CAD CAM EDM DRO - Yahoo Group Archive

Re: another transformer question

Posted by caudlet
on 2002-08-11 10:24:00 UTC
<snip> for 48VDC so should just make it under 50V, but the
measurement says
> 60VDC, so should I risk it and go ahead to use the same capacitor,
> even if only temporary? What happens when one exceed the rated
> voltage of a capacitor?
>
> Thanks
>
>

In the short term normally nothing happens. If the overvoltage lasts
too long or is way over the limit of the working voltage things can
get interesting in a hurry. The insulation layer starts to break
down and the cap starts to draw excessive current which results in a
rapid build up in internal heat and the electrolyte starts to turn to
steam. Usually the result in larger caps is a hissing noise with
gook flowing out of the cap. The cap can explode (smaller ones go
off like firecrackers) but the real danger is to down stream
components. If you loose the filter cap the electronics running off
of it are essentially running off half wave AC at 120HZ...not kind to
components expecting nice smooth DC!

A lot of transformers are designed and rated at close to full load to
account for losses in the windings and other magnetive things, so a
36VAC unit might go to 40VAC lightly loaded but 45Volts sounds
excessive. Your two 12VDC fans in series should really be spinning
at 60VDC! The resistor in series will reduce that some but you may
have to increase the value to keep the voltage across the fans 24VDC.

Discussion Thread

rekmac 2002-08-09 08:01:09 UTC transformer question caudlet 2002-08-09 08:21:05 UTC Re: transformer question rekmac 2002-08-09 08:56:54 UTC Re: transformer question Garry & Maxine Foster 2002-08-09 14:18:53 UTC Re: [CAD_CAM_EDM_DRO] transformer question JanRwl@A... 2002-08-09 18:22:04 UTC Re: [CAD_CAM_EDM_DRO] transformer question eforum3001 2002-08-10 10:17:16 UTC another transformer question Robert Campbell 2002-08-10 10:28:25 UTC Re: [CAD_CAM_EDM_DRO] another transformer question eforum3001 2002-08-10 10:48:12 UTC Re: another transformer question eforum3001 2002-08-10 11:24:12 UTC Re: another transformer question Robert Campbell 2002-08-10 11:52:04 UTC Re: [CAD_CAM_EDM_DRO] Re: another transformer question caudlet 2002-08-11 10:24:00 UTC Re: another transformer question caudlet 2002-08-11 10:24:01 UTC Re: another transformer question JanRwl@A... 2002-08-11 12:59:01 UTC Re: [CAD_CAM_EDM_DRO] Re: another transformer question JJ 2002-08-12 06:33:51 UTC RE: [CAD_CAM_EDM_DRO] Re: another transformer question turbulatordude 2002-08-12 08:58:58 UTC CAP's (again) (was Re: another transformer question mariss92705 2002-08-12 11:31:39 UTC CAP's (again) (was Re: another transformer question Keith Bowers 2002-08-12 12:14:18 UTC Re: [CAD_CAM_EDM_DRO] CAP's (again) (was Re: another transformer question turbulatordude 2002-08-12 13:45:04 UTC CAP's (again) (was Re: another transformer question caudlet 2002-08-12 13:45:56 UTC CAP's (once again) (was Re: another transformer question mariss92705 2002-08-12 15:10:42 UTC CAP's (once again) (was Re: another transformer question turbulatordude 2002-08-12 17:48:08 UTC CAP's (once again) (was Re: another transformer question turbulatordude 2006-05-06 15:59:03 UTC transformer question Jon Elson 2006-05-06 17:55:32 UTC Re: [CAD_CAM_EDM_DRO] transformer question turbulatordude 2006-05-06 19:25:20 UTC Re: transformer question Peter Reilley 2006-05-07 06:46:23 UTC Re: [CAD_CAM_EDM_DRO] transformer question Phil Mattison 2006-05-07 10:14:07 UTC Re: [CAD_CAM_EDM_DRO] transformer question Brad Dirks 2006-05-07 16:42:55 UTC Re: [CAD_CAM_EDM_DRO] transformer question Jon Elson 2006-05-07 17:20:51 UTC Re: [CAD_CAM_EDM_DRO] Re: transformer question