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A google search brings up manufacturers' data sheets for various capacitors, epcos make them up to 2500uF @ 500v which sound great but I can't find anywhere that sells them in small (~10) quantities.
I would be happy to spend $1000 on capacitors for this project, but size and weight are important factors, hence why I want to go with light energy dense Aluminium electrolytics over Oil and Paper Steel case capacitors
Registered Member #2901
Joined: Thu Jun 03 2010, 01:25PM
Location:
Posts: 837
How about these :
Meant for strobe lights, so slightly slower than the photoflash/pulse capacitors ... but coilguns have relatively slow discharges to begin with. These are rated for 1 ohm loads, which gives you a RC time of 120 us ... plenty fast. You have to put 15 or so in parallel of course.
Registered Member #2901
Joined: Thu Jun 03 2010, 01:25PM
Location:
Posts: 837
You pay for the name and the guarantee that it will work under certain conditions ... someone making an airplane or landing strobe light probably wants those. Someone making a coilgun should probably just look at best ESR for the $ and hope for the best :)
Thank you all for your responses. I think I need to really evaluate what's most important, and as Pinky's Brain said, just worry about getting the ESR as low as possible.
I was seeking Pulse related caps because of their long lifespans at high current discharge cycles, their low ESR and high discharge current capabilities.
Registered Member #2919
Joined: Fri Jun 11 2010, 06:30PM
Location: Cambridge, MA
Posts: 652
Adam wrote ...
Thank you all for your responses. I think I need to really evaluate what's most important, and as Pinky's Brain said, just worry about getting the ESR as low as possible.
I was seeking Pulse related caps because of their long lifespans at high current discharge cycles, their low ESR and high discharge current capabilities.
Are you constructing a commercial product, or a piece of lab equipment? If its for a personal project, you're pay a lot for an official guarantee, when standard electrolytics have been hobbyist-proven to work fine.
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