Re: Capacitor Question

From	gilber34 <fafa@invalid.com>
Newsgroups	sci.physics
Subject	Re: Capacitor Question
Date	2015-11-04 07:48 -0600
Organization	Aioe.org NNTP Server
Message-ID	<n1d2bg$mof$1@speranza.aioe.org> (permalink)
References	(2 earlier) <pan.2015.11.03.23.06.12@localhost.localdomain> <p2sngc-esb.ln1@mail.specsol.com> <pan.2015.11.04.02.49.26@localhost.localdomain> <Xhi_x.106405$962.6918@fx09.iad> <pan.2015.11.04.07.31.01@localhost.localdomain>

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On 11/4/2015 1:30 AM, Fabian Russell wrote:
> On Wed, 04 Nov 2015 02:17:11 -0500, benj wrote:
>
>>
>> These are pretty large and expensive units!
>> I presume you are drawing some serious current here.
>>
>
> Expensive?  No way.  DigiKey has 'em for $2.75 a pop.
>
> Serious current?  Not really.  3 amp regulators are no problem.
> I do a lot of audio work and the low voltages involved can often
> require a lot of current.
>
> I built a power supply for a 50 Watt audio amp.  I think
> I got 10 amp regulators in there. (I'll have to open it up
> for a look).  The big problem was finding transformers able
> to give a high enough current output.

true,  the old tube radios (20-60's) had higher current multi winding 
transformers which are impossable to replace, aka filiment winding of 20 
amps at 2.5 volts...

also good heat sinking the regulators is key


>
> But my supplies are general purpose and I can use them to power
> low current circuits as well.  It's good to have headroom even
> if not always needed.
>
>>
>> I'd suggest going with a modern switching supply instead.
>>
>
> There are two reasons for not using a switching supply.
>
> 1) They always have to have a load attached or else poof.

yep.

>
> 2) They are far more complicated in design and why burden
> oneself unnecessarily?

also some can add noise to a nice quiet audio amp, even if switching 
frequency high.



>
>>
>> Shorting caps is a safety issue. In fact if you drain them too
>> fast it can shorten the life.
>>
>
> I misused the word "short."  I actually have 10 megohm resistor
> between the two ends.
>

Thread

Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-03 22:14 +0000
  Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-03 16:35 -0600
    Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-03 22:59 +0000
      Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-03 18:10 -0600
  Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-03 22:47 +0000
    Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-03 23:07 +0000
      Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-03 23:20 +0000
        Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-03 23:42 +0000
        Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-04 02:49 +0000
          Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-03 21:40 -0600
            Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-04 04:01 +0000
              Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-04 06:03 +0000
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-04 07:07 +0000
                Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-04 20:29 +0000
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-04 20:51 +0000
                Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-04 21:08 +0000
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-04 21:53 +0000
                Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-04 22:20 +0000
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-04 22:42 +0000
                Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-04 23:07 +0000
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-05 00:28 +0000
                Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-05 00:46 +0000
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-05 00:39 +0000
                Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-05 00:58 +0000
                Re: Capacitor Question benj <none@gmail.com> - 2015-11-04 18:25 -0500
                Re: Capacitor Question benj <none@gmail.com> - 2015-11-04 18:37 -0500
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-05 00:09 +0000
                Re: Capacitor Question benj <nobody@gmail.com> - 2015-11-04 21:35 -0500
                Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-04 21:51 -0600
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-05 04:19 +0000
                Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-05 11:10 -0600
                Re: Capacitor Question "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-05 09:15 -0800
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-05 18:08 +0000
                Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-05 19:26 +0000
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-05 19:44 +0000
                Re: Capacitor Question jimp@specsol.spam.sux.com - 2015-11-05 19:56 +0000
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-05 20:53 +0000
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-05 21:52 +0000
                Re: Capacitor Question benj <none@gmail.com> - 2015-11-04 18:41 -0500
                Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-04 21:54 -0600
          Re: Capacitor Question benj <nobody@gmail.com> - 2015-11-04 02:17 -0500
            Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-04 07:30 +0000
              Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-04 07:48 -0600
              Re: Capacitor Question benj <nobody@gmail.com> - 2015-11-04 14:04 -0500
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-04 19:28 +0000
                Re: Capacitor Question benj <none@gmail.com> - 2015-11-04 18:49 -0500
                Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-04 20:41 -0600
                Re: Capacitor Question Fabian Russell <root@localhost.localdomain> - 2015-11-05 03:16 +0000
                Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-04 21:58 -0600
          Re: Capacitor Question "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-04 12:14 -0800
            Re: Capacitor Question benj <none@gmail.com> - 2015-11-04 18:44 -0500
              Re: Capacitor Question gilber34 <fafa@invalid.com> - 2015-11-04 20:41 -0600
  Re: Capacitor Question gyansorova@gmail.com - 2015-11-05 16:34 -0800

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