Light Therapy Box

Blue LEDs combat the Winter Blues

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.

This is a MEMBER ONLY article. You need a subscription to read this article.

Benefits of a subscription

Unlimited access to online Member Only articles
3 new editions Elektor Magazine (digital)
More than 5000 Gerber files
20% member discount on e-books (at elektor.com)
10% member discount on Products (at elektor.com)

View the offers
Available from €5.33 per month.

What is Elektor Exclusive?

Materials

081066-PCB.pdf

Gerber file

CAM/CAD data for the PCB referred to in this article is available as a Gerber file. Elektor GREEN and GOLD members can exclusively download these files for free as part of their membership. Gerber files allow a PCB to be produced on an appropriate device available locally, or through an online PCB manufacturing service.

Elektor recommends the Elektor PCB Service service from its business partner Eurocircuits or AISLER as the best services for its own prototypes and volume production.

The use of our Gerber files is provided under a modified Creative Commons license. Creative Commons offers authors, scientists, educators and other creatives the freedom to handle their copyright in a more free way without losing their ownership.

PCB

Download Gerber file: 081066-1-V10

Component list

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