LED is an electric drive application, and the switch damage is much larger than the conduction loss. The switching loss is related to the CGD and CGS of the power pipe and the driving ability and working frequency of the chip. So solving the heat problem of the power pipe can be solved from the following aspects:. MOS power tube can not be selected based on the size of the conduction resistance.
The rest is frequency and chip drive capability. Here we only talk about the influence of frequency. The frequency is directly proportional to the conduction loss.
So when the power tube is heating, we should first consider whether the frequency selection is a bit high. When the frequency is reduced, in order to get the same load capacity, the peak current must be larger or the inductance becomes larger, which may lead to the inductor into the saturation area. If the inductance saturation current is large enough, the CCM continuous current mode can be changed into DCM discontinuous current mode , which requires an increase of load capacitance.
Frequency reduction is mainly caused by two aspects. The ratio of input voltage to load voltage is small and system interference is large.
For the former, be careful not to set the load voltage too high, though the load voltage is high, the efficiency will be high. For the latter, we can try the following aspects: A, the smallest current set the smallest point; B, wiring clean point, especially the key path of sense; C, the selection of the inductor or the inductance of the closed magnetic circuit; D, RC low pass filter, this effect is a little bad. C is not good consistency, the deviation is a bit big, but it should be enough for lighting.
As the high power light-emitting diode operating voltage is only 3V, the full-bridge rectifier turns the V AC into DC, the voltage drop on the full bridge is about 1. According to the principle of three basic color synthesis white light, 31W high-power light-emitting diodes with red, green and blue are connected in series, and the brightness of the LED equivalent to the white light of 3W can be obtained. At the same time, 6 kinds of color light can be combined to satisfy people's preference for color conversion.
The LED drive circuit uses a switching power supply as the first level of control, and a pressure control constant current source as the second level of control. Combining the advantages of the two can ensure efficiency and control accuracy. Moreover, it is directly provided by the city with electricity, two-layer drive, high safety, and it is not easy to damage the expensive LED lights. What is an LED driver used for? LED drivers are devices which regulate and supply the power used to 'drive' runs of LED strip lighting.
Similar to traditional transformers, they transform mains voltage alternating current v AC to a lower voltage. Do I need a driver for LED lights? Every LED light source requires a driver.
Some LEDs already include an integrated driver within the bulb. What is the difference between a transformer and an LED driver? A transformer is by convention a double wound device, just ac in, ac out. Drivers are more sophisticated than that and usually give a dc output using a switched-mode system, also they have current regulating and monitoring circuits in them. Can a LED driver be used as a power supply? Constant current and Constant voltage drivers are both viable options for a power supply for LED light sources, what differs is the way in which they deliver the power.
How many LEDs can a driver power? How many lights can one driver power? Drivers are not limited by the number of LED lights they power. They are restricted by the total wattage of the LED lights they power. How long does an LED driver last?
Namely, the life of the driving circuit expires prior to when the LED stops emitting light or has its brightness dropped. The typical nominal lifetime of these elements is often times less than 25, hours, while the lifetime of LED itself could be as long as 50,, hours.
Do LED drivers get hot? Heat is the enemy of electronics and this goes for LED drivers too. This doesn't mean that LED drivers cannot operate in hot environments, they can. The output capacity of a switch-mode power supply, including LED drivers reduces as the temperature increases. How do I choose an LED driver? The driver must have a higher output power than your LEDs require for extra safety. If the output is equivalent to the LED power requirements, it is running at full power.
Running at full power may cause the driver to have a shorter life span. How do I know if my LED drivers are bad?
LED drivers rectify higher voltage alternating current to low voltage. Usually the circuits burn out and fail. How does an LED driver circuit work? The voltage drop across an LED is approximately constant over a wide range of operating current; therefore, a small increase in applied voltage greatly increases the current.
It is quite clear that economic growth is closely linked to energy availability. Energy availability can be approached by two ways; the first way is to build more power plants to cover the increased demand. The second way is to reduce the power consumption.
LED lighting has many advantages like high reliability, low maintenance cost, dimming in addition to the main advantage of energy saving and strong expected performance enhancement.
On the other hand, the disadvantages are mainly due to the initial cost of changing the lighting systems in addition to the need of a special power electronics circuitry to drive them for regulated intensity and brightness. The project goal is replace the halogen bulbs 50W to integrated led lamp 10W. LEDs have many advantages when compared with other light sources such as incandescent or fluorescent lamps.
The most significant advantages are fast turn-on, lower heat generation, lower power consumption and higher operating life. LEDs need to be driven properly to ensure optimal performance and long life. The driver must be cost effective, which is not usually achieved with discrete components but can be realized with integrated solutions.
You also can find more articles about electronic semiconductor through Google search engine, or refer to the following related articles. LED lighting circuit protection. We use cookies on our website to give you the most relevant experience. Manage consent. Close Privacy Overview This website uses cookies to improve your experience while you navigate through the website.
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But opting out of some of these cookies may have an effect on your browsing experience. Necessary Necessary. Other other. Advertisement advertisement. Analytics analytics. Analytics cookies are used to gather statistical data for use in improving the website content. Functional functional. All solution I was finding through the web in one post. Thank you very much for the time and effort :. Tip 1 year ago. Good instructable but you seem to have the wrong impression of why LEDs need to be constant current.
This continues with the LED getting hotter and hotter and conducting more and more power that even without "moving to a new environment" your LED will eventually fail and burn out regardless of how precisely you've set the voltage.
LEDs can never be driven by constant voltage unless you want them to die an early death. Question 1 year ago on Step 5. I would like to obtain a current source around mA. My Power Supply is 21V. Could you help me? I don't understand. Depuis un ans je suis dessus pour un avion Beechcraft Question 2 years ago. In the constant current led driver circuit you do state that in step 6, the input voltage varies from 3 volts right up to 60 volts.
Is the input voltage dc or ac? I want to achieve it without opening the LED it without messing with the invite circuit. What is a good approach to do this? Would an nchannel power mosfet do the trick? Thanks in advance! Question 3 years ago on Introduction.
Question 3 years ago. Dan, thanks for this clear and simple explanation. I see only higher voltage values. Hi I'd like to make a high power led strobe.
Something around lumens out put, can I use one of your designs to accomplish this task. Question 3 years ago on Step 1. Tip 3 years ago on Step 5. Concerning regulators, there are some very tiny regulators available online on eBay and Banggood. Therefore design of gate driver circuit is critically important in designing of power electronics converters.
Before selection of Mosfet driver you should check its compatibilty with your required power electronics converter circuit. For example at current source and current sinking ability, How much it turn on and turn off mosfet gate. All these things are usually mentioned in data sheet of Mosfet driver.
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