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Re: Old Capacitors
From: Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: Sunday, December 07, 1997 1:46 PM
To: Tesla List
Subject: Re: Old Capacitors
Hi Alan,
> From: Alan Sharp[SMTP:100624.504-at-compuserve-dot-com]
> Sent: Friday, December 05, 1997 4:54 AM
> To: INTERNET:tesla-at-pupman-dot-com
> Subject: Re: Old Capacitors
>
> Thanks everyone for the replies:
>
>
> >The clue to these units is the specification of +8% ripple
> >50Hz. This implies that while the DC rating is 10kV, the applied AC
> >may not exceed 800V (long term) without over heating the cap.
>
> >Likewise, this 8% rating implies that these caps have a very high
> >effective series resistance which limits their ripple current to
> >800*2*pi*50*0.1e-6 = 25mA!
>
> I see the logic to this - and its bad news! But better news than
> exploding caps - (maybe I could use them for forming sheet
> metal into molds). I may put all six in series and give them a
> short run - once I've built a stout wooden box for them - see
> how they fair.
>
> Looks like we're back to plan B - where's the plastic sheet
> and tin foil!
>
> Have fun,
>
> Alan Sharp (UK)
I don't think the HiVolt caps would explode. There is no oil in them.
As I say, I have used them on a TC at 1.6kW or so. Interestingly
enough, they *look* like sticks of dynamite or somesuch. To add to
the fun, I understand they are manufactured in Ireland. When my mate
sent me my two, there was some kind of mail mixup and we were left
wondering whether they had been seized by Customs until they finally
got here.
Malcolm