Search results
Results from the WOW.Com Content Network
Failed aluminium electrolytic capacitors with open vents in the top of the can, and visible dried electrolyte residue (reddish-brown color) The capacitor plague was a problem related to a higher-than-expected failure rate of non-solid aluminium electrolytic capacitors between 1999 and 2007, especially those from some Taiwanese manufacturers, [1] [2] due to faulty electrolyte composition that ...
Structurally, capacitors consist of electrodes separated by a dielectric, connecting leads, and housing; deterioration of any of these may cause parameter shifts or failure. Shorted failures and leakage due to increase of parallel parasitic resistance are the most common failure modes of capacitors, followed by open failures.
Applying a reverse polarity voltage, or a voltage exceeding the maximum rated working voltage of as little as 1 or 1.5 volts, can damage the dielectric causing catastrophic failure of the capacitor itself. Failure of electrolytic capacitors can result in an explosion or fire, potentially causing damage to other components as well as injuries.
If the failure is a short circuit (the most common occurrence), and current is not limited to a safe value, catastrophic thermal runaway may occur. This failure can even result in the capacitor forcefully ejecting its burning core. Tantalum electrolytic capacitors with solid electrolyte are marked at their positive terminal with a bar or a "+".
Capacitors used within high-energy capacitor banks can violently explode when a short in one capacitor causes sudden dumping of energy stored in the rest of the bank into the failing unit. High voltage vacuum capacitors can generate soft X-rays even during normal operation.
Peak inrush current into a high voltage capacitor upon power up can stress the component, reducing its reliability. Pre-charge of the powerline voltages in a high voltage DC application is a preliminary mode which limits the inrush current during the power up procedure.
Dielectric absorption is the name given to the effect by which a capacitor, that has been charged for a long time, discharges only incompletely when briefly discharged.. Although an ideal capacitor would remain at zero volts after being discharged, real capacitors will develop a small voltage from time-delayed dipole discharging, [1] a phenomenon that is also called dielectric relaxation ...
Another contributor to leakage from a capacitor is from the undesired imperfection of some dielectric materials used in capacitors, also known as dielectric leakage. It is a result of the dielectric material not being a perfect insulator and having some non-zero conductivity, allowing a leakage current to flow, slowly discharging the capacitor. [1]