Re: MMC from Microwave Caps

["Tesla list" <tesla-at-xxxxxxxxxx>]

Original poster: "manjinder bains" <manjinder_bains-at-yahoo-dot-com> 

i havne't tried MOT caps as an MMC...but i have tried
to kill em with 10kv..
they took the hits without severe loss
i think they'll be great if they could "ring" with ur
primary
(use bleeder resisters, those puppies hurt like heck)



--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "Kelly & Phillipa Williams"
> <kellyw-at-ihug.co.nz> 
> 
> Hi All,
> 
> I had an idea for a cheap 'MMC' using microwave
> capacitors.
> 
> The capacitors are 1 uF, (1 E -6 Farads)
> If I put 20 caps in series, (one string)
> the voltage rating would be a whopping 40 kV *RMS*
> or 56 kV DC!!
> (Assuming the faceplate voltage of 2000 VAC)
> 
> The capacitance would be 50 nF (0.05 uF)
> 
> At first glance, this seems like a great MMC, but
> there are a couple of
> problems I have
> thought of.
> 1) I remember someone telling the list that these
> caps have small internal
> leads and thin
>       plates, perhaps limiting their current
> discharging capability
> 2) Their dv/dt (Volts per microsecond) may not be
> high enough for TC use
> 3) Due to tolerances, the voltage stress on each cap
> may be unequal, leading
> to early failure.
>     (although the voltage rating of the whole cap is
> very high)
> 4) One string of caps may not be able to handle the
> current stresses
> 
> I have 23 microwave capacitors.
> I'd really like to be able to do this, (as it's
> free,) and I'm desperate for
> a cap for first light
> so I can spend some time thinking about what I want
> to buy for a more
> traditional MMC,
> as it will cost me quite a lot of money (for a
> student).
> 
> *Does anyone know of any problems with this idea, or
> can confirm my
> thoughts?*
> I don't care if the caps die in a few hours, I got
> them free.
> 
> Thank you very much,
> 
> Alan Williams
> 
> 
> 
> 


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