A capacitor is an elementary electronic component that stores electrical charge similar to a battery. Capacitors are versatile, and are used in very important electronic circuits such as radio tuners and signal generators. A capacitor is very simple: it consists of a positive and a negative terminal, separated by an insulator. One of the simplest capacitors is the salt water one, also called an electrolytic capacitor. Here are the instructions for building one.
Steps
Step 1. Fill a metal container, such as a paper cup or plastic bottle, with warm, salty water
Dissolve the salt in warm water.
Step 2. Cover the outside of the container with aluminum foil
Step 3. Put a metal object, such as a knife or nail, into the salt water
Foil is one of the terminals, and the metal object, combined with water, is the other. Do not let water or the metal object come into contact with the foil. Be careful not to spill water droplets from the rim of the container, or you will create a short circuit that will make it impossible to charge the capacitor.
You can later use a tester to check if the capacitor is capable of accumulating a charge
Step 4. Charge the capacitor by applying the charge of any battery, connecting it to the two poles
After a few seconds disconnect the battery and connect the tester to the capacitor. The display reading will indicate the accumulated charge.
