audio recording on IC -help wanted

[Andras Tantos]

Thanks for the replay.

This sounds vaguely like an A/D system I built circa 1970, and the
idea was not original then. Each stage consists of effectively
two op-amps. The input is in the range -V to +V. The first op-amp
computes the absolute value of the input, range 0..V, and emits a
digital bit based on the input sign. The second op-amp subtracts
the reference voltage V/2 (resulting in +- V/2) and multiplies the
result by 2 (range -V to +V). This gets fed to the next (less
significant) stage.

This is almost what I've done only I've used the saturation of the op-amps
to calculate the transfer functions. That would automatically center the
switching point in the middle of the input range.

The result is effectively a gray code, and the use of a few
digital delay lines to match the op-amp propagation delays makes
the whole thing a pipe-line, so that very high speed samples can
be taken of the digital values.

How did you match up the digital delays with the propagation of the analog
part? I would think you need sample-and-hold circuits on the analog side to
do that.

Each module (one per bit, with the two op-amps) can be identical.
As ever, the precision is dependant on resistor matching. Care
needs to be taken with the absolute value (rectifier) circuitry.
But note that whenever it is near the decision point (0 volts) the
stage output is at an extreme, and this extreme value remains at
all further stages. Monotonicity is automatic.

Yes, monotonicity is automatic with the Gray-coded version.

I sampled the results in gray code, and digitally converted to
binary for processing. The processor was a Microdata 800, about
the size and weight of a large PC today, with 512 16 bit words of
microcode available and 4k bytes of core memory. The microcode
was installed by mounting individual diodes (or not) end-on and
soldering. The result could sample into a buffer (burst limited
by storage and core cycle time etc.) at 1/2 megasamples per second
of 8 bits. In those days this was bleeding edge technology.

So you are basically saying that the idea (though it's far from being new or
mine) is good and one can make 'bleeding edge' technology out of it. I would
think if you'd re-implement your design with current technology, you would
get much better results.

Regards,
Andras Tantos

 

[Andras Tantos]

First.

bottom post.

I intermixed my answer with the original post. Isn't that acceptable?

Its just about impossible to come about with anything new. Its *all*
been done before. What surprises me, is that you have went to a lot of
trouble in your web page. Its looks all nice and neat, yet you readily
admit that you have lack "industry experience" and lack "Spice
experience". Why then, would you suppose that you could have come up
with something that no one has looked at before?

I would suppose that if I think about something I haven't heard of before
it's new until I'm prooved to be wrong. This case I was. But, the way I
could get to this point is asking. The way of asking is to present my
question on a form that's understandable to others. Since I know nowone in
person who would be an A/D guru I had to ask it on a news-group. In such a
remote communication I think it's especially important to present your
thoughts in a nice and comprehendable way.

If I would really belive that *all* has been done before, I would stop being
an engineer and start a new life as a mail-man.

Things are the way they are today, because most things have already been
rejected, and of couse, the millions of bad ideas dont get published,
usually.

Which is by the way unfortunate, since that would prevent re-inveting bad
designs over and over again.

I would be amazed if some *really* new and usefull, electronic
topology came about today. Most "new" ideas are simply variations on an
old theme. If you think you have something new, ask yourself "why has no
one else seen this". Really try and understand *why* your idea could
have been missed, by 100'000's of other experienced designers.

I've tried and I haven't found any *fatal* problems.

Around half of the people answering to my post said that:
- It's too flaky, not precise, not worth the time to even think about it
further
The other half said:
- It's an age old design, used here, and here, and here, nothing new about
it, and in fact showed me some really nice applications.

All in all: it's not a new idea, and hasn't been missed by 100'000's of
other experienced designers. It's used in various designs all over the
place.

Regrads,
Andras Tantos

 

[Andras Tantos]

Hi!

And you would indeed be correct. That's what he shows, in disguise. All
the design is doing is successively comparing each subtracted signal
depending on the prior signal. This is what the successive approximation
converter does. The only basic difference here is that instead of doing
the subtraction with the dac treated as the reference signal and
modifying this reference to the comparator, the signal itself is
modified and compared to a fixed reference. The obvious disadvantage is
that you now need N comparators, rather then just one.

As far as I know SAC converters cannot be modifed to procude n bits at a
time. This approach can (that's what many pipeline converters do as I
learned from this thread). The SAC converters can generate only base-2
representations, while this design can be extended to generate base-5 output
for example. Not that it makes any sense to do that but shows that the two
appraches are inherently different.

For example, you can't actually use the comparator outputs to drive the
subtract amplifier. It will never swing with high enougth accuracy to
the rails, in addition, the power supply noise will kill you.

I don't think I've ever said that the circuit's I've shown would actually
work without modification under any real-world sircumstances. I've even
stated that the amplifiers considered to be ideal except that they saturate
to the rails.

What you're talking about can be easily mitigated against by generating the
reference voltage from the output of two saturated comparators.

Power supply noise problems can be reduced by limiting the output swing of
the comparator stage by some other means.

Issues:

Bandwidth. The signal goes through N stages of gain of 2.

I don't see an issue here: th design has to wait until a single state
sattles anyway, and can step to the next phase only than. It's a discrete
time ciruit (at least the version you seem to talk about) and the maximum
operating frequency is determined by the time-domain behavior of one stage.

Accuracy. Gain and offset errors multiply up through the chain. How
much?

Accuray is a big issue, yes. But as other posters pointed out the technique
*is* used in high-speed, high-precision converters so (though through some
digital post-processing) the problems can be overcome.

Power. N precision amplifiers. N precision comparators.

In the design you're talking about yes, that's an issue. However still
better than a flash converter with it's 2^N comparators. There's a design
however which uses a single comparator and a single amplifier. It's N times
slower but the power requirement is lower too.

In all of these key parameters, the technique is inherently worse, then
the conventional SAC.

Still it seems to be used in a variety of converters. I admit, the idea is
far from being original, but also far from being useless.

Regards,
Andras Tantos

 

[Jim Thompson]

On Fri, 15 Aug 2003 08:48:34 -0700, "Andras Tantos"
<andras_tantos@tantos.yahoo.com> wrote:

[snip]

Around half of the people answering to my post said that:
- It's too flaky, not precise, not worth the time to even think about it
further
The other half said:
- It's an age old design, used here, and here, and here, nothing new about
it, and in fact showed me some really nice applications.

All in all: it's not a new idea, and hasn't been missed by 100'000's of
other experienced designers. It's used in various designs all over the
place.

Regrads,
Andras Tantos

Andras, Don't let the lurkers here get under your skin. Most can't
solve a simple Algebra problem.

While "your" idea has been used before, the rail-to-rail
signal-handling that can be accomplished with current technology does
add a new dimension to the basic idea.

The limitation in this approach is resistor ratios R1:R1, R2:R2, which
is why I could only do 7-bits with discrete components.
Monolithically I think you could add maybe 3-bits.

...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 | |
| Jim-T@analog_innovations.com Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

For proper E-mail replies SWAP "-" and "_"

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

 

[Terry]

Mjolinor wrote:

Bill: If may paraphrase? "resistance change from cold to hot".
Sounds like a smart idea; using the resistivity/temperature
coefficient of copper before and immediately after power is
disconnected.

The problem with using the AC is that the heating effect will not be just
related to current in the wire.
Better to do it with a DC current source and just measure the volt drop as
you increase the current. The readings from that will give you length of
wire and therefore a fairly accurate number of turns, assuming your into
length of spirals (don't fancy working that out on a square former). Current
would need to be kept small in order to be sure that the temerature wasn't
greater where the wires were in the middle of the windings. Using DC would
also remove any skin effect too. Getting a bit hypothetical here

Good point Mjolinar; but what I was assuming was that one would
measure a typical winding, cold. i.e. at room temperature. Then
run the transformer under its AC load for a period of time.
Disconnect, and immediately measure the selected winding again,
using a DC ohmmeter or Wheatstone bridge of some sort.
The change of temperature, due to all losses, including core flux
and resistive losses, within the transformer which has been
turned into heat, could then be determined by looking at the
ratio of the two DC resistances?
Before and after.
Regardless of the gauge of wire or its resistance would not the
ratio of those two resistances be an indication of how much
hotter the wire and therefore the interior of the transformer had
become?
Must admit hadn't even thought about skin effect; wonder if that
is a concern at frequencies such as 50 or 60 cycles? (Oops sorry!
50 or 60 Hertz. Mustn't forget about him and his Hertzian Waves.)
Terry.
PS. We had some customers telephone lines at one time that we
knew were at or even beyond their design limit. They were several
miles out on very fine gauge cable. But they worked OK. Then we
had some unusually hot sunny weather and some of these customers
then complained that they couldn't get dial tone; the loop
resistance had increased due to temperature. Each night the black
pole suspended telephone cables cooled down and service returned.
I was surprised that the temperature had so much effect; it was
the only time I ever experienced that.

 

[CBFalconer]

Andras Tantos wrote:

First.

bottom post.

I intermixed my answer with the original post. Isn't that acceptable?

Of course it is. However please try to preserve attribution lines
for any material you quote.

--
Chuck F (cbfalconer@yahoo.com) (cbfalconer@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!

 

[Bill Janssen]

Terry wrote:

Mjolinor wrote:

Bill: If may paraphrase? "resistance change from cold to hot".
Sounds like a smart idea; using the resistivity/temperature
coefficient of copper before and immediately after power is
disconnected.

The problem with using the AC is that the heating effect will not be just
related to current in the wire.
Better to do it with a DC current source and just measure the volt drop as
you increase the current. The readings from that will give you length of
wire and therefore a fairly accurate number of turns, assuming your into
length of spirals (don't fancy working that out on a square former). Current
would need to be kept small in order to be sure that the temerature wasn't
greater where the wires were in the middle of the windings. Using DC would
also remove any skin effect too. Getting a bit hypothetical here

Good point Mjolinar; but what I was assuming was that one would
measure a typical winding, cold. i.e. at room temperature. Then
run the transformer under its AC load for a period of time.
Disconnect, and immediately measure the selected winding again,
using a DC ohmmeter or Wheatstone bridge of some sort.
The change of temperature, due to all losses, including core flux
and resistive losses, within the transformer which has been
turned into heat, could then be determined by looking at the
ratio of the two DC resistances?
Before and after.
Regardless of the gauge of wire or its resistance would not the
ratio of those two resistances be an indication of how much
hotter the wire and therefore the interior of the transformer had
become?

I agree that the temperature is what you have to worry about. It
doesn't matter what caused it as long as you can reduce the load and
keep the temperature under control. Measuring the resistance change
will tell you the temperature rise.

Bill K7NOM

Must admit hadn't even thought about skin effect; wonder if that
is a concern at frequencies such as 50 or 60 cycles? (Oops sorry!
50 or 60 Hertz. Mustn't forget about him and his Hertzian Waves.)
Terry.
PS. We had some customers telephone lines at one time that we
knew were at or even beyond their design limit. They were several
miles out on very fine gauge cable. But they worked OK. Then we
had some unusually hot sunny weather and some of these customers
then complained that they couldn't get dial tone; the loop
resistance had increased due to temperature. Each night the black
pole suspended telephone cables cooled down and service returned.
I was surprised that the temperature had so much effect; it was
the only time I ever experienced that.

 

[Watson A.Name - 'Watt Sun]

In article <8M6%a.521$Ng.122977@kent.svc.tds.net>, file13@hotmail.com
mentioned...

But I WANT to use AM as I plan to broadcast to an old 1933 radio I am
restoring. I would like to send old time programs to it. The radio used to
belong to my Grandparents and I want to put it on active display at the next
family reunion. I thought it would be cool to have that old timer playing
Fibber McGee & Molly...

Oh, OK, I see..

I would definitely like to find out more about this wireless oscillator -
what it is and how to use it. Any project schematics, etc.. would be greatly
appreciated. I can find NOTHING about it on internet.

Have you done a Google search for Wireless AM microphone?
I got 59 thousand hits, including this one.
http://www3.brinkster.com/Redline/living/hobbies/P-Box/28-103.asp

Thanks for your response,
~Tom


"Watson A.Name - 'Watt Sun'" <alondra101@hotmail.com> wrote in message
news:MPG.19a663562b6bf774989bc5@news.inreach.net...
In article <o_Z_a.483$Ng.86320@kent.svc.tds.net>, file13@hotmail.com
mentioned...
I found an Archer "Wireless Oscillator" in my parts box. It was sold by
Radio Shack some years back, part number 277-237. I would like a
datasheet
and schematics on it's use. I can't find anything using Google.
Hopefully,
this will be the item I need to create a wireless AM broadcaster so I
can
use it as a baby monitor or listen to my MP3's while out working in the
garden. (At least I assume that that is what this is used for.) It has 6
pins on the bottom, 3 on each end.

I would appreciate any information anyone can provide on this item.
~Tom

I suggest you don't use AM, mainly because it takes a long wire for a
decent antenna. But when you use a transmitter with a microphone for
a baby monitor, your neighbors can hear everything that goes on in the
bedroom. It's a bit less of a problem if you use an FM transmitter
with lower power that transmits on the low end of the FM band, around
88 MHz. You can limit the range to a hundred feet or so by reducing
the power. You can build a decent 2 transistor wireless FM microphone
from plans on the web for a few dollars. Or btter yet, buy a kit for
ten or fifteen dollars.

Also if you're listening to music you probably want stereo. You can
buy a Ramsey FM-10 FM Tx for $35 (see www.ramseyelectronics.com). My
Sony walkman didn't even have an AM band on it.

--

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[R. Steve Walz]

Terry wrote:

Mjolinor wrote:

-------------
Oh no, another idiot who thinks he can measure current capacity by
shorting the thing through a meter!! The danger of using a meter
without an education...
-Steve

Bit unfair, uneducated maybe but there is no evidence for the guy being an
idiot. If it concerns you that he doesn't know then educate him so that he
will know.

Agree, unfair. Probably like most people I've blown up a few
things in my day and learnt from those 'mistakes'.
---------------

Sure. Yes, I'm sorry, I was tired and forgot which group I was on.

However, people should not really buy a meter without getting educated
in Ohms Law and basic circuits at their library. Meters should carry
a warning to that effect and extensive pages first on what NOT to do,
and why!!:

You see:
--
Each year at Xmas and also Father's Day, particularly, thousands of
meters are destroyed almost immediately upon being opened, by folks
trying to measure the "resistance" of an active powered circuit, or
by trying to measure the "current" capacity of a power source that
way, which you cannot do. And many families of wives and children
who were talked into buying him this present, unknowing, are
disappointed that it never really works and there is great gnashing
of teeth that convinces one and all into the very direst technophobia,
that spread familialy thereafter, and without any good cause, lest
someone finally become educated enough to explain it and break the
"family curse". I knew one family that went through three such meters
before discovering this, thinking each time that "they weren't really
very well made, now, are they?", or that they were congentially too
stupid to ever do electronics. Their family of several teen boys had
assiduously avoided science in school because of such experiences.
And all it would have taken is a couple federally mandated pages in
a manual, and whole lives/self-esteem/careers might be saved.
-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public

 

[Kevin Aylward]

Andras Tantos wrote:

Hi!

And you would indeed be correct. That's what he shows, in disguise.
All the design is doing is successively comparing each subtracted
signal depending on the prior signal. This is what the successive
approximation converter does. The only basic difference here is that
instead of doing the subtraction with the dac treated as the
reference signal and modifying this reference to the comparator, the
signal itself is modified and compared to a fixed reference. The
obvious disadvantage is that you now need N comparators, rather then
just one.

As far as I know SAC converters cannot be modifed to procude n bits
at a time. This approach can (that's what many pipeline converters do
as I learned from this thread). The SAC converters can generate only
base-2 representations, while this design can be extended to generate
base-5 output for example. Not that it makes any sense to do that but
shows

Thats right, it doesnt, so it isnt an advantage.

that the two appraches are inherently different.
Not really. Its a variation on a theme.

For example, you can't actually use the comparator outputs to drive
the subtract amplifier. It will never swing with high enougth
accuracy to the rails, in addition, the power supply noise will kill
you.

I don't think I've ever said that the circuit's I've shown would
actually work without modification under any real-world
sircumstances. I've even stated that the amplifiers considered to be
ideal except that they saturate to the rails.

What you're talking about can be easily mitigated against by
generating the reference voltage from the output of two saturated
comparators.

That's not how to make precise reference voltages. Saturation voltages
will vary with temperature and unit to unit. You cannot reliable connect
you main reference directly to a power supply in this way. I already
explained a technique that works. I also explained that it gets
bootstrapped back to regular dac.

Power supply noise problems can be reduced by limiting the output
swing of the comparator stage by some other means.

Why? There are already tried and trusted standard techniques that
already work.

Issues:

Bandwidth. The signal goes through N stages of gain of 2.

I don't see an issue here: th design has to wait until a single state
sattles anyway, and can step to the next phase only than. It's a
discrete time ciruit (at least the version you seem to talk about)
and the maximum operating frequency is determined by the time-domain
behavior of one stage.

The final bit is fed through *all* amplifiers, therefore the small
signal frequency response of this amplifier has to be much higher then
its equivalent would have to be in a conventional ADC, where only, say
one is required.

Accuracy. Gain and offset errors multiply up through the chain. How
much?

Accuray is a big issue, yes. But as other posters pointed out the
technique *is* used in high-speed, high-precision converters so
(though through some digital post-processing) the problems can be
overcome.

But they don't use 2^n stages. A gain of 16 stages, 65000 is not really
on.

Power. N precision amplifiers. N precision comparators.

In the design you're talking about yes, that's an issue. However still
better than a flash converter with it's 2^N comparators. There's a
design however which uses a single comparator and a single amplifier.
It's N times slower but the power requirement is lower too.

In all of these key parameters, the technique is inherently worse,
then the conventional SAC.

Still it seems to be used in a variety of converters. I admit, the
idea is far from being original, but also far from being useless.

But not in the exact way you described. The approach of gaining up by
say, 16 is quite useful. The exact technique used are ones that have
realised that the continuous chain version that you present, is not
really a good way of doing an ADC. The errors mount up way to much.

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.

 

[Kevin Aylward]

CBFalconer wrote:

Andras Tantos wrote:

First.

bottom post.

I intermixed my answer with the original post. Isn't that acceptable?

Of course it is.

I dont agree. Its a right bloody pain when people post a reply at the
top.

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.

 

[Kevin Aylward]

CBFalconer wrote:

Kevin Aylward wrote:
CBFalconer wrote:
Jim Thompson wrote:
andras_tantos@tantos.yahoo.com> wrote:

... snip ...

Have you done it with discrete components? I wouldn't be
surprised than. As other's pointed out they've used similar
techniques and reaching 23 bit precision so it seems it can
be done.

Seems to me that 23 bit performance would require incredible
matching accuracy.

You don't depend on matching, just stability. You convert the
value into a time interval and measure that.

Oh?... Since the input would go through 22 gain of two stages, what
output offset would you expect from from the first stage input
offset?

What gain - what stages? The fundamental analog method of
converting a value into a time is to charge a capacitor and
discharge it with a constant current. Measure the time between
starting the discharge and reaching zero via a single comparator
gating a clock into a counter. You trade conversion time for
accuracy. The primary problems are non-linearities, capacitor
hysterisis, odd-even count effects creating differential
non-linearity, etc.

I think we are discussing different circuits. I was discussing having
the 23 stages at a gain of two per stage.

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.

 

[Sverre Holm]

The color burst frequencies are 3.579545 MHz (NTSC) and 4.433619 MHz (PAL).
Since yours is rounded to 3.58 it is most likely a ceramic resonator rather
than a crystal.


--
Sverre Holm
---------------------------------
www.qsl.net/la3za

 

[Terry]

"R. Steve Walz" wrote:

However, people should not really buy a meter without getting educated
in Ohms Law and basic circuits at their library. Meters should carry
a warning to that effect and extensive pages first on what NOT to do,
and why!!:

Each year at Xmas and also Father's Day, particularly, thousands of
meters are destroyed almost immediately upon being opened, by folks
trying to measure the "resistance" of an active powered circuit, or
by trying to measure the "current" capacity of a power source that
way, which you cannot do. And many families of wives and children
who were talked into buying him this present, unknowing, are
disappointed that it never really works and there is great gnashing
of teeth that convinces one and all into the very direst technophobia,
that spread familialy thereafter, and without any good cause, lest
someone finally become educated enough to explain it and break the
"family curse". I knew one family that went through three such meters
before discovering this, thinking each time that "they weren't really
very well made, now, are they?", or that they were congentially too
stupid to ever do electronics. Their family of several teen boys had
assiduously avoided science in school because of such experiences.
And all it would have taken is a couple federally mandated pages in
a manual, and whole lives/self-esteem/careers might be saved.
-Steve

Steve; I agree with you and that many unnecessarily go through
life with a fixed idea that anything electrical or technical is
beyond them!
But, IMHO it is also a part of a snobbishness by some people,
who, from some imagined lofty educational height have an attitude
of; "I'm too much of an intellectual (with a couple of degrees
perhaps!) and too highly educated to learn or understand
something like that". These are the people who are equally
dangerous because they will put 35 amp fuses in a blown 15 amp
circuit and when the lights come on think they've fixed it!
This business, in our societies, of looking down on persons who
understand and can 'actually do things' (and get their hands
dirty) is really annoying. Sure dreamers can dream, intellectuals
can learn academic facts; but when it comes down to the
electricity being off (Hey there's a current topic!) or fixing
the TV, the computer or the car, it's at the point that a person
who technically actually knows how it works is needed!
Some people worsen the situation by using nicknames or
abbreviations, the word "Sparky" for an electrician for example.
Possibly that's Ok within a peer group of electrically minded
equals, or in the navy perhaps, where job functions and skills
are recognized; but in society generally it is in my opinion
demeaning.
When we post in this group asking for advice/guideance we are
sort of opening up to others acknowledging we don't know and
asking for help on a particular item.
That was a gracious apology btw. Terry.
PS. Our toaster went on the fritz yesterday! Haven't a clue yet
what's wrong! First task is to drill out the screws holding the
end with the controls into the main frame of the unit, which have
rusted and won't budge!
I may be back asking for advice; stand by!

 

[Zipperhead]

In article <3F3E9D7F.50589A@nf.sympatico.ca>, tsanford@nf.sympatico.ca
says...

"R. Steve Walz" wrote:

However, people should not really buy a meter without getting educated
in Ohms Law and basic circuits at their library. Meters should carry
a warning to that effect and extensive pages first on what NOT to do,
and why!!:

Each year at Xmas and also Father's Day, particularly, thousands of
meters are destroyed almost immediately upon being opened, by folks
trying to measure the "resistance" of an active powered circuit, or
by trying to measure the "current" capacity of a power source that
way, which you cannot do. And many families of wives and children
who were talked into buying him this present, unknowing, are
disappointed that it never really works and there is great gnashing
of teeth that convinces one and all into the very direst technophobia,
that spread familialy thereafter, and without any good cause, lest
someone finally become educated enough to explain it and break the
"family curse". I knew one family that went through three such meters
before discovering this, thinking each time that "they weren't really
very well made, now, are they?", or that they were congentially too
stupid to ever do electronics. Their family of several teen boys had
assiduously avoided science in school because of such experiences.
And all it would have taken is a couple federally mandated pages in
a manual, and whole lives/self-esteem/careers might be saved.
-Steve

Steve; I agree with you and that many unnecessarily go through
life with a fixed idea that anything electrical or technical is
beyond them!
But, IMHO it is also a part of a snobbishness by some people,
who, from some imagined lofty educational height have an attitude
of; "I'm too much of an intellectual (with a couple of degrees
perhaps!) and too highly educated to learn or understand
something like that". These are the people who are equally
dangerous because they will put 35 amp fuses in a blown 15 amp
circuit and when the lights come on think they've fixed it!
This business, in our societies, of looking down on persons who
understand and can 'actually do things' (and get their hands
dirty) is really annoying. Sure dreamers can dream, intellectuals
can learn academic facts; but when it comes down to the
electricity being off (Hey there's a current topic!) or fixing
the TV, the computer or the car, it's at the point that a person
who technically actually knows how it works is needed!
Some people worsen the situation by using nicknames or
abbreviations, the word "Sparky" for an electrician for example.
Possibly that's Ok within a peer group of electrically minded
equals, or in the navy perhaps, where job functions and skills
are recognized; but in society generally it is in my opinion
demeaning.
When we post in this group asking for advice/guideance we are
sort of opening up to others acknowledging we don't know and
asking for help on a particular item.
That was a gracious apology btw. Terry.
PS. Our toaster went on the fritz yesterday! Haven't a clue yet
what's wrong! First task is to drill out the screws holding the
end with the controls into the main frame of the unit, which have
rusted and won't budge!
I may be back asking for advice; stand by!

Best advice...Unplug it first.

 

[Mjolinor]

"Terry" <tsanford@nf.sympatico.ca> wrote in message
news:3F3E9D7F.50589A@nf.sympatico.ca...

"R. Steve Walz" wrote:

However, people should not really buy a meter without getting educated
in Ohms Law and basic circuits at their library. Meters should carry
a warning to that effect and extensive pages first on what NOT to do,
and why!!:

Each year at Xmas and also Father's Day, particularly, thousands of
meters are destroyed almost immediately upon being opened, by folks
trying to measure the "resistance" of an active powered circuit, or
by trying to measure the "current" capacity of a power source that
way, which you cannot do. And many families of wives and children
who were talked into buying him this present, unknowing, are
disappointed that it never really works and there is great gnashing
of teeth that convinces one and all into the very direst technophobia,
that spread familialy thereafter, and without any good cause, lest
someone finally become educated enough to explain it and break the
"family curse". I knew one family that went through three such meters
before discovering this, thinking each time that "they weren't really
very well made, now, are they?", or that they were congentially too
stupid to ever do electronics. Their family of several teen boys had
assiduously avoided science in school because of such experiences.
And all it would have taken is a couple federally mandated pages in
a manual, and whole lives/self-esteem/careers might be saved.
-Steve

Steve; I agree with you and that many unnecessarily go through
life with a fixed idea that anything electrical or technical is
beyond them!
But, IMHO it is also a part of a snobbishness by some people,
who, from some imagined lofty educational height have an attitude
of; "I'm too much of an intellectual (with a couple of degrees
perhaps!) and too highly educated to learn or understand
something like that". These are the people who are equally
dangerous because they will put 35 amp fuses in a blown 15 amp
circuit and when the lights come on think they've fixed it!
This business, in our societies, of looking down on persons who
understand and can 'actually do things' (and get their hands
dirty) is really annoying. Sure dreamers can dream, intellectuals
can learn academic facts; but when it comes down to the
electricity being off (Hey there's a current topic!) or fixing
the TV, the computer or the car, it's at the point that a person
who technically actually knows how it works is needed!
Some people worsen the situation by using nicknames or
abbreviations, the word "Sparky" for an electrician for example.
Possibly that's Ok within a peer group of electrically minded
equals, or in the navy perhaps, where job functions and skills
are recognized; but in society generally it is in my opinion
demeaning.
When we post in this group asking for advice/guideance we are
sort of opening up to others acknowledging we don't know and
asking for help on a particular item.
That was a gracious apology btw. Terry.
PS. Our toaster went on the fritz yesterday! Haven't a clue yet
what's wrong! First task is to drill out the screws holding the
end with the controls into the main frame of the unit, which have
rusted and won't budge!
I may be back asking for advice; stand by!

Find where the fuse is, saw the head off a bolt correctly chosen for it's
similar diameter to the fuse and insert in place of fuse. If resistance of
said bolt is too high then use a copper nail instead of said bolt.

Hope this helps

 

[Sverre Holm]

"Sverre Holm" <la3za.0junk4me@qsl.net> wrote in message
news:saK%a.21492$Hb.348244@news4.e.nsc.no...

The ceramic resonators are usually cheaper than crystals, see eg.

http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=311
096&e_categoryid=28&e_pcodeid=6484> $0.45, so there is no need to try to
replace it.

with a crystal, that is ....

 

[~^Johnny^~]

On Wed, 09 Jul 2003 08:00:09 -0700, Lizard Blizzard <NOSPAM@rsccd.org>
wrote:

Aw, c'mon! If it's not an ugly brown, then it's not bakelite! (Just
kidding)

It's nearly colorless in its raw state

http://www.deco-echoes.com/bakelite.html


--
-john


~~~~~~~~
Maybe I should ask Radio Shack. They claim they've got answers;
but frankly, if Radio Shack were our provider, we'd _really_ be in
trouble now, wouldn't we?
~~~~~~~~

 

[~^Johnny^~]

On Fri, 11 Jul 2003 03:28:55 -0700, "Dr. Rev. Chuck, M.D. P.A."
<cdub@_REMOVETHIS_erols.com> wrote:

Flexibility makes it superior...
...since wood expands

So, logically speaking, nitrocellulite would be good for blow-up
dolls? ;->




--
-john


~~~~~~~~
"When the world was flat as a pancake,
Mona Lisa was happy as a clam." - John Prine
~~~~~~~~

 

[William P.N. Smith]

peterdeco1@aol.com (PeterDeco1) wrote:

Does anyone know an easy way in DOS or Windows to control the 8 data lines in a
PC parallel port? I would like to selectively turn 1 or more on and off at
will. Thank you.

Yeah, just output a byte to the parallel port address, using whatever
programming language suits you. The port address will usually be
found in your BIOS setup routines, and can be 0x0378 for LPT1.

http://www.beyondlogic.org/spp/parallel.htm
http://ee.cleversoul.com/parallel_port.html

--
William Smith wpns@compusmiths.com N1JBJ@amsat.org
ComputerSmiths Consulting, Inc. www.compusmiths.com