Driver to drive?

[krw]

In article <nkvjf4trobgl87otc4ocooacallg3mob86@4ax.com>,
UltimatePatriot@thebestcountry.org says...

On Fri, 17 Oct 2008 07:17:29 -0700 (PDT), mpm <mpmillard@aol.com> wrote:

On Oct 17, 9:12?am, MooseFET <kensm...@rahul.net> wrote:

While we are at it where is the FCC in the constitution

It's the brainchild of the Communications Act of 1934, which replaced
the then Federal Radio Commission.

At least, that what is says on the back of my licenses...

Just curious?
Do you have a 'beef' with the FCC?
Maybe we could trade horror stories. :-0

$5 fee EACH MONTH for EACH hard line phone in the country amounts to
several hundred million dollars a month. Likely for all the air phones
too.

Their operating costs are not several hundred million dollars a month.

Phone lines are free? You really do have a warped sense of
economics.

--
Keith

 

[Eeyore]

mrdarrett@gmail.com wrote:

Eeyore wrote:
mrdarr...@gmail.com wrote:

Douglas Self didn't care for mosfet amps too much. That's why I posed
my original question.

I don't care for Doug Self too much come to that. Long story.

You don't care for Doug Self? Then why, in the Class A thread, did
you point the OP to Doug Self's website???

Because whatever I may feel about him, the info is good.

Graham

 

[krw]

In article <4eedade5-4182-4958-83f4-
ffb8f12c991c@v13g2000pro.googlegroups.com>, kensmith@rahul.net
says...

On Oct 17, 5:51 pm, krw <k...@att.bizzzzzzzzzz> wrote:
In article <26b1f724-0411-4976-b8d4-6e8ab7be5a61
@w39g2000prb.googlegroups.com>, kensm...@rahul.net says...



On Oct 16, 8:05 pm, krw <k...@att.bizzzzzzzzzz> wrote:
In article <48F7ED96.BD3C7...@hovnanian.com>, p...@hovnanian.com
says...

Jim Yanik wrote:

"Paul Hovnanian P.E." <p...@hovnanian.com> wrote in
news:48F54EF8.A413A4B@hovnanian.com:

Kris Krieger wrote:

"Paul Hovnanian P.E." <p...@hovnanian.com> wrote in
news:48F4E02F.18E854FA@hovnanian.com:

Kris Krieger wrote:

"B. Peg" <bent_pe...@worldnet.att.net> wrote in
news:QL0Jk.3229$x%.1609@nlpi070.nbdc.sbc.com:

His holding back on his records is disturbing and I don't think
all the fuss is over grades.

The lawyer (Berg) who is pursuing him not being a naturalized
U.S. citizen, hence disqualifying him from the POTUS spot, may
be on to something and it may be apparent on his school records.

B~

Since when do school records contain citizenship info?

And since when does an individual born within the USA need to
become a naturalized citizen?

Well, as I wrote to JF:

When did that start, is what I meant (I guess I could have phrased it
better).  I just hadn't heard of that.

I don't know. But some people just bite on any rumor, no matter how
improbable.

I seriously doubt any candidate would have made it through a DoJ
background check with such a hole in their records.

since when does DoJ vet potential Presidential candidates?

Background checks. Try running for or being appointed to any federal
(and many state) offices without one.

Where is a background check mentioned in the Constitution?

While we are at it where is the FCC in the constitution?

The FCC clearly falls under the IC clause.

That would mean that the FCC would only be allowed to regulate radio
waves that cross state lines and wired communications that run across
state lines.

Yes. Radio waves tend to do that.

Either the FCC is operating beyond their allowed powers
or the IC clause includes things that don't go across state lines.

If a radio wave cannot cross state lines it isn't regulated
(shielded inside an enclosure, for instance). Once you let it free
it's going to cross state lines, all on its own. ;-)

--
Keith

 

[MooseFET]

On Oct 19, 4:50 pm, Jasen Betts <ja...@xnet.co.nz> wrote:

On 2008-10-18, MooseFET <kensm...@rahul.net> wrote:

The loss of confidence in the election system puts the nation at
risk. If the losing party feels strongly enough that the will of the
people was thwarted and enough people agree, you have the makings of a
failed state.

This is why the voting system needs to be secure, understandable and
spread out over very many people. Many small errors leading to some
noise or bias in the result will be better tolerated than a few big
errors or even suspicion of error or intent.

what's wrong with pen and paper, tick a box.

There really is nothing wrong with a all paper system. The disabled
would need help to use it but this is also true of all of the
mechanical and electronic ones.

To run a paper system you need more people but since it is the future
of the nation I see no problem there. It would also take longer to
get the results to the central location but there is a long time
between the election and the actual taking of the oath for exactly
this reason.

put 20 markers (with anchoring string pre-attached) in the top of each
box of 5000 voting forms.

Yes and make a special version of the purple ink for the fingers.
While you are at it make the ink in the markers a special ink too.

We could get "Sharpie" or someone to make up special markers. The
plastic body of the marker could be some weird combination of colors
that are only used for elections.

With special ink for the finger marks and the marker and special
markers, owning any of them could be made against the law and declared
to be evidence of the intent to commit election fraud. This would
make things a lot more secure about extra votes being added.

To prevent ballot boxes from being tampered with or taken away, people
watching would work nicely. As many as 10 people picked at random
like jury duty may be needed. The ballot boxes could be shipped back
to where they are counted on the transit system's buses. On election
day, extra buses run while the polls are open to take people to vote.
When the polls close some of those same buses take the boxes to be
counted. In farming areas, the school buses and the like would be
called into service.

 

[Eeyore]

Kevin Aylward wrote:

A "good" audio amp, imo, will have at most, only one trim pot, and this is
to set the output bias.

I was delighted with the consistency of my D Series of bipolar amps. No trim
pots at all. Designed out in the design process. In fact the entire amp had not
one trimpot. That means faster production and final test plus a cost reduction.

Graham

 

[Jim Thompson]

On Sun, 19 Oct 2008 11:44:03 -0500, krw <krw@att.bizzzzzzzzzz> wrote:

In article <ng0kf4lvprc3j1n07s3q0sbj9l7s50r2t2@4ax.com>,
UltimatePatriot@thebestcountry.org says...
On Sat, 18 Oct 2008 07:55:24 -0700 (PDT), MooseFET <kensmith@rahul.net
wrote:

On Oct 17, 7:17 am, mpm <mpmill...@aol.com> wrote:
On Oct 17, 9:12 am, MooseFET <kensm...@rahul.net> wrote:

While we are at it where is the FCC in the constitution

It's the brainchild of the Communications Act of 1934, which replaced
the then Federal Radio Commission.

At least, that what is says on the back of my licenses...

Just curious?
Do you have a 'beef' with the FCC?
Maybe we could trade horror stories.  :-0

I have no beef. I am just pointing out a problem. Some would say:
The constitution is silent on the subject of radio waves so that must
obviously be a power left to the states. Others would say: Radio
signals cross state lines so they are interstate commerce.


Radio signals are not commerce at all.

Really? Commercial time is free? Broadcasters do it for the
jollies?

After the election there will be NO talk radio... that ought to make
the little bastard Dems happy :-(

But I'll have the last laugh... wonder how high the price of gasoline
will rise ?

What will be even more fun will be the price of heating oil in
Massachusetts [smirk]

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Liberals are so cute.  Dumb as a box of rocks, but cute.

 

[Eeyore]

John Fields wrote:

Eeyore wrote:
John Fields wrote:

As it is, all you seem to be intent on doing is promoting yourself as
some sort of audio Guru who claims to greatness but who refuses to
submit proof.

Suit yourself. Everything I claim does what it does. All you have to do is
buy one and test it yourself.

---
Why buy when I can build?
---

It would cost you LOTS more to build one yourself and you wouldn't replicate the
pcb pattern which can be critical for top performance.

Graham

 

[MooseFET]

On Oct 19, 8:29 am, "langw...@fonz.dk" <langw...@fonz.dk> wrote:

On 19 Okt., 00:41, MooseFET <kensm...@rahul.net> wrote:

On Oct 18, 1:11 pm, "RST Engineering \(jw\)" <j...@rstengineering.com
wrote:

THere are two ways to do reverse protection. One is, as you noted, a series
diode in line with the supply. THe other one is a diode to ground that
blows the fuse. That one costs you nothing in headroom. It is a bit more
inconvenient, but if the hamhand wiring it up blows the fuse, then hamhand
gets to fix it.

I prefer the series diode method because the equipment is used in a
environment where an external fuse holder is asking for trouble. The
ham-handed guy never admits to the error. The word that comes back is
"it was DOA".

polyfuse maybe?

I think you could get close to what you want with an ADSL driver maybe
two in parallel, but most only go as high as 24V supply, same with
the
few opamps that are r-r and high enough current

It comes down to a question of the amount of heat to get rid of
driving the package size. If someone made a TO-220-N packaged power
op-amp with the specs, it could work but a SO-8 package just can't get
rid of the heat so you need many of them.

The Polyfuses can't be trusted. If you take one, a very stiff 35V
supply, a hefty relay and a strong slow signal generator, you can
kludge together a tester for them. Testing them this way at about one
trip per every few minutes, very few last more than a few hours before
they no longer meet their specs. Some fail after only a few cycles.
They can take repeated cycles at low currents but at high currents,
they get damaged.

-Lasse

 

[krw]

In article <rO6dnU7YCYF3_2fVnZ2dnUVZ_gadnZ2d@earthlink.com>,
mike.terrell@earthlink.net says...

krw wrote:

In article <4JydnVDiZMudVmXVnZ2dnUVZ_vudnZ2d@earthlink.com>,
mike.terrell@earthlink.net says...

John Larkin wrote:

On Tue, 14 Oct 2008 21:52:51 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:


John Larkin wrote:

I need a new USB camera cable for home, because the cats ate the last
one. So I went to the Rite-Aid drug store to see if they had one. No,
but they had a Vivitar digital camera, with cable, with bonus LED
key-ring light, with AAA battery and software, for $9.99. It takes
movies and does webcam, too.


Dollar Tree has the cables around here for $1.

Radio Shack has them here for $22.


Radio Shack's new motto? You have money? We have ideas on how to rip
you off!

As bad as RadioShaft is, it's no match for BustBuy and
CircuitShitty. RS never got out of the minor leagues.

A new hhgregg store just opened across town. They want over $200 for
some video cables.

They also hire vultures as sales people. I didn't include them
because I didn't know how big they'd gotten (first ran into them in
Ohio last year). OTOH, I bought my 42" Plasma TV from them because
they beat BustBuy (on sale, though none in stock) on a price match.
They were disappointed that I bought no cables, though not because
they didn't try.

http://www.hhgregg.com/ProductDetail.asp?SID=n&ProductID=19654&BrandStore=All
is $249.99 for a 40 FOOT hdmi CABLE.

But is it gold plated?

35' HDMI cable; $65

https://www.cablewholesale.com/specs/hdmi-cable/hdmi-01135.htm

--
Keith

 

[MooseFET]

On Oct 19, 9:59 am, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
wrote:

MooseFET wrote:
On Oct 18, 1:11 pm, "RST Engineering \(jw\)" <j...@rstengineering.com
wrote:
THere are two ways to do reverse protection. One is, as you noted, a series
diode in line with the supply. THe other one is a diode to ground that
blows the fuse. That one costs you nothing in headroom. It is a bit more
inconvenient, but if the hamhand wiring it up blows the fuse, then hamhand
gets to fix it.

I prefer the series diode method because the equipment is used in a
environment where an external fuse holder is asking for trouble. The
ham-handed guy never admits to the error. The word that comes back is
"it was DOA".

Have you never heard of inserting power diodes in inverse parallel with the output
devices ?

Yes.

The output of the amplifier is less often exposed to the ham-handed
than the input power. This same system also has an RF oscillator, an
output-signal amplifier and a bunch of other electronics. The one big
rectifier is protecting all of that against backwards power.

We want to add some more components to another part of the design. We
want the new PCB to be the same size as the old so something has to
get smaller. I can also move some parts onto the back of the PCB
currently we only have 1206s back there.

 

[Eeyore]

John Fields wrote:

Eeyore wrote:
John Fields wrote:
Eeyore wrote:
Kevin Aylward wrote:
Eeyore wrote:
Damon Hill wrote:

But at such low distortion levels, is it worth it?

Everything is worth it.

?

If only for the technical challenge and personal reward.

---
Really?

You make those claims and then, conveniently, fail to back them up
because of the restrictions you claim are placed upon you by copyright
and contractual limitations.

Fine. Pay me and I'll do something similar for you and you'll own the
copyright.

---
Pay you???

Thanks, that's the best laugh I've had all day!

Well, let's face it, you don't have the necessary skills.

Graham

 

[Dirk Bruere at NeoPax]

krw wrote:

In article <6luv1iFe90meU1@mid.individual.net>,
dirk.bruere@gmail.com says...
JeffM wrote:
The official launch is Oct 13, but you can download it now.
http://distribution.openoffice.org/mirrors/#extmirrors

For those of you struggling with folks sending you crap
saved in M$'s new lock-in/lockout file formats, here's the good news:

-- New stuff --
Can open files from M$Office 2007, Office 2008 for OS X
(.docx, .xlsx, .pptx, etc.)

1024 Columns Per Sheet (was 256)
-- Excel 2007 will do 16,384 ! (x 1,048,576 !)

Support for (ISO standard) OpenDocument Format 1.2 (ODF)

Runs under OS X without X11

...and OOo has had some VBA support for a while now.

More details:
http://www.openoffice.org/dev_docs/features/3.0/
Just downloaded it.
I cannot understand why anyone would buy MS products when this is free.

Because, unless you are doing trivial work, it isn't compatible with
the other 99.9% who would rather pay for software.

Well, a number of governments think different.
And the way I heard it, it is MS who has been forced into compatibility
with ODF

--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff

 

[MooseFET]

On Oct 19, 10:01 am, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
wrote:

MooseFET wrote:
On Oct 18, 12:56 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com
wrote:
MooseFET wrote:
Eeyore wrote:
MooseFET wrote:
Eeyore wrote:
MooseFET wrote:
Not really "audio"

Specs:

Supply voltage: 0 - 35V
Load resistance: 10-20 Ohms
Frequency: 1KHz to 25KHz
Output swing: Rail-to-rail
Distortion: Products above 30KHz 60dB down

LM3886 should do it.

If it was rail to rail it would be the ideal part. That one spec is
the one that is killing me.

Almost NO power amp swings rail to rail. Ignore it.

I can just stay with the existing circuit which does go rail-to-rail.

Collectors or drains to output ? 'Almost' rail to rail.

On the bipolar one it is the collectors that are the output. On one
of the MOSFET ones, the sources are the output. It looks a little
like this:

Vcc
!
\
/ !!--Vcc
\ -!!-
+----!!---Vout ! !!-!s N-CHANNEL
! ! !
--!+\ ! !
! >----------------+ +------Vout
------------Mirror line here -----------------------

The supply voltage of the op-amp swings up and down as the output
does. The reduced voltage on the op-amp limits the swing of the G-S
voltage.

Is there anything stopping you increasing the supply voltage a tiny bit or using
high side drive ?

The supply voltage is "cast in paper". I don't understand your "high
side drive" comment.

A little background:

This is an existing product that we would like to improve by changing
part of the circuit. That part will need to get bigger. We want the
new PCB to fit exactly onto the existing assembly so the total size
can't grow. If I can shrink some other part, we can do it easily.

The specs for the existing product seem to have become sort of an
"industry standard" in that the requests for bids come with those
numbers on them. Some of our customers basically copy our spec sheet
and then send it out for bids. In some cases, the copying action
involves translation between languages and long delays for approval.

 

[Eeyore]

John Fields wrote:

Eeyore wrote:

You're a babe in arms in this discipline.

---
You wish.

I cut my teeth on audio and was designing and building bridge amplifiers
in the early '60's, even before RCA came out with them, as I recall.

The world has moved on John.

Graham

 

[MooseFET]

On Oct 19, 10:25 am, ggher...@gmail.com wrote:

RST Engineering (jw) wrote:
THere are two ways to do reverse protection. One is, as you noted, a series
diode in line with the supply. THe other one is a diode to ground that
blows the fuse. That one costs you nothing in headroom. It is a bit more
inconvenient, but if the hamhand wiring it up blows the fuse, then hamhand

I think I've seen that before. Does it depend on the diode failing as
a short?

If you use a huge enough diode it survives the fuse blowing so long as
the fuse is the one you supplied and isn't wrapped in foil. The fuse
wrapped in foil is a real case. The across the lines diode failed
shorted, the fuse holder welded its self and all the ground wires blew
open. It took a while to fix the unit but fix it we did.

 

[Eeyore]

MooseFET wrote:

Eeyore wrote:
MooseFET wrote:
On Oct 18, 1:11 pm, "RST Engineering \(jw\)" <j...@rstengineering.com
wrote:
THere are two ways to do reverse protection. One is, as you noted, a series
diode in line with the supply. THe other one is a diode to ground that
blows the fuse. That one costs you nothing in headroom. It is a bit more
inconvenient, but if the hamhand wiring it up blows the fuse, then hamhand
gets to fix it.

I prefer the series diode method because the equipment is used in a
environment where an external fuse holder is asking for trouble. The
ham-handed guy never admits to the error. The word that comes back is
"it was DOA".

Have you never heard of inserting power diodes in inverse parallel with the output
devices ?

Yes.

The output of the amplifier is less often exposed to the ham-handed
than the input power. This same system also has an RF oscillator, an
output-signal amplifier and a bunch of other electronics. The one big
rectifier is protecting all of that against backwards power.

We want to add some more components to another part of the design. We
want the new PCB to be the same size as the old so something has to
get smaller. I can also move some parts onto the back of the PCB
currently we only have 1206s back there.

You've got a tough challenge there. Using both sides sounds smart.

Graham

 

[Eeyore]

MooseFET wrote:

Eeyore wrote:

Is there anything stopping you increasing the supply voltage a tiny bit or using
high side drive ?

The supply voltage is "cast in paper". I don't understand your "high
side drive" comment.

That would only be of relevance to source follower output designs. Well, actually,
I've used with bipolars too but that's another story.

A little background:

This is an existing product that we would like to improve by changing
part of the circuit. That part will need to get bigger. We want the
new PCB to fit exactly onto the existing assembly so the total size
can't grow. If I can shrink some other part, we can do it easily.

I see your problem. Can you go to Class D ?

Do you have a full schematic of the existing design ?

Graham

 

[Eeyore]

MooseFET wrote:

If you use a huge enough diode it survives the fuse blowing so long as
the fuse is the one you supplied and isn't wrapped in foil.

Why do people do that ? Must be good for 100A peaks.

Graham

 

[Eeyore]

a7yvm109gf5d1@netzero.com wrote:

On Oct 13, 2:39 am, Eeyore <rabbitsfriendsandrelati...@hotmail.com
wrote:
"No more Ferraris: we are the masters now"

This is a momentous day in the history of capitalism, as governments the
world over prepare to take huge stakes in the hitherto independent banks
that have driven the West's economic success.

For believers in free markets, the bailout is nothing short of a
calamity. But when the only alternative appears to be the meltdown of
our entire financial system, economic survival is all that matters.


So, a global meltdown is your definition of success of independent
banks?

Uh ?

Graham

 

[John Larkin]

On Sun, 19 Oct 2008 10:07:41 GMT, "Kevin Aylward"
<kaExtractThis@kevinaylward.co.uk> wrote:

John Larkin wrote:
On Fri, 17 Oct 2008 18:06:47 -0700 (PDT), Allen Bong


Hi Graham,

Is this a good audio amp using HexFET for a starter?

http://users.otenet.gr/~athsam/power_amplifier_45w_hexfet_eng.htm

The driver and output stages use IRF9540 and IRF540 and the opamp is
LF411. THD is 0.2%. Power supply is +/- 30V.

I like it because the PCB design is included.

Allen


Not too bad,

Yes. "not too bad" in the strict sense of the phrase. That is, it is a bad
design, but not so bad as to be totally unusable. However, this does depend
on the definition of "good" somewhat. Assuming we give meaning to the term
"average", then this design can not in any reasonable way be classed as a
"good" or even an average design". It is a quick knock up, that serious
audio designers don't even give a second look to, well except when
commenting on how bad it is.

except for the biasing. Iq could have been set by a
pot+resistor from IC1 pin 4 to 7, and the DC offset trim should be
into the opamp, not fighting it.

A "good" audio amp, imo, will have at most, only one trim pot, and this is
to set the output bias.


The biasing/crossover of this type of circuit is potentially perfect,
in that both stages run at some idle current and signal makes one pick
up,

For very high speed, audiophile performance, this output device
configuration is very poor. The gates of the transistors are connected via
two much speed lag. This usually results in very, large shot through
currents when hit by 100n pulses.

but leaves the opposite side idling. As opposed to a lot of
circuits where conduction on one side actively shuts off the other.

DC bias on the output fets depends on their thresholds, not so good;
closing local loops on the fets (with more opamps) would be better.

Oh...a sure-fire recipe for disaster, if done correctly...It will generate
additional de-stabilising poles. That particular technique can be useful for
reducing LF. distortion, but it does it at the expense of BW, i.e. higher HF
distortion. I would be surprised if this "design" could stand having its HF
IMD compromised any further.

My NMR and MRI gradient amps use a similar topology... the driver
opamp has its supply rails cascoded to make signal currents, and the
upper and lower power stages are active current mirrors. I'd argue
that adding an opamp per power fet makes things faster, stability
better, and compensation simpler, since the gate/Miller capacitance
disappears... each fet now looks like a very fast, pF input
capacitance, DC-perfect device, and essentially disappears from the
overall loop dynamics. Now just pile on as many opamp+fet pairs as you
need. DC balance and current sharing become as good as the opamp
offset voltages, microvolts if you like, so fet gate threshold
variations and transfer curves don't matter any more. So use very
small source resistors and cut losses.

My amps often work in pulse mode, when doing chemical NMR. They settle
to PPMs of the target value (which is current, since we're driving
gradient coils) in 10's of microseconds. My customers use nuclear
spins to resolve magnetic field imperfections to better than a part in
1e9, which sorta blows away Audio Precision gear. I got nailed once on
60 Hz hum that was about -120 dB down, a bit below 1 PPM. Part of the
fix was to reverse the primary of one of my power transformers, so
some magnetic fields cancelled instead of adding. The rest was to use
one phenolic spacer instead of aluminum.

The amp referenced above has "circuit" problems, but the topology is
really interesting.

John