Make LED Throwies
An LED Throwie is a fun, cheap and pretty decoration ideal for fridges. It will stay lit for about a week, but they are easy to make so you should never run out!
Steps
- Know your battery. Your disc-shaped battery has a positive side and a negative side. The negative side has less surface area than the positive side. The positive side is larger and has a (+) symbol and includes the side of the battery.
- Examine your LED. It probably looks like a tiny plastic bullet with two legs or leads. One lead is longer and possibly darker, this is the anode and needs to touch the positive side of the battery only. The other lead is shorter and possibly lighter, this is the cathode lead and needs to touch the negative side of the battery only. If the cathode lead touches the positive side of the battery, you will probably cause a malfunction in the LED. You can find out what color of LED by correctly attaching it to your power source, the battery. An LED is a light emitting diode, not a light bulb. The color is not determined by the plastic bullet shape, but by the semiconductor material inside the LED.
- Tape the LED to the battery. Cut a 1" x 7" piece of duct tape. Holding one wire from the LED to each side of the flat battery, wrap the tape around the outside of the wires and battery. Wrap it one time around, neat and tight. The LED should come on. If it flickers, you did it wrong. Do over. You should have a portion of the tape strap hanging off to one side.
- Attach the magnet. Place the magnet against the side of the wrapped battery and continue wrapping the tape around until it covers the magnet. From this point on, do not pick up the Throwie by the LED. Handle it always by the battery/magnet.
- Throw the Throwie. Lightly toss the device onto the front of your metal refrigerator or other similar surface. The strong magnet will attach to the fridge and continue to burn for as long as the battery will last.
Tips
- Batteries will likely last longer on green, blue or white LEDs, than red, yellow, or orange LEDs.
- The Voltage a diode drops is constant, so adding a resistor in series will make your battery last longer. If the Diode turns on at 1.8V, a 3V battery must drop 1.2 V on the leads, making near infinite current. Putting a resistor in will assure the current stays in check. Just make sure the value allows the current across the LED to be enough to be bright.
- If you own a steel bridge or tower, you can throw a bunch of these up very high and stick them to form lighted designs in the dark. Climb up and remove the Throwies before they decay into some type of waste hazard.
- You can make Throwies that stick to all kinds of objects by wrapping them with double-stick tape.
Warnings
- Don't let little children swallow the throwie or batteries.
- Always dispose of the batteries safely.
Things You'll Need
- LEDs in any colour. They cost anywhere from 3p-15p each. Red, yellow and green are cheapest. Standard 10mm size is best.
- Adhesive tape, like Duct Tape
- Small Neodymium magnets, .5x.125". You can buy 25 for $13.00 online. Keep these powerful magnets away from your computer and other electronics!
- CR2032 Button batteries like found in calculators, 3V Lithium.
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