USB Dimmable Desk Lamp From Mounting Board

It's me again building stuff out of mounting board. The purpose of this project is simple: illuminate a desk with decent amount of light so that it is comfortable to work on. The concept is pretty simple, connect USB to a boost converter which then feeds into a 555 timer PWM and finally to some LED strips. Oh yeah, this project is built upon my mounting board tripod project, so go check that out as well, but no one is going to stop you from making your own mount.

By the way, the dimmable part of this project is completely optional and you can skip it. I just add it because i think it is cool.

Don't ask me about the first desk lamp I made. (yes it is made from toilet roll)

Tools

• Soldering iron
• Utility knife
• White/Clear glue
• CA glue and baking soda (or any other suitable adhesive, for 3D construction)

Materials

• Mounting board
• Some 12v LED strips
• MT3608 boost converter
• Aluminium foil
• Screws (for joint)

Dimmer unit

• 555 timer IC
• 510R, 100R resistors
• 10k potentiometer
• 1N4007 diode (x2) (or faster diode like 1N4148)
• 0.1u, 0.01u, 10u (or bigger, interference cap, omit this if you don't value your ears) capacitors
• IRFZ44N MOSFET (or any other suitable MOSFET)

Diffuser

• White plastic bag
• Transparent plastic sheet (book cover or any product packaging)

Let's me first introduce the parts of this desk lamp. It consists of a shade, upper beam, and lower beam. From now on, I will refer to those parts with the names above. Before you can start doing anything, of course you have to prepare the materials. There are 9 total parts you need to cut (refer to cutout attached, measurements in mm):

Lower beam

1. layer1 - 125x15 with one rounded end (x1)
2. layer2,4 - 120x15 with one rounded end (x2)
3. layer3,5 - 140x15 with both ends rounded (x2)
4. layer6 - 105x15 square ends (x1)
5. support - 15x15 (x4)

Upper beam

1. 2long - 100x15 both ends rounded (x3)
2. 2short - 80x15 one rounded end (x3)

Shade

1. side - isosceles trapezium, parallel sides with length 35 and 65, inclined side 21 (x2)
2. shade - rectangle, 155x77.4, scored (refer cutout) (x1)
3. joint - 25x15 one rounded end (x4)
4. joint_support - rectangle, 5x15 (x10)

This step is simple, stack the materials in the correct order and glue them together. Refer to images for the arrangement. The only thing you want to make sure is that the finished sides are facing outward, unless that's not the effect you're trying to achieve. Make sure to clamp them or press them together and give enough time for the glue to dry. Otherwise the beams might warp.

First, cut some aluminium foil with appropriate size. Then glue the aluminium foil on top of the shade piece. Similarly, press them together with weight and let dry.

Stick a layer of tape on top of the aluminium foil. You don't want it to cause short circuit when LED strips are put on it.

Next, score the outer side of the shade piece at the lines (refer cutout), and fold the shade into a trapezium shape. Don't worry about getting precise angle, you'll fix that later.

You may have notice that I cut the edges of the aluminium foil. This provide site for gluing the side pieces on it, since the aluminium foil-shade join may not be very strong.

When you see rounded end, it means time for drilling hole (at least for this project). Insert the lower and upper beam together and drill a hole at the centre of the curve. The size of the hole depends on the size of screw you are planning to use. Do the same thing for the other two ends.

Then, you just need to insert the screw and joint the parts together.

Solder the LED strips together in parallel. Attach a connector (any kind that you like, I used JST connector) at the side which will be used for connecting to power. Remove the double sided tap at the LED strips and stick it on the shade.

Glue the side pieces to the shade. This is the step where you fix the angle of the fold of the shade. I ran out of hot glue at the time of doing this, so I decided to use CA glue and baking soda, but any suitable adhesives would work.

Then you need to prepare the attachment that join the shade to the beams. Stack the joint and joint_support pieces according to the image and glue them together. A clip that can put decent amount of pressure is helpful in this step, since it will be hard to use weight to press them in place. After the glue dried, I hot glued the attachment to the centre of the shade.

Attach screws to join the shade, beams, and the tripod together and you have a desk lamp! Technically, the project is done at this stage, but I decided to add dimming feature and a diffuser to it, which will be helpful in certain scenarios.

Ok this step you have to follow the schematic and solder everything together correctly. Good luck getting it working on the first try.

Don't worry too much about the value of C3, C1 and R2. Use any values close enough if you don't have the exact value. Also you don't need to worry about getting the exact same MOSFET, generally any N-channel appropriate parameters would work fine, read the datasheet.

The circuit is the classic 555 timer based PWM driver, which you can find the explanation on how it works online. I based my design off this Instructable.

Make sure to calibrate the MT3608 module to 12V. Solder a USB cable to the input of the MT3608 module with correct polarity.

Next, you just need to make an enclosure for the driver circuit.

For the diffuser, cut an appropriately sized piece of white plastic bag, preferably non-biodegradable one (for obvious reason, also a good time to reuse those waste). Also prepare a similarly sized transparent plastic sheet, which can be found on photocopied books or product packaging, or you may buy one. Glue the white plastic bag piece onto the transparent plastic sheet with ordinary clear glue and get rid of any air bubbles. Let it dry while being clamped under pressure (e.g. put inside book).

To hold the diffuser in place, I glue two pieces of arbitrarily sized mounting board at the sides of the shade, which allow the diffuser to be slid in place.

Hook the lamp to the power via the dimmer unit. Now you have a USB powered desk lamp made out of mounting board.