Circadian Friendly LED Desk Lamp (no Programming Required!)

I designed this lamp to be circadian rhythm friendly. At night, it's easier for your sleep because only the warm coloured LEDs can turn on. During the day, it can keep you awake because both the cool-white and warm-coloured LEDs can turn on at the same time. Since it relies on an outlet timer to select, enable, and disable the white LEDs, you don't need programming or a real-time clock!

Step 1: Materials

• Outlet timer
• 2 - 12V 2A power supplies
• 8 - red or yellow LEDs
• 6 - cool white LEDs
• 4 low dropout LED drivers such as dan's LED drivers
• Heatsinks
• 2 - 2.1mm conectors
• Cookie box
• Diffuser
• Double pole switch

Step 2: Drill the Box

Drill the box for the switches, wires, vents, screws, and cable ties.

Step 3: Cut the Cover

The dimensions of the cut also depend on the desired cutoff of the beam. Make sure the margins are large enough for the diffuser.

Step 4: Switch Wiring

I wired a DPST so that the positive connections of both power supplies are isolated. Only the power supply for the white LEDs will connect to an outlet timer, and the other will always be powered.

Step 5: LEDs Wiring Configuration

I used red and yellow LEDs for the warm colours with a configuration of 4S2P. One string was in the box to light the work area, and the other was outside pointing up to light the ceiling and walls for ambient lighting.

For the white LEDs is has a configuration of 3S2P. Just like the warm colours, one string was in the box, and the other was outside. The difference was that I placed the white LEDs higher up, using the uncut part of the cover to reduce the glare.

Step 6: Cable Tie the Wires

Step 7: Setting the Timer

Set the timer to enable and disable the white LEDs at your preferred day and night times, respectively. For example, the outlet may turn on at 6 am and turn off at 6 pm. If you're working nights, you may prefer the opposite or somewhere in between, depending on your work schedule.