Floating LEDs on Water

Before Christmas I thought about experiment with LEDs. I discovered, how
to power leds with electrolyte. Electrolyte is just liquid which conduct eletric current, when 2 electrodes connected to voltage source are sink to electrolyte. I make video, but belowe are steps.

Step 1: Material

For this experiment you will need:

• leds, e.g. 5 mm leds
• source of higher voltage e.g. I use just battery with step up module, which convert input voltage to 20 V or 2x 9V batteries.
• cables
• aluminium foil or anything from aluminium to make electrodes e.g. nails
• anything which float on water, like peanuts or polystyrene
• water and case

Step 2: Making Floating Led

Firstly, you need to prepare leds. I use peanut cover, which is simple and make holes into. Then insert led.

Step 3: Circuit

I use 20 V module for convert battery voltage (which were 3.3 V) to 20 V. Higher voltage is necessary, as water have high resistance. For electrode I use aluminium foil.

Finally, you can insert leds on water. Because led conduct eletrict current on in one way, led glow only in correct direction (longer terminal on led must be closer to electrode connected to + on battery).

Comments

[wannabemadsci]

Thanks for posting.

Your instructable illustrates the concept of a voltage gradient over distance. The farther apart your LED lead wires are the greater voltage will be present across them.

This has some real world applications. I believe this is why experts recommend squatting low during a lightning storm and not to lay out flat on the ground. If lightning should strike nearby there will be a voltage gradient across the ground. If you were to lay out flat on the ground there may be enough potential across the length of your body to kill you. If you squat the gradient is only over the distance of your feet instead of the length of your body.

This concept with water was illusrated on a larger scale when many years ago two swimmers where in a swimming pool that had the pool light fail and energize the pool water. The one swimmer next to the light was electrocuted nearly instantly. The second swimmer several feet away was bobbing vertically and was fine, but when they moved into a horizontal position to swim away the voltage gradient from head to toe was enough to kill them also. A sad sorry, but tragically illustrates the same principle.