The dielectric,usually the insulator between the plates of a capacitor, can be overstressed by the application of too high voltages applied to the capacitor plates. The dielectric breaks down and a current flows between the plates until,either they are discharged, or an equilibrium is reached,below the working voltage of the capacitor. If the dielectric is damaged in this process he capacitor must be replaced. Some dielectric material self heal and can recover from an over voltage.
definetion of cavity breakdown
Changing the dielectric causes the capacitance to change.
The dielectric stress is the stress placed upon a material when a voltage is placed across it.
The dielectric material between the plates.
According to a few charts I was able to find, the most realistic material with the highest dielectric strength happens to be Mica, with dielectric strength of 118.
Yes. Once dielectric breakdown occurs the circuit is now completed through a conductive breakdown channel in the dielectric. The current injected in one end of the dielectric is matched by the current coming out of the other end.
The dielectric breakdown strength is 3,000 volts per millimeter.
Dielectric breakdown of air occurs when the electric field strength exceeds the dielectric strength of air. Factors that contribute to this include high voltage levels, sharp edges or points, humidity levels, and the distance between conductors.
The dielectric breakdown strength is the maximum electric field that a dielectric material can withstand before it breaks down and allows electrical current to flow through it. It is a measure of the insulation properties of the material.
definetion of cavity breakdown
Generally, dielectric breakdown strength decreases with increasing humidity. In air, exact relationships between dielectric strength and humidity are hard to derive, due to the numerous other variables compounding the relationships (e.g. electrode size and shape, air temperature and pressure). Sources: http://www.scienceforums.net/topic/37206-dielectric-strength-of-air/ http://en.wikipedia.org/wiki/Dielectric_strength
Generally, increased moisture levels will lower breakdown strength, especially if the dielectric readily absorbs water. Increasing temperature generally decreases breakdown strength of solid dielectrics. The dielectric strength of some materials may increase with temperature within limited temperature ranges. However, dielectric strength eventually begins to decrease at higher temperatures.
ASTM D149 - 09 Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies
Oxid failure is the most common type of ESD damage. When the voltage across a dielectric region excesses its dielectric tolerances, the result is a puncture of the dielectric. Once the dielectric has been punctured, small amount energy will be enough to create a short circuit. A device, after dielectric breakdown, will usually exhibit lower breakdown voltage, increased, leakage current and increased noise but not a catastrophic failure
3KV/mm or 3X10^6 V/M
Stanley Whitehead has written: 'Dielectric phenomena' -- subject(s): Dielectrics 'Dielectric breakdown of solids' -- subject(s): Dielectrics
The dielectric breakdown field in air is typically around 3 kV/mm to 6 kV/mm. This is the minimum electric field that can cause air to become conductive and allow current to flow through it.