Page 2 of 3

Posted: Tue Oct 28, 2008 4:10 pm
by rp181
try sampling capacitors from CDE, even if your not a company (dont even try to lie) theyle still sometimes give you some, if you just say its for a project.

Posted: Tue Oct 28, 2008 5:13 pm
by jrrdw
Maby you could get some from old tv sets and things alike.

Posted: Tue Oct 28, 2008 5:14 pm
by POLAND_SPUD
uhmm sorry for going off topic... but would it be usefull for buildign a coil gun ? http://www.allegro.pl/item467347172_kon ... v_nos.html

Posted: Tue Oct 28, 2008 5:30 pm
by rp181
poland: too low capacitiance, and that high voltage isnt needed. Also, those type wont take well to pulsing. Best cost/preformance capacitor's for coilguns are electrolytic.
http://www.alltronics.com/cgi-bin/categ ... tem=21P001
is a very good extremly cheap capacitor, thats 7 dollars for 300joules (alot of energy) Make sure you know what your doing, it takes 16 joules through the heart to kill.

Jrrdw: Capacitors from old apliances wont work well because of the extremly high frequency and cycling. Wrong types will blow up.

Posted: Tue Oct 28, 2008 6:17 pm
by MaxuS the 2nd
Don't use Electrolyte Capacitors for pulses!

Use Polypropelene, they're the only type that will work for a long time without fatigue.

Posted: Tue Oct 28, 2008 7:33 pm
by rp181
electrolyctic are fine for pulses (like coil/rail gun). There just bad for fast cycling rates.

Posted: Wed Oct 29, 2008 2:48 am
by MaxuS the 2nd
..Still wouldn't use them.

Posted: Wed Oct 29, 2008 5:26 pm
by psycix
Ahh tesla coils.
One thing I will want to make someday when I have time and money left to build something cool (besides spudguns)
How much time and money does it cost to build a decent tesla coil?


And ofcourse, a tesla coil becomes three times as awesome if it can play the super mario theme. :D

Posted: Wed Oct 29, 2008 5:31 pm
by rp181
It all depends on how big and how profesional you want it to be. To audio modulate, and get big sparks, it would get expensive with the IGBT's. A basic SGTC will range from free-500$ depending on resources. Capacitors are the most expensive part.

Posted: Thu Oct 30, 2008 5:47 am
by MaxuS the 2nd
The bigger, the better ;)

Posted: Thu Oct 30, 2008 9:28 am
by psycix
Then dance around closely with a group of friends.
Last one standing wins the game.
Or let other people do it and place bets. :D

Posted: Mon Dec 22, 2008 1:47 pm
by MaxuS the 2nd
Well I practically finished it.

Just needs tuning and I need to fit the proper toroid.

[youtube][/youtube]

Posted: Mon Dec 22, 2008 2:48 pm
by jrrdw
EUREKA! It works. I thought there had to be a contact for the arc to jump to?

Posted: Mon Dec 22, 2008 5:16 pm
by MaxuS the 2nd
Nah, I think that's just if you want to lengthen the spark.
It's because the electric field ionises the air around the output point and sparks and streams jump from there.

It's a pretty cool thing to read about, let alone build :D

Posted: Mon Dec 22, 2008 7:17 pm
by rp181
Thats the cool thing about Tesla coils. There such high voltage that going to anything works. Its like a static shock, a doorknob isnt the other end of you =p

Maxus: is it a sgtc, sstc, or drsstc?