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If I crumple and unfold a piece of foil, am I increasing it's surface area? Since it's malleable, if I step on it with golf spikes, without completely piercing it, will it gain surface area?
SamsonWell I mean the conductors, not the dielectrics. Film capacitors are metalized so that might be hard to do. But ceramics have solid electrodes I believe. Why don't they increase their surface area?
Wow! thats great ! and i think its really fun doing that indeed.To increase the capacitance of my homemade caps. A lot of the things I'm doing needs very specific specs that I don't find available. Also, I enjoy making them.
No, I'm looking at overlapping plate surface area.You're looking at the volume of the dielectric, its surface area times thickness, not a fractal surface area of the plates when calculating capacitance.
I'm using foil and glycerol right now. I tried activated carbon but I've just made a messy method of powder coating things black.un doing that indeed.
I suggest use foil as an alternative capacitance for your homemade c
It is not manipulable in the sense you want. If the dielectric spacing is small compared to the scale of the surface irregularities, and you can "nest" your enhanced surface area plates like cupcake pans, it's worth the effort. Scaling each layer differently to roll sheets of cupcake pans isn't worth the engineering and fabrication headaches.Is it no manipulable?
Electrolytics aren't really capacitors --- they're batteries with low capacities and high discharge rates, and electrode surface area does make a difference.Why do they etch the aluminium in electrolytic capacitors?
If you just make the surface of the electrodes 'rough' you may be increasing the area but you are also increasing the spacing between some parts of them and that must decrease the overall capacitance, I think. If you make 'spikes' then you would need to produce matching spikes in dielectric and the other plate, which would be difficult - especially at home because of the possible tolerances. The clever thing about good conventional capacitor design is to make the spacing and dielectric thickness as uniform as possible because it is the point of least separation that determines the maximum operating voltage.Im more interested in very small imperfections. For example, if I etch my foil with hcl, will this increase the capacitance?
I have carbon aerogel composite papers and I'll be using a liquid dielectric, glycerol. If I am able to prevent shorting, do you thing the increased surface area of the electrodes would outperform the same setup with aluminium foil?If you just make the surface of the electrodes 'rough' you may be increasing the area but you are also increasing the spacing between some parts of them and that must decrease the overall capacitance, I think. If you make 'spikes' then you would need to produce matching spikes in dielectric and the other plate, which would be difficult - especially at home because of the possible tolerances. The clever thing about good conventional capacitor design is to make the spacing and dielectric thickness as uniform as possible because it is the point of least separation that determines the maximum operating voltage.
If you want to make good home made (tubular) Capacitors then you need very flat foil with no burrs on the cut edges and a very uniform thickness dielectric. Also, you have to wind them (Swiss Roll construction) uniformly tightly and exclude any dust or dirt. I have given students the task of producing Capacitors for a homework task and they mostly are just not careful enough to get good results - internal shorts are very common. If you are very careful, though, you should be able to achieve something worth while. Good luck.