Why do capacitor leaks?
there is no perfect insulation and the capacitor has some conductivity inside. which acts as a great resistance to shunt and leads to current leakage
it is also an eccentric charged charged subatomic particles – they are agitated insects, especially protons, and electrons eager to jump into their grave, but in no circuit, no component works perfectly the theory suggests that this should and there are innumerable reasons why. if you’ve loaded a capacitor and put it in a perfect vacuum, well, theoretically, he should not run away …
every thing has its limits if you cross these limits then you know what happened as if a capacitor has a limit that you see in capacitor the value is given 220uf / 20v like this when you give a voltage as you give 30v to the capacitor and then to the dielectric is burned and attached to the coding plates, then you called it short capcitor or leak capcitor
some types of electrolytic use an electrolyte paste as they need to get the capacity maximum in the smallest paskage. If this happens in an application where the alternating current passes through, the low internal resistance heats up a bit and finally, the housing expands and leaks. This type of component has a limited life depending on the application. it is a common and inexpensive failing item to replace. some reliable dry high dry elctrolytics motherboards
I would agree that an ideal capacitor never leaks.
but since lived in a practical world, a practical capacitor is a combination of resistance in parallel with an ideal capacitor.
therefore, the leak is due to the resistance.
hope this is helpful.
What I see above is an electrolytic capacitor, and this brown liquid is the electrolyte.
it could have leaked for the following reasons: –
a wrong polarity was given, the electrolytic capacitor is a capacitor with positive and negative sides (anode and cathode)
the capacitor shorted
the capacitor was used for a long time, through many charge and discharge cycles, generating heat, it causes a build-up of pressure, an electrolyte leakage (there is a safety vent that lets the liquid leak, otherwise the capacitor would explode)
age usually contributes. nothing is perfect, so there are leaks.
leakage corresponds to a resistance in parallel with the capacitor. constant exposure to heat can cause dielectric breakdown and excessive leakage, a problem often observed in older vacuum tube circuits, particularly when oiled paper and foil capacitors have been used. In many vacuum tube circuits, inter-stage coupling capacitors are used to transmit a variable signal from the plate of a tube to the grid circuit of the next stage. a leaking capacitor may cause the network circuit voltage to increase relative to its normal bias setting, which may result in excessive distortion of the signal or current in the downstream tube. In power amplifiers, the plates may become glowing or the current limiting resistors may overheat or fail. Similar considerations apply to semiconductor amplifiers (transistors) made with components, but because of the lower heat generation and the use of modern polyester dielectric barriers, this once common problem has become relatively rare.