I really need some help in describing how to build large and small capacitors to
ID: 3349121 • Letter: I
Question
I really need some help in describing how to build large and small capacitors to store a large volume of charges? Any suggestions or examples on how to do this would be amazing.
I was thinking that one way to build a bigger capacitor in a smaller space is to place several capacitors in parallel with each other. When they are placed in parallel the surface areas of the plates of each capacitor is added together would allow you to store a greater amount of voltage. However like I said, I really don't have much else to go on, and need someone more knowlegable to help.
Explanation / Answer
The method described in your question to increase capcitance is would end up giving you the same result as it would with a single big capcitor of the same kind. To understand this we can think of a capcitor as a water tank. You might be familiar with this concept if you have studied the analogy between hydraulic systems and electrical systems. Putting small capacitors in parallel is like having small buckets adding up to the same capacity to hold water. For example, for making 100 micro Farad capacitance we can either take a single 100 micro farad capcitor or 10 smaller 10 micro Farad capacitance in parallel.
Coming to the geometry, we often say in books that a 1F capcitor is difficult to design. This is because the geometery of it is difficult to design. If I want a capacitor of fixed capcitance in smaller space then it is not possible since both area and distance play a role in it. Intutively we think that decrease in length would get us a large value. However in this case the distance between the capcitors would become so small that it would be practically impractical to implement.
Here a helpful thing can be changing the operating voltage used. If we want to increase the amount of charge stored then we can either change the capcitance (C) or can change the operating voltage. (Using Q= C*V)
The high energy density capacitors are developed for specific applications for example -- millitary applications. These work on very high voltages. A major drawback of such a system is that the discharge cycle of a battery is severely affected by operating at high voltages thus leading to a lower lifetime of capacitor.
Another helpful thing, where research work is currently going on, is finding non conventional dielectrics which can help us acheive our goals. Polymers are being developed in this regard.