Quality high voltage capacitors can range between $20-200 a piece. With some around the house supplies capacitors can be made for as little as a dollar each. Because of their versatility, having the knowledge to build capacitors could save you money the next time you're experimenting with high voltage.
Intro: What is a capacitor
Capacitors are used in many important devices today such as computers, phones, wall adapters, heaters, printers, etc. The main purpose of a capacitor is to store an electrical charge for a short period of time. A basic capacitor has a dielectric and conductors.
This is a fun project to see how capacitors work, but I do not recommend using these with any expensive or sensitive equipment. This is by no means an accurate capacitor for filtering voltage or holding consistent amounts of charge.
*****WARNING THIS PROJECT USES HIGH VOLTAGE. DO NOT TRY WITHOUT PROPER PROTECTION AND EXPERIENCE*****
Step 1: Supplies
•Power Supply (preferably 1 KV or higher)
•2 Ziploc Sandwich Baggies
•Insulated Wire (recommended at 10 KV or higher)
Step 2: Cut Off the Top of the Baggies
Start off with cutting the top off the Ziplock bag indicated by the red doted line. Make sure to keep the cut clean and even.
Step 3: Laminate the Cut End of the Baggie
Cut a 5 inch (Approx. 13 cm) piece of electrical tape and place it over the cut end. Make sure to have half the electrical tape overhang (side 1). Next flip over the baggie (side 2) and cut another 5 inch piece of electrical tape. Place the electrical tape on top of the baggie making sure that the tape overhangs to match the opposite side. This will laminate the bag shut on the cut end. Once this is done you may trim the ends of the tape marked by the doted lines in the photo above.
Step 4: Creating the Conductor
Cut two 4 x 4 inch (Approx. 10 cm x 10 cm) sheets of Aluminum foil. Place one of the sheets of aluminum foil onto the ziplock making sure that the foil does not overhang one the edge of the Ziploc baggie.
Step 5: Connecting the Conductor to Dielectric
Now cut 4 4.5 inch (Approx. 11 cm) pieces of electrical tape. Place the tape on the edge of the foil with an overhang onto the baggie. This is done so that the piece of tape holds the foil to the plastic baggie. This is illustrated in the photo above. Once you are done, flip the bag onto the other side and repeat.
Step 6: Preparing the Wires
Next you will need connecting wires for your conductors. First cut two 1 foot (Approx. 30 cm) long wires. Next strip 2 inches of insulation on both sides of each of the wires. Afterwards, fray the wire on one end of both of the wires as shown above.
Step 7: Connecting the Wires to the Conductors
After the wires are prepared place the frayed end of one of the wires on top of the conductor, preferably near the edge of the exposed foil. After doing this, place tape on top of the wire securing it to the foil. This can be done with multiple pieces of tape ( length of tape does not mater as long as the wire will not fall off the foil ). Next flip the bag and repeat this step.
I found placing the connecting the wires on each side with opposite directions made things more clean and neat. This is shown in one of the photos above.
Step 8: Extra Step for Preventing Leaking Voltage
First bend both wires so that they follow in one direction. Then slide the capacitor into a second Ziploc baggie. After this step you're done! Make sure to by careful when experimenting with high voltage, hope you have fun building this device!
Step 9: Power Supply
To test the capacitor I used a 7,000 volt power supply. This is just a glimpse of what kind of power can be used with such a capacitor.