Driver to drive?

[Andrew Holme]

Pooh Bear wrote:

How are you planning to get any realistic coupling ?

Disk read/write head fly mere microns above the platter surface. And
has been noted, provide uV of output.

Robert Baer wrote:

What may be bothersome, is the nasty question: what about
controlling the flying head height, and all of those *huge* (in
comparison) dust particles????????????
In short, haven't you scratched the sh*t out of the platter surface,
making it useless?

Yes, the head gap would have to be large enough to tolerate dust and small
enough to give good coupling. I don't know if this is possible. I was
planning to mount the head over the surface with a piece of paper between
them which I would later pull out. That is about the extent of my precision
mechanical engineering capabilities.

The magnetic disk in this old computer was not air tight -
http://www.wps.com/projects/LGP-21/Documentation/Photos/index.html

I don't know how it worked. Maybe they had soft pads between the heads and
the disk. I wonder how the disk coating differs from modern disks.

 

[Ratch]

"xray" <notreally@hotmail.invalid> wrote in message
news:83cmo0lj8dj7dral376ohs02j1i0mf1l0p@4ax.com...

On Fri, 05 Nov 2004 03:56:51 GMT, "Ratch" <Watchit@Comcast.net> wrote:

That's got to be one of the dumbest theories/explanations I ever
heard.
Let me get this straight. If I deplore stealing, cheating, bullying, or
any
other antisocial act, then I probably participate in one or more of the
above? Do you realize how you come across on your last post? Whether
you
agree with my position on the original topic or not, your explanation
really
sounds stupid. Ratch

I agree with you Ratch. These liberals can't accept the simple truth.

You are just a dangerous bigot.

Nothing wrong with being a bigot, if for/against certain groups or
principles. An example, I am against the KKK, or Communism as practiced by
the former Soviet Union.

No need to try to put a sympathetic spin

on you.

Don't even bother. Ratch
>

 

[Kevin Aylward]

Pinchy wrote:

I am building a waveformgenerator. To increase the output current I
intend to use a push pull class amplifier (NPN - PNP) in the feedback
loop of the last opamp. Hence it has to go up to 100 kHz I am looking
for the most recommended transistorset to build this stage. It should
be able to provide up to 15 V / 50 ohm (output resistance) = 300 mA in
order to get an automatic shortcut protection circuit (50 ohm acting
as a load)

The combination BC457 - BC557 (100 mA) is not suitable. The other
BD139 - BD140 (5A) is giving trouble in high frequency range as the
junctions of these are getting pretty big. The last option is a BC141
- BC161 (1A) but those are getting pretty old. Has anyone a better
idea (European parts) ?

Have a look at mosfets.

Is it usefull to bypass the collector - base
junction with Schottky diodes (as in digital 74LS, ALS, AS, ...) to
inprove the discharge speed of the collector junction ?

Not in a linear amplifier.

Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Neil]

"Rich Grise" <rich@example.net> wrote in message
newsan.2004.10.31.07.34.52.228864@example.net...

Well, I ran out of political crap to read, so went over to
alt.religion.wicca, to see if I could foment some rebellion over
there, and stumbled on this article:

508faeb7.0410300832.39b3d765@posting.google.com

That's a message-id; I don't know if you can just click it.

But it's all very logical, about the RFID debit card implants,
but it gets a little silly around the middle:
---------------------
One billion "bio-chips" are being produced by MONDEX a year. It's been in
production for at least a year. They discovered that if the chip would be
in a card, they would encounter serious problems. The chip could be cut
and information would be changed or falsified. The value could be
manipulated, stolen or lost. After you receive the card, it will expire
within one to two years. In the end, real money will be insecure in the
general market.
There is only one solution for this problem, embraced by MOTOROLA.
implanting the "bio-chip" in the right hand or the head, where it cannot
be removed. If it is removed by surgery, the small capsule will burst and
the individual would be contaminated by the Lithium and the chemical in
the micro bacteria, and the Global Positioning System (GPS) will detect if
it was removed, and will alert the authorities. Notice MONDEX means "Money
on your hand." MON = MONetary
DEX = DEXter = Right-hand side
WILL YOU TAKE IT SERIOUS ?
------------------------

It gets wackier, as it goes on about the biblical prophecies and stuff.
So, of course, it's another Sign. ;-)

Cheers!
Rich
have you looked at the Windows logo - the flying pattern one ?

there are three rows of black bits - each with 6 bits in
so three rows of 6 = 666 = Bill Gatres is really satan !
and BT (british telecom) have a piper logo, but in the right light it looks
like a snake
= symbol of devil, so bt = satan
so using phone line (devil) for modem and windows (= devil) is pretty bad
stuff.
I'll stick to linux and cable ...

 

[John Fields]

On Fri, 05 Nov 2004 03:08:51 GMT, "Ratch" <Watchit@Comcast.net> wrote:

"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:udklo0h3gh5f79bsjvfusanuphhej3cqec@4ax.com...
On Thu, 04 Nov 2004 21:59:51 GMT, "Ratch" <Watchit@Comcast.net> wrote:

You behave the way you're wired, and so do they; it's only a toss of the
chromosomes that made you straight.

No one knows for sure if chromosomes are the reason or not. That's
immaterial. The point is that some people are not normal, but they have a
obligation to society not to misbehave by exhibiting certain specific
abnormalities.

---
Like being Black?

--
John Fields

 

[Tilmann Reh]

Pinchy schrieb:

I am building a waveformgenerator. To increase the output current I
intend to use a push pull class amplifier (NPN - PNP) in the feedback
loop of the last opamp. Hence it has to go up to 100 kHz I am looking
for the most recommended transistorset to build this stage. It should
be able to provide up to 15 V / 50 ohm (output resistance) = 300 mA in
order to get an automatic shortcut protection circuit (50 ohm acting
as a load)

The combination BC547 - BC557 (100 mA) is not suitable.

Correct. Too small.

The other
BD139 - BD140 (5A) is giving trouble in high frequency range as the
junctions of these are getting pretty big.

Exactly.

The last option is a BC141
- BC161 (1A) but those are getting pretty old. Has anyone a better
idea (European parts)?

There are much more modern parts than these really old fashioned types.
In this application, you'd also have to look at the power dissipation,
since at heavy loads, one transistor may have to dissipate 15V * 300mA
= 4.5W. Too much for anything without heat sink.

Look at BD 237/238 and BD 437/438. They are pretty standard and rather
fast for their power ratings. AFAIR, especially the 437/438, which also
have good gains (which is handy if you want to drive them from the
OPamp directly).

I would *not* suggest MOSFETs due to their large G/S capacity, and since
you have to drive their gates far beyond the supply voltage if you use
them in source follower circuit.

Is it usefull to bypass the collector - base
junction with Schottky diodes (as in digital 74LS, ALS, AS, ...) to
inprove the discharge speed of the collector junction ?

No, this is only to prevent BJTs from going into saturation. In your
emitter-follower stages, this will never happen anyway.

--
Dipl.-Ing. Tilmann Reh
Autometer GmbH Siegen - Elektronik nach Maß.
http://www.autometer.de

 

[Fred Bloggs]

Frank Bemelman wrote:

"Ratch" <Watchit@Comcast.net> schreef in bericht
news:dPLid.572077$8_6.417120@attbi_s04...


It is YOU who has a problem with him. Just about every citizen of this
planet will be affected to a certain degree by what he does.


That's why it such a tragedy to see that this piece of shit is
elected for the *second* time. All Bush voters are ignorant peasants.
Fucking ignorant peasants. No fucking brains at all. Fucking
puppets on strings.

I know more than a few people who are frustrated to the point of so much
anxiety, depression, and distraction over the election and four more
years of Bush that they need therapy. I have never in my life seen this
level of discontent over a Presidential election. There is a very
serious and large scale problem here.

 

[Jim Thompson]

On 5 Nov 2004 07:08:16 -0800, jdurban@vorel.com (Product developer)
wrote:

[snip]

And what's with the gay male dialect transformation?

They tend to all sound like Carol Channing or Susan Etheridge to me!

Yeth ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Keith Williams]

In article <kiuko0l274e3quupd83224734tr4inimrj@4ax.com>,
thegreatone@example.com says...

On Thu, 4 Nov 2004 10:52:23 -0800, "Joel Kolstad"
JKolstad71HatesSpam@Yahoo.Com> wrote:

"Paul Burke" <paul@scazon.com> wrote in message
news:2uukkhF2d5084U1@uni-berlin.de...
But if it's a school exercise, use the freeware you already have- your
brain. An 8 input map is cumbersome, but not impossible, and you'll soon
realise why most people use HDLs these days.

I wasn't aware that Karnaugh maps could be (systematically) used for more
than 5 variables? Can they be? Back when I was in school we used the
'table method' (I've forgotten the real name) beyond 4.

And 4 is enough to convince people of the value of HDLs, I think!


Naaah! 8 is easy as long as you are neat with your partitioning. But
I'm going to have to learn some HDL of some flavor or another... a lot
of my recent CMOS analog chip designs require a lot of addressing,
sometimes 12-wide :-(

The subset of VHDL used in logic synthesis is pretty easy to learn.
The complete language is a bit harder. ;-)

--
Keith

 

[Keith Williams]

In article <UIKdnUGeKu0rOxfcRVn-uQ@comcast.com>,
JKolstad71HatesSpam@Yahoo.Com says...

"Active8" <reply2group@ndbbm.net> wrote in message
news:yohtgk252jwq$.dlg@news.individual.net...
That's the road I statrted on and most of what I read indicated that
Verilog was the way to go - can't remember why - yet VHDL still
lives.

Would the group opine?

Hopefully not-too-inflammatory comparisons:

Nope, fairly well balanced.

-- VHDL is somewhat more sophisticated in terms of what all the language
itself is capable of doing. But... much of that 'sophistication' is only
usable for testbenches as it isn't synthesizable.

GENERATE is pretty powerful in synthesis. Does Verilog have an analog
to GENERATE?

-- VHDL is a VERY strongly typed language. (And unlike, say, C++, 'there's
no escape' via automatic conversion). This can be a major pain to people
who like loosely or untyped languages. Verilog is better in such cases.

Worse. ;-)

-- VHDL is a lot more 'wordy.' If you like C, you'll like Verilog's syntax.
If you like Cobol, VHDL will be more to your liking.

Actually PL/I is ADA in an EE wrapper. VHDL is very PL/I like. The
SELECT/WHEN construct is very PL/I like, strong types, etc. I don't see
it as being COBOL like at all. But you're right, Verilog looks a lot
like 'C'.

-- If you learn one, you can pick up the other pretty quickly. (A book,
"HDL Chip Design" has a bunch of boilerplate design examples with VHDL and
Verilog side by side... nice.) My personal philosophy is to get the more
annoying one (VHDL) out of the way first, others might go for easier
(Verilog) first.

I learned VHDL a few years back. It took a couple of weeks to pick up
enough to do synthesis. The hardest part for me (of the synthesizable
subset) was avoiding latches. Once I got my head around that I was off
and running. I've had no need for Verilog, so...

-- VHDL in the U.S. seems more popular on the east coast. Globally, VHDL
seems much more used in Europe than the US.

Yes, and VHDL is more common in FPGA development for some reason. I
originally picked up VHDL for an FPGA design (I had a choice). I chose
well, since I'm on the east coast (our processors are designed in VHDL
and moved over to that group).

With both VHDL and Verilog, you're usually far more limited by your own
knowledge/cleverness and the limitations of the device you're targeting than
language.

One would hope the language wouldn't get in the way of one's
cleverness. However, I believe VHDL is more powerful.

--
Keith

 

[Keith Williams]

In article <O42dnThI3qKM5xfcRVn-gg@comcast.com>,
JKolstad71HatesSpam@Yahoo.Com says...

"Paul Burke" <paul@scazon.com> wrote in message
news:2uukkhF2d5084U1@uni-berlin.de...
But if it's a school exercise, use the freeware you already have- your
brain. An 8 input map is cumbersome, but not impossible, and you'll soon
realise why most people use HDLs these days.

I wasn't aware that Karnaugh maps could be (systematically) used for more
than 5 variables? Can they be? Back when I was in school we used the
'table method' (I've forgotten the real name) beyond 4.

Quine McClusky?

And 4 is enough to convince people of the value of HDLs, I think!

Four variable minimization with a K-map is trivial.

--
Keith

 

[Jim Thompson]

On Fri, 5 Nov 2004 10:20:11 -0500, Keith Williams <krw@att.bizzzz>
wrote:

[snip]

The subset of VHDL used in logic synthesis is pretty easy to learn.

[snip]

Keith, Can you recommend a text/tool for just the logic synthesis?

Thanks!

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Fred Bloggs]

Ratch wrote:
[..snip..]
YOU'RE A FUCKING LIAR!!!! You live in Minnesota- there is no way in hell
you are seeing the ostentatious behavior you claim to see. You are A
GODDAMED RELIGIOUS RIGHT NUTCASE WHO HAS BEEN SUCKERED INTO BUYING A LOT
OF JERRY FALWELL VIDEOS!- that is exactly what you are- a goddammed
deceitful religious right shithead. Here's the deal, scumbag- you people
made a BIG BIG BIG mistake electing Bush- you will now be CRUSHED!

 

[Frank Bemelman]

"Fred Bloggs" <nospam@nospam.com> schreef in bericht
news:418B98B1.1070009@nospam.com...

Frank Bemelman wrote:
"Ratch" <Watchit@Comcast.net> schreef in bericht
news:dPLid.572077$8_6.417120@attbi_s04...


It is YOU who has a problem with him. Just about every citizen of this
planet will be affected to a certain degree by what he does.


That's why it such a tragedy to see that this piece of shit is
elected for the *second* time. All Bush voters are ignorant peasants.
Fucking ignorant peasants. No fucking brains at all. Fucking
puppets on strings.


I know more than a few people who are frustrated to the point of so much
anxiety, depression, and distraction over the election and four more
years of Bush that they need therapy. I have never in my life seen this
level of discontent over a Presidential election. There is a very
serious and large scale problem here.

I wonder how Bush voters will think of their support of this piece
of shit after a year or so. They are *fully* responsible for *all*
new disasters to happen.

Had I been an American, and voted for Kerry, I'd keep the sign
in my front garden. Have it laminated perhaps, to make it last
for the next 4 years. As a continious protest.

--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

 

[Fred Bloggs]

Ratch wrote:

You should care. They are determined to confront you and force you to
take a stand on how society should feel about and tolerate them.

That statement applies more to the religious right than anyone else.
Want to talk about something that should not be tolerated? Then let's
talk about giving tax exempt status to a highly politicized religious
group- those days will come to an end soon. Most of America is fed up
with you morons and we will destroy you. You are not going to use *our*
tax dollars from the public trust to promulgate your filthy and ignorant
mindset anymore!

 

[John Fields]

On Fri, 05 Nov 2004 04:52:21 GMT, Rich Grise <rich@example.net> wrote:

Women are property, in the nazi dystopia.

And I've never understood homophobia - what the heck, for every
two guys that jump into the sack together, that's two more women
available to us straight guys!

---
Ah, yes! The orchard of indiscriminate, "available" women, from which
we can pick the peach of our choice without the slightest of
objections from the peach?

--
John Fields

 

[Keith Williams]

In article <3r6no0l6aj8hd9voksja5nckjpo0at27r0@4ax.com>,
thegreatone@example.com says...

On Fri, 5 Nov 2004 10:20:11 -0500, Keith Williams <krw@att.bizzzz
wrote:

[snip]

The subset of VHDL used in logic synthesis is pretty easy to learn.

[snip]

Keith, Can you recommend a text/tool for just the logic synthesis?

I text I used was "Essential VHDL" by Rajan
(http://www.vahana.com/vhdl.htm).
It's very well organized for the experienced logic designer who wants
to learn VHDL for synthesis. I got my copy "free[*]" from Synplicity
when I was starting out. The language reference of record is "The
Designer's Guide to VHDL", by Ashenden. You really have to know VHDL
to make use of Ashenden though.

For the tools side, I'd likely start with the free Xilinx ISE WebPACK.
Free software wasn't available when I started out ('99ish), so I used
Synplify and Xilinx Alliance. I was quite happy with Synplicity, but I
wasn't paying the bills either.

[*] "free" ended up approaching six figures.

--
Keith