Sunrise Simulator With Adjustable Lamp Colour and Intensity

by hanlin_y in Circuits > LEDs

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Sunrise Simulator With Adjustable Lamp Colour and Intensity

Sunrise Simulator Test (Diffuser added)
DIY Sunrise Simulator Lamp Mode
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Sunrise simulator for waking up more naturally. The sunrise simulator also has lamp mode. Its features include:

  • 15/30 minute sunrise duration
  • Half/full power sunrise intensity
  • Perceived brightness correlated to sunrise time
  • Up to 65,535 brightness levels
  • Sunrise begins three minutes after turning on the unit
  • Standby mode begins two hours after sunrise
  • Adjustable colour temperature and brightness for lamp mode

Materials

  • Metal box
  • Copper cladded boards
  • Heatsink
  • Aluminum bars
  • Screws
  • Nuts
  • Washers
  • 19V 3A DC power supply
  • 4 - 3W Step-down LED drivers
  • 8 - 3W white LEDs
  • 5 - 3W yellow LEDs
  • 5 - 3W red LEDs
  • LED base plates
  • Outlet timer (the timer should have an override switch)
  • Translucent tape
  • Clear plastic sheet
  • Wire grommets
  • 2 - 100k potentiometers
  • 1 - NO momentary switch
  • 2 - On/off switches

For the remaining materials, please see the attached BOM files.

Circuit Boards

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Only the microcontroller module had a custom made PCB.

W3 and W7 should be attached to an on/off switch. Their readings should be only 0V and 5V.

W10 and W11 should be attached to a potentiometer. Their readings should vary between 0V and 5V.

W12 should be attached to a normally open button. Its readings should be only 0V and 5V.

Update: The microcontroller module files with high/low PWM output were added. For the drivers I used, a high level turns off the LEDs and a low level turns them off so you should use the updated version. Sorry for the inconvenience.

ATtiny84 Microcontroller Code

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8 MHz internal clock should be selected.

In the code, fan control is optional and was disabled.

You can also update the sunrise brightness levels, and the timeouts before and after the sunrise.

Drill and Cut the Box

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Cut the Box Cover

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Tape the Window to the Box Cover

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Cover the Window With Translucent Tape

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Cut and Drill the Heatsinks

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Drill holes for

  • attaching the LED base plates
  • attaching the heatsinks to the box

Tapping may be needed.

Make the Stands

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Drill three holes for each stand. Two would be used for attaching the stand to the box. One would be used for balancing it. Tapping the bars may be preferable.

Install the Stands to the Box

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Attach the LEDs to the Heatsinks

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You can use epoxy or screws to attach them. If you're using screws, thermal paste should be used.

Make sure that the LEDs are wired so that two LED drivers connect to the white LEDs and two LED drivers connect to the red and yellow LEDs.

The required power supply voltage depends on the dropout voltage of the LED driver and the forward voltages of the LEDs. The 5V regulator needs at least 7V for stability. If you increase the power supply voltage, the regulator may need a heat sink. The following calculations were used for LED drivers with a dropout voltage of 3V. For four white LEDs with forward voltages of 3.8V, you'll need at least 18.2V. For six yellow/red LEDs with forward voltages of 2.4V, youll need at least 17.4V.

Attach the Remaining Parts to the Box

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The remaining parts include the

  • LED heatsinks
  • LED drivers
  • Connector
  • Grommets
  • Cable ties
  • Circuit boards
  • Two Potentiometers
  • Two Switches
  • Button

You can also add LED lenses to the exterior LEDs.

The wires should be strain relieved. You can use hot glue to do this.

To prevent short circuit, an insulator such as a plastic sheet should be under the LED drivers.

Using the Sunrise Simulator

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Sunrise mode

Set the timer to turn on before waking up, and turn off after waking up. You can set it to turn on 30 minutes before waking up. Set the sunrise intensity and duration switches connected to W3 and W7 before turning on the unit. Three minutes before the sunrise starts, the indicator LED would blink slowly. During sunrise, the indicator LED would fade. Once sunrise is over, the indicator LED would be solid. Two hours after sunrise, the unit would go to standby mode with the indicator LED flashing.

To end the sunrise earlier, press the button for 0-0.25s. It will be set to standby to set it to standby. You can also end it with the timer's override switch.

Manual lamp mode

To use it as a lamp, turn it on using the timer's override switch. You have three minutes to set it to lamp mode before sunrise starts. Press the button for 0.25 to 2s to go to this mode. In this mode, you can adjust the brightness and colour temperature with the two potentiometers. The colour of the lamp can be adjusted from yellow to yellow+white to and white.

Warning: If you need to wake up on time, you should use an alarm clock too.

Mode button

Pressing the button changes the mode. The modes are based on the following button pressed durations:

0-0.25s: Standby (lamp is off with indicator LED flashing)

0.25s to 2s: Manual lamp (indicator LED solid)

2s to 5s: Sunrise top (indicator LED solid)

5s or longer: Reset sunrise (indicator LED fading)

Possible Improvements

Use higher efficiency and lower forward voltage LEDs such as Cree and Luxeon LEDs.

Use PC amber LEDs instead of amber LEDs for reduced heat sensitivity

Use single LED base plates instead of four LED base plates for improved light distribution

Use a high quality diffuser

Use a boost driver or a higher voltage power supply for reduced driver count

Use LED strips for improved light distribution and simpler circuitry