Investigation into the use of single inductor for driving multiple series-connected LED channels

This paper gives an investigation into the use of single inductor for driving N series-connected LED channels. Each LED channel has a parallel-connected switch for controlling the channel current and the inductor current. Compared with the conventional structures having (N+1) switches and all LED channels connected in parallel, the proposed structure has the merits of 1) requiring N switches only, 2) being insensitive to the duration of the transition switching from one channel to another, and 3) allowing all channels to be driven concurrently in every switching cycle. Mathematical analysis on the topological operations will be discussed. The proposed concept will be demonstrated on a two-channel system.

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