Re: Capacitor sourcing?

On Fri, Mar 18, 2011 at 1:22 PM, Joseph Magiera <joemagiera@ameritech.net>wrote:

> I'm trying to rebuild some Bally Midway power supplies. Does anyone have
> any leads on finding 20,000 (or 22,000) uf, 16VDC (or higher) axial
> capacitors (at a reasonable price)? I tried Mouser, Bob Roberts, MCM, MPJA,
> Unicorn, Allied, Jameco, Newark, Digikey, ebay, and a few others. I am
> looking for 5 of them. The cheapest I could find was Digikey, at $7.19,
> with a min order of 100 of them. I found some on ebay for $10 each (and
> higher). Yikes!
>
> Joe (joemagiera at ameritech dot net)
> joemagiera@ameritech.net
>

Axial lead capacitors are quickly going away, aren't they?

There are 3 major things to look for in a replacement:
     1) Capacitance value...in this case the minimum is 20,000 uF, maximum
doesn't matter (IN THIS CASE!).
     2) Voltage rating...stay between 16 and (at the most) 35 volts. On
electrolytic capacitors the dielectric can deform if used at much less
voltage than the part is rated for, this can decrease the capacitance over
time. On the other hand a higher voltage part will usually be larger which
helps get rid of heat.
     3) On power supplies, ripple current capabilities are important. A
lower ripple current part will run hotter and not last as long.

Funny story time: I once upon a time ordered a replacement for a Big Blue
from Wico. What they sent me was a little radial part the size of my
thumb. Capacitance was right, voltage was right, but ripple current
capability and life span would be WAY lower. End of funny story time.

So, for a cheap but usable part try DigiKey
P6868-ND<http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P6868-ND>for
$3.29, a 16 volt, 22,000 uF, 6.1 Amp ripple current part. Yeah, it's
radial lead, just solder some wires to it and stick it to the board with
silicone sealant.

But if it were me I'd take TWO
P6865-ND<http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P6865-ND>capacitors
and hook them together end-to-end. This gives you a total of
30,000 uF, 16 Volts, and 10.52 Amps of ripple current capability for $5.74
and a longer life span.

---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com
Received on Fri Mar 18 17:44:01 2011