Introduction to stage lamps and lanterns is how to maintenan
In recent years, with the continuous progress of LED technology, it is known for its energy saving, high efficiency advantages, colorful lights, quickly become the latest must-haves in the lighting field. In order to let customers learn more about the LED lamps and lanterns, this article will introduce and analyse the failure reasons of the LED, which appropriate circuit protection method.
A, LED the damaged reasons mainly include the following:
1, the power supply voltage rise suddenly. There are several reasons for sudden high voltage: such as lightning, transient switching noise of switch power supply, power grid voltage fluctuation, switching power supply quality, wrong power supply, or the user use undeserved wait for a reason, can let the power supply voltage jump;
2, circuit board on a certain element, lines or other sundry short circuit, cause local short circuit, LED drive circuit to make this part of the higher voltage;
3, one LED by quality causes damage to form a short circuit, its pressure drop will be passed on to other LED above;
4, the temperature of lamps and lanterns, LED, the characteristics of the change. When the LED junction temperature rising to a certain extent, light attenuation, by volume, also shorten the service life.
5, the water inside the lamp, which leads to the short circuit;
6, when assembling, did not do a good job anti-static, the LED chip damage by static electricity, reduce the performance of it, even if the work voltage and current in the normal range, the LED is also easy to damage.
These reasons are willing cause the LED working current rise sharply, leading to the LED chip overheat and burn out.
2, when using the LED lamps and lanterns, we give full play to its advantages of energy saving, high efficiency, color is rich, how to ensure that the series of lamps and lanterns of high reliable performance? Several commonly used circuit protection mode, make and give you a simple introduction and comparison:
1, the protection way 1: use the fuse (tube)
Due to the fuse is a one-off, and slow reaction, the effect is poor, use of trouble, so the fuse is not suitable for use in LED lamps and lanterns. Because the LED lamps and lanterns in the show, commercial lighting, and designs city-lighting project use, it LED to protect circuit is very demanding, should immediately start when beyond normal use current protection, after the lamps and lanterns of normal and can automatically restore power, so it's very hard to adopt the way of fuse implementation.
2, protection way 2: use transient suppression diodes (TVS)
Transient suppression diode is a kind of highly efficient protection of diode device, when it's poles by reverse transient voltage surge, within 10 to the minus 12 power seconds, make themselves between the poles of high resistance to low resistance immediately, to absorb as much as several kilowatts of power surge, voltage clamping between the poles within a predetermined voltage value. Original effective protection of the electronic circuit, the transient suppression diode has a fast response time, the transient power, low leakage current, breakdown voltage deviation good consistency and clamping voltage control more easily. No damage limit, small volume light good points. But in actual use, found that could satisfy the requirement of voltage value for TVS device is not easy to no weapon LED lamp bead damage is mainly due to the current caused by overheating too ambassador chip, and TVS can detect over-voltage cannot detect overcurrent. To choose the appropriate voltage protection point it is difficult to grasp, so the device can't batch production, also with difficulty in actual use.
3, the protection way 3: use the restore fuse (PTC)
Since the recovery fuse is also called the polymer positive temperature thermistor, hereinafter referred to as PTC. It is composed of polymer and conductive particles, after special processing, the conductive particles in the polymer of conductive path, in the normal work of electric shed, PTC self recovery fuse in low resistance state; When the circuit is abnormal in current through (or abnormal temperature rise) heat generated by the polymer rapidly expand, cutting off the conductive particles made of conductive pathways, PTC self recovery fuse went into a state of high resistance at this moment, when the circuit overcurrent disappear (or ultra high temperature), polymer cooling, return to normal size, then again conductive particles to the electrical pathways, PTC self recovery fuse into a state of low resistance. Since the recovery fuse in the normal working state of heating is very small, in abnormal working state its high heat resistance is very big, is limited by the current, thus play a protective role.
The above three kinds of protection way, the last one is direct against over current, circuit protection, fast response speed, elements are small volume, simple circuit, and automatic reply function. In contrast, this way is more appropriate. In the specific circuit, we can use the following two ways:
1, shunt protection: generally LED lamps and lanterns is a lot of concatenated branch, we can add a PCT in front of each branch element respectively, such high precision and good reliability.
2, overall protection: in front of all the LED a PTC element, added to protect the whole lamp, the benefits of this approach is simple, does not occupy a volume, in the actual use of the result is satisfactory.
----------Archled Technology Co.,Limited