Fluorescent tubes are widely used in daily life, such as supermarkets, schools, office cities, subways, etc., but in public places that can be seen, you can see the extensive use of fluorescent lamps! The energy saving performance of LED fluorescent lamps has been going through for a long time. A lot of publicity, everyone has been very recognized, but the LED fluorescent tubes bought at high prices, now many have come to the same situation as cheap energy-saving lamps: energy saving and no money! And a lot of wasted money, how to make LED service life and brightness meet the standard of satisfactory use, is a very significant topic! LED fluorescent tube to maintain long life and high brightness, the problem to be solved is: power supply, LED light source, heat dissipation, safety four key technologies .
First, the power supply
The primary requirement of the power supply is high efficiency and high efficiency. If the heat is low, the stability will be high. Generally, there are two schemes of isolation and non-isolation in the power supply part. The isolation volume is large and the efficiency is low. In use, there are many problems in installation. It is not as good as the market prospect of non-isolated products. Here we mainly discuss non-isolation. Drive solution.
The non-isolated LED fluorescent lamp power supply is based on the A704WFT of Taiwan Guangpeng Technology Co., Ltd., and the MOS tube of the A704WFT is plugged in. The basic circuit is shown in Figure 1:
Basic circuit diagram
Power characteristics:
1. Mains power supply (85~265V), external MOS, power is not limited;
2, low power consumption, high efficiency, high power factor;
3, with load open circuit and short circuit protection, output overvoltage protection function, current ripple characteristics, output current is similar to DC DC, no lamp flash phenomenon, high load capacity, can drive up to 600mA current;
4, the customer has made 15W standard circuit, efficiency 88%, power factor 0.91, can pass CE certification, including EN55015 EMI test, lighting fixtures below 25W class C harmonic standard, EFT 1000V pulse group test, ESD 2000V Static test. The 15-string application can control the output low voltage, eliminating the need for traditional large capacitors and controlling the output harmonics of the current.
5, A704's LED daylight application program is relatively mature and reliable, we can provide PCB line and EMC table reference for LED fluorescent lamp to improve the speed of customer design and development products!
Second, LED light source
Adopting the patented LED lamp bead of Taiwan Mingmings, the chip is placed on the pin, the thermal energy passes through the silver foot directly to the tropical part produced by the chip node, and the traditional in-line product and the traditional patch product are in the heat dissipation. There are qualitative differences, the node temperature of the chip will not accumulate, thus ensuring the good use of the light source bead, ensuring the long life of the light source bead, low light decay.
Although the traditional patch products can be connected to the positive and negative electrodes through the gold wire of the chip, and the thermal energy generated by the chip is connected to the silver foot through the gold wire, the conduction of heat and electricity is conducted by money, and the heat accumulation time is long. Will directly affect the life of LED fluorescent tubes.
The traditional heat transfer route and method of patch products are shown in Figure 2:
The LED conduction route and method of Simings is shown in Figure 3:
The patented heat dissipation structure of the LEDs of the ç‰æ˜Žæ–¯ enables the heat generated by the chip nodes to be quickly taken out, and no heat accumulation occurs at the chip, so that the LED light source lamp beads can be used for a long life. Moreover, in the life test of LED, Simings has made a complete experimental analysis for various complex application environments such as high and low temperature impact, over reflow, high temperature and high humidity, ensuring low light decay in normal use. long life!
Third, heat dissipation
The introduction of infrared radiation heat dissipation and application to fluorescent tubes is an important means to improve the service life of the lamps. In the heat dissipation consideration, we separate the heat dissipation of the LED light source bead and the heat dissipation of the power supply, and do not interfere with each other, thereby ensuring the rationality of heat dissipation.
There are three ways of heat conduction, convection, conduction and radiation. In a closed environment, convection and conduction are less likely to be achieved, and the emission of heat by radiation is the focus of fluorescent tube considerations. The following is the test data of the LED fluorescent tube we made. The temperature measured outside the LED silver solder joint is only 58 degrees.
Test report result
The above data is a test report with an input power of 11.2 watts and a luminous flux of 890 LM. The maximum temperature inside the tube is 40.213 degrees. This temperature allows the capacitor of the power supply to work for a long time, thus ensuring the long life of the power supply!
Fourth, security
Safety, here mainly refers to PC flame-retardant plastic tube, because infrared heat can penetrate PC tube, we design to consider the safety of LED light when using it, use physical insulation of plastic, even if it is used The isolated power supply also guarantees the safety of use.
The development of LED fluorescent lamps has been going on for quite a long time. From the perspective of energy saving, its future application is quite broad. In addition to energy saving, its safe and long-life use is something we should pay more attention to!
Safety! In the design of LED fluorescent lamps, it is the first element. The fluorescent lamps using PC flame retardant materials can improve the life after solving the safety problems. The solutions proposed by the above projects are expected to be provided to many LED fluorescent tube manufacturers. More ways to think!
- The Description of wifi Antenna
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When selecting the antenna, it is necessary to pay attention to whether the connector of the antenna matches the connector of the connected device. Generally, SMA and TNC are used for WIFI
To use on the router, but on the 2.4 G wireless monitoring equipment fittings, if match, also can achieve the enhancement effect of the wireless signal transmission Magnetic antenna base, can suck on metal surfaces, makes the antenna signal is stronger Plug and play, without any additional conditions, but the antenna gain and directional property management are key points to consider. - The first standard WIFI antenna products were made by LTCC process, because of its width and general performance. Abroad, Airgain has launched a standard antenna with high temperature resistance and plastic seal, which is used in laptop computers, and a series of WiFi antennas with magnetic dielectric in mobile phones have been launched in China.
- The Picture of wifi Antenna
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