1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Capacitors for Tesla Coil

Discussion in 'High Voltage' started by Rob76, Apr 13, 2017.

  1. Rob76

    Rob76 New Member

    Joined:
    Apr 13, 2017
    Messages:
    1
    Likes:
    0
    I bought 100 30 kv 102 ceramic caps the other week for my first TC, just finished soldering 3s9p bank.. I do wish I'd checked around the internet first as it seems they won't work well. Ah well.

    Question though - Will submerging the cap bank in mineral oil improve performance at all? I'm still a way to go before I get the full coil up and running and don't wanna fork out more funds for better caps if these can still be used effectively.

    Cheers!
     
  2. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,500
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    Hi Rob, welcome to ETO!

    No, the mineral oil will not improve the performance of standard ceramic capacitors.

    The concern about capacitors used in Tesla coils is the dissipation factor (The ratio of the ESR over the reactance of the capacitor). Higher dissipation factors can cause the circuit to operate inefficiently, leading to heating from the inside out. This won't be helped much (if at all) by mineral oil.

    You really need some MKP or MMKP capacitors (metalized polypropylene). These tend to have much lower dissipation factors and are ideal for Tesla coil applications. The dissipation factor should be less than 0.001 in order for a given capacitor to work well in a Tesla coil primary tank circuit.
     
  3. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,500
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    Another question, what sort of high voltage transformer are you using that supposedly matches to a 3nF capacitor bank?
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. shortbus=

    shortbus= Well-Known Member

    Joined:
    Mar 23, 2008
    Messages:
    1,227
    Likes:
    77
    Location:
    youngstown, oh
    ONLINE

    Derstrom, and Rob, don't know if you know about this place, they have about the best price around for that type caps. They have all kinds of electronic stuff there too at good prices. And will ship worldwide. https://www.surplussales.com/index/Polypropylene-Polyester-Box-Type-Capacitors.html
     
    • Thanks Thanks x 1

Share This Page