Solving high-voltage off-line HB-LED constantcurrent contro-circuit issues

Abstract

High Brightness LED manufacturing tolerances and drifts over temperature do not allow the use of simple current control methods. Therefore regulation circuitry more complex than popular current-limiting resistors is necessary. This paper describes a new topology, which takes advantage of the circuit's intrinsic time delays to continuously monitor the load current and constantly regulate it to a pre-set value. The paper presents experimental results to demonstrate the advantages of this method.