1 circuit
Need to use more LED products, LED series, will require a higher voltage of the LED driver output: if all the LEDs in parallel, you need a larger current of the LED driver outputs. All the LEDs in series or in parallel, not only limited by the strict usage of the LED and parallel LED load current larger, drive the cost will increase, the solution is to use the hybrid approach. String, the number of parallel LEDs evenly distributed, so that allocation of the series branch circuit voltage in an LED 200W with a series of slip in the current on each LED is basically the same, consistent brightness through each series branch current also similar.
(2) the performance of the circuit
A series branch has an LED of poor quality and short-circuit the regulator drive or constant current drive, will increase the current through the series circuit, very easy to damage the series LED branch. Large current through the damage to the LED strings, due to the current passing through more than the performance of the circuit. Series branch off an LED Flood light 10W, if the regulator drive, the drive output current will be reduced without affecting the remaining LED work properly.
If you use a constant current LED drive mode, the output current of the drive remain unchanged, distribution in the rest of the LED current will increase, easy to damage the LED. The solution is as much as possible in parallel LEDs, so that when a particular LED is disconnected, the allocation of the remaining current in the LED Blue 150W is not, does not affect the rest of the LED work properly.
This first series of the advantages of the parallel line is the line is simple, stable brightness, high reliability, and consistency requirements of the device is low, no special selection of devices, even though the individual LED single tube failure, the entire light-emitting components The impact is also small. In the case of larger changes in the work environment factors, the use of this connection in the form of light-emitting components better.
Before and after the string of mixed connection consisting of light-emitting components in a single set of parallel LED, due to the difference of the device and conditions of use, the individual LED chips in a single group may lose the PN junction characteristics, short-circuit. Entire group of individual failure of the LED Spotlight 30W device short circuit causes loss of operating current of the IF 'cause the LED is off, the total current through all from the short-circuit device, a long time the short circuit current will make the device internal bonding wire or other parts of the burned appeared open. At this time, the non-failure LED regain current resume normal luminous, but the work current, IF, than the original point. This is this connection in the form of light-emitting components appear first group with a few LED is off, after a period of one LED is not lit, the other LED to restore the normal reasons.
Hybrid approach, there is another connection, that is, the LED average allocated block in parallel, and then each group connected in series. Poor quality of an LED and short circuit regulator drive or a constant flow-driven approach, the LED will be parallel in this branch does not shine. If you use a constant current LED drive mode, the drive output current remains unchanged, except in parallel with the shorted LED parallel branch, the rest of the LEDs are working properly. More number of assumptions parallel LED drive current of the drive, only short-circuit the LED Floodlight 80W current will increase. Large current through the LED of only short-circuit, it is easy to become open circuit. More parallel LEDs, an LED is disconnected, the average distribution of current changes little, the rest of the LED is still working properly, so only one LED in the LED light does not shine.
3 drives the choice of
By the above analysis, the drive and load with the choice of LED 400W series / parallel is very important when the power LED constant current mode to drive, not suitable for parallel load: Again, the regulator LED drivers are not suitable for use in series to load. 、