A single stage converter for feeding high power leds which can be used in a project based learning of electrical circuits

This paper deals with a single stage power electronic converter used for feeding at constant current series connected high power LEDs by taking power from the mains at unity power factor. It is shown that the control of the converter can be achieved by combining a bang-bang control of the current taken from the mains with a feedforward action on the amplitude of this current which is based on the voltage across the diodes. As this control strategy can be easily understood by undergraduate students (before they learn automatic control), the design and analysis of a low voltage variant (without galvanic insulation) of the proposed circuit can be a support to a project based learning of the fundamentals of electrical circuits : applications of Kirchoff laws, study of simple transients, use of operational amplifier both in linear and non linear operation modes, basics of signal processing through filtering, power in AC and DC circuits. It is also easy to implement it in a simulation software like PSpice^® to realize virtual labs.