Driver to drive?

Jim Thompson <thegreatone@example.com> wrote:

The only aid we should provide should be for restoration of health and
safety.

Giving money so that resorts can be rebuilt is foolish. Let the
resort's insurance cover that. If they don't have insurance... tough!
Click to expand...
Don't worry. Knowing Asian people, they don't need our money to
rebuild the resorts. There is enough money and cheap hands around
there to do that by them selfes.
BTW: Yesterday I heard some British tourists already arrived in
Thailand for a holiday in the disaster region. The hotel owner
guaranteerd them a perfect holiday.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl
 
Active8 wrote...
Maybe you could comment on my confusion over that author saying it's
best to never convert to a voltage after the diff stage. What could
he have meant?
Click to expand...
Was that us you're referring to? Where'd we say that?


--
Thanks,
- Win
 
In article <41d3f649$0$6212$e4fe514c@news.xs4all.nl>,
Frank Bemelman <f.bemelmanq@xs4all.invalid.nl> wrote:

That's not a bad guess.. Thanks for calling the 74HCT4096
modern, makes me feel a bit better about the choice ;)
Click to expand...
You should see the date stamps on some of the 4000 CMOS
I have.

--
Tony Williams.
 
I read in sci.electronics.design that Tony Williams
<tonyw@ledelec.demon.co.uk> wrote (in <4d2569fb72tonyw@ledelec.demon.co.
uk>) about '74HCT4094', on Thu, 30 Dec 2004:
In article <41d3f649$0$6212$e4fe514c@news.xs4all.nl>,
Frank Bemelman <f.bemelmanq@xs4all.invalid.nl> wrote:

That's not a bad guess.. Thanks for calling the 74HCT4096
modern, makes me feel a bit better about the choice ;)

You should see the date stamps on some of the 4000 CMOS
I have.

MDCCCLXXXVIII?
Click to expand...
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
On Thu, 30 Dec 2004 11:37:20 -0700, Jim Thompson wrote:

On Thu, 30 Dec 2004 13:28:10 -0500, Active8 <reply2group@ndbbm.net
wrote:

On Thu, 30 Dec 2004 11:22:48 -0700, Jim Thompson wrote:

[snip]

That's where slew-rate and "power-bandwidth" come into play in OpAmp
descriptions.


So IOW pumping up the Miller cap with a stiff current is preferred
to a large voltage with small current capability?

Huh?

If there's not enough current to pump the miller cap, slew rate
Click to expand...
suffers. Could you spell it out a bit more for me please, or am I on
track? He said it's best to not convert to a voltage at all.

--
Best Regards,
Mike
 
Active8 wrote...
I found it in Hans Camenzind's 7MANUAL.PDF p. 5-11.

He goes on with the Miller effect a bit more and then he talks about
the cascode fix for the Miller cap and here's the killer:

quote
The cascode stage is only a halfhearted use of current amplification.
A better approach (at least for high-frequency performance) would be
to avoid converting to a voltage altogether. </quote

That's where I was left hanging. Maybe he just means that the large
swing across Mr. Miller kills the highs.
Click to expand...
No, it's a general comment. One can do better sticking with current-
amplification stages, if one can devise them. Once you start going
down that path, it's surprising what can be accomplished. I've only
played with this a little myself, but I have a few books, some thesis
copies and plenty of papers on the subject. "Analogue IC Design, the
Current-Mode Approach," C. Taumazou, et al, is an oft-quoted example.

Generally one eventually has to convert the signal to a voltage, but
sometimes one can continue with current all the way out of the IC.
For example, many multiplier, DA and DDS chips have current outputs.


--
Thanks,
- Win
 
I read in sci.electronics.design that Active8 <reply2group@ndbbm.net>
wrote (in <166lfs2cecurc.dlg@news.individual.net>) about 'active
collector loads (audio freq)', on Thu, 30 Dec 2004:

Yes. I know you need enough current to charge the cap. Han's (see quoted
text that was snipped) said it's best to not convert to a voltage at
all. That's what I'm confused about.
Click to expand...
Me, too. I abandoned the concept of 'converting a current to a voltage',
or vice versa, around the age of 14 and I don't really expect to back-
track now.

I think he's saying that the Miller
stage has voltage gain (non-cascode) which shows up across the cap and
therefore much current is needed to charge it up (plus, of course, the
cap value is mutiplied by the voltage gain which exacerbates the
situation.) So we'd like to keep the voltage swing low while amplifying
current?
Click to expand...
Yes, if you have a stage that has Miller capacitance, configuring it as
a current amplifier (i.e. making the load impedance low) gives you more
bandwidth. But you now need enough d.c. collector current to supply the
load impedance.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
On Thu, 30 Dec 2004 19:36:46 GMT, "Nicholas O. Lindan" <see@sig.com>
wrote:

Stick two
pieces of copper into wet ground and you will have a voltage
between them.
Click to expand...
Which one will be the positive, and which one negative?

John
 
Palmer,

OK, the cost of a 1/2" x 1/2" PCB will cost a lot.
Building a larger board and cut up into small pieces will be good.

Using a vector board with the wireing you are looking for would be the
easiest.

If I understand your circuit each board would look like this:

LED LED LED LED
o--o-|<-o--o o--o-|<-o--o o--o-|<-o--o o--o-|<-o--o
o----------o o----------o o----------o o----------o
board 1 board 2 board 3 board 4
Are the LEDs surface mount ?

This would put all the LEDs in series.
What does you power supply look like ??

PS: Got to www.digikey.com and search for "vector board".


Palmer wrote:
I'm looking at either finding or making some small PC boards. They need to
be about a 1/2 inch square. I'm wanting to mount an LED on each board but
I'll need to connect 4 LED boards in series but each board will be connected
to the next with insulated wires. I could either have a board with 4 holes
right down the middle but then I would have a long length of wire for the
negative side of the source. I was thinking of having a board with four hole
on the upper half and two on the bottom half. The bottom two holes would
just be a place for the negative wire coming in and one going out to the
next board. The two center holes on the top half would be for the LED wires
and the outer holes on either side would be for the positive coming in and
one going out to the next board.
So would it be easier to make a board as such or find something to work? I'm
new at this so I'm looking for help and direction. The only thing is that
the side the LED is mounted on to remain smooth so that means all the wires
and LED legs to be soldered on the back side.
Thanks for your comments and help.
Palmer
Click to expand...
 
You are correct on how the boards will look and be arranged. ( I could have
never drawn that on the computer)
The power will be coming from the car in which they will be installed.....
so it will be a 12 volt to 13.6 volt source. What I have seen are the LEDs
that are bought at places like Radio Shack. They look like a small dome with
a small flared bottom. What I am after is being able to drill a hole the
same size as the LED and inserting it from the back side of the hole and the
flared bottom and or the PC board stopping the LED from going any further
in. That is also why would like all the wires and LED legs to be on the
back side of the board.
I tried searching for vector board but not too sure what that is and what
I'm looking for. I've seen boards at R.S. that are just a bunch of drilled
holes that I could cut down but I wasn't sure how to apply the connections
between the holes...like a circuit board is. Like in your drawing ....the
"--" are connected via copper trace...if that is what it is called.
Again thanks for your help.

"hamilton" <hamilton@deminsional.com> wrote in message
news:41cf77a8$1_4@omega.dimensional.com...
Palmer,

OK, the cost of a 1/2" x 1/2" PCB will cost a lot.
Building a larger board and cut up into small pieces will be good.

Using a vector board with the wireing you are looking for would be the
easiest.

If I understand your circuit each board would look like this:

LED LED LED LED
o--o-|<-o--o o--o-|<-o--o o--o-|<-o--o o--o-|<-o--o
o----------o o----------o o----------o o----------o
board 1 board 2 board 3 board 4
Are the LEDs surface mount ?

This would put all the LEDs in series.
What does you power supply look like ??

PS: Got to www.digikey.com and search for "vector board".


Palmer wrote:
I'm looking at either finding or making some small PC boards. They need
to be about a 1/2 inch square. I'm wanting to mount an LED on each board
but I'll need to connect 4 LED boards in series but each board will be
connected to the next with insulated wires. I could either have a board
with 4 holes right down the middle but then I would have a long length of
wire for the negative side of the source. I was thinking of having a
board with four hole on the upper half and two on the bottom half. The
bottom two holes would just be a place for the negative wire coming in
and one going out to the next board. The two center holes on the top half
would be for the LED wires and the outer holes on either side would be
for the positive coming in and one going out to the next board.
So would it be easier to make a board as such or find something to work?
I'm new at this so I'm looking for help and direction. The only thing is
that the side the LED is mounted on to remain smooth so that means all
the wires and LED legs to be soldered on the back side.
Thanks for your comments and help.
Palmer
Click to expand...
 
On Sun, 26 Dec 2004 12:10:06 -0800, John Larkin wrote:

On Sun, 26 Dec 2004 19:14:16 GMT, nico@puntnl.niks (Nico Coesel)
wrote:

John Larkin <john@spamless.usa> wrote:


If it's only 2 layers and has no ground plane, and power and ground
are just skinny routed traces, I'd be astonished if it actually
worked.

You'll be amazed what can be accomplished by using only 2 layers if
the bypass capacitors are well placed and the power is well routed. I
actually have a 2 layer 386SX 33MHz motherboard which was available
commercially (not my design, just something that ended up in a box
with PC stuff).


Yeah, but it takes some luck, and maybe a few iterations, especially
in a mixed-signal design with fast parts, like this is. And if it's
autorouted, a lot of the traces will make the grand tour of the board.
It might work, or it might be a nightmare.

Moderm PCs have a lot of layers... anybody know how many?
Click to expand...
The processor I've most recently worked on has 10 layers of metal (with
more than a few power and grounds). ;-) I hightly doubt that well give up
any of 'em soon.

--
Keith
 
On Thu, 30 Dec 2004 14:59:27 -0700, Jim Thompson wrote:

On Thu, 30 Dec 2004 16:47:02 -0500, Active8 <reply2group@ndbbm.net
wrote:

[snip]

Also, IIRC, Win and Jim agreed that lower diff stage gm can increase
slew rate - is that what was said? How can that be if the diff stage
current is lower (lower gm)?

No, not quite. Lower gm allows a smaller pole-splitting capacitor,
so, for the same available current, slew rate increases.
Click to expand...
I see it, but how do I lower gm without lowering available current,
if for a bjt

gm = 40.Ic ?

--
Best Regards,
Mike
 
On Thu, 30 Dec 2004 16:46:20 -0700, Jim Thompson wrote:

<snip>
I see it, but how do I lower gm without lowering available current,
if for a bjt

gm = 40.Ic ?

Pad resistors in emitters ?:)

Cute. You're serious? Hard to tell when you use the positive
Click to expand...
emoticon more often than not. And is the question mark indicating a
question or is indicative of your hair style :)


We are talking the same toplogy, right? The emitter current
source/sink (the available current) provides emitter current equally
for both sides of the diff pair when in balance... The same current
that would go through those resistors... So to lower the gm I have
to lower the current available.

--
Best Regards,
Mike
 
John Woodgate wrote:
Rich The Philosophizer wrote:

Kevin claims he has proof that http://www.godchannel.com wasn't
channeled from God.

Is the proof entirely general? I mean, does it apply to all 27765489
gods? Or only a few?
Click to expand...
27765489 gods?? There are only 27765488 gods!!! DIE, HERETIC!!!!!
^ ^
 
Joe wrote:
Yes, war-for-oil is much better than oil-for-food.
Click to expand...
Hey Joe!

That is a poem that reply!

Should be framed, replicated, put in every truly
american home.

The truth man!

The truth.
 
Gactimus wrote:

http://news.scotsman.com/latest.cfm?id=3944374

United States President George Bush was tonight accused of trying to
undermine the United Nations by setting up a rival coalition to
coordinate relief following the Asian tsunami disaster.
Click to expand...
Damned if we do and damned if we don't. If the U.S. government did not
make money available it is "stingy". If it does, then it is undermining
the U.N.. We can't win for losing.

Bob Kolker
 
Jim Thompson wrote:
... nothing but a bunch of scummy bastards thieving
over the spoils.

...Jim Thompson
Click to expand...
You're talking about Bush and the neo-cons there.
 
Fred Bloggs wrote:
The numbers say it all.
Click to expand...
Americans are more valuable than wogs.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
 
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