Electrolytic capacitors are made with a foil, paper, dielectric and a electrolyte solution.
Tantalum capacitors are made with a sponge and wire.
See this "link":http://www.ami.ac.uk/courses/topics/0136_ec/index.html to learn more about tantalum and electrolytic construction.
Ceramic capacitors are made with layered electrodes separated by a ceramic dielectric. See this "link":http://my.execpc.com/~endlr/ceramic.html to learn more about ceramic capacitor construction.
Polar capacitors are acidic wet dielectric type capacitors which work only when there is a DC voltage present between its two leads in right polarity. Polar capacitors are ideally suited for a DC power supply ripple filter. When connected in wrong polarity, chemical reactions within a polar capacitor can cause them to blow up, often violently, causing injury to someone nearby. Most polar capacitors these days come with a safety valve to release internal pressure build up.
Non polar capacitors are usually dry types made of ceramic, mylar, polyester or any possible dry insulator as a dielectric. Two polar capacitors connected back to back also make a non-polar capacitor. They work well in all situations whether there is any DC voltage present between their leads or not. Non polar capacitors are often very large and impractical in most applications except where a small capacitance value is required.
Some good applications for non-polar capacitors are: an AC motor starter, an AC line spike filter and a crossover network. Since voltages across an AC motor or inside a speaker system consist only of pure AC, polar capacitors cannot be used in those cases.
"A non-polarized (""non polar"") capacitor is a type of capacitor that has no implicit polarity -- it can be connected either way in a circuit. Ceramic, mica and some electrolytic capacitors are non-polarized. You'll also sometimes hear people call them ""bipolar"" capacitors.
Polarized fixed capacitor
A polarized (""polar"") capacitor is a type of capacitor that have implicit polarity -- it can only be connected one way in a circuit. The positive lead is shown on the schematic (and often on the capacitor) with a little ""+"" symbol. The negative lead is generally not shown on the schematic, but may be marked on the capacitor with a bar or ""-"" symbol. Polarized capacitors are generally electrolytics. Thanks!!!!!!!"
