Re: [TCML] Voltage - Gap

[jhowson4@xxxxxxxxxxx]

Ah yes I see the posts you are talking about back in the archives. 

I am going to spend a little bit of time reading threw this material! 

So for the 2000Vdc cap, and the heat dissipated for the standard .15 2Kv would be .9W, seems reasonable. 
I don't really see how this is all that useful to me yet, but i am sure after reading thew the material you helped me find, I will learn what to do with it. 

Going back to what you said earlier, with 
before you work too hard modeling fine details, do a simple subset and 
see if it makes a significant difference. You might find that in an RMS 
current, heating sense that it doesn't make much difference between one 
big pulse at Imax and 3 successive pulses at Imax/3, because the duty 
factor is lower at the former. (Yes, heating goes as the square of 
current, so that's clearly not true in this specific example, but it's 
what I was able to come up with before my coffee as a direction to look) 

Its definitely something I need to consider, does this really matter? 
Well I am having a good time learning about all this stuff in the process, so why not try and figure it all out. Plus if i do i might be able to correlate some interesting things and add to the general knowledge base for everyone to learn from. 

another interesting thing about my coil in particular, Because I am basing it on Steves DC design, but optimizing the parameters, I can pretty much assume that the tank cap will be fully charged on what ever time scale I want it to be charged on. meaning that I can pick my BPS to be what ever I want and still achieve the maximum bang energy, assuming I have the current to push the system of course. I am designing for 600bps because that's the maximum my gap will be able to push. Hence my heavy interest in the RMS current, because that means a huge difference in price of the MMC. Its will all be too expensive for me anyway and I will be making my own poly caps in the end. But its been an interesting and knowledgeable exercise thus far, so I might as well keep going. FOR SCIENCEEEEEE!! 





Thanks, 
John "Jay" Howson IV 


"Why thank you, I will be happy to take those electrons off your hands." 

----- Original Message -----
From: "Jim Lux" <jimlux@xxxxxxxxxxxxx> 
To: tesla@xxxxxxxxxx 
Sent: Monday, January 30, 2012 9:34:45 PM 
Subject: Re: [TCML] Voltage - Gap 

On 1/30/12 6:13 PM, jhowson4@xxxxxxxxxxx wrote: 
> I actually have no idea how to do the calculations you speak of, not even a ball park idea. Is there a specific parameter on the data sheet that tells you how much energy these can dissipate in the form of heat? And if so could you give a few hints as to how I would go about these calculations. 
> 
> 

There is some discussion *way* back in the archives... 

But what you want to look at is things like the current rating (usually 
given as RMS amps) and the ESR (Equivalent Series Resistance), as well 
as dV/dt. 

Think of the capacitor having a resistor in series, and the RF current 
through the cap dissipates some power. 

The problem is that most capacitors have terrible thermal properties. 

look at http://www.cde.com/catalogs/942c.pdf 


The 0.15 uF, 2kV part is 5 mOhm ESR 2879 V/us, 432 Ipk, and 13.5 Irms 
(at 100kHz) 
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