LED driver 4 connection modes
Now many LED products use constant current drive mode to drive LED, LED connection mode also according to the actual circuit needs to design different connection mode, generally there are series, parallel, mixed and array four forms.
1. series mode
This series connection circuit is relatively simple, end to end connected together, the current flow of LED work is very good, because LED belongs to the current device, so it can basically ensure that the luminous intensity of each LED is consistent. The circuit of this LED connection is simple and convenient. But there is also a fatal disadvantage, that is, when one of the LED open circuit failure, will cause the entire LED lamp string extinguished, affecting the reliability of the use, which requires to ensure that the quality of each LED is excellent, so that the reliability will be improved accordingly.
It is worth noting: If driven by constant voltage LED power to drive the LED, so when a short-circuit time will lead to an LED circuit current increases, when the reaches a certain value when the LED will be damaged, leading to the back of the LED all the damage, but if use the LED constant current drive power to drive the LED, when a certain LED short-circuit current basic remains the same, It has no effect on the LED behind. Either way, once an LED is open, the entire circuit is not lit up.
2. parallel mode
Parallel mode is characterized by the parallel connection between the end and end of LED, and the voltage on each LED is equal when working. However, the current is not necessarily the same, even for the LED of the same model and the same specification batch, because of the production process and other reasons. Therefore, the uneven distribution of current of each LED may cause the life of the LED with excessive current to decline lossy compared with other LED, which is easy to burn out over time. This kind of parallel connection circuit is relatively simple, but the reliability is not high, especially in the case of a large number of LED, the possibility of failure is higher.
It is worth noting: Parallel connection way of the voltage needed to lower, but positive pressure drop is different, because each LED to each LED brightness is different, and if a short-circuit, LED the whole circuit will short circuit, the rest of the LED don't work for a certain LED circuit, if use constant current driver, is assigned to the rest of the LED current will increase, This may cause damage to the rest of the LED, but using constant voltage drive will not affect the normal operation of the entire LED circuit.
3. Mixed connection mode
Mixed connection is the use of series and parallel mode of mixing, first a few LED series, and then connected together in parallel at both ends of the LED drive power supply, in the case of LED basic consistency, the use of such connection makes all branches of the voltage is basically equal, the current flow on each road is also basically consistent.
It is worth noting that the use of mixed connection mode is mainly applied in the case of a large number of LED, because this way to ensure that the LED failure in each branch only affects the normal light of the branch, compared with the simple series, parallel form of improved reliability. At present, many high-power LED lamps and lanterns are generally used in this way, to achieve a very practical effect.
4. Array mode
The main structure of the array mode is as follows: Branches are composed of three leds, which are respectively connected to the Ua, Ub, and Uc output terminals of the driver. When all three leds in one branch are normal, all three LEDS glow at the same time. If one or two LEDS fail to open, at least one OF them can be ensured to work normally. In this way, the reliability of each group of LED luminescence can be greatly improved, and the overall reliability of the whole LED luminescence can be improved. In this way, multiple input power supplies are required to improve the reliability of LED work and reduce the incidence of overall circuit failure.