Driver to drive?

[Rhyanon]

Well, through your eyes, the view is all shit, since your head is
permanently ensconed in yer ass. Typical xstain.

"John Fields" <jfields@austininstruments.com> wrote in message
news:3arsu09nfnpmko4qloe82aql1di3rgtgft@4ax.com...

On Tue, 18 Jan 2005 21:45:20 -0600, "Rhyanon" <pissoff@uberbitch.com
wrote:

You're a 'deviate' , not 'deviant'... Or at least, you fantasize you
are....

---
Well, through your eyes, a deviant must be someone who is so totally
unlike you that they _aren't_ knuckle-draggers.

--
John Fields

 

[Larry Brasfield]

"Andrew" <xxragexx@gmail.com> wrote in message news:1105721712.037700.67320@f14g2000cwb.googlegroups.com...

I found this company: www.rencousa.com. It seems that their product
RL1256-8-470 (http://www.rencousa.com/RL-1256.pdf) is the proper item
for this purpose. It doesn't list weight, but it does list size (about
2.5" cube, actually cylinder).

I am trying to confirm that adding an inductor of this type would
correct my heating problem?

I would design an LC filter instead of simply
trying to block with an inductor. You may well
find that a multi-section LC will let you get away
with less overall inductance and smaller volume.

Is it normal that I am receiving this heating issue?

I would predict it. Unless the laminations in your motor
are paper thin, the eddy current induced in them will be
hellacious at your PWM carrier frequency.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Rich Grise]

On Fri, 14 Jan 2005 11:18:17 -0800, Andrew wrote:

Jamie, would a DC voltage in this fashion prevent the motor from
delivering its maximum torque at low speeds? I think driving the motor
with essentially a lower DC voltage will also lower its possible
torque, whereas using PWM will allow full torque, even at slow speeds.
Is this accurate?

Well, in the first place, I think Jamie's description of eddy currents was
confusing.

Eddy currents are simply currents induced in the iron core, as if it's a
one-turn secondary of a transformer. They can also be induced by a moving
magnet, and that takes place in a motor in addition to the eddy currents
from the driving source - the drag from the armature is reflected as back
EMF; the power going into the core just turns into heat - this is "eddy
current loss(es)".

I think you're trying to drive the thing at way too high a frequency,
unless you put in an ultrafast catch diode. There is no antiparallel here,
unless they mean antiparallel to your switch. This is also called a
free-wheeling diode. At least that would let current continue to flow when
you switch off, rather than make that inductive spike, and try to ring.

So, try the diode - I'm not going to say whether to mount it closer to the
motor or closer to the switch - that's a religious thing, but I'm sure
there'll be a consensus of some kind - and I'd try a much lower frequency
of drive, like maybe 780 Hz. The inductive reactance of 80 uH at 7.8KHz is
3.92 ohms, more than the DC resistance of the winding. So the motor is
trying to be an antenna. ;-)

Good Luck!
Rich

 

[John Larkin]

On Thu, 20 Jan 2005 00:02:40 GMT, Rich The Philosophizer
<rtp@example.net> wrote:

Do you choose cowardice and death? Judgement? Rigidity? Order? Structure?
Death?

In this ng, I choose electronics. Really, you should try it sometime.
It might give your mind something real and useful to do.

John

 

[John Fields]

On Thu, 20 Jan 2005 08:56:21 -0600, "Rhyanon" <pissoff@uberbitch.com>
wrote:

"Aunty Kreist" <Aunty_Kreist@satanickittens.net> wrote in message
news:3595jsF4j4g2sU3@individual.net...

But, you raise a good point...when does a fetus become a human life?

Very gray area, but it would seem to me that it's when the fetus can survive
outside the womb. Given med. technology, that's around the middle of the
second trimester....

---
Then, with the inevitable advances in medical technology one would
expect, that "time of survival" will be pushed closer and closer to
the time of conception until it will be possible to bring a fertilized
egg to term out of the womb. If such is the case, then you argue that
life begins at conception but that we can't currently support it
ex-utero that early?

--
John Fields

 

[Kevin Aylward]

Kryten wrote:

"Kevin Aylward" <salesEXTRACT@anasoft.co.uk> wrote in message
news:WL8Hd.137634$C8.35238@fe3.news.blueyonder.co.uk...
Kryten wrote:
For my own part,
if I ever employed people I would give job agencies very short
shrift.

You wont get many applicants. Seriously. Agencies are the focal
point for both employer and employee. Its just the way things are
done in this market, today. Sure, on occasions you might be lucky
with a direct application, but this not normal, in my view.

Agencies seem to be another hurdle in the way then.

They can be, but on average, if you have enough experience in the right
areas, they can fall over backwards to help you.

Originally you just had to persuade an employer you was worth their
time. I don't find that too difficult.

Now you have to persuade an agent you are worth their time.

I agree that this does happen, but for me its only happened a few times.

I wish some geeks would set up an automated system that registered
people's profiles of what they can offer and correlate them with what
profiles were wanted. The system would then return a list of best
matches. Current systems seem to just look for buzzwords in CVs,

Yep.

they
do not know about skill ratings.

I get a feeling that maybe, your CV isn't putting you in the best light.
Despite some qualms expressed in this NG on my English skills, I am
actually rather good at CV's. Overall, agencies show an amazing amount
of respect for mine. If you want, you could email me yours and I could
give a second opinion on it.

my list of absolute no-nos includes married or spoken for.

The last one cuts the choice down to zero.
Females are *always* already taken.

Attractive people are taken most of the time.
There's always plenty of unattractive people who are not taken.
But they were not a choice in the first place eh?

Indeed.

You *have* to steal them off someone else.

Damn my own integrity for closing this option.

I suffer no such moral dilemma. The only issues that worry me is about
how large is the dude that I have to steal them from. That's what guilt
is all about. Acknowledgment of the consequences of ones actions, e.g.
http://www.anasoft.co.uk/replicators/emotions.html

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.

 

[Chuck Harris]

Rick Thompson wrote:

On Mon, 17 Jan 2005 11:46:53 -0500, Chuck Harris
cf-NO-SPAM-harris@erols.com> wrote:


I want to go to Debian, but I am finding it hard to get excited about
ripping my system apart and starting over...If only there was a safe
and easy way to move from RedHat to Debian...


The EDA vendors only support RedHat, so I'm sticking with it, whatever
its faults. And, finally, after all these years, we now actually have
a professional Linux distribution, that's not just put together by
hackers. But I'll tell you what really pi**es me off about it - they
now charge an *annual* subscription for it. I've been buying Windoze
distributions for 20-odd years, and I've never once had to pay an
annual subscription. I bought my current Win2K 4 years ago, and I can
still download updates and security fixes for free. What exactly makes
RedHat think that they can charge year-on-year for that? If they'd
just asked me for a one-off $200 then I'd have paid it. I'm running
FC2 now, despite having to download the whole thing.

Rick

There is no reason that you have to pay RedHat. The amount you pay is
purely for their support. You can get the entire distribution from a
number of places. One is www.tux.com

-Chuck

 

[John Woodgate]

I read in sci.electronics.design that John Fields <jfields@austininstrum
ents.com> wrote (in <1bjvu0pc3k9s8105f8k8tmd9sih0vpqsj7@4ax.com&gt about
'Peterson's Death Sentence', on Thu, 20 Jan 2005:

On Thu, 20 Jan 2005 07:57:55 GMT, Parse Tree
account@domain.extension> wrote:

Aunty Kreist wrote:

But, you raise a good point...when does a fetus become a human life?

It doesn't. It's a parasite until it leaves the host.

---
Then you're arguing that it becomes human when it leaves the host, no?

Unfortunately in some cases, leaving the host doesn't guarantee that
the parasitic behavior will end.

The parasitic stage is succeeded by the commensal stage (eating the same

food) and that, if you are lucky, is succeeded by the symbiotic stage
(living together for mutual advantage).
--
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

 

[John Fields]

On Thu, 20 Jan 2005 09:33:09 -0600, "Rhyanon" <pissoff@uberbitch.com>
wrote:

Such talk from a chreeshtun! Your gawd would damn you to hell, if it or
gawd actually existed. Lucky for you!

---
So, cRHYbaby, if God existed, _you'd_ be making rules for It?

--
John Fields

 

[John Woodgate]

I read in sci.electronics.design that David <dwmoar@findmoore.net> wrote
(in <2Kmdneg1joxuS3LcRVn-pA@megapath.net&gt about 'Peterson's Death
Sentence', on Thu, 20 Jan 2005:

If I remember the good
book says "Thou shall not kill"

So it does, but it also has lots of casualty lists.
--
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

 

[Dirk Bruere at Neopax]

John Fields wrote:

On Thu, 20 Jan 2005 16:59:09 +0000, Dirk Bruere at Neopax
dirk@neopax.com> wrote:


John Fields wrote:


---
I agree, but for it to develop it must be alive. And if it's alive...

That's not really the question.
It is 'when is it a human life'.
My view is when it exceeds the neural complexity of the smatest ape.


---
If the fertilized egg will develop into a monkey, then it's a monkey
life pushing it.

If the fertilized egg will develop into a human, then it's a human
life pushing it.

So? Potential is not actuality.
Additionally, Rights are social construct
http://www.theconsensus.org/uk/principia/judicial/index.html

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org

 

[Rich Grise]

On Tue, 18 Jan 2005 12:40:03 -0500, Mark Jones wrote:

For the hardcore experimenter, maybe the primary coil of a microwave
oven transformer (MOT) could be used as an inductor, or rewinding such
a core. But as far as I understand it, the laminated silicon-steel is
not going to work well at high frequencies, but if you have one laying
around, why not try it? It could be a big waste of time, but if you're
out of ideas and don't know what else to try...

It's too bad you can't buy ferrite in all kinds of large sizes, like
say a 4" diameter toroid. Then again, winding that behemoth would be a
bitch!

Putting an inductor in series with the motor windings sounds exactly
counter-productive to me. You've already got more inductive reactance than
DC resistance at that drive frequency - there is no real power getting to
the motor. It's trying to be an antenna.

Does the OP even have the _ability_ to even _try_ a more sane drive
frequency, like 78 Hz?

Good Luck!
Rich

 

[Spehro Pefhany]

On Thu, 20 Jan 2005 11:06:13 -0600, the renowned John Fields
<jfields@austininstruments.com> wrote:

On Thu, 20 Jan 2005 09:36:45 -0600, "Rhyanon" <pissoff@uberbitch.com
wrote:

Well, through your eyes, the view is all shit, since your head is
permanently ensconed in yer ass. Typical xstain.

---
"Ensconed"? Typical cretin.

Embedded in one of these things:

http://www.ukstudentlife.com/Britain/Food/Cooking/Scone/Scone.jpg

With (spreadable) clotted cream and jam:

http://www.ukstudentlife.com/Britain/Food/Cooking/Scone/SconeJamCream.jpg


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Aunty Kreist]

"John Fields" <jfields@austininstruments.com> wrote in message
news:lmqvu0tder92bb9bisb4ivtnlbrcglleu2@4ax.com...

On Thu, 20 Jan 2005 09:33:09 -0600, "Rhyanon" <pissoff@uberbitch.com
wrote:

Such talk from a chreeshtun! Your gawd would damn you to hell, if it or
gawd actually existed. Lucky for you!

---
So, cRHYbaby, if God existed, _you'd_ be making rules for It?

--
John Fields

Uh....aren't you the fool that just posted this in our group?

What Is God?

God is the creator of our universe.

~~~~~~~~~~~

So why are you trolling in ARW, but pretending something else when your own
"group" can see you?

 

[Joerg]

Hello Mike,

If you try to use 3.6V, the memory retention current can go up
substantially. Ran into this problem when I tried to replace two
nicads with a lithium...yes I disconnected the charge current.
Ditto when I tried to replace a rechargeable lithium backup with a
nicad. Not a problem if you use the system regularly. I needed
something that could stay dormant for a year.

That's what I was concerned about. Thanks for the info. I'll also follow
Tam's advice of measuring what the current consumption is in retention
mode, to see if NiCd is really called for here. The only downside is
that any lithiums or alkalines here in the stores cannot be soldered and
I don't trust battery holders much. So it may have to be NiCd or NiMH
just for that reason. We don't live in a metropolis, actually some folks
call it a truck stop (arghhh) and the next electronics store is an hour
away. Heck, even our little Radio Shack shut down. Sigh.

Regards, Joerg

http://www.analogconsultants.com

 

[Chris Graham]

<larwe@larwe.com> wrote in message
news:1106225883.280723.327190@c13g2000cwb.googlegroups.com...

- Is anyone aware of other products using USB in this way?
- To keep the costs down I would not want to use standard USB
connectors
internally - just headers (but still shielded cable). It this likely
to

Laptops routinely use USB as an internal interconnect, particularly for
WLAN cards and for built-in flash memory readers. They generally seem
to use 2mm pitch pin headers on the PCB and rather thin shielded cable
(similar to the type of cable used for off-the-shelf CD-ROM audio
cables).

Excellent! I assumed that might be the case, but I wasn't sure. (I'm more
of a software guy than a hardware guy)

That interconnect system would be ideal for my design.

- Chris

 

[Aunty Kreist]

"John Fields" <jfields@austininstruments.com> wrote in message
news:1bjvu0pc3k9s8105f8k8tmd9sih0vpqsj7@4ax.com...

On Thu, 20 Jan 2005 07:57:55 GMT, Parse Tree
account@domain.extension> wrote:

Aunty Kreist wrote:

But, you raise a good point...when does a fetus become a human life?

It doesn't. It's a parasite until it leaves the host.

---
Then you're arguing that it becomes human when it leaves the host, no?

Unfortunately in some cases, leaving the host doesn't guarantee that
the parasitic behavior will end.

No kidding, look at you.

Are you gonna preach about how God is the creator of the Universe again?

--
John Fields

 

[Aunty Kreist]

"Reg Edwards" <g4fgq.regp@ZZZbtinternet.com> wrote in message
news:csnt0v$d8h$1@hercules.btinternet.com...

Proof? I expect you to give cites.

======================

How can cites provide proofs?

They are merely yet more opinions, no more reliable than the person who
didn't quote one.

Often more unreliable because of being taken out of context or misquoted.

Either you accept a statement or you dont accept it.

John has this habit of informing people what they believe. It's very kind of
him.

 

[Aunty Kreist]

<uvcceet@juno.com> wrote in message
news:41efc8e5$1$woehfu$mr2ice@news.aros.net...

In <41efc801$1$woehfu$mr2ice@news.aros.net>, on 01/20/05
at 07:57 AM, uvcceet@juno.com said:

In <3595jsF4j4g2sU3@individual.net>, on 01/20/05
at 02:40 AM, "Aunty Kreist" <Aunty_Kreist@satanickittens.net> said:
If killing an unborn child is not murder, how come scotty boy is gonna
die >> for doing it?

Um....because he also killed the human the fetus was attached to.


Uh, no. The death penalty was imposed because he committed TWO murders.
If the baby inside his wife had not been killed, or was not considered to
be a living being, they jury could not have imposed the death sentence.

I wonder what the outcome of the case would have been, had Lacy not been as
far along in her pregnancy as she was.

So we can see, that it is murder to kill a baby inside the mother. When
is it a baby? Go ahead and argue that one for the rest of your life.
Logic will answer that question to anyone who really considers it.

IMO, I say the third trimester should be considered as it being a baby.
Anything before that is a glob of cells.

 

[Aunty Kreist]

"Kevin Aylward" <salesEXTRACT@anasoft.co.uk> wrote in message
news:vcQHd.180974$48.99058@fe1.news.blueyonder.co.uk...

John Fields wrote:
On Thu, 20 Jan 2005 02:40:41 -0500, "Aunty Kreist"
Aunty_Kreist@satanickittens.net> wrote:


But, you raise a good point...when does a fetus become a human life?

---
That's been argued to death, already, but in my view it's when the new
strand of DNA is assembled.

But since such a condition is not conscious, that opinion is not
scientifically justifiable. Its just a well that's what I believe for no
good reason.

Sure I agree, that deciding just when an object is first conscious is
almost impossible, but it aint when an egg is just fertilised. Its
certainly after a few months minimum though.

And, sure, current science alone, is not enough to dictate all moral
issues like this, but its a no brainer for the first months of
conception. A foetus is just an amorphous blob of chemicals, and that's
all the respect it deservers. Where is the dividing line between 9
months and 2 months? I don't know, and it doesn't matter if one wants to
restrict to prior to two months.

If you can give an actual *argument* as to why a non conscious amorphous
blob of chemicals should be given rights that a conscious blob of
chemicals is given, lets hear it. Hint: I don't take kindly to "gods
divine will" bullshit.

The only feasable thing I can come up with is that the fetus is given rights
( as in the Peterson case) when the parent's choice of whether or not to
have the child is forcibly taken away from them. If Lacy had chosen to
abort, the fetus wouldn't have any rights. Since that decision was forcibly
taken from her, the fetus qualifies as having rights.

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.