What is the basic difference between disc type capacitor and electrolytic capacitor?

Answer 1

A: it is the value disc type are small while electrolytic are big in value.

1. The dielectric in a disc capacitor is ceramic, the dielectric in an electrolytic capacitor is a very thin corrosion layer on one of its metal foil plates.
2. The conductive plates in a disc capacitor are two metal thinfilms on opposite sides of the ceramic, the conductive plates in an electrolytic capacitor are one of the metal foil plates and the electrolyte paste between the metal foil plates.
3. A disc capacitor is ready to sell and use as soon as it has been built, an electrolytic capacitor will not work at all when it is first built (it is an electrical short circuit) it must be formed by passing a controlled current through it for several hours to cause corrosion of one of the metal foil plates.
4. The parasitic inductance of a disc capacitor is less than that of any other type of capacitor, the parasitic inductance of an electrolytic capacitor is greater than that of any other type of capacitor. This makes disc capacitors better for use in circuits involving high frequencies and electrolytic capacitors better for use in circuits involving very low frequencies and/or DC.
5. The parasitic resistance of a disc capacitor is extremely high resulting in extremely low leakage, the parasitic resistance of an electrolytic capacitor is low resulting in high leakage. In fact this leakage current in an electrolytic capacitor is essential to keeping it healthy and working in use, without it the corrosion layer dielectric slowly dissolves away into the electrolyte paste. Reversal of polarity of an electrolytic capacitor dramatically hastens this, rapidly removing the corrosion layer and shorting the capacitor resulting in both uncontrolled heating and electrolysis of the water in the electrolyte paste; the extremely rapid generation of gases causes a violent explosion of the electrolytic capacitor!
6. The capacitance of a disc capacitor tends to be low in relation to its physical size compared to other types of capacitor, the capacitance of an electrolytic capacitor is higher in relation to its physical size than any other type of capacitor. This is due mostly to the differences in the thickness of the dielectrics.