A fruit clock is a substitute for the traditional battery powered clock that does not require the use of actual batteries. It is a sustainable way to tell time as well as providing a way to get rid of some fruit that nobody's eating or that wasn't quite ripe. The clock can be build with any battery powered clock and any citrus fruit (although oranges worked best for me). The fruit clock is relatively simple to build and if done correctly can supply a week's worth of power.
3 copper wires
6 alligator clips
2 pieces of fruit
1 battery powered clock
2 paper clips (non-coated)
https://www.youtube.com/watch?v=Ers2gT1RxaA (photo above)
Step 1: Prepare the Wires
First strip the wires, if needed, on both sides and attach the alligator clips to the ends via clamping or soldering. Take the first wire and attach the penny to it. Then take the second wire and put a penny on one side and a paper clip on the other. For the third wire attach a paper clip.
Step 2: Attaching the Wires to the Fruit
Start of by rolling and squeezing the fruit to break apart some of the cell walls and to mix the pulp.Take the fruit and make two incisions in each roughly an inch and a half apart. Place the first wire into one of the outside incisions making sure the penny is in the fruit. For the second wire place the paper clip side into the inside incision of the fruit with the first wire. Then insert the penny side into the inside incision of the other fruit. Finally insert the paper clip side of the third wire into the outside incision.
Step 3: Attach the Wires to the Clock
The last step is quite simple. Attach the alligator clip side of the first and third wires to the battery terminal of the clock. If the clock normally requires multiple batteries then you may have to take it apart in order to find the leads. Once they are properly connected it should complete the circuit between the acidic electrolyte (orange juice) and the metal electrodes (the pennies and paper clips) creating electrolysis and immediately turning on the clock.