jb Shares What is Electrolytic Capacitors And Aluminum Electrolytic Capacitors
Electrolytic Capacitors
Electrolytic capacitors differ from other capacitors. One of the plates in an electrolytic capacitor is a liquid.
The liquid is an electrolyte (an ion bearing liquid that conducts electricity, which is what gives the electrolytic capacitor its name.
During the manufacturing process, a thin layer of oxide builds up between the electrolyte and the plate.
This thin layer of oxide forms the insulating dielectric. Because the plates are large and the dielectric is thin, the capacity to store electricity is larger in electrolytic capacitors than in any other type.
This makes electrolytic capacitors the capacitor of choice when building power supplies.
Aluminum Electrolytic Capacitors
Aluminum electrolytic capacitors have an aluminum plate and the dielectric is aluminum oxide.
This type of electrolytic capacitor is inexpensive and is found in many power supplies.
Their range in value from 1 farad down to less than a microfarad. E-caps can work voltages up to several hundred volts.
Aluminum electrolytic capacitors can break down if they go through long periods of no power (the oxide breaks down.)
Elco caps can be rejuvenated if connected to a power supply and a resistor--the long low current restores the oxide.
Elco caps are not suitable for working with high frequencies, and they're also used in radio frequency amplifiers or anywhere there are high currents and low frequencies.
-----From jb Capacitors Company sales department
