HELP.. I NEED A GOOD DIY CAPACITOR SITE.

[Ansil]

anyone know of a good diy capacitor site.  i was looking to make a 6volt 50farad or so cap. i used to have a good site to make hydraulic oil filled cylinders for massive high voltage homemade caps but lost it when the computer crahsed.

[spongebob]

Probably not what you were looking for, but if you build this you really are a geek!  :lol:
http://www.thegeekgroup.org/projects/bucketcap/

[R.G.]

i was looking to make a 6volt 50farad or so cap.

That's going to be hard, even with a good DIY site on it. Here's why - you can't get stuff thin enough to be the right insulator, and you can't carry the materials for the insulators you can get.

Most dielectric materials have voltage ratings in the thousands of volts per mil (i.e. 0.001"). So you either have to use high voltage films to insulate, or you have to grow the super-thin insulator chemically on a metal film (can anyone say electrolytic? I knew you could.   )

In the capacitor sense, voltage is equivalent to thickness. Plastic, paper, cellulose etc. films thin enough to be rated under 20V will be so thin that they will tear with random air currents. That's why electros can get such high capacitance ratings - they can grow aluminum oxide insulators in micro-inch thicknesses.

There are some new electrochemical/polymer caps that get you farads at 6V, but they are clearly descended from electrolytic methods.

Not being able to get insulators thin enough flips you to the other end - whatever you do will be big and heavy. Because capacitance decreases as you move the plates apart, higher voltage (i.e. thicker) insulators necessarily mean more surface area is needed. So you have to have a LOT of metal film and insulator plate area, and it gets big.

For a good book on the subject, see "High Power Capacitors" from the '50's. I can look up the author if you like.

There are reasons that farad-class caps are not common. Mother Nature has made them not very practical for our current level of technology.

[zachary vex]

i answered your same question in the other thread:


man, that's a lot of foil rolling.  good luck.  you  might just investigate getting a supercapacitor.  here's a 50 Farad 2.5V cap.

http://www.mouser.com/?No=10&D=*supercapacitor*&handler=data.listcategory&Ntt=*supercapacitor*&terms=supercapacitor&Dk=1&crc=true&N=0&Ns=MfgrPartNumber%7c%7cSField

[puretube]

3 of`em in parallell, the same 3 times in series: voila 50F/7.5V...
(somebody distribute the voltage evenly, please...).


Didn`t Moses use a big hi-voltage cap to hinder people touching what they shouldn`t touch? (gold-wood cap on a mountain... charged with lightning tension?)

(- no, not Isaac Hayes in this case -)

[Ansil]

THANKS EVERYONE  sorry zach i didint' see it wheni originally posted it.  thanks again.