Light Therapy Box
Blue LEDs combat the Winter Blues
Published in issue 395, November 2009
During the winter many people suffer from Seasonal Affective Disorder (SAD), which is commonly known as the winter blues. With the help of blue light these symptoms can be reduced. The blue-light generator described here has a built-in timer and is perfect for this task.
Resistors
R1,R6 = 150kOhm
R2 = 2.2MOhm
R3,R8 = 100
R4 = 100kOhm
R5 = 220kOhm
R7 = 10kOhm
R9–R16 = 15kOhm
R17–R58 = 270
P1,P2 = 1MOhm potentiometer, linear
P3 = 100kOhm preset, horizontal
Capacitors
C1,C5,C6,C9 = 100nF MKT, lead pitch 5mm or 7.5mm (0.2” or 0.3”)
C2 = 2.2nF MKT, lead pitch 5mm or 7.5mm (0.2” or 0.3”)
C3 = 82nF MKT, lead pitch 5mm or 7.5mm (0.2” or 0.3”)
C4 = 4.7nF MKT, lead pitch 5mm or 7.5mm (0.2” or 0.3”)
C7,C8 = 1000µF 16V axial, lead pitch 28mm (1.1”)
C10 = 1nF ceramic, lead pitch 5mm (0.2”)
Inductor
L1 = 40µH 2A, axial (Epcos B82111EC23, Farnell- # 9753354)
Semiconductors
D1,D2,D3 = 1N4148
D4.–D87 = blue LED, 5mm, 300mcd, wavelength 465nm, (e.g. Optek OVLLB8C7, Farnell # 1678692)
D88 = Schottky diode 60V 2A, (e.g. STPS2L60, Farnell # 9907637)
T1 = SPP18P06P (P-channel MOSFET 60V 0.13O, Farnell # 1056550)
T2–T9 = BC547B
IC1 = 4093
IC2 = 4060
IC3 = 4015
Miscellaneous
S1 = push button, panel mount
2-way pinheader, right-angled
2-way pinheader
2 3-way pinheader, right-angled
2 3-way socket
PCB # 081066, see www.elektor.com/081066
|
Click below to download a PDF copy of this article from Elektor magazine. Please note. In view of the complexity of international markets, Elektor cannot guarantee the availability of components for this project.
|
Informative articles
Password forgotten?
)
