Driver to drive?

bill.sloman@ieee.org wrote in
news:4c636fb5-d3e3-4359-a510-57f4546647a1@b2g2000prf.googlegroups.com:

[snip]
The polynesian culture spead from Tiawan into Micronesia and
Melanesia.

http://en.wikipedia.org/wiki/Polynesian_culture

Indonesia seems to have been primarily populated by immigrants
orginating from Tiawan aat the same time, around 2000 BC (give or take
a hobbit or two, and a bunch of Australian Aborgines on their way to
Australia) where they arived about 60.000BC), but Indonesian culture
was exposed to Indian influences early on, and Muslim influences after
that and the culture is not usually described as polynesian.

http://en.wikipedia.org/wiki/History_of_Indonesia
Interesting link. THe article seems to be well-referenced, which is good.
And a lot of history *has* been clarified in the years since I
studied/read about world history.

The main idea, tho', that I was trying to get at was that there seems to
be a link, to some degree (and nope, I dunno enough to estimate that
degree) between degree of strictness of sexual mores, and exposure or
non-exposure to STDs (although syphilis seems to have developed in the New
World, teh majority of STDs arose in Eurasia). "Less strict" not, of
course, meaning that eveyone has wanton orgies. Also not meaning that
every independent culture was the same. This is admittedly general, but
epidemiology sometimes is very general, at least at the start, and history
can be nebulous if precise written records don't exist (which is most
often the case).

Anyhoo, the "nutshell version" is that a fair number of religious laws
concerneing health, cleanliness, and sex do seem to have been based upon
observatiosn of things that tended to cause illness - which is still a
very imperfect system, in that cause and effect are often different from
what they might seem to be from simple observation.

SO, variosu laws became incorporated into various religions. ANd, as
religions became power hierarchies, at least some poeple in those
hierarchies realzied that all of the laws and threats and rules coudl be
used to maintain and increase power and wealth.


I don't think too many details need to be spun out to make that general
statement (and yeah, I can get just as distracted by, and hung up on,
tangential details as anyone, and more so than most - all one can do is
try to refocus onto the central concpets).

snip

Then too, I know that my communiction is far from perfect, and I don't
mi
nd
correction, but I *do* mind egregious mistatements...

Me too.
Well, IMO that means it time for a cold brew ;)
You prefer a lager or an ale?
 
bill.sloman@ieee.org wrote in news:ed038b96-7283-4600-8daa-
155930219cad@a29g2000pra.googlegroups.com:

On Sep 24, 4:53 pm, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
John Larkin wrote:

[snip]
A FEW.  Good grief!!

Sloman lives to prove how smart he is and how dumb you are. He doesn't
have much else to do. You're rassling with pigs here. Very, very
boring pigs.

   Be careful.  That pig is wearing lipstick, and has developed a t
aste
for American blood.

Michael does like mixing his metaphors.
I don't go with all the pig talk. I don't have any personal axe to grind,
and don't get set against someone just because I might disagree with them on
one point or another if disagreement is civil. As I always say, One can't
learn anything new from people who simply agree with everything one says, and
simply do the exact same things that one does.

Anyhoo, I prefer to reserve pigs for BBQ, bacon, sausage, and other forms of
deliciousness ;)
 
John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
news:85gid45tefdkqvthelm9se7h7ee4sc2p53@4ax.com:

On Tue, 23 Sep 2008 12:54:18 +0100, Richard Swaby
reswaby@dsl.pipex.com> wrote:

On Mon, 22 Sep 2008 11:59:18 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 22 Sep 2008 09:05:32 +0100, Richard Swaby
reswaby@dsl.pipex.com> wrote:


Why the hell does the US believe that it has the right to plant
anything, anywhere in the rest of the world?

That's a subject that deserves serious consideration. If one has the
power to save lives, or to promote freedom, is it a sin of omission to
do nothing? Do we respect the national soverignty of a country ruled
by an un-elected genocidal thug?

S. Hussein was indeed a genocidal thug, but well down the list of
thugs, elected or otherwise.

The probloem is that the US is selective about where it desires to
plant things. It's usually the case that the places of strrategic
usefulness are the first to be considered..


probloem?

strrategic?



BTW the correct spelling is GOERING.

Hilarious.

John
WHat I'm wondering is, How is any of the above differnt from any other
nation? The main "difference" is that the US is a huge country and has the
resources to do what every nation (or at least, government) wants to do:
project its power. Certainly the USSR had done the same, and Russia has
shown it's own desire to return to that tradition.

Although I'm not a fan of reckless involvement in the affiars of other
nations, it's also true that a significant proportion of the complaints
against teh US are "sour grapes".

This was also IMO a valid and important question:
If one has the
power to save lives, or to promote freedom, is it a sin of omission to
do nothing? Do we respect the national soverignty of a country ruled
by an un-elected genocidal thug?
Also, even in a situation where a nation asks the US for assistance in
defending its sovereignity, the fact is that there will still be some
poeple who complain - most typically, the ones who had impinged upon said
nation's sovereignity. That's why it's important to at least *try* to
separate out the "spin".

In a way, it's similar to the saying that "Everyone in prison is
innocent" - IOW, even the guilty will try to improve their personal
situation by feigning innocence. It's human nature. And human nature
doesn't magically disappear at some specific level of organization.


As for being selective re; "planting" things and using strategic
significance as a consideration for doign so - again, in what way is that
differnt from any other nation, and for that matter, from any other
*group*? Individuals join groups becasue they see sopme benefit from doing
so, even if htat benefit is only personal enjoyment; and further up the
levels of organizational complexity, groups also act in their own self-
interest. Just look at the stupidities propagated in the name of Party
Politics.

In the end, regardless of what the US (or any other group!) does do, or
doesn't do, *someone* will kvetch about it, simply because doing something
that benefits Group/Nation X means that less (or no) benefit goes to
Group/Nation Y. ANd "benefits" can mean everything from money, to
infrastructure, to "face"/social standing, and so on.

Furtheremore, groups tend to dislike comprimise, becasue comprimise means
relinquishing some of the benefits that a group or nation deisres. And
many see that as 'loss of face", which makes negotiation a delicate
process.


So, has the US gov.t done some things thet I think are wrong? Yup. But
nobody is perfect, and there is plenty of wrongness to go around - the US
has also been described as the most generous nation in the world. So
there ya go. Yin and yang, very, very few things are are purely any one
thing; almost all are some blend of things. That includes the US.
 
Rich Grise <rich@example.net> wrote in
news:pan.2008.09.23.23.48.53.373398@example.net:

On Tue, 23 Sep 2008 20:11:22 +0000, Ben Jackson wrote:
On 2008-09-23, John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com
wrote:

You can get down to about 100 ps, 3 GHz or so, with Xacto knives and
copperclad. Kapton tape can be really helpful...

Are you crazy?? I can't afford kapton tape! ;-)

But seriously, is there a supplier for kapton that's not $25-40/roll?

It depends on how much you want:
http://www.mcmaster.com/#catalog/114/3352
(scroll down a little)

Cheers!
Rich
Holy cow, that place sells everything... I dunno qwhat the OP thinks, but
for my part, Good link, thanks!
 
Richard The Dreaded Libertarian <null@example.net> wrote:

So what we have is "Fiat money"
I used to drive one of those. IIRC the electronics were something
unspecial.


--
ha
Iraq is Arabic for Vietnam
 
John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
news:7h5ld45p8400ikdf0igoepivtu3b31vp6q@4ax.com:

On Wed, 24 Sep 2008 12:20:04 -0500, Kris Krieger <me@dowmuff.in
wrote:

John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
news:85gid45tefdkqvthelm9se7h7ee4sc2p53@4ax.com:

On Tue, 23 Sep 2008 12:54:18 +0100, Richard Swaby
reswaby@dsl.pipex.com> wrote:

On Mon, 22 Sep 2008 11:59:18 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 22 Sep 2008 09:05:32 +0100, Richard Swaby
reswaby@dsl.pipex.com> wrote:


Why the hell does the US believe that it has the right to plant
anything, anywhere in the rest of the world?

That's a subject that deserves serious consideration. If one has the
power to save lives, or to promote freedom, is it a sin of omission
to do nothing? Do we respect the national soverignty of a country
ruled by an un-elected genocidal thug?

S. Hussein was indeed a genocidal thug, but well down the list of
thugs, elected or otherwise.

The probloem is that the US is selective about where it desires to
plant things. It's usually the case that the places of strrategic
usefulness are the first to be considered..


probloem?

strrategic?


WHat I'm wondering is, How is any of the above differnt from any other
nation? The main "difference" is that the US is a huge country and has
the resources to do what every nation (or at least, government) wants to
do: project its power. Certainly the USSR had done the same, and
Russia has shown it's own desire to return to that tradition.

For the US, "projecting its power" consists of helping to establish
independent democracies that may or may not act in our immediate
interest. China "projects its power" in Tibet a lot different from the
way we have projected into Germany, Italy, or France. If Puerto Rico
or the American Virgin Islands voted for independence, they would have
it.
Even aside from motives, just purely and simply, "projection of power" -
all nations seek to do that, so as to gain a benefit, so it doesn't make a
lot of sense to condemn the US for it, but not any other nation.

THe main reason to do such a sleective condemnation is to try to tap into
"American guilt", the main problem being that that was largely a product of
the 60's and 70's, but I don't think (may be wrong, tho') that it's as
common today.

Is there a moral dilemma in the idea of forcing democracy onto people?
I mean, if they don't want it, they can always vote to become slaves
again.
That brings up the additional questions.
To what extent is a nation to gov.t, and to what extent is a nation its
poeple? If a people wishes for freedom, is it a breach of sovereignity to
remove the government, or is it a breach to not assist the people?

It can get very messy, especially when you get tyrants claiming that they
"only invaded becasue the people wanted them to". ((I'm thinking of
Russia's issuance of docuemnts to Ossetians, and then invading because
"Goergia provoked an attack". Now, maybe Goergia did poke them with a
stick so to speak, but teh imbalance of might was jsut ridiculous - there
is no way Russia could claim that Georgia was "a threat".))

Although I'm not a fan of reckless involvement in the affiars of other
nations, it's also true that a significant proportion of the complaints
against teh US are "sour grapes".


This was also IMO a valid and important question:
If one has the
power to save lives, or to promote freedom, is it a sin of omission
to do nothing? Do we respect the national soverignty of a country
ruled by an un-elected genocidal thug?

Also, even in a situation where a nation asks the US for assistance in
defending its sovereignity, the fact is that there will still be some
poeple who complain - most typically, the ones who had impinged upon
said nation's sovereignity. That's why it's important to at least *try*
to separate out the "spin".


How does one define "other nations." Is a country run by a homocidal,
unelected, murderous bunch of thugs to be respected for its soverign
rights? By UN standards, yes.
And by historical precedent. Historically, a nation was its governemnt -
and more specifically, histoprically, in monarchies, the nation was the
monarch, so evenif the entire nation were to eb destroyed, as long as teh
monarchlived, the nation still existed.

A lot of attitudes *seem* to be changing now, such that a nation is, it
seems, increasingly seen as being the people, but that's just an
impression/opinion, not something I've studied - but it could be an
interesting thing to look into. If this is, indeed, what's happening, it'd
set off some changes in international law.


I think we should keep trying to spread democracy, carefully of
course, but using force when necessary,
Well, having worked in the intelligence community, I retain many of my
attitudes re: thepotential benefits of doing things subtly ;) . Military
force is generally (but of course not always) a blunt instrument, and force
is generally met with counterforce. OTOH, if the seed of an idea can be
planted, it can be like many drops of waer eventually joining to wash away
the old regime.

and let others whine all they
like.
Agreed. Granted, it's not smart (becasue it's not useful) for the US to
rant about any other nation being "the axis of eveil" or similar things -
all taht does is piss people off; part of being an effective dimplmat is
have the ability to make one's point without resorting to overtly
provacative accusations; that being said, it's one thing to listen to the
concerns of other nations and poeples (and I'm sure you know by now that I
think diplomacy is *nearly* always the best first step),
*but it's an entirely different matter to cower in fear every time someone
launches into an accusatory rant.*

It's simply true that no matter what a nation (or group, or individual)
does or says, there will always be *someone* who reacts with resentment or
hatred or criticism. THe trick is to knw when criticism is useful (helps
the nation/group/parson) to improve, and when criticism is merely intended
to paralyze the target with guilt. Guilt itself is a choice, and differes
from both ethical responsibility, and trying to set right a past bad act.
I've found guilt to be generally unconstructive and wasteful, so I see no
use for it in national affairs- if a wrong was done, if "someone screwed
the pooch" so to speak, the only constructive thing is to spologze and try
to give recompense. Sitting around hand-wringing helps nobody.

Corrollary idea: confidence isn't being absolutely sure one is right, it's
being sure that one tries, to the best of one's ability, to do what is
right. Everyone screws up, individuals and nations alike - the
constructive thing is to try to set it right, and try to avoid making the
same mistake twice. THe problem with guilt is that, from what Iv'e seen,
it does neither. And people/gov.ts who try to instll guilt in otehrs
*want* neitehr - the goal is to paralyse, as a scorpion's venom can
paralyse. The US isn't perfect, but that's not the important point - what
matters is that America sticks to its foundational ideas of "liberty and
justice for all", and does not fall into the error of developing delusions
of empire.

Not doing so is a sin of omission and a disservice to the poor
of the world. If you have the power to improve lives, one is obliged
to do it.

John
I agree in essence, but possibly not in method ;) It's also a matter of
degree. The first duty of a governemnt is to protect its own people. It's
one thing to be compassionate; it's another thing to ravage one group of
peole so as to support another group of people. So I think that programs
(such as the Peace Corps) which try to help poeple learn how to improve
their own situation are necessary. Send food and materiel when an
emergency sitation exists, but shift quickly into teaching the poeple to
conserve an dbetter-use, etc., their local resources. SPeaking by analogy,
it's no use to send a village a stove if tehre is no gas or electricity to
run it - but it *is* useful to show them how, fo rexample, to make "solar
ovens" (simple things that can be made from any sort fo a box, and some
aluminuum foil - they work amazingly well).

All of that being said, and going back to the very top, there is nothing at
all wrong IMO with strategic thinking - if a gov.t's duty is to take care
of its citizens, it stands to reason that it cannot do so if it refusesd to
also look after the national interest.

"Stratigic thinking", it seems to me, is in essence jsut thinking ahead,
studying other nations and their peoples to try to get a sense fo how they
will react in certain situations. THe opposite of strategic thinking is
mere reactionism, always waiting for toehrs to make a move. That doesn't
work becasue sometimes, that first move will be an attack, or somthing htat
could be harmful to the nation. It's similar to an individual's
life/actions. "If I do X, what are the possible outcomes, and how will
those affect me?" WHen peole don't do this sort of analysis, they get
themselves into trouble. Same goes for nations. It is IMO a grievous
error, for a nation, group, *or* indovodual, to simply follw the assumption
that "stratigic thinking" in any way equates to "psychopathic manipulation
to the detriment of others". It's simply one tool used in self-
preservation.

Which is a whole 'nother topic but I've been yammering on for way too long
as it is <LOL!>

- Kris
 
John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
news:u26ld49c38b8j0uauliu237dueqqa3u1l6@4ax.com:

On Wed, 24 Sep 2008 12:22:44 -0500, Kris Krieger <me@dowmuff.in
wrote:

Rich Grise <rich@example.net> wrote in
news:pan.2008.09.23.23.48.53.373398@example.net:
[snip]

It depends on how much you want:
http://www.mcmaster.com/#catalog/114/3352
(scroll down a little)

Cheers!
Rich


Holy cow, that place sells everything... I dunno what the OP thinks, but
for my part, Good link, thanks!

McMaster is amazing, even for "electronic" stuff, like ceramic tubes
to wind power resistors on, or water-cooled cold plates and fittings,
or all sorts of insulating materials and goodies.

John
There is just too damn much interesting stuff in the world ;)
 
Rich Grise <rich@example.net> wrote in
news:pan.2008.09.24.17.41.04.166946@example.net:

On Wed, 24 Sep 2008 08:33:17 -0400, Arny Krueger wrote:
"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in
I expect the phone would be good enough for you ?

Depends on the phone. If I make a phone up out of a good vocal mic and
some studio monitors, it will be pretty good. These days really good
electret mics cost pennies, while good earphone elements are relatively
small and cheap compared to speakers. Most of the inherent losses in
modern phones are in the communications channel, which is wildly
bandwidth-reduced. As bandwidth becomes cheaper, there is a possibility
that good-sounding telephones will become commonplace.


If NASA can send broadcast quality video down from the shuttle or ISS,
howcome their audio still sounds like a fast food clown?

Thanks,
Rich
I wonder, tho', whether their secure/encrypted comms are as bad. I'd suspect
not - I'd imagine that a secure channel woudl be able to carry mroe data, and
therefore be "cleaner". But that's just a guess...
 
Jim Thompson <To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote in
news:bikkd4dc5cl5hg924n1nng97l6o9d2tal5@4ax.com:

On Wed, 24 Sep 2008 08:18:24 -0400, default <default@defaulter.net
wrote:

On Wed, 24 Sep 2008 11:15:34 GMT, Ross Herbert
rherber1@bigpond.net.au> wrote:

On Tue, 23 Sep 2008 15:26:42 -0400, default <default@defaulter.net
wrote:

:Does anyone have a schematic for a simple four pin HEI ignition
:module from 1970's+ ignition systems. They appear to contain an SCR
:and a pair of diodes and resistors.
:
:pickup Coil connects to two terminals and battery and induction coil
:primary the other two, mounting screw provides a ground connection.
:
:Original type mounted to the distributor plate on GM cars and others
:and was ~1/4 round shape - I want to adapt it to a motorcycle that
:has pickup coils mounted remote from the modules.



Most 70's era street bikes would run from the 12V battery supply so
you would have to buy a kit suitable for this power supply. I don't
know where you are but here is one kit
http://www.jaycar.com.au/productView.asp?ID=KC5442

The bike is 80's runs from the battery. They call it a CDI but it
isn't - runs from 12V with no HT generator coil - the module just has
4-5 components in it (potted in black goo) induction coil is ~3.5
ohms.

[snip]

Doesn't take much to make a CD Ignition, see....

http://analog-innovations.com/SED/CD-Ignition-Basic.pdf

...Jim Thompson
considering the rough automotive electrical environment and the critical
nature of the ignition system,I would BUY a kit from a racing supply auto
store.Then you don't have to worry about your car dying unexpectedly and
probably in the worst place(Murphy's Law).


If there's no HT coil used,then how does the HEI circuit develop the 30-40
KV needed to fire spark plugs?? even a CDI uses a coil,it just feeds it
with 400VDC instead of 12V.(and they tend to break down plug wires.)


--
Jim Yanik
jyanik
at
kua.net
 
"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:hVACk.1362$Ws1.1079@nlpi064.nbdc.sbc.com...
What's the jelly-bean level shifter du jour, the most popular?

Need to shift three sigs 3.3V to 5V and another three 5V to 3.3V.
Stuff us analog dudes normally don't do. The TXB0104 looks ok, so does
the 74LVC4245. But the specs for both are horrible, incomplete at
best. Not much in drive levels mentioned, or just for one direction.

The topper is a comment in the TXB spec, "OE should be tied to GND
through a pulldown resistor; the minimum value of the resistor is
determined by the current-sourcing capability of the driver" That
driver is obviously on the chip. Duh! Of course they also forgot what
to do if not needed. Pull up? Leave open? Who knows. Well, maybe they
had a kegger the night before ...

Here's what seems to qualify as a datasheet these days:
http://focus.ti.com/lit/ds/symlink/txb0104.pdf

VOH and VOL at 20uA. Microamperes! Couldn't believe it.

--
Regards, Joerg
I third the LV parts, should be fine either direction.
I vaguely remember something about Fairchild's tiny logic too.

Cheers
 
"Eeysore the Lunatic "


** Gobbledegook plus a massive non-sequitur.

Read how it works.

** Insane false logic.



Anyone that can't hear the distortion of QSC USA or MX series must have
severely damaged hearing.

** Shame how the rest of us do not have any of the defective examples
YOU
claim YOU came across that lacked forward bias current in the output
devices.

The classic QSC arrangement with grounded collectors has no qiescent
current in the output devices.


** Massive BLATANT LIE !!

You are ridiculous, stupid damn LIAR Stevenson.




....... Phil
 
"Eeysore the Lunatic "
Anyone that can't hear the distortion of QSC USA or MX series must
have
severely damaged hearing.

** Shame how the rest of us do not have any of the defective examples
YOU claim YOU came across that lacked forward bias current in the
output
devices.

The classic QSC arrangement with grounded collectors has no qiescent
current in the output devices.

** Massive BLATANT LIE !!

You are ridiculous, stupid damn LIAR Stevenson.

You have it 100% incorrect.

** Five QSC MX series amps I have here RIGHT NOW prove you WRONG.

All have about 20 mA per output BJT at idle - more when hot.

You have no proof whatever of you MAD & WRONG assertion.




...... Phil
 
"Eeysore the Lunatic "

The classic QSC arrangement with grounded collectors has no qiescent
current in the output devices.

** Massive BLATANT LIE !!

You are ridiculous, stupid damn LIAR Stevenson.




....... Phil
 
The topper is a comment in the TXB spec, "OE should be tied to GND
through a pulldown resistor; the minimum value of the resistor is
determined by the current-sourcing capability of the driver" That driver
is obviously on the chip. Duh! Of course they also forgot what to do if
not needed. Pull up? Leave open? Who knows. Well, maybe they had a
kegger the night before ...
I expect they mean the driver on the bed of nails tester setup.

It has to overpower the pulldown to turn off the tri-state drivers
in the chip so its other hand can drive the outputs of the chip.

If I didn't need that for testing, I'd use a 0R pulldown. (I use ones
that don't show up on the BOM. The board vendor gives them to
me for free.)

--
These are my opinions, not necessarily my employer's. I hate spam.
 
"Eeysore the Lunatic "
Anyone that can't hear the distortion of QSC USA or MX series must
have severely damaged hearing.

** Shame how the rest of us do not have any of the defective examples
YOU claim YOU came across that lacked forward bias current in the
output devices.

The classic QSC arrangement with grounded collectors has no qiescent
current in the output devices.

** Massive BLATANT LIE !!

You are ridiculous, stupid damn LIAR Stevenson.

You have it 100% incorrect.


** Five QSC MX series amps I have here RIGHT NOW prove you WRONG.

All have about 20 mA per output BJT at idle - more when hot.

I suppose you set them that way.

** That is they are - from the factory.

YOU are NOT in any position to know how QSC set the bias current.

YOU have no proof WHATEVER of your MAD & WRONG assertion.


Stevenson is completely INSANE with:


1. Congenital autism.

2. Massive narcissism.

3. Manic personality disorder.


He tells massive lies, thousands of them.




...... Phil
 
"Eeysore the Lunatic "
Anyone that can't hear the distortion of QSC USA or MX series
must
have severely damaged hearing.

** Shame how the rest of us do not have any of the defective
examples
YOU claim YOU came across that lacked forward bias current in the
output devices.

The classic QSC arrangement with grounded collectors has no qiescent
current in the output devices.

** Massive BLATANT LIE !!

You are ridiculous, stupid damn LIAR Stevenson.

You have it 100% incorrect.

** Five QSC MX series amps I have here RIGHT NOW prove you WRONG.

All have about 20 mA per output BJT at idle - more when hot.

You have no proof whatever of you MAD & WRONG assertion.

BORING

** What a completely insane reply.




....... Phil
 
"Eeysore the Lunatic "
The classic QSC arrangement with grounded collectors has no qiescent
current in the output devices.

** Massive BLATANT LIE !!

FACT.

** But it is not fact.

And you have no proof.

Cos it is simply not true.




....... Phil
 
"Eeysore the Lunatic "

The classic QSC arrangement with grounded collectors has no qiescent
current in the output devices.

** Massive BLATANT LIE !!

You are ridiculous, stupid damn LIAR Stevenson.

That's what you always say when you're caught out.

** This is a simple matter of fact where opinion is of no relevance.

But the congenitally mentally defective Stevenson lunatic cannot see that
crucial point.

What pathetic, sub human creature he has become.





...... Phil
 
"Don Pearce Pommy Liar Extrordaire"

Just had a look at a few QSC schematics, and it is apparent that the
output transistors are biased - not quite to zero current, but certainly a
very low current.

** Wot absolute fucking drivel.

Only seeing a REAL example of a QSC amp allows one to tell what the bias
current setting is.

As it depends critically on the adjustment of a trim pot.


This is held in position a by a long time constant RC pair,

** There is no such RC pair involved - you congenital, criminal dim wit.




...... Phil
 
"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:0cgCk.1383$YU2.167@nlpi066.nbdc.sbc.com...
Most schematics for half bridges contain two caps, like this one:

http://schmidt-walter.eit.h-da.de/smps_e/hgw_smps_e.html

What's the point? If you leave off one of the caps it works just as well.
Unless the bridge can coast which it usually can't there also won't be any
advantage in avoiding a DC run-up.
each half cycle uses one of those 2 capacitors, if there was one missing
the high frequency part of the one half of the switching current would be
taking a longer route via the electrolytic with increased impedance.
this is bad for rfi and voltage acros the fets.

you could have a smaller hf bypass cap, or a cap across the electrolytic
but then youve got 2 caps still, cheaper to have 2 the same than 1 big 1
small.

the dc offset is an issue depending on the size of the capacitors
but could be dealt with by carefull soft start.

many PC smps ive seen use 2 190v electrolytics in series with a full
bridge for 240vac operation and a voltage doubler for 110 volt operation.
although the voltage doubler isnt seen in recent ones ive looked at.
you still need hf bypass capacitors but not as big.

the most recent one ive seen has a PFC module.
ive recently built up a small collection of PSU with faulty capacitors.
I might make something interesting out of the bits one day im not sure what,
the plasma cutter I worked on once was cool.

Colin.
 

Welcome to EDABoard.com

Sponsor

Back
Top