[Milsurplus] Re: Milsurplus Digest, Vol 6, Issue 1
Mike Hardie
mike46 at shaw.ca
Fri Oct 1 08:55:40 EDT 2004
Marty,
Might be worth more than 2 cents. In my case V = 450, L = 13. 25K bleeder
gave current of around 20ma. AC component was almost not measureable, in
the fraction of a percent.
Problem with power supply was not AC ripple but a 7812 in the filament
supply to a tube. SS = mucho noise.
Mike VE7MMH
----- Original Message -----
From: <milsurplus-request at mailman.qth.net>
To: <milsurplus at mailman.qth.net>
Sent: Friday, October 01, 2004 1:01 AM
Subject: Milsurplus Digest, Vol 6, Issue 1
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> Today's Topics:
>
> 1. test (KD4MVC at aol.com)
> 2. Re: WTB Manuals and Power Supply Question
> (Unserviceable but Repairable)
> 3. RE: WTB Manuals and Power Supply Question (John Schmitz)
> 4. RE: WTB Manuals and Power Supply Question
> (Unserviceable but Repairable)
> 5. RE: WTB Manuals and Power Supply Question (John Schmitz)
> 6. Manuals (Lloyd KK7IZ)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 30 Sep 2004 11:21:26 EDT
> From: KD4MVC at aol.com
> Subject: [Milsurplus] test
> To: milsurplus at mailman.qth.net
> Message-ID: <145.34f460ef.2e8d7e76 at aol.com>
> Content-Type: text/plain; charset="US-ASCII"
>
> test
>
>
> ------------------------------
>
> Message: 2
> Date: Thu, 30 Sep 2004 11:43:19 -0400 (EDT)
> From: Unserviceable but Repairable <cosmoline at ba-watch.org>
> Subject: Re: [Milsurplus] WTB Manuals and Power Supply Question
> To: milsurplus at mailman.qth.net
> Message-ID: <200409301543.i8UFhJVP014694 at fracas.netboobie.org>
>
> > Capacitors work on voltage, chokes work on current.
>
> Well, sorta.
>
> Smoothing chokes have a gap so L same over wide range.
>
> Swinging chokes have no gap & their L goes from hi to low as current
> gets near max.
>
> The bleeder R of a LC-filtered power supply with smoothing choke
> ought to place that choke up into "flat line."
>
> And that's just a few ma on a 200ma choke
>
> My 2 ct.s
>
> Marty
>
>
> ...and the C oughta be picked to deliver load V within ripple-limits
> between rectifier pulses.
>
> --i8UFcg53014649.1096558722/fracas.netboobie.org--
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Thu, 30 Sep 2004 10:59:00 -0500
> From: "John Schmitz" <cjs004 at comcast.net>
> Subject: RE: [Milsurplus] WTB Manuals and Power Supply Question
> To: <milsurplus at mailman.qth.net>
> Message-ID: <HLELLHGLIAEPMJLHDDBLKEJADCAA.cjs004 at comcast.net>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Going back to my basic electronics days, it would seem that if load
current
> decreases (an increased load resistance and thus an increased RC time
> constant) the filter caps would not discharge as much and thus maintain a
> higher charge value (less ripple) thus compensating the reduced inductor
> action on ripple at low load currents.
>
> My 2 cents?
>
> John
>
>
> -----Original Message-----
> From: milsurplus-bounces at mailman.qth.net
> [mailto:milsurplus-bounces at mailman.qth.net]On Behalf Of Unserviceable but
> Repairable
> Sent: Thursday, September 30, 2004 10:43 AM
> To: milsurplus at mailman.qth.net
> Subject: Re: [Milsurplus] WTB Manuals and Power Supply Question
>
> > Capacitors work on voltage, chokes work on current.
>
> Well, sorta.
>
> Smoothing chokes have a gap so L same over wide range.
>
> Swinging chokes have no gap & their L goes from hi to low as current
> gets near max.
>
> The bleeder R of a LC-filtered power supply with smoothing choke
> ought to place that choke up into "flat line."
>
> And that's just a few ma on a 200ma choke
>
> My 2 ct.s
>
> Marty
>
>
> ...and the C oughta be picked to deliver load V within ripple-limits
> between rectifier pulses.
>
> --i8UFcg53014649.1096558722/fracas.netboobie.org--
>
>
> ______________________________________________________________
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>
>
>
> ------------------------------
>
> Message: 4
> Date: Thu, 30 Sep 2004 12:17:20 -0400 (EDT)
> From: Unserviceable but Repairable <cosmoline at ba-watch.org>
> Subject: RE: [Milsurplus] WTB Manuals and Power Supply Question
> To: cjs004 at comcast.net
> Cc: milsurplus at mailman.qth.net
> Message-ID: <200409301617.i8UGHKJX014842 at fracas.netboobie.org>
>
> John it looks like we sed same. Fr'instance
> u sed (kinda)
>
> > it seems from memory that as load drops, so too does ripple
>
> & I 1st sed
>
> > ...and the C oughta be picked to deliver load V within ripple-limits
> between rectifier pulses.
>
> If it does it for full load, it'll sure give lower ripple @ less load
>
> The decay's given by
>
> -t/RC
> V = Vp X e
>
> Where t, give or take, is near .5 the peak spacing. So as RC gets bigger
> the drop decreases to nothing.
>
> And why if there's a near B+ short lotsa hum results. An often-missed
> consequence leading to unneeded filter cap. change-out
>
>
> ------------------------------
>
> Message: 5
> Date: Thu, 30 Sep 2004 11:54:51 -0500
> From: "John Schmitz" <cjs004 at comcast.net>
> Subject: RE: [Milsurplus] WTB Manuals and Power Supply Question
> To: <milsurplus at mailman.qth.net>
> Message-ID: <HLELLHGLIAEPMJLHDDBLEEJCDCAA.cjs004 at comcast.net>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Absolutely, we are on the same page. Love that basic electronics stuff.
Good
> point about the high load current due to faulty circuit components (leaky
> decoupling caps etc) causing high ripple and hum and being mistaken for
> needed additional filter capacitance. Bet that misunderstanding is made a
> lot.
>
> John
>
>
> -----Original Message-----
> From: milsurplus-bounces at mailman.qth.net
> [mailto:milsurplus-bounces at mailman.qth.net]On Behalf Of Unserviceable but
> Repairable
> Sent: Thursday, September 30, 2004 11:17 AM
> To: cjs004 at comcast.net
> Cc: milsurplus at mailman.qth.net
> Subject: RE: [Milsurplus] WTB Manuals and Power Supply Question
>
> John it looks like we sed same. Fr'instance
> u sed (kinda)
>
> > it seems from memory that as load drops, so too does ripple
>
> & I 1st sed
>
> > ...and the C oughta be picked to deliver load V within ripple-limits
> between rectifier pulses.
>
> If it does it for full load, it'll sure give lower ripple @ less load
>
> The decay's given by
>
> -t/RC
> V = Vp X e
>
> Where t, give or take, is near .5 the peak spacing. So as RC gets bigger
> the drop decreases to nothing.
>
> And why if there's a near B+ short lotsa hum results. An often-missed
> consequence leading to unneeded filter cap. change-out
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
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>
>
>
> ------------------------------
>
> Message: 6
> Date: Thu, 30 Sep 2004 15:49:21 -0700
> From: "Lloyd KK7IZ" <kk7iz at cox.net>
> Subject: [Milsurplus] Manuals
> To: "Mil-Surplus" <milsurplus at mailman.qth.net>
> Message-ID: <000d01c4a73f$ba160500$63780244 at userlvnwsus9dr>
> Content-Type: text/plain; charset="iso-8859-1"
>
> By popular demand:
> Do seller search for
> got2muchjunque
> He is a friend of mine, 82 years old and I can't keep up with him. There
> will be a bunch more manuals.
>
> Thanx
> Lloyd KK7IZ
> kk7iz at cox.net
> Visit my NEW web site
> www.lloydsdipsydumpster.com
> Collecting OLD civilian aircraft radios and literature
> Particularly Lear. Got anything?
> Some boatanchors got wings
>
> Lloyd Godsey KK7IZ
> 1315 N. Udall Circle
> Mesa, Az. 85203
> 480-620-7145 (cell)
>
>
>
> ------------------------------
>
> ______________________________________________________________
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> End of Milsurplus Digest, Vol 6, Issue 1
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