Satisfy the requirements of wide range, high brightness, color change and matching between LED and matching driver. Light-emitting diode matched with a variety of connection methods, different connection methods have different characteristics, and the requirements of the driver is different, especially in the case of a single light-emitting diode failure circuit work, the overall reliability of the light, to ensure that the overall light-emitting diode as far as possible to continue to work the ability to reduce the total light-emitting diode failure rate and so on has become particularly important. One, mixed mode  Mixed mode is a combination of series and parallel mode of the respective advantages of the proposed, the main way there are the following two.

    1、Mixed connection method of parallel and then series If the dry LEDs are mixed connection method of parallel and then series. Matching selection, the operating voltage and current as far as possible the same LED as a parallel group, or to each LED series small current resistance to solve.

    2、The first series after the parallel mixing mode  The whole circuit has a relatively simple structure, easy to connect, higher efficiency features, suitable for the application of a large number of light-emitting diodes. The use of the first series and the main mixed mode is to ensure a certain degree of reliability (each string of LED failure only affects the string of normal light at most), but also to ensure that the matching of the drive circuit (the driver output suitable voltage), than the pure series connection to improve reliability. Second, the cross-array mode  Cross-array mode is mainly to improve the reliability of the light-emitting diode, reduce the failure rate. The main structure is: each string of three LEDs for a group, respectively, access to the driver output Va, Vb, Vc output. When a string of three LEDs are normal.

    3、A light-emitting diode light at the same time; Once one or two of the light-emitting diode failure open-circuit, can ensure that at least one light-emitting diode normal operation. This can greatly improve the reliability of each group of light-emitting diode light, but also to improve the overall reliability of the whole light-emitting diode light.

    Overall Parallelism

    1、Individually matched parallel mode  Individually matched parallel mode of each LED has a current independent adjustability, to ensure that the current flowing through each LED in the range of its requirements, with a good driving effect, a single LED to protect the integrity of the fault does not affect the other LED work, can be matched with a large difference in the LED and other features. The only shortcoming is: the composition of the entire drive circuit is more complex, the device's high cost, occupies too much volume, is not suitable for a larger number of LED circuits.

    2、Parallel mode  Parallel mode in the first and last parallel connection of the LED, the work of each LED to withstand the voltage is equal. By the characteristics of the light-emitting diode can be seen, it belongs to the current-type devices, added to the light-emitting diode on the voltage of the small changes will cause a large change in current. In addition, due to the limitations of the manufacturing technology of LEDs, even for the same batch of LEDs, there are differences in performance, so when the first and last LEDs are connected in parallel, the current flowing through each LED is not equal. It can be seen that the uneven distribution of each LED current may make the current is too large LED life shrinkage, or even dead lights.   Although the parallel connection of light-emitting diodes is relatively simple, but the reliability is not high, especially for the number of light-emitting diodes is more likely to cause the application of the use of faults.

    Overall cascade method

    1、With parallel zener diode series mode  In the parallel zener diode series mode, each zener diode breakdown voltage is higher than the operating voltage of the light-emitting diode. In the normal operation of the light emitting diode, due to the zener diode VD1 ~ VDn does not conduct, the current mainly flows through the LED1 ~ LEDn, when the light emitting diode string of damaged light emitting diode caused by the string of open-circuit, due to the VD1 ~ VDn conductive, in addition to faulty light emitting diode, the other light emitting diode is still a current through and light.

    2、Tandem mode  Tandem form of LED has a simple circuit, easy to connect and so on. Light emitting diode series connection mode in the first and last connected, light emitting diode work when the current flow is equal. For the same specifications and batches of LED to speak, although a single LED on the voltage may have a small difference, but because the LED is a current-type devices, so you can ensure that the respective luminous intensity consistent.   Take series connection should pay attention to when one of the light-emitting diode open-circuit failure, will cause the whole light-emitting diode extinguished, resulting in the use of light-emitting diode reliability. Therefore, in the actual combination of circuits, the correct choice of appropriate LED connection is extremely important.