PCB ครับ
BOM นะครับ
U1 = MC14517
U2 = LM317T or LT1085CT
D1 or U3 = TL431
LED1
VR1 = VR 5k
R 1/4W 5% or better
R1 = 200 ohm (calulated from ((5V-2V)/15mA)
R2 = 200-240 ohm
R3 = 75 ohm
R4 and R5 = 1.2k ohm
C1 = 100uF 25V
C2 = 10uF 16V (improve the ripple)
C3 = 0.1uF 16V
C4 = 0.1uF 16V