A model to design light emitting diodes matrix driven by constant current source

It is always desirable to operate LEDs within its designed maximum temperature for maximized life. For LEDs driven by a constant current source it is possible to improve LED life by putting more LEDs in parallel to share current and reduce temperature, but the cost would increase. This paper proposes a general LED model to estimate the relationship between temperature, operating current, luminous flux, life and reliability of light emitting diodes. This model can direct LED matrix design with respect to the required parameters. The model would help lighting designers to consider the driving current and number of LED in a lamp matrix in order to achieve the desired light flux, efficacy and life with desired cost. A method involved power electronic technique is proposed to form a dynamic matrix that can response to the changing ambient temperature. This allows the engineer to build the real desired matrix flexibly.