A control apparatus for LED diodes includes a dimmer TRIAC electrically connected in series between a power supply and a LED lighting converter. The converter comprises a transformer, with a primary winding coupled with an input terminal and a secondary winding coupled with an output terminal, and a switch coupled to the primary winding to regulate the current through the primary winding and regulate the output voltage. The apparatus comprises a control device adapted to control said switch determining the on period and the off period of the switch to maintain constant the output current to supply said LED diodes. The apparatus comprises a detector connected to the secondary winding of the transformer and adapted to detect the conduction angle of the TRIAC; the control device is adapted to regulate the output current to supply said LED diodes in response to the TRIAC conduction angle detected by the detector.