodia said, "Your (Yadav) broad allegations are Arvind (Kejriwal) does not listen to the suggestions of the PAC (Political Affairs Committee). I am surprised reading your email interlinings because till the time Kejriwal agreed with you, he was democratic." Sisodia was referring to the recent row between Naveen Jaihind and Yadav after which Jaihind quit the National Executive and the latter the PAC membership.
Yadav and Jaihind had unsuccessfully contested from Gurgaon and Rohtak Lok Sabha seats respectively. The former was the Haryana in-charge while the latter was the party's state convener.
Sisodia and Yadav were not immediately available for their comment.
The letter, which was written earlier this week, said that Lainiere De Picardie Interlining it was Kejriwal who backed Yadav's decision of contesting from Gurgaon despite other PAC leaders opposing the move, but the AAP chief managed to convince others.
"When you wanted to become Haryana in-charge and wanted to be projected as the CM candidate despite opposition from other PAC members, Arvind backed you. At that time he was democratic (for you).
"The state of affairs of the party in Haryana is in a shambles. Volunteers talk about your fight with Jaihind," he said.
Sisodia said, "You want strict action against Naveen (Jaihind) and when Kejriwal does not agree with you, then you call him of being a party supremo."
The former Delhi Minister said Kejriwal, after resigning as Interlining Manufacturers in India the Delhi Chief Minister, was not in favour of contesting Lok Sabha polls across the country, but wanted to focus on Delhi.
But Yadav along with other PAC members were in favour of contesting the polls and "the results are before us", Sisodia said.
"After the fall of our government in Delhi, you conducted a survey in Haryana which said that party may get around 23% of votes in the state, but under your leadership, it has managed to get only 3% of votes. This requires introspection," Sisodia said.
A senior AAP leader said the letter was written after the party's rout in Haryana.
"We were not expecting this dismal performance in Haryana and in fact Punjab was a surprise. The recent squabbles between Jaihind and Yadav prompted Sisodia to write the letter," the AAP leader said.
In a letter written in response to Yadav's email, Sisodia said, "Your (Yadav) broad allegations are Arvind (Kejriwal) does not listen to the suggestions of the PAC (Political Affairs Committee). I am surprised reading your email interlinings because till the time Kejriwal agreed with you, he was democratic." Sisodia was referring to the recent row between Naveen Jaihind and Yadav after which Jaihind quit the National Executive and the latter the PAC membership.
Yadav and Jaihind had unsuccessfully contested from Gurgaon and Rohtak Lok Sabha seats respectively. The former was the Haryana in-charge while the latter was the party's state convener.
Sisodia and Yadav were not immediately available for their comment.
The letter, which was written earlier this week, said that Lainiere De Picardie Interlining it was Kejriwal who backed Yadav's decision of contesting from Gurgaon despite other PAC leaders opposing the move, but the AAP chief managed to convince others.
"When you wanted to become Haryana in-charge and wanted to be projected as the CM candidate despite opposition from other PAC members, Arvind backed you. At that time he was democratic (for you).
"The state of affairs of the party in Haryana is in a shambles. Volunteers talk about your fight with Jaihind," he said.
Sisodia said, "You want strict action against Naveen (Jaihind) and when Kejriwal does not agree with you, then you call him of being a party supremo."
The former Delhi Minister said Kejriwal, after resigning as Interlining Manufacturers in India the Delhi Chief Minister, was not in favour of contesting Lok Sabha polls across the country, but wanted to focus on Delhi.
But Yadav along with other PAC members were in favour of contesting the polls and "the results are before us", Sisodia said.
"After the fall of our government in Delhi, you conducted a survey in Haryana which said that party may get around 23% of votes in the state, but under your leadership, it has managed to get only 3% of votes. This requires introspection," Sisodia said.
A senior AAP leader said the letter was written after the party's rout in Haryana.
"We were not expecting this dismal performance in Haryana and in fact Punjab was a surprise. The recent squabbles between Jaihind and Yadav prompted Sisodia to write the letter," the AAP leader said.
Tuesday, April 29, 2014
Under LED lights, your clothes can’t get “whiter-than-white”
LED lightbulbs are incredibly energy efficient (pdf), but they could do a number on your crisp white button-downs: According to a new study led by Kevin Houser, a professor of architectural LED street light purchaser engineering at Penn State University, the most common type of LED lightbulb renders clothing brighteners—the chemicals in detergents that claim to make your whites whiter—useless.
+ Unlike bleaches, those detergents don’t actually change the fabric’s color: but they make it look whiter, at least under the lights we’re used to. Optical brighteners are used to make white clothes (and other things, including printer paper and blond highlights) appear whiter. These “fluorescent whitening agents” produce a subtle blue glow under most sources of light, counteracting dingy yellow tones and creating a perception of brightness LED flood light in usa. They have been engineered over decades to work well under sunlight, fluorescent light, and incandescent light.
+ But if you are one of the many people making the switch to blue-pumped LEDs, your life (or at least your laundry) might get a little bit dingier. The whiteners only glow under violet and ultraviolet light, which the most common type of LED bulb—the blue-pumped LED—lacks.
The study compared test subjects’ perception of different levels of fluorescence on white backgrounds (with progressively more optical brighteners) under several lighting conditions. A halogen lamp was used, along with a typical blue-pumped LED bulb and three violet-pumped LEDs. Sure enough, participants saw the more fluorescent objects as whiter with each increase in violet light emission. And when they tried to sort the objects by perceived “whiteness” under the light of a blue-pumped LED, they seemed to guess randomly.
The market for LEDs is expected to increase rapidly in the coming years: A recent projection by the consulting group McKinsey & Company estimated that dropping costs and an increase in bans on incandescent bulbs mean that LEDs will make up 45% of the global general lighting market by 2016, and 69% of the market in 2020 (pdf).
+ For those moving from incandescent light to a more energy-efficient source, many prefer LEDs to fluorescents. And indeed, research has established that colors are still distinguishable and pleasing to the eye under blue-pumped LEDs, the researchers said. But in a home or business lit with 31W LED Panel Light, you might not see the sparkling white products you’ve grown used to—ranging from paper documents to platinum blond hair to tablecloths. That’s because of a mismatch between the way fluorescent whitening agents were engineered and this new form of lighting.
The researchers offer a solution to this mismatch: If companies producing lightbulbs focus on putting violet light into household LEDs, they suggest, we might end up feeling a lot better about our freshly-laundered gym socks.
+ Unlike bleaches, those detergents don’t actually change the fabric’s color: but they make it look whiter, at least under the lights we’re used to. Optical brighteners are used to make white clothes (and other things, including printer paper and blond highlights) appear whiter. These “fluorescent whitening agents” produce a subtle blue glow under most sources of light, counteracting dingy yellow tones and creating a perception of brightness LED flood light in usa. They have been engineered over decades to work well under sunlight, fluorescent light, and incandescent light.
+ But if you are one of the many people making the switch to blue-pumped LEDs, your life (or at least your laundry) might get a little bit dingier. The whiteners only glow under violet and ultraviolet light, which the most common type of LED bulb—the blue-pumped LED—lacks.
The study compared test subjects’ perception of different levels of fluorescence on white backgrounds (with progressively more optical brighteners) under several lighting conditions. A halogen lamp was used, along with a typical blue-pumped LED bulb and three violet-pumped LEDs. Sure enough, participants saw the more fluorescent objects as whiter with each increase in violet light emission. And when they tried to sort the objects by perceived “whiteness” under the light of a blue-pumped LED, they seemed to guess randomly.
The market for LEDs is expected to increase rapidly in the coming years: A recent projection by the consulting group McKinsey & Company estimated that dropping costs and an increase in bans on incandescent bulbs mean that LEDs will make up 45% of the global general lighting market by 2016, and 69% of the market in 2020 (pdf).
+ For those moving from incandescent light to a more energy-efficient source, many prefer LEDs to fluorescents. And indeed, research has established that colors are still distinguishable and pleasing to the eye under blue-pumped LEDs, the researchers said. But in a home or business lit with 31W LED Panel Light, you might not see the sparkling white products you’ve grown used to—ranging from paper documents to platinum blond hair to tablecloths. That’s because of a mismatch between the way fluorescent whitening agents were engineered and this new form of lighting.
The researchers offer a solution to this mismatch: If companies producing lightbulbs focus on putting violet light into household LEDs, they suggest, we might end up feeling a lot better about our freshly-laundered gym socks.
Thursday, October 18, 2012
Swiss Oris Lady Diamond Watches, Brand New Big Watch Crown Show Out the Romantic Golden Autumn
A lots of world famous watches was launched in this golden Autumn, and especially the Swiss Copy Watches UK as the representative. The Oris watch brand which was established in the early twentieth century brings brand new big crown ladies’ diamond watches for young ladies in this romantic golden Autumn. The two bright color which are marca dragon green and lilac purple are very beautiful and make the Autumn and Winter be not so cold again, and fully of the sweet and happiness fo the Spring and Summer.
Since the establishment of Oris in 1904, Oris insisted to create the mechanical wrist watch with Swiss technology, which was warmly welcomed by young people. So the price of Oris watches is made between four hundred and eight hundred dollars, and many people can afford it. Taiwan is the second world big market of Oris. The Third Generation BC3 of Big Crown series was launched in 1999, it is the most extremely selling Hour Angle Replica Audemars Piguet Watches among all kinds of wrist watches.
The brand new Big Crown lady diamond watches is so fresh and bright. There are thirteen bright diamond set at the hour markers on the exquisite mother pearl watch dial, which is very grace and charming. More than that, the designers satisfied the demand of modern women, to offer all kinds of leather strap or stainless steel bracelet. From classical black or whit to the good look Nude or marca dragon green and lilac purple, Oris tried its best to satisfied the demand of the customers.
Oris especially design the simple Cartier replica watches dials for the classical Big Crown in the golden Autumn this year, and show its unique styles, let people enjoy the sweet and happiness of Spring and Autumn again. In Hong Kong, the Brand Ambassador of Oris is the super star Xie Tingfeng who is warmly welcomed actors by young people. Oris invented him especially to deduce the OrisArtix series. Xie Tingfeng is full of confidence, working hard and working with perseverance, his professional spirit is correspond the brand philosophy of Oris.
If you are a fan of wrist watches as well, remember to buy high-end ones for they can bring you good luck, confidence and high quality life.
Since the establishment of Oris in 1904, Oris insisted to create the mechanical wrist watch with Swiss technology, which was warmly welcomed by young people. So the price of Oris watches is made between four hundred and eight hundred dollars, and many people can afford it. Taiwan is the second world big market of Oris. The Third Generation BC3 of Big Crown series was launched in 1999, it is the most extremely selling Hour Angle Replica Audemars Piguet Watches among all kinds of wrist watches.
The brand new Big Crown lady diamond watches is so fresh and bright. There are thirteen bright diamond set at the hour markers on the exquisite mother pearl watch dial, which is very grace and charming. More than that, the designers satisfied the demand of modern women, to offer all kinds of leather strap or stainless steel bracelet. From classical black or whit to the good look Nude or marca dragon green and lilac purple, Oris tried its best to satisfied the demand of the customers.
Oris especially design the simple Cartier replica watches dials for the classical Big Crown in the golden Autumn this year, and show its unique styles, let people enjoy the sweet and happiness of Spring and Autumn again. In Hong Kong, the Brand Ambassador of Oris is the super star Xie Tingfeng who is warmly welcomed actors by young people. Oris invented him especially to deduce the OrisArtix series. Xie Tingfeng is full of confidence, working hard and working with perseverance, his professional spirit is correspond the brand philosophy of Oris.
If you are a fan of wrist watches as well, remember to buy high-end ones for they can bring you good luck, confidence and high quality life.
Saturday, August 11, 2012
Advanced customization wrist watch of 2012, you are the master of your style
A nice men’s watch can show the charming and grade of a man absolutely. The replica swiss watches for men are such as jewelry for women. However, a senior custom men’s wrist watch brand is a symbol of a successful man. Let’s see which is suit for you in 2012.
This wrist watch has seven parts, it nearly cover all the custom. It is such one with 2475/ SC/1 movement or 2460 QH calendar wrist watch. You can choose your favorite to collocate. Its other accessories include the machine core, the dial and the strap and so on. There are nearly 400 kinds of mix collocation you can choose. The material including rose gold, titanium, palladium available for your choice. You can also be free to collocate the dial with gray, white and black color.
You can choose the materials of the cover of the watch by yourself, to collocate the constant flywheel. The advantage of this watch is its 24 hour dial display settings and the 94900 hand operation machine core. And its back can show the map and the horizon and the setting of sunrise and sunset. It can show a leap year and the days as well. It also has the 30 meters waterproof effect.
The function of this kind of customized watch is very strong. It has the LV103 automatic machine core and 90 hours of power storage. You have many chose on material of the dial color such as gold, rose gold and platinum material. The dial is designed as hollow out.
. The cover is made with grind eriaceous titanium mental with a diameter of 50mm. the small second hand and the tourcostson will shows at he 9 o’clock position. It will show when at 8 o’clock with the sunrise and it will hiss at 4 o’clock in sunset. I heard of this wrist watch will stop the production. So the gentlemen who want to buy, you should take your ation in a hurry.
This wrist watch has seven parts, it nearly cover all the custom. It is such one with 2475/ SC/1 movement or 2460 QH calendar wrist watch. You can choose your favorite to collocate. Its other accessories include the machine core, the dial and the strap and so on. There are nearly 400 kinds of mix collocation you can choose. The material including rose gold, titanium, palladium available for your choice. You can also be free to collocate the dial with gray, white and black color.
You can choose the materials of the cover of the watch by yourself, to collocate the constant flywheel. The advantage of this watch is its 24 hour dial display settings and the 94900 hand operation machine core. And its back can show the map and the horizon and the setting of sunrise and sunset. It can show a leap year and the days as well. It also has the 30 meters waterproof effect.
The function of this kind of customized watch is very strong. It has the LV103 automatic machine core and 90 hours of power storage. You have many chose on material of the dial color such as gold, rose gold and platinum material. The dial is designed as hollow out.
. The cover is made with grind eriaceous titanium mental with a diameter of 50mm. the small second hand and the tourcostson will shows at he 9 o’clock position. It will show when at 8 o’clock with the sunrise and it will hiss at 4 o’clock in sunset. I heard of this wrist watch will stop the production. So the gentlemen who want to buy, you should take your ation in a hurry.
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