Re: [TCML] NST Terry filter

[Steve Ward <steve.ward@xxxxxxxxx>]

http://www.grandbrass.com/balls.cfm

Has awesome balls for cheap.  Something coilers should know about!

Steve

On Tue, Dec 8, 2009 at 8:27 PM, <ConorPerry@xxxxxxxxxxx> wrote:

> I bought this same kit and was happy with it.  Nice guy, quick shipping.  I
> added some 3/4" threaded brass balls from "ToolSupply" on ebay, just search
> for "brass balls threaded" and you'll get lots of hits.  He sells a set of 5
> for $22 with shipping.  5 is nice because you'll use 3 on the Terry Filter,
> then the other 2 you can use as a spark gap, or protection gap accross the
> NST.  You can see some pictures of my build at the end of this video:
> http://www.youtube.com/watch?v=Rj5a3vuxihQ
>
> CP8071
>
>
> ----- Original Message ----- From: "Paul Brodie" <pbbrodie@xxxxxxxxxxxxx>
>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Sent: Tuesday, December 08, 2009 8:36 PM
> Subject: Re: [TCML] NST Terry filter
>
>
>
>  There is a complete Terry Filter kit advertised on eBay nearly all of the
>> time for $58.80 plus $14.35 shipping. It includes the following parts:
>> (2) 100 watt 1K ohm Dale resistors
>> (16) MOV's 1800V  (Metal Oxide Varistor)
>> (12) 0.0033uF 1600V Metal Polypropylene Capacitors
>> (12) 10M Ohm 1/2 Watt 5% Resistors
>>
>> It is offered by the eBay store, Teslastuff, which is Rainy Lake
>> Electronics.
>> Just go to eBay and search for "Terry Filter" and it will come up. There
>> is a complete Terry Filter for sale on eBay right now, too. It is completely
>> assembled and has a safety gap made from brass balls.
>> Paul
>> Think Positive
>>
>> ----- Original Message ----- From: "Lau, Gary" <Gary.Lau@xxxxxx>
>> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
>> Sent: Tuesday, December 08, 2009 8:51 AM
>> Subject: RE: [TCML] NST Terry filter
>>
>>
>> No, the resistors cannot be replaced with chokes of any kind.  The
>> resistors are an integral part of the R-C low pass filter.  The R-C filter
>> is specifically designed to avoid the resonance that any L-C filter would
>> have. Filters using chokes were widely used until a more thoughtful analysis
>> and simulation was performed, and it then became apparent that L-C filters
>> cause more problems than they solve.  See more comments and analysis of NST
>> filter networks at http://www.laushaus.com/tesla/protection.htm
>>
>> But yes, you can use the two ceramic caps instead of the string.
>>
>> Regards, Gary Lau
>> MA, USA
>>
>>  -----Original Message-----
>>> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
>>> Behalf Of Jeremy Chan
>>> Sent: Tuesday, December 08, 2009 8:20 AM
>>> To: TCML
>>> Subject: [TCML] NST Terry filter
>>>
>>>
>>> Hey all,
>>> I am trying to build a terry filter for a 15/30 NST according to the
>>> following
>>> diagram:http://www.classictesla.com/download/NST_Filter.jpgbut am having
>>> problems finding the 1K 100W resistors.What is their function, and would
>>> chokes
>>> wound using flyback cable rated at 40KVDC on ferrite cores help in
>>> filtering out the
>>> hf? If so, how many turns on the chokes would be required?Also I plan to
>>> replace
>>> the cap and 10M resistor string with 2 1nF 15KV ceramic caps in series on
>>> each
>>> side to give 30KV 500pF sans the 10M resistors. Is that workable?
>>> Thanks and regards,Jeremy
>>>
>>
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>
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