Capacitors, where to get them?

for a school project, Me and my friend build a medium sized railgun, however, we can't keep the capacitors we used to power it.
My question would be, Where can I get some capacitors to replace the used capacitorbank. I am looking for capacitors with both a high voltage rating, and a large amount of capacitance. (the total bank contained 8 1000uF, 385 volt capacitors, I would like to get at least half of this out of my replacement-bank)
so does anyone know:

places where I can buy this kind of capacitors for a small amount of money, which do ship in europe.

common used electronics containing this kind of capacitors to salvage. I already found some in a computer PSU, one in a computer monitor. And I know they are used in disposable flash cameras, which are not very much used any more, and can hardly be found here (Unless I buy them, which is going to cost me a very large amount of money)

Places where those capacitors are commonly used, and where I might get them for little money.

They don't actually need to have the exact same voltage and capacitance, but I would prefer them to be somewhat close to it. ( > 100 uF, > 100 Volts)

I am also looking for a new charger. chargers from disposable cameras might work, but tend to overheat and break down rather fast, I would like to know if there is something better.


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lemonie7 years ago
Most things with a DC power supply will do, like you've mentioned plus old TVs stereos, radios etc. or you go internet-shopping.
8000uF doesn't sound like much though, do you not want to aim bigger?

L
It'd be 600 Joules, fully charged. A fair bit of energy....
Other projects go bigger though don't they?

L
Oh aye, but at a cost. Railguns are another FDAW
kirdaiht (author)  steveastrouk7 years ago
those caps were all we got. But they worked quite well, I might make an instructable for the railgun soon. I already went around the internet a bit, looking for photo-flash capacitors, but the only thing I found were some chinese corporations, who did not list prices and only shipped in bulk quantities.


The following links have some good deals on largish ( > 100 uF, > 100 Volts) electrolytic capacitors, but unfortunately this seller is located in the Former U.S. (not Europe)

Electrolytic caps
http://www.goldmine-elec-products.com/products.asp?dept=1222&pagenumber=1&sort_on=price&sort_by=ASC
Flash Camera Inside Assembly
http://www.goldmine-elec-products.com/prodinfo.asp?number=G16329

Anyway, this info might not be immediately helpful, but it might provide some clues, as to what to look for in your neighborhood.

Regarding junked consumer electronics that might have suitable capacitors, you've already mentioned camera flash circuits.  Also switching power supplies often contain one or two big electrolytic caps rated at 1x or 2x the peak mains voltage, meaning circa 1.4142*(110 or 220 V) = 150 or 300 V.  Actually I just found a picture of this, here:
http://en.wikipedia.org/wiki/File:ATX_power_supply_interior-1000px_transparent.png
The  "input filter capacitors" are the ones I'm talking about.
8000uF of 400V caps, ~110 USD, 55 bucks each for you and your friend. Known good and working.