Power LED driver module (PLDM)

This year, for the first time, the efficiency of LEDs has overtaken that of fluorescent tubes. Power LEDs are thus now a realistic and energy-saving alternative to other forms of lighting. Getting them to light up, however, needs a bit of electronics, and hence the universal module described in this article.One thing is for sure: the twenty-first century will be the age of semiconductor light sources. This universal current source can drive up to eight white LEDs.

Resistors
R1 = 1O / 2W (carbon film or metal film)
R2 = 10k
R3 = 1k
R4 = 2kO2
P1 = 10k

Capacitors
C1 = 1000µF 50V*
C2 = 100nF
C3 = 220µF 35V*

Semiconductors
D1,D2,D3 = SB340*
D4 = ZPD33V*
IC1 = LM2575Z-ADJ*
IC2 = LM385Z1.2

Miscellaneous
L1 = 330µH / 1.9A* (SMD power inductor, e.g. FASTRON PISR-331M-04 (Reichelt # L-PISR 330µ)
Tr = 2 x 6-27 V*
PCB, ref. 071129-1