What is it?
The Illuminating LED Coaster is a simple and inexpensive way to build your own transparent LED powered coaster. This step-by-step tutorial is designed to help one create his or her own Illuminating LED Coaster using easily available and affordable materials.
How does it work?
The Illuminating Coaster will simply remain off until a beverage is placed upon the coaster. In essence, the coaster acts like a “pressure sensor.” The weight of the beverage causes pressure to the positive lead of the LED, which in turn, makes contact with the positive side of the 3V lithium battery, illuminating the LEDs inside the coaster.
Step 1: Materials and Tools
· Two Acrylic plastic sheets (0.05 inch thickness)
· Four 3mm LEDs (any color)
· Two 3V lithium batteries
· Foam insulation tape
· *Plastic cutter (acrylic cutter)
· *Hot glue gun
· *Soldering iron
· Straight edge
*Please note to always remember to use appropriate safety equipment including eye protection and gloves when using the plastic cutter, hot glue gun, and soldering iron.
Step 2: Prepare the Acrylic
Tip: This step can be a little exhausting and frustrating, do not try to snap off your piece too early or you will crack your entire sheet in half!
Once both acrylic squares are made, use the scissors to cut off the appropriate amount of foam insulation tape to form a square perimeter along the edges of one of the acrylic squares. Peel off the back of the foam insulation tape and apply to the acrylic square as shown in Figure 3.
Step 3: Attach LEDs to Battery
Tip: If you are unfamiliar with soldering, please watch this video for a quick lesson.
Now that the negative leads are soldered together and to the negative side of the battery, flip the battery upside down to the positive side. With a little repositioning, align the two positive leads of the two LEDs so that they form a small intersection point near the tips. Apply solder to this intersection point, but DO NOT solder the positive leads to the battery, otherwise the LEDs will constantly remain lit. Repeat this process for the other battery.
Step 4: Attach Circuitry to Acrylic
Tip: Since using a hot glue gun can be a little tricky and messy, this step will require some patience. Also remember to check the height of each battery so that they are level with the foam insulator.
Step 5: Assemble Housing
Tip: Remember to test your coaster by placing a beverage on top before sealing it to ensure complete functionally.