CAD CAM EDM DRO - Yahoo Group Archive

Re: What size capacitor should I use?

Posted by caudlet
on 2005-01-26 08:00:51 UTC
--- In CAD_CAM_EDM_DRO@yahoogroups.com, Simon Arthur <chroma@m...>
wrote:
> You may end up with higher ripple on the output voltage if your
capacity
> is too large.
>
> A. G. Eckstein wrote:

The higher the value of capacitor the *lower* the ripple. The ripple
frequency on a standard linear supply is 120hz. Motors don't need
ultra low ripple DC (like audio) but do need the ability to supply
current for motor peaks.

I most circumstances builders are over designing the power circuits
by several factors. To simply take the motor plate rating then
multiply by the number of motors then add in some "fudge factor" is
to oversize and overpay for the supply. On chopper type circuits you
will find the average current draw to be a lot less than the max
ratings on the motor. In additon not many people run all 3 (4)
motors full out at the same time. Most people feel good that they
have extra capacity in their power supply just sitting there for the
day something shorts and there is enough reserve power to weld
components to the chassis (:-)

Things like transformers have the ability to supply several times
their average current rating in short bursts. Semiconductor circuits
have to be designed using instantaneous peak ratings while passive
components are based on average values over time.

I think the 100% overvoltage rating is extremely conservative. It
works fine for small caps where the price difference is a few pennies
but in big filter caps you pay a lot for that wider margin. The
manufacture arrives at those ratings based on worst case tests of
ripple, temperature and time. The voltage rating is not an "explode
now" level. Most engineers are comfortable with 30 to 50% ratings
over the high line voltage.

That's my story and I'm sticking to it!!

Discussion Thread

rllalonde2000 2005-01-26 04:28:01 UTC What size capacitor should I use? A. G. Eckstein 2005-01-26 04:58:31 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? Simon Arthur 2005-01-26 05:38:23 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? R Rogers 2005-01-26 06:56:31 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? Terrenoire, Adrien L 2005-01-26 07:00:14 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? Andy Wander 2005-01-26 07:01:23 UTC RE: [CAD_CAM_EDM_DRO] What size capacitor should I use? turbulatordude 2005-01-26 07:07:50 UTC Re: What size capacitor should I use? - voltage ? A. G. Eckstein 2005-01-26 07:13:30 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? caudlet 2005-01-26 08:00:51 UTC Re: What size capacitor should I use? Bengt 2005-01-26 09:11:26 UTC Re: What size capacitor should I use? Jon Elson 2005-01-26 09:28:27 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? Roy J. Tellason 2005-01-26 09:44:34 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? turbulatordude 2005-01-26 09:58:26 UTC Re: What size capacitor should I use? Andy Wander 2005-01-26 10:19:07 UTC RE: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? caudlet 2005-01-26 11:29:56 UTC Re: What size capacitor should I use? Roy J. Tellason 2005-01-26 11:41:56 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? Rob Polley 2005-01-26 11:43:12 UTC Looking for advice Dan Mauch 2005-01-26 12:18:29 UTC Re: [CAD_CAM_EDM_DRO] Looking for advice Codesuidae 2005-01-26 12:34:15 UTC Re: [CAD_CAM_EDM_DRO] Looking for advice victorlorenzo@y... 2005-01-26 12:55:47 UTC Re: Looking for advice Stephen Wille Padnos 2005-01-26 13:38:53 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? John 2005-01-26 14:04:29 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? Simon Arthur 2005-01-26 14:09:40 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? erie 2005-01-26 14:33:11 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? Stephen Wille Padnos 2005-01-26 14:37:28 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? R Rogers 2005-01-26 14:56:53 UTC [CAD_CAM_EDM_DRO] Toroidal transformer ratings?? Amps? Kv? Kva? JanRwl@A... 2005-01-26 15:04:42 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? Les Newell 2005-01-26 15:05:07 UTC Re: [CAD_CAM_EDM_DRO] Toroidal transformer ratings?? Amps? Kv? Kva? cnc_4_me 2005-01-26 15:08:24 UTC Re: What size capacitor should I use? David Paulson 2005-01-26 15:10:21 UTC Re: [CAD_CAM_EDM_DRO] Toroidal transformer ratings?? Amps? Kv? Kva? cnc_4_me 2005-01-26 15:23:15 UTC Re: Toroidal transformer ratings?? Amps? Kv? Kva? JanRwl@A... 2005-01-26 15:40:19 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? R Rogers 2005-01-26 15:49:48 UTC Re: [CAD_CAM_EDM_DRO] Toroidal transformer ratings?? What after being rectified? cnc_4_me 2005-01-26 15:55:58 UTC Re: What size capacitor should I use? cnc_4_me 2005-01-26 16:14:14 UTC Re: Toroidal transformer ratings?? What after being rectified? R Rogers 2005-01-26 16:18:19 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use?sizing supply Ron Ginger 2005-01-26 17:01:36 UTC Re: Looking for advice polaraligned 2005-01-26 17:09:38 UTC What size capacitor should I use? Polaraligned 2005-01-26 17:25:09 UTC Re: Toroidal transformer ratings?? Amps? Kv? Kva? R Rogers 2005-01-26 17:29:00 UTC Re: [CAD_CAM_EDM_DRO] Re: Looking for advice cnc_4_me 2005-01-26 18:05:05 UTC Re: What size capacitor should I use? victorlorenzo@y... 2005-01-26 18:19:00 UTC Re: Looking for advice codeSuidae 2005-01-26 18:32:59 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? cnc_4_me 2005-01-26 18:54:06 UTC Re: What size capacitor should I use? Ken Langston 2005-01-26 18:56:05 UTC Re: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? Amps? Kv? Kva? cnc_4_me 2005-01-26 19:01:47 UTC Re: Toroidal transformer ratings?? Amps? Kv? Kva? Rob Polley 2005-01-26 19:24:26 UTC Re: [CAD_CAM_EDM_DRO] Re: Looking for advice codeSuidae 2005-01-26 19:26:51 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? cnc_4_me 2005-01-26 19:35:49 UTC Re: Looking for advice bobmcknight@c... 2005-01-26 19:37:07 UTC Re: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? Amps? Kv? Kva? bobmcknight@c... 2005-01-26 19:37:08 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? cnc_4_me 2005-01-26 19:54:55 UTC Re: What size capacitor should I use? turbulatordude 2005-01-26 19:57:22 UTC Re: What size capacitor should I use? resistors.... cnc_4_me 2005-01-26 20:08:00 UTC Re: What size capacitor should I use? resistors.... JanRwl@A... 2005-01-26 21:34:22 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? JanRwl@A... 2005-01-26 21:43:19 UTC Re: [CAD_CAM_EDM_DRO] Toroidal transformer ratings?? Amps? Kv? Kva? codeSuidae 2005-01-26 21:56:30 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? Jon Elson 2005-01-26 21:56:33 UTC Re: [CAD_CAM_EDM_DRO] Toroidal transformer ratings?? What after being rectified? Mariss Freimanis 2005-01-26 21:58:04 UTC Re: What size capacitor should I use? resistors.... Jon Elson 2005-01-26 22:08:03 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? JanRwl@A... 2005-01-26 22:09:14 UTC Re: [CAD_CAM_EDM_DRO] Re: Looking for advice Jon Elson 2005-01-26 22:22:35 UTC Re: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? Amps? Kv? Kva? Jon Elson 2005-01-26 22:29:43 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? resistors.... Jon Elson 2005-01-26 22:33:41 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? resistors.... Simon Arthur 2005-01-27 00:01:53 UTC Re: [CAD_CAM_EDM_DRO] What size capacitor should I use? Polaraligned 2005-01-27 04:15:31 UTC Re: What size capacitor should I use? Polaraligned 2005-01-27 04:29:29 UTC Re: Toroidal transformer ratings?? What after being rectified? turbulatordude 2005-01-27 06:26:30 UTC Re: What size capacitor should I use? resistor or not ?? turbulatordude 2005-01-27 06:45:41 UTC Re: Toroidal transformer ratings?? What after being rectified? Leslie Watts 2005-01-27 07:04:52 UTC RE: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? What after being rectified? Jon Elson 2005-01-27 10:30:37 UTC Re: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? What after being rectified? Jon Elson 2005-01-27 10:40:20 UTC Re: [CAD_CAM_EDM_DRO] Re: What size capacitor should I use? resistor or not ?? cnc_4_me 2005-01-27 10:47:17 UTC Re: Toroidal transformer ratings?? What after being rectified? Les Newell 2005-01-27 12:49:45 UTC Re: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? What after being rectified? Polaraligned 2005-01-27 13:39:18 UTC Re: Toroidal transformer ratings?? What after being rectified? Stephen Wille Padnos 2005-01-27 14:44:25 UTC Re: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? What after being rectified? Polaraligned 2005-01-27 18:13:16 UTC Re: Toroidal transformer ratings?? What after being rectified? Steve Stallings 2005-01-27 18:18:44 UTC Re: Toroidal transformer ratings?? What after being rectified? Stephen Wille Padnos 2005-01-27 18:28:46 UTC Re: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? What after being rectified? Jon Elson 2005-01-27 21:35:23 UTC Re: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? What after being rectified? Kevin Martin 2005-01-28 05:32:28 UTC RE: [CAD_CAM_EDM_DRO] Re: Toroidal transformer ratings?? What after being rectified? m0nkey0ne 2005-01-28 11:22:47 UTC Re: Toroidal transformer ratings?? What after being rectified? Mcginnis, Darrell S 2005-03-22 14:43:20 UTC RE: [CAD_CAM_EDM_DRO] What size capacitor should I use?