Presently, more and more LED lighting products are used in our daily lives, from outdoor lighting applications to indoor lighting applications. LED is new developed technique which is more environmental friendly, more durable, more easily to control and of course can save more energy. LED tube is one of the most widely used indoor LED lighting products.
LED tubes drivers can be divided into two types: isolated drivers and non-isolated drivers.
The input and the output of an isolated driver are “blocked” by transformers. These transformers can improve the security of the entire device but reduce the efficiency (around 85%) as well. Another disadvantage is that these transformers are too large to be put into the limited space within LED tubes.
Different from isolated drivers, the input and the output of non-isolated drivers are connected directly by circuits. Although these drivers are more efficient, they are somehow life-threatened. Currently, the most commonly used LED tube drivers are non-isolated BUCK drivers: convert AC to DC through rectifiers and meanwhile drop voltages through Buck block to maintain a constant current.
These improved drivers are much simpler in circuit design, smaller than isolated drivers. The normal efficiency of them is 80% ~ 90%. One can support more than 100 LEDs (in cascade or in parallel or both). However, these LED tube drivers have their own defects. Since non-isolated drivers will introduce the high energy from input to output, risking user’s live. To solve this problem, an insulated PCB will be inserted between AC input and aluminum cover. This design can block as high as 2000V voltage, even so it cannot pass the CE Certificate.
Comprehensively, both of isolated drivers and non-isolated drivers have their own advantages and disadvantages. Non-isolated drivers think more of efficiency, reducing energy consumption; while isolated drivers are safer to use. In fact, most people intend to use isolated drivers due to their small sizes, high efficiencies, low costs, more cost-effective.
LED tube drives can be divided into internal drivers and external drivers. LED tubes using internal drivers can directly replace the traditional fluorescent tubes without any changes. There are two different internal drivers: 1. Rectangular driver, installing within the aluminum shell. It is less practical due to the unevenly heat distribution. LED chips around the power supplier will continuously worked in high temperature. LED tubes using this kind of drivers usually have shorter service life. 2. Divide the entire power supplier into two parts and mounted separately on both sides of the tube. Because of the limited space of tube ends, design is more complicated.