MMC where to buy

Status
Not open for further replies.
Aghh It's so frustrating! It's the last part of my tesla coil (besides the control box) and also the hardest to find and get. Someday though I WILL FIND SOME!
 
billybob said:
Aghh It's so frustrating! It's the last part of my tesla coil (besides the control box) and also the hardest to find and get. Someday though I WILL FIND SOME!
Click to expand...
Now that I think about it, this is precisely the reason I never finished my own medium-size Tesla coil - I got stuck on the cap bank and then life happened, and I ran out of time
 
DerStrom8 said:
Now that I think about it, this is precisely the reason I never finished my own medium-size Tesla coil - I got stuck on the cap bank and then life happened, and I ran out of time
Click to expand...
I can't let that happen!!! Ive spent too much time and money on this to be stopped by a few capacitors!!
 
Would these be suitable? Epcos B32654A1154J000 "high pulse" rated polypropylene caps, 150nF, 1600V DC, 27.5mm lead spacing.

RS Components are selling them rather cheaper than any other place I can find; £0.84 + VAT but you have to buy 200, which makes the total cost almost exactly £200.. Part number 194-3738

They are not quite a match for the Cornell Dubilier 0.15uF 2000V ones that some people online are using - but those seem to be nearer £5 each!

The description in the RS item page is wrong, it says 0.47uF - but all the list entries correctly say 0.15uF for that part number, eg. here:

More info in the Epcos datasheet, they are on page 20 for the specific part:
 
My concern with those would be the current rating. The 942C20P15K-F capacitors from Cornell Dubilier are selected by Tesla Coil enthusiasts because their peak current rating is 432A (WOW!!!). I am not able to find the peak current rating in the datasheet for the EPCOS parts.

That being said, I have seen capacitor banks made up of these caps, but that was for a small Tesla Gun, which uses a QCW driver. If I'm not mistaken, this is much less taxing on the capacitor bank in terms of current rating requirements. I have yet to build a QCW coil though.
 
Last edited:
Ah thats too bad
 
That's not to say they can't be used, the MKP style of capacitors are great at high frequencies. It would just take more parallel strings to split up the current, and that will greatly increase the number of capacitors required to make a suitable MMC.
 

Information Unlimited - Shopping Cart

information unlimited, science projects, tesla, tesla coils, high voltage engineering, high voltage power supplies, marx generator, plasma globe, anti gravity, security devices, ultrasonics, hypnotism, mind control, electronic kits, plans, books, videos, pyrotechnics, neon, neon power supplies...
www.amazing1.com
What about these? They say they are 2000k volts
Need to calculate how many I'll need if they work.
 
You'll have to link the actual product page, you can't share shopping carts that way.
 
From the info contained in the data sheet, voltage vs. frequency, they are rated to stand 9.5A RMS continuously at 20 KHz.
The maximum pulse charge or discharge rate is 1000V per uS.

I'm sure there must be a way to calculate the current for that, but it's not a calculation I've ever needed!
>google<
For a constant current to give a certain rate of change, the formula appears to be:
V(t) = (I*t)/C

From that, if I have it correct, 1000V per uS on a 0.15uF cap means it is rated to handle 150A ??
 
DerStrom8 said:
You'll have to link the actual product page, you can't share shopping carts that way.
Click to expand...

.15ufd at 2KVAC Metallized Polypropylene Film Foil Capacitor

information unlimited, science projects, tesla, tesla coils, high voltage engineering, high voltage power supplies, marx generator, plasma globe, anti gravity, security devices, ultrasonics, hypnotism, mind control, electronic kits, plans, books, videos, pyrotechnics, neon, neon power supplies...
www.amazing1.com

I determined that 8 would work for a 9k 60 mA power source. With almost enough power rating
 
Those also don't give a peak repetitive current rating. Again, they're MKP which is great, but without knowing how much current they can handle it'll be a gamble.
 
DerStrom8 said:
Those also don't give a peak repetitive current rating. Again, they're MKP which is great, but without knowing how much current they can handle it'll be a gamble.
Click to expand...
Hmmm and the price difference isn't a significant difference. Guess I'll keep looking
 
Another cap you might want to keep your eyes open for are the Aerovox RBPS20591KR6GNZ IGBT snubber caps, 2uF/530VAC. Those are the ones I used on my DRSSTC. They are absolutely spectacular, with an individual peak current rating of around 900A. You will need quite a few in series to meet your capacitance requirements, so cost may become a concern, but if you're able to find a good deal they will handle the high current quite well. I bought 50 of them for $1/ea back in the day, though last I checked the price went up significantly. Due to their high capacitance you would need over 100 for your coil (110-120, somewhere in there). There are other caps in that series that may be worth a look as well.

 
Why do some have more than 2 prongs?
 
billybob said:
Why do some have more than 2 prongs?
Click to expand...
Most likely they're designed to be mounted on a PCB, so individual pins are needed, but impedance needs to be reduced so they use multiple pins. My guess is that all of the pins on one side are connected to the same point internally.
 
DerStrom8 said:
Most likely they're designed to be mounted on a PCB, so individual pins are needed, but impedance needs to be reduced so they use multiple pins. My guess is that all of the pins on one side are connected to the same point internally.
Click to expand...
oh ok
 
Status
Not open for further replies.

Similar threads

  • Question
What to expect ?
Replies
3
Views
3K
Externet
G
  • Locked
  • Question
AC Motor controller to shift frequency from 50Hz to 60Hz
2
Replies
34
Views
10K
Ian Rogers
R
  • Question
Re: Circuit building to perform electrolysis for flow visualization
Replies
0
Views
4K
rakkiran
R
  • Question
How to power-up a CRT ?
Replies
17
Views
17K
Nigel Goodwin
C
  • Question
Need HELP driving my IGBT (Toshiba MG300Q1US)
Replies
2
Views
4K
Tony Stewart
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…