Question about capacitor voltage and inner dielectric effects?

In summary, a capacitor is connected to a HVDC power supply which provides a minimal current. When the volage reaches the capacitor plates the dielectric material in the capacitor polarizes. If there existed a barrier between the dielectric and the capacitor plate the capacitor could theoretically also operate like a transistor. If the voltage applied to the plates was high enough to break through the barrier free electrons will enter into the dielectric.
  • #1
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A capacitor is connected to a HVDC power supply which provides a minimal current.
When the volage reaches the capacitor plates the dielectric material in the capacitor polarizes.

Now, if there existed a barrier between the dielectric and the capacitor plate the capacitor could theoretically also operate like a transistor. If the voltage applied to the plates was high enough to break through the barrier free electrons will enter into the dielectric.

My question is, if this could occur would the excess electrons entering into the dielectric material cause the capacitors voltage to rise above the power supply voltage?
 
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  • #2
No, the capacitor voltage can only rise to the supply voltage. Where would any extra voltage come from?

If the dielectric breaks down, the voltage across the capacitor drops rapidly.
 
  • #3
When the dielectric breaks down, the water conducts electricity. Conductivity allows current, so potential energy is converted into electron movement. There is a scientific effect known as Avalanche Effect which may occur in this situation, but I'm not sure. there may be temporary electron holes causing an avalanche, which again means lots of current, and potential energy is converted into movement of electricity rather than it's previous static built up state.

It is interesting that dielectric breakdown is not taught as an alternative to faraday electrolysis in schools. As far as I know dielectric breakdown means that no salts (electrolytes) are needed, so this would be a cheaper method of breaking down water, since salts cost money to add to a device, and salts clog up/dirty up the device with contaminants. Theoretically, distilled water could be used without any salts and still produce hydrogen, since distilled water does conduct electricity without any salts at a dielectric break down. WIthout the dielectric breakdown, water is not a good conductor. Faraday did not have this knowledge back in the day when he was doing his tests.
 

1. How does the voltage affect the inner dielectric of a capacitor?

The voltage applied to a capacitor directly affects the electric field within the inner dielectric material. As the voltage increases, the electric field strength increases, which can lead to breakdown of the dielectric material if it surpasses its dielectric strength.

2. What types of dielectric materials are commonly used in capacitors?

Some common dielectric materials used in capacitors include ceramic, electrolytic, and plastic films. The choice of dielectric material depends on factors such as the required voltage rating, capacitance, and frequency range of the capacitor.

3. How does the thickness of the dielectric material affect the capacitor's performance?

The thickness of the dielectric material plays a crucial role in determining the capacitance of the capacitor. A thicker dielectric material allows for a higher capacitance, but it also increases the distance between the plates, which can lead to decreased performance at higher frequencies.

4. Can the inner dielectric material affect the overall lifespan of a capacitor?

Yes, the inner dielectric material can significantly impact the lifespan of a capacitor. If the dielectric material is not able to withstand the voltage and electric field, it can experience damage or breakdown over time, leading to a decrease in the capacitor's lifespan.

5. How does temperature affect the inner dielectric of a capacitor?

Temperature can have a significant impact on the performance of a capacitor's inner dielectric material. As the temperature increases, the properties of the dielectric material can change, altering its capacitance and causing a decrease in performance. It is essential to consider the temperature range in which a capacitor will be operating when selecting the appropriate dielectric material.

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