Low-Drop Constant Current Source
for Ultrabright LEDs
Materials
Gerber file
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Component list
R1 = 6Ohm 8 or 18Ohm (see text)
R2 = 33kO
R3 = 820Ohm
R4 = 10MOhm
R5 = 22kOhm or 0 Ohm (see text)
R6 = 10kOhm
Capacitors:
C1 = 100µF 40V radial
C2 = 470µF 40V radial
Semiconductors:
D1,D2 = BAT41 or similar Schottky diode with IF>80mA
D3 = zener diode 15V, 0.5W
D4,D5 = LED (see text)
T1 = BC557B
T2 = BC550B
Miscellaneous:
S1 = switch (see text)
PCB, order code 040008-1 from the PCBshop
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