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.
Leakage increases power consumption and if sufficiently large can cause complete circuit failure. Leakage is currently one of the main factors limiting increased computer processor performance. Efforts to minimize leakage include the use of strained silicon , high-κ dielectrics , and/or stronger dopant levels in the semiconductor.
When subjected to reversed polarity (even briefly), the capacitor depolarizes and the dielectric oxide layer breaks down, which can cause it to fail even when later operated with correct polarity. [75] 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.
Some capacitors have a "pressure-sensitive interrupter" design that causes them to fail before internal pressures can cause serious injury. One such design causes the top of the capacitor to expand and break internal wiring. [7] Over many years of use the capacitance of the capacitor drops; this is known as a "weak capacitor".
As with any industrial product, specific causes of failure modes are known for aluminum electrolytic capacitors with non-solid electrolytes. They can be differentiated in failures causes by capacitor development and production, by device production, by capacitor application or by external influences during use. [64]
In many vacuum tube circuits, interstage coupling capacitors are used to conduct a varying signal from the plate of one tube to the grid circuit of the next stage. A leaky capacitor can cause the grid circuit voltage to be raised from its normal bias setting, causing excessive current or signal distortion in the downstream tube.