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(Help) Reducing MMC capacitance for Tesla Coil

Radit204

Jul 26, 2015
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Jul 26, 2015
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Hi. I am new to this forum and in need of help with my first Tesla Coil Project, mainly in the capacitor bank.

Straight to the point here, is it possible to reduce capacitance from an MMC (Multi Mini Capacitors) by adding a small capacitance capacitor in series ?

Details:
Due to a lack of materials here in Indonesia, my capacitor options are limited to these two Caps (for tesla coil operation) ; WIMA FKP-1 2000V 2,2uF and WIMA FKP-1 400v 0,22uF. Combining only the 2Kv Caps in series results in a cap bank to large to be usable. There for i want to add these small caps in series. I am aiming for a 0.02uF cap bank.
The power source i'm using creates DC peeks at 10Kv

Can it be done?, Is it safe to use this method?, And is there any other way to create a 10KV cap bank at 0.02uF using only THESE caps?
(without just chaining 100 of the 2KV's in series)

Thanks in advance.
 

Arouse1973

Adam
Dec 18, 2013
5,178
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Dec 18, 2013
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Is this a spark gap tesla coil. Are these the capacitors that get charged up and supply the energy to the primary winding?
Adam
 

Radit204

Jul 26, 2015
2
Joined
Jul 26, 2015
Messages
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Is this a spark gap tesla coil. Are these the capacitors that get charged up and supply the energy to the primary winding?
Adam
Yes, this is tesla coil uses a Asynchronous Rotary spark gap, and all the caps are used to deliver energy to the primary
 

Arouse1973

Adam
Dec 18, 2013
5,178
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You can connect capacitors in series to reduce the overall capacitance. But you have to be careful connecting different values of capacitance with different working voltages together.

The voltage across the smaller capacitance may exceed it's rating. For example 1000 Volts across series connected 2.2 uF and 0.22uF will produce approx. 90 Volts across the 2.2 uF but approx. 910 Volts across the 0.22 uF.

The other concern I would have working at such high voltages is if any of the capacitors failed in a way that reduced their value. I personally would try and get one capacitor at the correct voltage rating.
Adam
 

Laplace

Apr 4, 2010
1,252
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Apr 4, 2010
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1,252
I am aiming for a 0.02uF cap bank.
Distributing 10,000 volts equally requires a string of 25 equal-valued capacitors so that 400 volts will charge each capacitor. But with using the 0.22 µF capacitors, the total capacitance of the string will be only 0.0088 µF.
EP-68#1.png

To achieve a total capacitance of 0.02 µF requires three strings of thirty-three 0.22 µF capacitors in parallel, but in this case each capacitor is charged to only 303 volts max.
EP-68#2.png
 
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