LED tube lights with energy-efficient design features

Try not to use electrolytic capacitors 
LED tube lights  driver circuit in the end not to use electrolytic capacitors? There are supporters and opponents, supporters believe that if you can control the temperature of the circuit board, in turn prolong life of electrolytic capacitors to achieve the purpose of, for example, use 105 degrees high temperature life of 8000 hours electrolytic capacitors, electrolytic capacitors according to the prevailing life estimation formula "temperature decreasing by 10 degrees, doubling the life," then it is 95 degrees in the environment working life of 16,000 hours at 85 degrees in the environment working life of 32,000 hours at 75 degrees in the environment working life of 64000 hours, if the actual operating temperature lower, then life will be longer! Seen in this light, as long as the selection of high-quality electrolytic capacitors of the drive power of life is no effect! 
There's supporters believe that the non-electrolytic capacitor of the high frequency ripple current caused by the human eye blinking be some physical discomfort caused by large amplitude low frequency ripple will lead to some digital camera equipment occurred between frequency flashing light and dark grid. Therefore, high-quality light fixtures still need to electrolytic capacitors. But opponents argued that since the electrolytic capacitor 
However, aging, in addition, LED lamps extremely difficult to control the temperature, so the electrolytic capacitor life is bound to decrease, thus affecting the life of LED lamps. 
In this regard, Doug Bailey believes that the LED driver circuit input section can be considered without electrolytic capacitors, actually uses the PI LinkSwitch-PH will save electrolytic capacitors, PI single-stage PFC / constant current design allows designers to eliminate large capacitance at the output circuit, high voltage ceramic capacitors can be used instead of electrolytic capacitors thereby enhancing the reliability 
Sex, "Some people in the design of two circuit when the output using a 400V electrolytic capacitor, which will seriously affect the reliability of the circuit, the proposed single-stage circuit with ceramic capacitors on it." He stressed. "For less concerned about the dimming function, high-temperature environment and industrial applications that require high reliability, I strongly recommend not using electrolytic 
Yung design. " 
If the design is not very high power LED lamps, Doug recommended MOSFET integrated LED driver products, because the benefits of doing so is an integrated MOSFET's on-resistance less heat generated less than discrete, in addition, is integrated MOSFET is the controller and the FET together, generally have a shutdown function, the MOSFET overheating will automatically shutdown circuitry to protect the purpose of LED lamps, which LED lighting is very important, because the LED lamps generally very small and difficult to carry out air cooling . "Sometimes burning due to overheating will occur LED hurtful situation, but we never such a program." He said. 
Try using a single-stage architecture circuit Doug indicates that some LED circuit uses two architectures, namely "PFC (Power Factor Correction) + isolation DC / DC converter" architecture, this design will reduce the efficiency of the circuit. For example, if the PFC efficiency was 95%, while the DC / DC efficiency of some 88%, the efficiency of the entire circuit will be reduced to 83.6%! "PI's LinkSwitch-PH device while the PFC / CC controller, a 725 V MOSFET and MOSFET driver integrated into a single package, the drive circuit efficiency to 87%! "Doug pointed out that" such a device can be greatly simplified board layout design, up to eliminating the traditional isolated flyback designs used 25 ons! eliminating components include high-pressure high-capacity electrolytic capacitor and the optocoupler. "Doug said that LED two architectures must be used for the second constant current drive circuit to make the PFC LED tube lights constant current drive old drive. These designs are outdated and no longer cost-effective, so in most cases, the best single-level design. 
Do not use a bipolar power devices 
Doug Bailey pointed out that as bipolar power devices cheaper than the MOSFET is generally about 2 cents one, so some designers in order to reduce the cost of the use of LED drivers bipolar power devices, it will seriously affect the reliability of the circuit, because as The LED driver board temperature increases, the effective work of bipolar devices quickly narrow range, this will cause the device to malfunction in the temperature rise which affects the reliability of LED lamps, the correct approach is to use MOSFET devices, MOSFET devices using life is much longer than the bipolar devices. 
Do not use a MOSFET voltage 600V 
A MOSFET cheaper voltage 600V, many LED tube lights that the input voltage is generally 220V, so that a sufficient voltage 600V, but many times the circuit voltage to 340V, when in a surge, 600V breakdown of the MOSFET can be easily , thus affecting the life of LED tube lights, in fact, use 600V MOSFET may be some cost savings, but it is to pay the cost of the entire board, so "do not use 600V breakdown voltage MOSFET, the best selection of the MOSFET voltage exceeding 700V . "he stressed.