| Title |
Design of Adaptive Current Control Circuits for LEDs |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2015.29.12.008 |
| Keywords |
LED Drive ; Linear Current Regulator ; Over-Current Protection ; Failure Detection of LED |
| Abstract |
An effective way to ensure that LEDs produce wanted light output is to use a current driving topology, because the brightness of LEDs is directly related to their current. However, this topology may lead to the lifetime shortening of a illumination system because over-currents may flow through non-damaged LEDs in case some LEDs are damaged. This paper presents an adaptive current control circuits for LEDs, which protect LEDs in a good state by limiting the driving currents according to the number of damaged ones. The proposed control circuits consist of a simple constant-current driver and a micro-controller which monitors the voltage of LED array without any auxiliary current sensors for fault diagnosis. And the driving current is automatically controlled into 6-levels according to the number of failures. |