elektroda.net NewsGroups Forum Index - Electronics Design - Maintaining a Vbe Multiplier's bias value
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JosephKK
Guest
Guest
Sun Feb 14, 2010 2:51 am
On Fri, 12 Feb 2010 08:24:24 -0800, John Larkin <jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
Quote:
On Fri, 12 Feb 2010 10:03:11 -0500, Phil Hobbs
pcdhSpamMeSenseless_at_electrooptical.net> wrote:
Build a man a fire, you keep him warm for a night. Set a man afire, you
keep him warm for the rest of his life. ;)
Cheers
Phil Hobbs
Got snow?
John
pcdhSpamMeSenseless_at_electrooptical.net> wrote:
Build a man a fire, you keep him warm for a night. Set a man afire, you
keep him warm for the rest of his life. ;)
Cheers
Phil Hobbs
Got snow?
John
My brother in Dallas TX does.
Richard Torrens (News)
Guest
Guest
Sun Feb 14, 2010 11:59 am
In article <jg91n5d684ru5imsq1cfcjpjd1vddg2b2l_at_4ax.com>,
Jon Kirwan <jonk_at_infinitefactors.org> wrote:
Quote:
I'd like to consider the Vbe multiplier often used in audio
amplifiers to maintain a bias voltage for the output stage.
The purpose is to better mitigate against ripple in the
unregulated power supply rails and against the the VAS
voltage output resulting from amplified signal voltages.
amplifiers to maintain a bias voltage for the output stage.
The purpose is to better mitigate against ripple in the
unregulated power supply rails and against the the VAS
voltage output resulting from amplified signal voltages.
Two things sprng to mind:
1: run the circuit at a constant current.
See
http://www.4qdtec.com/pwramp.html
which uses two diodes, but at a constant current.
2: bootdstrap it.
See
http://www.4qdtec.com/Audio/Neoteric/cct.png
which is the ciurcuit of sir Clive Sinclair's Neoteric - a very high
quality amp of its day.
Why do so many people here insist on quoting the whole of the original
article...
--
------------------------------------------------------------------
Richard Torrens. News email address is valid - for a limited time only.
http://www.Torrens.org.uk for genealogy, natural history, wild food, walks, cats
and more!
John Larkin
Guest
Guest
Sun Feb 14, 2010 4:16 pm
On Sun, 14 Feb 2010 09:59:56 +0000 (GMT), "Richard Torrens (News)"
<News+14654_at_Torrens.org.uk> wrote:
Quote:
In article <jg91n5d684ru5imsq1cfcjpjd1vddg2b2l_at_4ax.com>,
Jon Kirwan <jonk_at_infinitefactors.org> wrote:
I'd like to consider the Vbe multiplier often used in audio
amplifiers to maintain a bias voltage for the output stage.
The purpose is to better mitigate against ripple in the
unregulated power supply rails and against the the VAS
voltage output resulting from amplified signal voltages.
Two things sprng to mind:
1: run the circuit at a constant current.
See
http://www.4qdtec.com/pwramp.html
which uses two diodes, but at a constant current.
2: bootdstrap it.
See
http://www.4qdtec.com/Audio/Neoteric/cct.png
which is the ciurcuit of sir Clive Sinclair's Neoteric - a very high
quality amp of its day.
Jon Kirwan <jonk_at_infinitefactors.org> wrote:
I'd like to consider the Vbe multiplier often used in audio
amplifiers to maintain a bias voltage for the output stage.
The purpose is to better mitigate against ripple in the
unregulated power supply rails and against the the VAS
voltage output resulting from amplified signal voltages.
Two things sprng to mind:
1: run the circuit at a constant current.
See
http://www.4qdtec.com/pwramp.html
which uses two diodes, but at a constant current.
2: bootdstrap it.
See
http://www.4qdtec.com/Audio/Neoteric/cct.png
which is the ciurcuit of sir Clive Sinclair's Neoteric - a very high
quality amp of its day.
3. Hang a big cap across it.
John
Jon Kirwan
Guest
Guest
Sun Feb 14, 2010 8:14 pm
On Sun, 14 Feb 2010 07:16:38 -0800, John Larkin
<jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
Quote:
3. Hang a big cap across it.
Assume, just for a moment, that one wants to actually learn a
little about _designing_ the part that goes across those cap
terminals.
Jon
Jim Thompson
Guest
Guest
Sun Feb 14, 2010 8:40 pm
On Sun, 14 Feb 2010 11:14:46 -0800, Jon Kirwan
<jonk_at_infinitefactors.org> wrote:
Quote:
On Sun, 14 Feb 2010 07:16:38 -0800, John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
3. Hang a big cap across it.
Assume, just for a moment, that one wants to actually learn a
little about _designing_ the part that goes across those cap
terminals.
Jon
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
3. Hang a big cap across it.
Assume, just for a moment, that one wants to actually learn a
little about _designing_ the part that goes across those cap
terminals.
Jon
Just Larkin, as typical, throwing sand in the air.
Simulate it, it's crap for other than low current applications... some
_really_ bizarre behavior.
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Fred Abse
Guest
Guest
Sun Feb 14, 2010 11:09 pm
On Fri, 12 Feb 2010 11:02:34 -0800, Jon Kirwan wrote:
Quote:
Almost. It's more like: I'd like to get to Fresno Flats
(aka Oakhurst, near Yosemite) from Portland
(aka Oakhurst, near Yosemite) from Portland
Oakhurst is too touristy/resorty these days.
I usually stop at a little diner in Coarsegold, a few miles before, when
I drive into Yosemite that way.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
Fred Abse
Guest
Guest
Sun Feb 14, 2010 11:09 pm
On Sat, 13 Feb 2010 11:40:42 -0800, Jon Kirwan wrote:
Quote:
On Sat, 13 Feb 2010 09:09:39 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
On Fri, 12 Feb 2010 19:05:46 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Fri, 12 Feb 2010 19:28:51 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
[snip]
Learn Laplace short-hand, it'll be invaluable!
...Jim Thompson
I'm gradually getting more comfortable with Laplace, as I
continue to work more problems. It is an especially nifty
way to solve some differential equations, which is what it
was designed to do, I think.
Jon
Actually, shorthand Laplace was created by none other than Oliver
Heaviside: http://en.wikipedia.org/wiki/Oliver_Heaviside
...Jim Thompson
Now that's an impressive man. Thanks! I'll dig in!
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
On Fri, 12 Feb 2010 19:05:46 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Fri, 12 Feb 2010 19:28:51 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
[snip]
Learn Laplace short-hand, it'll be invaluable!
...Jim Thompson
I'm gradually getting more comfortable with Laplace, as I
continue to work more problems. It is an especially nifty
way to solve some differential equations, which is what it
was designed to do, I think.
Jon
Actually, shorthand Laplace was created by none other than Oliver
Heaviside: http://en.wikipedia.org/wiki/Oliver_Heaviside
...Jim Thompson
Now that's an impressive man. Thanks! I'll dig in!
He was self-taught, too.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
Fred Abse
Guest
Guest
Sun Feb 14, 2010 11:09 pm
On Thu, 11 Feb 2010 14:27:58 -0800, Jon Kirwan wrote:
Quote:
On Thu, 11 Feb 2010 11:50:23 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
<snip>
Quote:
Once upon a time there was JEDEC, and all 2N2222A's had to be the
same in regards to essential specifications.
Okay. That's gone, then.
same in regards to essential specifications.
Okay. That's gone, then.
I still get regular emails from JEDEC. They all seem to be about some
conference or seminar on lead-free.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
Fred Abse
Guest
Guest
Sun Feb 14, 2010 11:09 pm
On Wed, 10 Feb 2010 03:07:34 -0800, Jon Kirwan wrote:
Quote:
On Tue, 9 Feb 2010 17:58:30 -0800, "Bob Monsen"
rcmonsen_at_gmail.com> wrote:
"Jon Kirwan" <jonk_at_infinitefactors.org> wrote in message
news:1g34n513mhonq98prjqeggc6h15mtplfu2_at_4ax.com...
On Tue, 09 Feb 2010 17:13:50 -0800, I wrote:
BTW, do you have a link to that cool LTSpice -> ASCII program? I'd
forgotten
that you wrote it. I've been laboring over a hot 'andy's ascii' program
for
schematics that I already have in LTSpice...
Hehe. Sure.
Sorry... I didn't stick in the link. Because it isn't set
up well, right now. Let me fix that and post it up and then
I will add the link.
Jon
No hurry. Thanks, Bob Monsen
It's at:
http://www.infinitefactors.org/misc/asc.zip
It contains just two files, the EXE and a library symbol
file. Place both in some directory that is in the path. You
need to use DOS, sadly. I didn't set these up for Windows --
wanted to focus on the task, not get mired in Windows
sideshows.
If you run the program without a filename, it will say:
: asc version 1.2.1, (library C:\TOOLS\BIN\ASC.SYM found)
:
: This program converts LTSpice schematics into ASCII schematic output (or
: files.) If you specify no files at all, it accepts the LTSpice schematic
: from its standard input device. If you specify exactly one file, it dis-
: plays the ASCII schematic output to the standard output device. If you
: specify more than one file, it then generates .TXT files otherwise having
: the same name as the specified schematics.
:
: These options are supported:
: +h requests this help message, -h disables it.
: +r enables rectangle drawing, -r disables it (default is -r)
: +c enables clipboard copying, -c disables it (default is -c)
: +c<char> enables clipboard copying and prepends <char> to each line
:
: Usage: asc <options> <filename> [<filename>]...
There are some options, like the clipboard. But post
Win2000, that mechanism was broken and I haven't set up the
additional DLL I'd need to remedy it. (Something I may yet
take care of.) So under WinXP, for example, I just run it
into a file and use notepad to call it up. Something like:
ASC amplify.asc >amplify.txt
NOTEPAD amplify.txt
It gets the job done. Under Win98SE, I just use the +c
option and then paste the text, as desired, in Windows.
The library is semi-okay. There's some symbols I've probably
not yet added to it because I don't use the parts that much.
I won't mind extending it (it's not hard to do) if there is
anything you use and would like put in. I just use a text
editor and hack in the new ASCII and then save it. The
program automatically parses it every time it runs.
Jon
rcmonsen_at_gmail.com> wrote:
"Jon Kirwan" <jonk_at_infinitefactors.org> wrote in message
news:1g34n513mhonq98prjqeggc6h15mtplfu2_at_4ax.com...
On Tue, 09 Feb 2010 17:13:50 -0800, I wrote:
BTW, do you have a link to that cool LTSpice -> ASCII program? I'd
forgotten
that you wrote it. I've been laboring over a hot 'andy's ascii' program
for
schematics that I already have in LTSpice...
Hehe. Sure.
Sorry... I didn't stick in the link. Because it isn't set
up well, right now. Let me fix that and post it up and then
I will add the link.
Jon
No hurry. Thanks, Bob Monsen
It's at:
http://www.infinitefactors.org/misc/asc.zip
It contains just two files, the EXE and a library symbol
file. Place both in some directory that is in the path. You
need to use DOS, sadly. I didn't set these up for Windows --
wanted to focus on the task, not get mired in Windows
sideshows.
If you run the program without a filename, it will say:
: asc version 1.2.1, (library C:\TOOLS\BIN\ASC.SYM found)
:
: This program converts LTSpice schematics into ASCII schematic output (or
: files.) If you specify no files at all, it accepts the LTSpice schematic
: from its standard input device. If you specify exactly one file, it dis-
: plays the ASCII schematic output to the standard output device. If you
: specify more than one file, it then generates .TXT files otherwise having
: the same name as the specified schematics.
:
: These options are supported:
: +h requests this help message, -h disables it.
: +r enables rectangle drawing, -r disables it (default is -r)
: +c enables clipboard copying, -c disables it (default is -c)
: +c<char> enables clipboard copying and prepends <char> to each line
:
: Usage: asc <options> <filename> [<filename>]...
There are some options, like the clipboard. But post
Win2000, that mechanism was broken and I haven't set up the
additional DLL I'd need to remedy it. (Something I may yet
take care of.) So under WinXP, for example, I just run it
into a file and use notepad to call it up. Something like:
ASC amplify.asc >amplify.txt
NOTEPAD amplify.txt
It gets the job done. Under Win98SE, I just use the +c
option and then paste the text, as desired, in Windows.
The library is semi-okay. There's some symbols I've probably
not yet added to it because I don't use the parts that much.
I won't mind extending it (it's not hard to do) if there is
anything you use and would like put in. I just use a text
editor and hack in the new ASCII and then save it. The
program automatically parses it every time it runs.
Jon
Runs fine under dosemu here. "ASC file.asc file.txt" produces an empty file,
"ASC file asc > file.txt" (output redirect) works.
Obviously the source won't compile for linux.
It needs someone that knows far more about C (yecch!) than I do to port it.
Any offers?
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
Jon Kirwan
Guest
Guest
Mon Feb 15, 2010 1:19 am
On Sun, 14 Feb 2010 14:09:21 -0800, Fred Abse
<excretatauris_at_invalid.invalid> wrote:
Quote:
On Fri, 12 Feb 2010 11:02:34 -0800, Jon Kirwan wrote:
Almost. It's more like: I'd like to get to Fresno Flats
(aka Oakhurst, near Yosemite) from Portland
Oakhurst is too touristy/resorty these days.
I usually stop at a little diner in Coarsegold, a few miles before, when
I drive into Yosemite that way.
Almost. It's more like: I'd like to get to Fresno Flats
(aka Oakhurst, near Yosemite) from Portland
Oakhurst is too touristy/resorty these days.
I usually stop at a little diner in Coarsegold, a few miles before, when
I drive into Yosemite that way.
:)
I last visited there in the 90's. The big deal there at
Oakhurst, at the time, was "The Imagination Network." I had
many mixed feelings during that visit.
Jon
Jon Kirwan
Guest
Guest
Mon Feb 15, 2010 1:20 am
On Sun, 14 Feb 2010 14:09:23 -0800, Fred Abse
<excretatauris_at_invalid.invalid> wrote:
Quote:
On Sat, 13 Feb 2010 11:40:42 -0800, Jon Kirwan wrote:
On Sat, 13 Feb 2010 09:09:39 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
On Fri, 12 Feb 2010 19:05:46 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Fri, 12 Feb 2010 19:28:51 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
[snip]
Learn Laplace short-hand, it'll be invaluable!
...Jim Thompson
I'm gradually getting more comfortable with Laplace, as I
continue to work more problems. It is an especially nifty
way to solve some differential equations, which is what it
was designed to do, I think.
Jon
Actually, shorthand Laplace was created by none other than Oliver
Heaviside: http://en.wikipedia.org/wiki/Oliver_Heaviside
...Jim Thompson
Now that's an impressive man. Thanks! I'll dig in!
He was self-taught, too.
On Sat, 13 Feb 2010 09:09:39 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
On Fri, 12 Feb 2010 19:05:46 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Fri, 12 Feb 2010 19:28:51 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
[snip]
Learn Laplace short-hand, it'll be invaluable!
...Jim Thompson
I'm gradually getting more comfortable with Laplace, as I
continue to work more problems. It is an especially nifty
way to solve some differential equations, which is what it
was designed to do, I think.
Jon
Actually, shorthand Laplace was created by none other than Oliver
Heaviside: http://en.wikipedia.org/wiki/Oliver_Heaviside
...Jim Thompson
Now that's an impressive man. Thanks! I'll dig in!
He was self-taught, too.
Well, then. Maybe there is hope for me, too? ;)
Jon
Jon Kirwan
Guest
Guest
Tue Feb 16, 2010 8:35 am
On Sun, 14 Feb 2010 12:40:03 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
Quote:
On Sun, 14 Feb 2010 11:14:46 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Sun, 14 Feb 2010 07:16:38 -0800, John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
3. Hang a big cap across it.
Assume, just for a moment, that one wants to actually learn a
little about _designing_ the part that goes across those cap
terminals.
Jon
Just Larkin, as typical, throwing sand in the air.
Simulate it, it's crap for other than low current applications... some
_really_ bizarre behavior.
...Jim Thompson
jonk_at_infinitefactors.org> wrote:
On Sun, 14 Feb 2010 07:16:38 -0800, John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
3. Hang a big cap across it.
Assume, just for a moment, that one wants to actually learn a
little about _designing_ the part that goes across those cap
terminals.
Jon
Just Larkin, as typical, throwing sand in the air.
Simulate it, it's crap for other than low current applications... some
_really_ bizarre behavior.
...Jim Thompson
My instincts were alerted as soon as I saw it.
Jon
John Larkin
Guest
Guest
Fri Feb 19, 2010 11:47 pm
On Mon, 15 Feb 2010 23:35:21 -0800, Jon Kirwan
<jonk_at_infinitefactors.org> wrote:
Quote:
On Sun, 14 Feb 2010 12:40:03 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
On Sun, 14 Feb 2010 11:14:46 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Sun, 14 Feb 2010 07:16:38 -0800, John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
3. Hang a big cap across it.
Assume, just for a moment, that one wants to actually learn a
little about _designing_ the part that goes across those cap
terminals.
Jon
Just Larkin, as typical, throwing sand in the air.
Simulate it, it's crap for other than low current applications... some
_really_ bizarre behavior.
...Jim Thompson
My instincts were alerted as soon as I saw it.
Jon
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
On Sun, 14 Feb 2010 11:14:46 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Sun, 14 Feb 2010 07:16:38 -0800, John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
3. Hang a big cap across it.
Assume, just for a moment, that one wants to actually learn a
little about _designing_ the part that goes across those cap
terminals.
Jon
Just Larkin, as typical, throwing sand in the air.
Simulate it, it's crap for other than low current applications... some
_really_ bizarre behavior.
...Jim Thompson
My instincts were alerted as soon as I saw it.
Jon
If your intent is to keep a constant voltage across the Vbe
multiplier, you instincts should approve of the big cap.
John
Jim Thompson
Guest
Guest
Sat Feb 20, 2010 12:01 am
On Fri, 19 Feb 2010 14:47:05 -0800, John Larkin
<jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
Quote:
On Mon, 15 Feb 2010 23:35:21 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Sun, 14 Feb 2010 12:40:03 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
On Sun, 14 Feb 2010 11:14:46 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Sun, 14 Feb 2010 07:16:38 -0800, John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
3. Hang a big cap across it.
Assume, just for a moment, that one wants to actually learn a
little about _designing_ the part that goes across those cap
terminals.
Jon
Just Larkin, as typical, throwing sand in the air.
Simulate it, it's crap for other than low current applications... some
_really_ bizarre behavior.
...Jim Thompson
My instincts were alerted as soon as I saw it.
Jon
If your intent is to keep a constant voltage across the Vbe
multiplier, you instincts should approve of the big cap.
John
jonk_at_infinitefactors.org> wrote:
On Sun, 14 Feb 2010 12:40:03 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_My-Web-Site.com> wrote:
On Sun, 14 Feb 2010 11:14:46 -0800, Jon Kirwan
jonk_at_infinitefactors.org> wrote:
On Sun, 14 Feb 2010 07:16:38 -0800, John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
3. Hang a big cap across it.
Assume, just for a moment, that one wants to actually learn a
little about _designing_ the part that goes across those cap
terminals.
Jon
Just Larkin, as typical, throwing sand in the air.
Simulate it, it's crap for other than low current applications... some
_really_ bizarre behavior.
...Jim Thompson
My instincts were alerted as soon as I saw it.
Jon
If your intent is to keep a constant voltage across the Vbe
multiplier, you instincts should approve of the big cap.
John
That's not the way it "works", it snaps around (saturation of the
appropriate device) to effect current steering. Seems to work really
good with extremely high betas
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
elektroda.net NewsGroups Forum Index - Electronics Design - Maintaining a Vbe Multiplier's bias value
