Re: Photoflash capacitors for EDM use

I reapeatly come across 12 and 24 V power supplies from phone or
intercom systems. often 30 amp or larger supplies.

The ones I looked at today had 10 volt Caps so I just kept walking.

Any suggestions what I might look for out of a switching power
supply ?

Dave






--- In CAD_CAM_EDM_DRO@yahoogroups.com, Dave Dillabough <dgd@b...>
wrote:

> If you are going to use these caps make sure that you monitor the
> temperature. Photo flash caps are probably not designed to be

repeatedly

> charged and discharged at the frequency that an EDM would use. If

an

> electrolytic cap gets hot enough it will vent or blow the end out.

Makes

> quite a bang and a mess.
>
> For use in an EDM you want a cap with a low ESR (Equivalent Series
> Resistance) so that it will not heat up when you charge and

discharge it at

> a high frequency. If you can find them in the right value oil

filled caps

> like the ones uses on motors work well. For scrounging a switching

power

> supply would be a good place to look.
>
>
> At 06:45 PM 3/17/03 +0000, you wrote:
> >A while ago someone suggested using photoflash capacitors in EDM
> >usage. I found some at All Electronics, 150 mf at 350 volts and a
> >nice compact size, 9/16" dia x 1.5" long, and only 75 cents

apiece. I

> >haven't hooked them up yet but it looks like they could be fitted
> >right on an electrode feed head with really short leads to the
> >electrode which should give a nice snap!. Richard.
> >
> >P.S. cat # PPC-1536
> >
> >
> >Addresses:
> >FAQ: http://www.ktmarketing.com/faq.html
> >FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> >Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com
> >
> >Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> >Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> >List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com,

wanliker@a...,

> >timg@k...
> >Moderator: pentam@c... indigo_red@q... [Moderators]
> >URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> >
> >OFF Topic POSTS: General Machining
> >If you wish to post on unlimited OT subjects
> >goto: aol://5863:126/rec.crafts.metalworking or go thru

Google.com to

> >reach it if you have trouble.
> >http://www.metalworking.com/news_servers.html
> >
> >http://groups.yahoo.com/group/jobshophomeshop I consider this to

be a

> >sister site to the CCED group, as many of the same members are

there, for

> >OT subjects, that are not allowed on the CCED list.
> >
> >NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING
> >THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO

EXCEPTIONS........

> >bill
> >List Mom
> >List Owner
> >
> >
> >
> >Your use of Yahoo! Groups is subject to

http://docs.yahoo.com/info/terms/