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Topic: Other capacitors for crystal (Read 2653 times) previous topic - next topic

liudr

I've recently seen super capacitors in the size of a "sub"capacitor, from Cooper Bussmann, the powerstor, up to 100F. I guess I really don't know what they do inside of those magic cylinders as a physics teacher. I'll have to find out. They can discharge very slowly to provide almost battery-like actions or very fast to fuel a flash light of something. Just amazing. Anyone used them in the past? How do you like them?

I have a few of them on a few scrap PCB I got from a surplus store. They are very short like mushrooms.  ;D

westfw

The supercaps essentially use a carbon electrode with massive surface areas compared to their weight/volume.  Earlier models use activated charcoal, and have a relatively high internal resistance.  Later versions use carbon aerogels with significantly better conductivity.  I imagine nanotubes are being hotly researched in the same space, but I don't think I've heard anyone claiming to be using them yet.

We have them in a few products for memory backup.  Your cellphone probably has some variety that saves cpu start long enough to change batteries...

There power density compared to batteries is pretty (very) low, but they lack other problems that have been inherent in batteries.

liudr

Very interesting. My dad used to work on these nanotubes. They have quite a bit of surface area over volumn.

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