A new technique to equalize branch currents in multiarray LED lamps based on variable inductor

In this paper a new technique to equalize LED currents in multiarray LED lamps is proposed. The current through the LEDs is controlled by changing the inductance value of a variable inductor. The proposed system can be employed to control the current through each LED branch independently. The operation principle of this technique and a design example of the proposed system are presented in this paper. As an example, a forward converter has been selected to supply the LED branches, which can be designed to operate with one or several outputs. The components values of the converter as well as the LED current control circuit are also provided. A prototype of the circuit has been implemented and the experimental results obtained at the laboratory are satisfactory and according to the proposed design methodology.