LED Wall Lamp in the Shape of a Logo

Students

Screen Shot 2019-05-05 at 10.44.54 PM - Tanner Kliewer

Tanner Kliewer
Mechanical and Aerospace Engineering, 2019

Project Description

The purpose of this project is to enhance any space such as a theatre room or patio with LED light displayed in a package that represents something of meaning to the user. The main piece of the lamp is made from acrylic and can be laser cut into any logo. In this case, the Princeton shield logo was used. Two pieces of acrylic were used, one with complete logo and one just the outline so that LEDs can be installed and hidden. The custom cut piece can be chosen from a wide range of colors to match the logo and the LED color can be chosen to match as well. Since Princeton’s colors are orange and black the lamp is made from black acrylic and LEDs are installed. The LEDs are then connected to an AC to DC power supply so that they may be plugged into any standard wall outlet. The power supply could be hooked up in series with a relay controlled by a microcontroller to provide a level of automation but that was not included in this build. This project interests me because I like to make custom and unique household items for decoration. If technology can be added to make the piece more one of a kind, then I believe that is positive.

Technical Background

One aspect of this project is the wiring of LED strip lighting. LED strip lights are just several LEDs (light emitting diode) wired together in series and placed in a protective package. A light emitting diode is a semiconductor that lights up when current passes through it. LEDs have a much longer lifespan then a typical incandescent lightbulb because they do not burn out in the same way. When something is wired in series they are connected along the same path. Things wired in series receive the same current, but the voltage drops after each component in the path. On the other hand, things wired in parallel are connected by different paths splitting the current but keeping the voltage the same across all components. Due to LED strips having many LEDs wired in series they suffer from voltage drop. The available voltage decreases with each LED along the path. This can cause the LEDs at the end of the strip to be less bright or not light up at all. It might seem like a good idea to just increase the voltage from the power source so that there will be plenty remaining at the end of the strip. However, this cannot be done in practice because the increased voltage will damage the LEDs at the beginning of the strip. LED strip lighting typically requires 12 or 24V input and cannot be run at voltages other than what is specified. The best way to combat voltage drop is by cutting the LED to shorter lengths with each strip wired to the voltage source in parallel. The voltage with be same across each strip because it is connected in parallel and the power source can easily be chosen to provide enough current to each strip.

Scully, Taylor. “Your Ultimate Guide on Buying LED Strip Lights.” LEDSupply Blog, www.ledsupply.com/blog/ultimate-guide-on-buying-led-strip-lights/.

Harris, Tom, and Wesley Fenlon. “How Light Emitting Diodes Work.” HowStuffWorks, 31 Jan. 2002, electronics.howstuffworks.com/led.htm.

Design Drawings

Fabrication Process

Originally, the Princeton Shield wall lamp was intended to be made out of birch plywood carved by the X-carve. After the model was completed and a workpiece was ordered the first prototype was attempted using the X-carve. During the carving process, the lettering broke loose from the rest of the piece because it was too thin. The thickness was increased, and a second prototype carving was attempted. This time the carve went well until the final outline was attempted. The thin sections that connect the bottom of the shield to the top were too thin to be carved using the X-carve. A decision had to be made to either increase the thickness of the thin sections or use a different machine. I did not want to increase the thickness because it would change the proportions of the shield. Instead, I decided to laser cut the piece to get the precision needed. I decided to use two 12” by 12” pieces of black acrylic one .125” thick and one .25” thick as the material for the shield. I first used a laser cutter to cut the Princeton Shield logo out of the .125” thick plate. This was used as the top plate. Next, I laser cut the same shield outline but with an indentation for the LED strip lighting to be installed in. These cavities allow for the LED strip lighting to not be hidden once the lamp is finished. Once both plates had been laser cut they were glued together using Loctite 401 instant adhesive. The main part of the lamp was now finished and LED strip lighting needed to be added. Three strips of LED lights were cut to the appropriate length and attached to the laser cut back panel using the adhesive on the back of the strip. Next, a positive and negative wire was soldered to each of the three strips. After the wires were soldered to the strip a piece of heat shrink tubing was placed over the wires to provide some strain relief. The three positive wires were all twisted together and soldered to the positive wire coming from the power supply. Heat shrink tubing was again added and the process was repeated for the three negative wires and the negative wire of the power supply. A 12 volt 2 amp wall power supply was used to power the lights and the single positive and negative wires were connected to it using crimped on ring terminals. The last step was to hide the wiring of the LED strip lighting as much as possible from being seen when the lamp is viewed from the front. Black electrical tape was used to secure the wiring behind the acrylic.

Students

Project Description

Technical Background

Design Drawings

Fabrication Process

Final Result