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Re: power factor correction capacitors (fwd)
---------- Forwarded message ----------
Date: Mon, 02 Jul 2007 12:32:13 +0000
From: David Rieben <drieben@xxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Cc: drieben@xxxxxxxxxxx
Subject: Re: power factor correction capacitors (fwd)
Hi Scott,
Check this out:
http://cgi.ebay.com/New-100UF-100-UF-RUN-OIL-CAPACITORS-CAPACITOR-370V_W0QQitemZ170124898221QQihZ007QQcategoryZ4662QQrdZ1QQcmdZViewItem
These make excellent PFC caps and have a realtively high capacitance
so that you would only need 3 of them to achieve your desired 295 uFd
(you'd actually exceed it by 5 uFd, which is close enough). Also, their 370
VAC rating allows them to be used with either 120 or 240 volts without
worry of overvolting them. I have personally purchased these capacitors
before and they are a great capactior for the money.
David Rieben
-------------- Original message --------------
From: "Tesla list" <tesla@xxxxxxxxxx>
>
> ---------- Forwarded message ----------
> Date: Sun, 01 Jul 2007 21:57:59 -0400
> From: Scott Bogard
> To: tesla@xxxxxxxxxx
> Subject: Re: power factor correction capacitors (fwd)
>
> Considering that I don't get to the junkyard everyday (sadly), and since DC
> capacitors are relatively cheap for their voltage/capacitance rating, could
> I use two parallel strings of DC caps, each protected by a diode to keep the
> power flowing the right way, or would this not work (or if I grounded the
> strings)? For my power supply, Java TC is suggesting I need a 295 uf cap
> size, and considering how low the values of motor run capacitors generally
> are, I would need a whole lot of them! Thanks.
> Scott Bogard.
>
>
> >From: "Tesla list"
> >To: tesla@xxxxxxxxxx
> >Subject: Re: power factor correction capacitors (fwd)
> >Date: Sun, 1 Jul 2007 17:25:04 -0600 (MDT)
> >
> >
> >---------- Forwarded message ----------
> >Date: Sun, 01 Jul 2007 12:33:25 -0400
> >From: David Speck
> >To: Tesla list
> >Subject: Re: power factor correction capacitors (fwd)
> >
> >Scott,
> >
> >IMHO, it's not worth it to try to build a PFC cap. You can get metal
> >can (oval or round) oil filled motor run caps for free from dead air
> >conditioners, refrigerators, some furnaces, or dehumidifiers at your
> >local recycling center. Usually, the bigger the original device, the
> >bigger the cap. They are also available from eBay. Even microwave oven
> >caps work, but at only 1 uF each, you would need several in parallel.
> >Motor run caps will have a definite capacitance value, like 6 uF at some
> >voltage, stamped into the case.
> >
> >Do not use round black plastic encased electrolytic motor start caps --
> >they are intended for a duty cycle of only a few seconds, and get hot
> >and explode if run continuously. Start caps usually have a very wide
> >range of capacitance printed on the case, like 50 - 120 uF at some
> >voltage.
> >
> >Dave
> > > Hey everybody,
> > > Can anybody tell me where I can get, some capacitors to use for
> >power
> > > factor correction (and how much it would cost me)? Would it be insanely
> > > difficult to build one? Could I use motor start or run capacitors?
> >Thanks.
> >
> >
> >
>
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