Microwave capacitors

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Illicium Verum <sebas@xxxxxxxxxxxxxxxx>

Hello Chris,
200 dollars is a lot, if you would have asked on the list.... I can
buy them here in Thailand for 1,82 USD each, buying ten plus shipping
would have saved you some money. You can use them for a power factor
corection, but as a primary capacitor they won't do well. I use high
speed 450VAC pulse capacitors with a speed of 3300 Vµs. The speed
3300 Vµs does not mean that the capacitor is made to handle 3300 Volt.
It only indicates how fast a capacitor can be charged and discharged.
In this case the capacitor is rated at 1000 Volt DC and can charge and
discharge itself 3.3 times in 1 µs. The speed of the capacitor is
related to the time it takes the Tesla coil to produce a spark and
should therefore be as high as possible.


Wednesday, June 15, 2005, 6:07:59 AM, you wrote:

> Original poster: "Chris Rutherford" <chris1@xxxxxxxxxxxxxxxxxxx>

> I can't answer your question, but I'm slowly building/designing my first
> Tesla coil, unfortunately I *may* have just waited about $200 on some
> capacitors that may be useless.  I purchased 10 * 2500V 1.3uF microwave
> capacitors, they charge up nicely and produce a nice crack when discharged,
> except when thinking about their make up (liquid filled) and their 50Hz
> frequency rating, when I start to pulse them in the Khz range they may
> start to heat up due to losses etc.  Can anyone advise?  If they're no good
> as high voltage pulse capacitors would they be any good in a voltage
> multiplier circuit to drive a pulse capacitor? Or should I just use 4 * 4KV
> transformers with secondary in series??  Any ideas what I can do with 10 *
> 2500V 1.3uF 50Hz capacitors in relation to making a Tesla coil??

> Thanks

> Christopher

> ----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Tuesday, June 14, 2005 7:02 PM
> Subject: Re: Perfecting my final design...


>>Original poster: "Adam R." <arabraxas@xxxxxxxxxxx>
>>
>>
>>I'd like to go with a large cap but I just expanded it! I am using the CD
>>caps (2000v .15uF) and have two strings of 15 for a .02uF cap bank
>>total...it does not look like I can easily get some more of those caps
>>(cheaply).
>>
>>Here are the results of the spread sheet, the inductance is much higher
>>than I thought.
>>
>>Diameter of tubing 0.25
>>separation of turns 0.25
>>Number of turns per spiral 10
>>Radius inner turn 4
>>Separation of spirals 2
>>length     TOTAL 2.5
>>n            TOTAL 100
>>L            TOTAL 3003.5
>>
>>Also, shouldn't the two spirals be wound in opposite directions so the
>>magnetic field matches?
>>
>>I'm worried working with the acrylic: I don't have special bits to drill
>>with it or saw it so I hope when drilling it won't crack and its only 1/4"
>>thick. To hold the copper tubing in I'm using PE cutting board strips. How
>>can I bolt the PE down? I'm guessing just extand 1/8" nylon bolts on the
>>strips.
>>
>>The distances btw the two coils will be adjustable so I can experiment
>>differing setups.
>>
>>Even just using two layers of 5 turns (6 or even 6.5"dia center) of .25"
>>Cu tubing spaced .25" apart (hopefully enough room to put 1/8" bolts?)
>>sounds like it'd work (with the .02uF cap). I'm just worried about using
>>thin bolts (1/8") but then that'd lower the risk of fracturing the
>>acrylic. (However, the center holes for the secondary are 1/4")....so
>>should I shoot for 5 turns? I might even be able to make a crappy mock
>>setup and test it with my L meter.
>>
>>






--
Best regards,
Sebastiaan