The present invention is based on a regulation circuit for making available a constant current supply on the basis of a transformer principle, in which there flows through the luminescent diodes (D1, . . . , DN) a triangular a.c. current varying periodically around a DC current value. Both a charging and a discharging current of inductive reactance connected in series to the luminescent diodes (D 1, . . . , DN), functioning as a storage choke for filtering of mains harmonics, flows as diode current through the luminescent diodes (D 1, . . . , DN). According to one exemplary embodiment of the invention the ceramic circuit board of the LED illumination module in accordance with the invention has a direct mains current supply, which for protection from mechanical damage is accommodated in a transparent housing having a highly transparent polymer mass serving as optically active lens surface.