Build a Capacitor
A capacitor is an elementary electronic component that stores electrical charge, somewhat like a battery. Capacitors are versatile, and are used in such vital electronic circuits as radio tuners and signal generators.
A capacitor is very simple. It consists of a positive and negative terminal close together, separated by an insulator. One of the simplest capacitors is the saltwater capacitor, which is an electrolytic capacitor. The instructions for building on of these devices are enumerated below.
Steps
- Fill a non-metallic vessel (such as a paper cup, or a plastic bottle) with warm saltwater. Use warm water to dissolve the salt.
- Wrap the outside of the vessel with aluminum foil, or tin foil.
- Place a metal object (such as a knife, a nail, etc) in the saltwater. The foil is one terminal, and the water/metal object combination is the other. Do not allow the water or the metal object to touch the foil or spill over the side. This will short the capacitor and make it impossible to charge.
- Later you can use a voltmeter to verify if the capacitor can hold a charge.
- Charge it up, by applying the voltage from an ordinary household battery, to both terminals. After a few seconds disconnect the battery and connect the voltmeter to the terminals of the capacitor. Any reading (mV-V) will indicate a charge.
- Congratulations, you have a working capacitor, capable of holding an electric charge!
Tips
- You can charge it up with a battery, or with static electricity. You cannot charge a capacitor with an alternating current, only with a direct current.
Warnings
- Capacitors are very dangerous. Do not touch one after it has been charged by a power source, because it will shock you.
Things You'll Need
- Warm water
- Salt
- Non-metallic vessel (paper cup or plastic bottle)
- Aluminum or tin foil
- Metal object (knife or nail)
- Volt-ohm meter (optional)
- Battery
