Driver to drive?

[CK@@L]

I hope the below is useful for you folks to help....

17.2 IDE Seagate HDD
Win98SE running on PC-500 P3 128Mb ram on Intel VC820 chipset board
Tried to transfer data into a new drive using Seagate disc wizard program
when it got zapped within 2min (guess it was not 100% reformatted)
Drive still has some residue data file000 , mostly FrontPage which I do not
use (clusters recovered from MS scandisk)
My 5year old hdd had abt 16Gb of data before & had 9Kb of bad sectors
(that's why changing to new one)
I have taken out the hdd & use a new one now but not sure the Scandisk have
wiped the old files/ bad sectors


"Mhound" <argyle1nospam@hotmail.com> wrote in message
news:mvUmd.252488$nl.44216@pd7tw3no...

You will have to give a lot more information...
What hard drive do you have
What operating system
What happened ? accidental erasure ?
Hard Drive failure ?
How much data.
Any thing else you can think of
Do not copy anything on to this drive, or you will overwrite information !

M

 

[Robert Baer]

Leon Heller wrote:

"Robert Baer" <robertbaer@earthlink.net> wrote in message
news:419B16E8.3A91B1C5@earthlink.net...
Reg Edwards wrote:

New program SELFRES2.exe
--------------------------------------
Input data :

Length and diameter of solenoid.
Number of turns.
Conductor diameter
Length of line in which the coil is inserted.
Testing frequency.

Output data :

Coil self-capacitance.
Coil self-resonant frequency.
Choke impedance vs frequency.
Insertion loss of choke in dB.

Performance is based on a choke wound with coaxial cable of the same type
as
the transmission transmission line in which it is inserted. Conductor
diameter is that of the coax outer. It behaves a single wire. Coax
inner
diameter is of no consequence.

Choke insertion loss is a measure of the reduction in power radiated from
the feedline. But, despite the attention it attracts, actual power
radiated
from the feedline WITH the choke will never be known because the power
radiated WITHOUT the choke is indeterminate.

SELFRES2 is 51 K-bytes. Download from website below in a few seconds. It
is
not zipped-up and will run immediately.
----
...........................................................
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
...........................................................

Incomplete.
No core specifications and/or no way to change core specs.
I dare say, that with a given totoid size, that one would see
differences uing wood, air, plastic, iron, pyrolytic graphite, between
the various ferrites (over frequency), etc.
Then change the dimensions for more fun and games (big as a pea or
small as a truck?).

A coax choke doesn't have a core! It's just coax cable wound into a coil
shape. Very convenient, as one can often just coil up the coax feeder where
it connects to the antenna.

Leon

I am used to seeing coax cable being used to make RF and pulse
transformers; the coax is wound on a ferrite core (which is necessary)
and the shield is the primary and the center conductor is the secondary
(or vice-versa depending on the needs). And turn ratios are not limited
to 1:1 either.
Now these chokes, using coax cables, are they 2-terminal or
4-terminal?
If 2-teminal, then the use of coax cable is a rather expensive
proposition.
And in both cases, the inclusion of a core material, whether the coil
has a solenoid structure or a toroidial structure, would make a large
difference in inductance and could add useful loss factors above certain
frequencies.
Even with air core (no, not the flyboys), the dimensions make a big
difference.

Sounds like the drawing board needs to be used some more.

 

[ChrisGibboGibson]

Rich Grise wrote:

On Wed, 17 Nov 2004 22:42:01 +0000, ChrisGibboGibson wrote:

Rich Grise wrote:

On Wed, 17 Nov 2004 01:10:05 +0000, ChrisGibboGibson wrote:

No. Not safely. That's why the spec exists in the first place. You
pillock.


This is misleading and rude.


No it isn't.

You _can_ safely exceed the breakdown voltage of a junction, IF
you ensure that the power dissipated in the device is less than
some given specified value, which you can find in the data sheet.


If you measure the voltage across the diode you will find it hasn't
actually
exceeded the breakdown voltage.

If you don't believe this, then please go look up "zener diode"
and "reverse breakdown" in any reasonably qualified electronics
reference.


I think perhaps you'd better do that.

Put 20 volts across a 10 volt zener, not via a resitor. I want you to
"measure*
20 volts across the zener. See what happens. This is rather basic.


Oh - I see your point - you can't get a voltage _over_ the breakdown
voltage, because that's where the zener knee is.

Exactly.

OK, fair enough. But just doing that doesn't automatically destroy
the diode, as long as you limit the current and are happy with
the resulting (possibly poorly) regulated voltage.

But limiting the current will simply prevent the voltage from going above the
breakdown voltage. So you still can't do it!

So I was wrong, but only to the extent that I misunderstood
what you were trying to say.

But it was still rude to call the guy names. >:-[

But it was a pleasant name. With a smiley so it's ok.

Gibbo

 

[ChrisGibboGibson]

Winfield Hill wrote:

[snip]

Rich, you were correct, and was Chris wrong. You certainly can go
well above the specified breakdown voltage. That's because this is
simply the manufacturer's value, above which at some point you will
encounter real breakdown. And when you do finally have breakdown,
you'll find it's like a stiff zener plus an internal resistance, so
the measured breakdown voltage depends on the current. Furthermore
breakdown voltage increases as the junction heats up (AoE fig 6.20).
Bottom line, the voltage will be above the manufacturer's breakdown
spec. Moreover, no damage will occur if breakdown energy (current
* voltage * time) is low enough to keep junction heating below safe
maximums. As detailed with transient thermal dissipation curves
(i.e. (maximum surge-power) and thermal mass calculations. That's
safe. It's basically what you said. Avalanche can be your friend.
You can that to the bank. :&gt Yep, that's my educated opinion.

The original question was "Can the PIV of a diode be "safely" exceeded?"

And the answer is no, it can't be "safely" exceeded.

There are certain circumstances where, with a particular diode, the PIV rating
can be exceeded but only because that particular diode has an actual breakdown
voltage somewhat higher than the PIV rating.

If you exceed the breakdown voltage you will, almost certainly, destoy the
diode. If you limit the current, then you will not be exceeding the breakdown
voltage *across the diode*.

Gibbo

 

[Rene Tschaggelar]

John Fields wrote:

On Tue, 16 Nov 2004 06:27:57 +0000, Guy Macon
http://www.guymacon.com> wrote:


John Fields <jfields@austininstruments.com> wrote...


I've designed multi-kilowatt underwater projectors driven by a 50 ohm
source by doing what was necessary to get a conjugate match to the
ceramic.

Are they, by any chance, used in an application where marine mammals
are exposed to the acoustic output?


---
The short answer, since they all swam in the same ocean in which the
device was used, is "yes".

However, I have no data relating to whether they would have been
adversely affected by it, if that's what you're getting at.

There is a controversial system spanning the pacific where the
US believes to be able to detect stray submarines with incredibly loud
pulses. It operates from LA and someplace in Australia plus others.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

 

[Terry Pinnell]

"CK@@L" <kanglck1@singnet.com.sg> wrote:

Hi, I was asked to referred to this newsgroup for some expert advise, can
anyone help pls!

"CK@@L" wrote in message :-

I have accidentally wipe out my years of data in my HDD & now is zero

files. Can anyone advise how to retrieve the lost data & can recommend

where to go to restore the data. Thanks.

Where are you? In the UK I reckon I'd call one of the many services,
such as
http://www.dataclinic.co.uk/?source=GoogleAdwords
http://www.ontrack.co.uk/promotions/google_0704.asp?psearch=google

If you're in Singapore (just my guess based on seeing 'singnet' in
your header), then here are 3 I found with google
http://crash.to/datarecovery
Micro Innovation, at CentrePoint
Mr.Yew 012-396-3232

Alternatively there's a ton of software if you want to tackle it
yourself. For example, Repoman looks good:
http://www.zdnetindia.com/downloads/info/10155920.html
-------
From the developer: "RepoMan is a menu driven DOS program allowing
technicians and end users to conduct their own data recovery. RepoMan
is a 'hybrid', 'real time' data recovery solution; Most data recovery
software either aims to extract data from a damaged unit without
repairing the logical disk structures as the partition tables, where
others concentrate fixing logical damage. RepoMan 2.5 is designed to
do both. RepoMan rebuilds partition tables from scratch
(FAT/FAT32/NTFS), repairs corrupt FAT and FAT32 partitions, or allows
you to mount corrupt FAT and FAT32 volumes and extract files from
them.
"Also includes: RepoMan Image Rescue is a Windows program that allows
media files to be recovered from so called memory cards. Memory cards
are often used by digital camera's. DataBack 1.1 Lite. DataBack is a
Windows program allowing deleted files to be recovered, even if the
recycle bin was emptied. DataBack supports FAT and FAT32 type
partitions as well as diskettes."

Note:The DataBack Lite demo is a 3-use trial. RepoMan Image Rescue is
not included with the demo. RepoMan is in 'read-only' mode.
-------

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Winfield Hill]

Joel Kolstad wrote...

Winfield Hill wrote ...

I should add that most of the HV meter probes one finds around a typical
workbench are *not* suitable for pulse measurements. I'm referring to
the DC probes with the 6" proboscis tip and a double banana plug on the
other end of the cable, for use with a multimeter. These employ a long
high-voltage resistor and do not have proper internal shielding, so they
will give you an erroneous (e.g., too high) result for short pulses.

...due to capacitive coupling 'around' the resistor? Or is there some
other mechanism at work?

Capacitive coupling to the 1/1000 side from all over. The portion from
the resistor's body could be compensated (to first order only) with
capacitance on the output side, but additional exposure from E fields
from wiring near the measured voltage create large indeterminate errors
that cannot be compensated. It's a mess and cannot work as delivered.


--
Thanks,
- Win

 

[Jim Douglas]

http:\\www.google.com --> recover data from drive. A few years back it was
a couple hundred $$ to recover the disk, well worth it!


"CK@@L" <kanglck1@singnet.com.sg> wrote in message
news:cngvp0$eva$1@reader01.singnet.com.sg...

Hi, I was asked to referred to this newsgroup for some expert advise, can
anyone help pls!

"CK@@L" wrote in message :-

I have accidentally wipe out my years of data in my HDD & now is zero

files. Can anyone advise how to retrieve the lost data & can recommend

where to go to restore the data. Thanks.

 

[Quack]

But it is doable, so I've heard, as long as it hasn't actually
been overwritten.

I read somewhere that some really special (probably government) labs
have the ability to even recover data, even after random overwrites of
the entire disc.

By using some kind of 'super microscope', each bit of data can be
viewed at a massive magnification, and its magnetic resting place on
the disc depends on what it was before the previous write. Or
something along those lines.
Apparently each 'bit' has a discernable history (maybe only 1 write
deep though).

anyway, would probably cost a few hundred thousand dollars to perform


Alex.

 

[Product developer]

"CK@@L" <kanglck1@singnet.com.sg> wrote in message news:<cngvp0$eva$1@reader01.singnet.com.sg>...

Hi, I was asked to referred to this newsgroup for some expert advise, can
anyone help pls!

"CK@@L" wrote in message :-

I have accidentally wipe out my years of data in my HDD & now is zero

files. Can anyone advise how to retrieve the lost data & can recommend

where to go to restore the data. Thanks.

Be very careful if you elect to use a do it yourself utility like
"recover my files" etc. There are many half-baked recovery programs
out there that will only recover partial or fragmented files and upon
recovery conclusion can make more of a mess than you started with.

If the data is valuable send the drive to a service.

 

[Dbowey]

Mark posted:

(big snip)

Steve wrote:
"We cannot, through ANY act of supposed "will", change what we believe, not
even the smallest thing. But other things from within and from without will
change us, even if against our "will"."

Then Mark wrote:
" This is either your opinion or a lie. Please present objectively verifiable
evidence so I may discern which."

__

What Steve says is clearly true. Read it again without your mind made up. You
will find you agree even though it is against your will.

Don

 

[deaks]

"CK@@L" <kanglck1@singnet.com.sg> wrote in message news:<cngvp0$eva$1@reader01.singnet.com.sg>...

Hi, I was asked to referred to this newsgroup for some expert advise, can
anyone help pls!

"CK@@L" wrote in message :-

I have accidentally wipe out my years of data in my HDD & now is zero

files. Can anyone advise how to retrieve the lost data & can recommend

where to go to restore the data. Thanks.

The best software i have come across for reading a hard drive is
'getdataback'
There is a version for ntfs and another for fat.
Any use of the disk will without doubt reduce the amount of info you
can retrieve. However, I foud that it retrieved info I thought was
already lost in previous formats.
Good luck!
deaks

 

[Frank Birbacher]

Hi!

Rich Grise wrote:

Just for the sake of pedantry, it's a comparator that compares magnitudes.

(i.e., the value of the positive whole number represented by the bits in
binary, AKA base-two.)

Well, some of the chips are named "equality comparator" and some
are "magnitude comparator", but I just cannot see the difference.
To me they just compare two n-bit numbers/inputs/.. for equality.

Yes, I've finally bothered to look at some of the links I've so graciously
provided for you, and, by golly, you're absolutely right. 7485? I _know_
that there's a chip out there somewhere that has that, but how about some
sideways thinking: If the timebase counter is monotonic[0] which I presume
it is, since you haven't said otherwise, and the point "zero" is well-
defined, then you could infer "less than" from "hasn't reached equal-to
yet."

Well, I want to do pwm with it:

8bit data LED
[8bit reg]-------------\ "is less" output |
[8bit less cmp]-------------------[FET]
[8bit counter]---------/ |
GND

So while the counter holds a value less than the reg, the LED is
on, and while the counter holds a value greater or equal to reg,
the LED is off. With more effort I could do it with an equality
comparator and a flipflop, by resetting the flipflop if the
counter is zero, and setting it when the counter reaches reg. But
that has a disadvantage: With the solutino above I can achive
more noise in the output by connecting the data lines of the
counter in reverse order to the comparator (As suggested by Ken
Smith in the thread "how to control current digitally?" started
on 10/24).

I'll tell you, when I'm done.


Actually, I know I, and think that probably others, actually do, kidding
aside, appreciate it when folks actually come back to tell results of
their research.

Ok.

Frank

 

[Rich Grise]

On Thu, 18 Nov 2004 09:22:24 +0000, ChrisGibboGibson wrote:

Winfield Hill wrote:

[snip]

Rich, you were correct, and was Chris wrong. You certainly can go
well above the specified breakdown voltage. That's because this is
simply the manufacturer's value, above which at some point you will
encounter real breakdown. And when you do finally have breakdown,
you'll find it's like a stiff zener plus an internal resistance, so
the measured breakdown voltage depends on the current. Furthermore
breakdown voltage increases as the junction heats up (AoE fig 6.20).
Bottom line, the voltage will be above the manufacturer's breakdown
spec. Moreover, no damage will occur if breakdown energy (current
* voltage * time) is low enough to keep junction heating below safe
maximums. As detailed with transient thermal dissipation curves
(i.e. (maximum surge-power) and thermal mass calculations. That's
safe. It's basically what you said. Avalanche can be your friend.
You can that to the bank. :&gt Yep, that's my educated opinion.


The original question was "Can the PIV of a diode be "safely" exceeded?"

If you want to get really pissy-techy, I could always counter-claim
that "The PIV is a rating from the data sheet. Diodes are routinely
rated less than what they'll take in practice. So a diode with
a PIV of 1000V could theoretically go as high as 1100, maybe 1200V
before it actually breaks down, exceeding the PIV all the way."

But you didn't want to get _that_ (p)icky, did you?

I didn't think so.

Thanks,
Rich

 

[Rich The Philosophizer]

On Thu, 18 Nov 2004 17:01:18 +0000, Dbowey wrote:

Mark posted:

(big snip)

Steve wrote:
"We cannot, through ANY act of supposed "will", change what we believe, not
even the smallest thing. But other things from within and from without will
change us, even if against our "will"."

Then Mark wrote:
" This is either your opinion or a lie. Please present objectively verifiable
evidence so I may discern which."

__

What Steve says is clearly true. Read it again without your mind made up. You
will find you agree even though it is against your will.

Feh. You people don't even know what "will" _is._

Changing your beliefs is as easy as changing your mind. But when you
get punched in the gut, there's not much belief involved - you _will_
know you're punched. ;-)

Good Luck!

;^j
Rich

 

[Rich Grise]

On Sat, 13 Nov 2004 08:23:33 -0800, Winfield Hill wrote:

Winfield Hill wrote...

I'm going to sign off now, get breakfast, and shovel the snow. :&gt
Then I'll poke around and find an old post of mine to edit and put
up as my entry for Numan's 150A linear regulator.

I came across this old beast, wihch uses 75 pass transistors, for
amusement. It's a 1.8V 250A quad Pentium linear regulator. :&gt

Winfield Hill wrote,

no-spam@baggypants.com wrote...
cant find any quad-pentium mobo for my cars computer, so i,m
designing my own but the 1.8V power supply is hard- it needs up
to 250 amps from the engines 42V batt. i NEED a seatwarmer to
anybody has aome thoughts?

Hi baggypants, you have two interesting problems, which I can solve with
one circuit. You should use what we call a linear regulator, because a
sensitive computer motherboard needs an electrically-quiet environment.

[Absolutely Gorgeous, albeit Mind-Boggling, Circuit Snipped - Thanks!]

Circuit Notes: Twenty-eight places 2n5686 or equivalent NPN TO-3, mounted
on a pair of isolated leaf-blower heat sinks, with thin heat-sink grease,
and no insulating pads; each heat sink dissipates about 4kW at 250A> and
5kW under 300A short circuit condition. Each resistor bank dissipates up
to 0.7kW.

"Seat Warmer???!?!?!?" Try "Whole-Carcass Toaster Oven!" ;-)

Cheers!
Rich

 

[Rich The Philosophizer]

On Sun, 14 Nov 2004 10:05:53 -0600, John Fields wrote:

On Sun, 14 Nov 2004 09:22:17 GMT, Rich The Philosophizer
null@example.net> wrote:

Well, the most recent "information" I've heard about Fallujah was that
there was surprisingly little resistance encountered, and they're about
to declare it "secure."

What would it happen if the "terrorists" just laid low for a few
months, acting like it's normal friendly occupation forces, serving
drinks in the off-base clubs and all that "entertain the GIs" crap,
and when it's loaded with GIs, and it's so secure that troops are
going there for R&R from Afghanistan and Pakistan, and when it gets
loaded to capacity, blow up the whole town?

---
Then the whole town and everybody in it would be killed.

Yes, we established that in the previous paragraph.

Then what?

Thanks,
Rich

 

[Dbowey]

Rich (the loopy) philosopher posted:

(snip)

<< Feh. You people don't even know what "will" _is._

Changing your beliefs is as easy as changing your mind. But when you
get punched in the gut, there's not much belief involved - you _will_
know you're punched. ;-)
What does that mean? I think you had one too many with lunch. ;-) right
back....

 

[Zuzej Maaya]

On Thu, 18 Nov 2004 21:49:21 +0000, Dbowey wrote:

Rich (the loopy) philosopher posted:

(snip)

Feh. You people don't even know what "will" _is._

Changing your beliefs is as easy as changing your mind. But when you
get punched in the gut, there's not much belief involved - you _will_
know you're punched. ;-)


What does that mean? I think you had one too many with lunch. ;-) right
back....

sounds like hes saying the difference betewwn beliefeing what you hear
or believeing what you feell. this rich hpilosofizes allot abouut feelings,
and imkinda a feeling kinda guy, but dont tell nobody, ok? cuz the babes
like 'em ruff andtuff.

TNX,
Zuzej Maaya

 

[Guy Macon]

Kim wrote:

I don't have enough experience, or common sense to complete this project, so
I need some help, and finally realised that I will have to pay for someone
else to do it for me. I'll list the basic requirements, but Email me for
specifics for the job, or if you are willing to take it on, along with a
price quote. As well, if you think that the project is impossible, then also
let me know. There is no real time constraints, so if you only do it in
your spare time, and it takes a long time to do, that will also be ok.

I require a circuit that will:
-display in 5 second increments, every time a switch is closed, on a basic 1
line lcd display (it wont actually be a 5 second increment in reality, this
is count, not a time, but the count has to be in 5 second increments)
-add up these 5 second increments, until they "rollover" into minutes, hours
days months, years.
-be battery operated (If it could be run for long periods of time on button
cells, or equivalent batteries, then that would be great, if not... a few
AAA cells, or a 9v batteries size is ok).
-the display only needs to turn on for a minute after the switch is closed,
if this will help extend the battery life.
-and be as small, and thin as possible (space is at a ABSOLUTE premium)
-the unit can be hard-wired or wire-wrapped, it doesn't need to look
"finished", or be done on a pcb.
-as a matter of fact, if I can be supplied with a chip, display, and
schematic, I can wire it myself.

IF there is a way to do this with a small, single chip
microcontroller....fairly easily, please let me know.
If you require more specifics, please email me with any questions you may
have. This is NOT going into mass production, so I WILL NOT be making
buckets of cash with this. This is just a item for a specific piece of
machinery at my work, and will DEFINATLY be a one-off.

This is a perfect match for a BasicX controller, and I think that
you can do it all yourself (possibly with a few questions posted
here) using that technology.

Check out the BasicX BX-24 and associated display here:
http://www.basicx.com/Products/BX-24/bx24main.htm
http://www.basicx.com/Products/SLCD/2X16LCDoverview.htm
http://www.basicx.com

If someone points you to a Basic Stamp by Parallax, don't listen.
You need the real-time clock and crystal timebase of the BasicX,
and the Basic Stamp uses a ceramic resonator that isn't accurate
enough for your purpose.

If you really want someone to do this for you, I can squeeze you in
(see http://www.guymacon.com), but I really think that you can do
this yourself.