W
william coleman
Guest
Kruminilius W. wrote:
A
Alan Adrian
Guest
"Kruminilius W." <anonymous@a.com> wrote in message
news:C3Uue.71$vX1.16@newsreader1.level3.com...
Al...
news:C3Uue.71$vX1.16@newsreader1.level3.com...
50 cent electric gear motor with a knob on the end?
Al...
R
Rich Grise
Guest
On Thu, 23 Jun 2005 17:35:41 -0700, detroitstylz wrote:
or modified square wave output, and your meter is possibly reading
"average" instead of RMS; AFAIK the "average" to "RMS" ratio is different
for a square wave than a sine wave.
For a quick test, plug in an ordinary lamp. If the output is really that
low, the lamp will be way dim.
Good Luck!
Rich
First, try to find a "true RMS" meter. Your inverter probably has a square
or modified square wave output, and your meter is possibly reading
"average" instead of RMS; AFAIK the "average" to "RMS" ratio is different
for a square wave than a sine wave.
For a quick test, plug in an ordinary lamp. If the output is really that
low, the lamp will be way dim.
Good Luck!
Rich
J
Jonathan Kirwan
Guest
On 24 Jun 2005 12:00:45 -0700, "Chris" <cfoley1064@yahoo.com> wrote:
No Windows stuff. So you have to use a command line to work it.
Other than that, it's easy.
The source code all fits into a single source file, so it's
uncomplicated to compile and link. It is designed for Microsoft's VC
1.52C, however. In any case, I don't recommend messing with that part
of it, unless you really *do* have some time to play.
However, you can add new symbols easily. Just edit the ASC.SYM file
in an ASCII editor. You can define each orientation for parts, but
you don't have to define all the orientations if you don't care about
unusual cases. It uses what it can find, doesn't use what it can't.
I've already added the more obvious discrete parts but it does NOT
handle LTSpice's .ASY files that define complex part shapes and pins
as I just haven't yet struggled to deal with those and the WINDOW
definitions in the .ASC files, yet. So some things work well, but
where it doesn't know what to do it just leaves that part blank.
Someday, I'll work harder at examining the ramifications of dealing
with the .ASY files in a general and useful way and then it be a lot
more broadly useful.
I *do* like the ability to work with simple, discrete schematics in
LTSpice, check them out, etc., and then spit them out in ASCII for the
..basics group, though. Seems a good fit and it cuts my time down, a
lot, when trying to verify what I say before I say it and then produce
an ASCII representation that accurately reflects what I tested.
To produce that last schematic, I just typed "ASC j.asc" and it
generated the output on the DOS screen. I then copied that with the
clipboard and pasted it into my post. Must like with Andy's system.
I'd love to have some feedback about it, so let me know if you do.
Thanks for the kind comments, too.
Jon
It's darned easy to use. However, it *is* a DOS box kind of thing.
No Windows stuff. So you have to use a command line to work it.
Other than that, it's easy.
The source code all fits into a single source file, so it's
uncomplicated to compile and link. It is designed for Microsoft's VC
1.52C, however. In any case, I don't recommend messing with that part
of it, unless you really *do* have some time to play.
However, you can add new symbols easily. Just edit the ASC.SYM file
in an ASCII editor. You can define each orientation for parts, but
you don't have to define all the orientations if you don't care about
unusual cases. It uses what it can find, doesn't use what it can't.
I've already added the more obvious discrete parts but it does NOT
handle LTSpice's .ASY files that define complex part shapes and pins
as I just haven't yet struggled to deal with those and the WINDOW
definitions in the .ASC files, yet. So some things work well, but
where it doesn't know what to do it just leaves that part blank.
Someday, I'll work harder at examining the ramifications of dealing
with the .ASY files in a general and useful way and then it be a lot
more broadly useful.
I *do* like the ability to work with simple, discrete schematics in
LTSpice, check them out, etc., and then spit them out in ASCII for the
..basics group, though. Seems a good fit and it cuts my time down, a
lot, when trying to verify what I say before I say it and then produce
an ASCII representation that accurately reflects what I tested.
To produce that last schematic, I just typed "ASC j.asc" and it
generated the output on the DOS screen. I then copied that with the
clipboard and pasted it into my post. Must like with Andy's system.
I'd love to have some feedback about it, so let me know if you do.
Thanks for the kind comments, too.
Jon
R
Rich Grise
Guest
On Wed, 22 Jun 2005 08:30:18 -0700, galt_57 wrote:
And in a current transformer application, the primary current is limited
by the load itself, so that's certainly not a problem, but do pay
attention to that burden resistor!
Good Luck!
Rich
an inaccurate answer.
And in a current transformer application, the primary current is limited
by the load itself, so that's certainly not a problem, but do pay
attention to that burden resistor!
Good Luck!
Rich
J
John Bokma
Guest
"Dave" <dmcomm_ads@yahoo.com> wrote:
feelings are justified.
--
John MexIT: http://johnbokma.com/mexit/
personal page: http://johnbokma.com/
Experienced programmer available: http://castleamber.com/
Happy Customers: http://castleamber.com/testimonials.html
I can't imagine how others feel about you right now, but I think their
feelings are justified.
--
John MexIT: http://johnbokma.com/mexit/
personal page: http://johnbokma.com/
Experienced programmer available: http://castleamber.com/
Happy Customers: http://castleamber.com/testimonials.html
R
Rich Grise
Guest
On Wed, 22 Jun 2005 10:57:34 -0700, harrisonmarshall wrote:
If it's there, it'd be a little rectangular recess with a slider at
the bottom, with a slot in the slider so you can switch it (it's
a slide switch with the knob lopped off) with a tiny screwdriver.
It should also be marked 110 on one side and 220 on the other (or
something to indicate the range). If there really is nothing like
this, and it really is clearly marked like you said before, then
it should work. Worst case, you'd only blow the fuse anyway.
Good Luck!
Rich
switch, somewhere near where the mains power cord enters the brick.
If it's there, it'd be a little rectangular recess with a slider at
the bottom, with a slot in the slider so you can switch it (it's
a slide switch with the knob lopped off) with a tiny screwdriver.
It should also be marked 110 on one side and 220 on the other (or
something to indicate the range). If there really is nothing like
this, and it really is clearly marked like you said before, then
it should work. Worst case, you'd only blow the fuse anyway.
Good Luck!
Rich
J
Jonathan Kirwan
Guest
On 24 Jun 2005 15:26:35 -0700, "obliquez" <obliquez@gmail.com> wrote:
descriptions, no one understands what is the real goal and this only
works to sow frustration -- which we all will reap.
too clear. And all this from a few tiny button batteries, too?
that design will need to be modified.
sensor also specified?
pointed at shows three wires in a picture, describes three wires in
the details below, etc. So this means there is something else yet to
be resolved. I think this is more your responsibility than anyone
else's. You'll have to let us know what you find out.
In any case, I hope electronics is and remains both fun and
challenging and the struggles not so much as to dissuade you from
considering it an important part of your life.
problem, yet.)
Jon
It's far, far easier to have the whole picture. If you piecemeal the
descriptions, no one understands what is the real goal and this only
works to sow frustration -- which we all will reap.
That's clearer. Though the part about the tilt sensor's effects isn't
too clear. And all this from a few tiny button batteries, too?
With the other requirements impacting this one, I'm almost certain
that design will need to be modified.
It appears that the LLE was specified by the teacher. Isn't the tilt
sensor also specified?
Only in knowing what they do. The specification you originally
pointed at shows three wires in a picture, describes three wires in
the details below, etc. So this means there is something else yet to
be resolved. I think this is more your responsibility than anyone
else's. You'll have to let us know what you find out.
Somewhat, yet.
Ah. Mind if we know your first name?
In any case, I hope electronics is and remains both fun and
challenging and the struggles not so much as to dissuade you from
considering it an important part of your life.
For getting you to tell us more? (We haven't helped you solved the
problem, yet.)
Jon
J
John Popelish
Guest
obliquez wrote:
8<
8<
Yes, you. OP=original poster
C
Charles Jean
Guest
On 23 Jun 2005 18:30:07 -0700, "davidd31415" <davidd31415@yahoo.com>
wrote:
and my math is limited to one year of calculus, but I would like to
see if I have a correct conception of what's going on here. I can see
that any periodic function can be put through the Fourier transform to
obtain an infinite series of sin and/or cos terms to completely
describe the original function. This applies to electronic circuits,
musical instruments, vibrational analysis of bridge decks, etc.
So, when one sees a "perfect square wave" on the oscope, it is
actually always a mixture of sine waves of f(fundamental-the frequency
of the square wave as seen on the oscope),3f,5f,7f...... frequencies.
A more complex wave like that produced by a violin string would look
different than either a sine wave or a square wave, because the
mixture of waves producing it are not at the amplitude/frequency
required by the Fourier transform to produce a square wave. If I were
to see what looks like a very low distortion sine wave on the oscope,
I can infer that this is a "true sine" wave, with very little
contribution from any higher harmonics, and not some weird lucky mix
of higher sin/cos frequencies that are significant compared to the
fundamental? Or would the use of a spectrum analyzer be required to be
sure?
For circuit elements like capacitors and inductors, whose reactance
varies with frequency, what happens when dealing with a square wave?
what frequency does one use in the reactance formulas, knowing that
you're dealing with a mixture of them? I would instinctively just put
in the fundamental frequency, but is this right? TIA for clearing any
of this up for me.
wrote:
This post got me to thinking about a related subject. I'm a hobbyist,
and my math is limited to one year of calculus, but I would like to
see if I have a correct conception of what's going on here. I can see
that any periodic function can be put through the Fourier transform to
obtain an infinite series of sin and/or cos terms to completely
describe the original function. This applies to electronic circuits,
musical instruments, vibrational analysis of bridge decks, etc.
So, when one sees a "perfect square wave" on the oscope, it is
actually always a mixture of sine waves of f(fundamental-the frequency
of the square wave as seen on the oscope),3f,5f,7f...... frequencies.
A more complex wave like that produced by a violin string would look
different than either a sine wave or a square wave, because the
mixture of waves producing it are not at the amplitude/frequency
required by the Fourier transform to produce a square wave. If I were
to see what looks like a very low distortion sine wave on the oscope,
I can infer that this is a "true sine" wave, with very little
contribution from any higher harmonics, and not some weird lucky mix
of higher sin/cos frequencies that are significant compared to the
fundamental? Or would the use of a spectrum analyzer be required to be
sure?
For circuit elements like capacitors and inductors, whose reactance
varies with frequency, what happens when dealing with a square wave?
what frequency does one use in the reactance formulas, knowing that
you're dealing with a mixture of them? I would instinctively just put
in the fundamental frequency, but is this right? TIA for clearing any
of this up for me.
C
colin
Guest
"william coleman" <william.coleman@asu.edu> wrote in message
news:d9hgm7$odi$1@news.asu.edu...
best
Colin =^.^=
news:d9hgm7$odi$1@news.asu.edu...
or a knob with a loose grub screw, i like the cheap 50cent dc motor idea
best
Colin =^.^=
C
colin
Guest
"Charles Jean" <alchemcj@earthlink.net> wrote in message
news:b7dpb1pcld7pq69efji589vlfks51bkfj1@4ax.com...
infinite series of sine waves to fully define it.
a squarewave isnt necessarily made up of sinewaves its just very useful
indeed to be able to consider it as a series of sinewaves.
a pure sinewave cant be split into other sinewaves. you can probably tell on
the scope if its say a 90% pure sinewave or more.
if you feed a squarewave into a circuit with a non flat frequeucny response
you can think of it by seperating it into the harmonics, then seeing how big
each harmonic is afterwards but also what phase, and then try and
reconstruct the waveform.
it all depends what you want to do with the reactive circuit, sometimes you
want to filter out the fundemental so you would chose that as the frequency,
but you might also want to use one of the other harmonics instead and filter
out one of those and you have a frequency multiplier. unless of course its
an inductor for a power supply in wich case you would want to filter out as
much as posible.
Colin =^.^=
news:b7dpb1pcld7pq69efji589vlfks51bkfj1@4ax.com...
Dont forget any practicaly generated squarewave isnt going to need an
infinite series of sine waves to fully define it.
a squarewave isnt necessarily made up of sinewaves its just very useful
indeed to be able to consider it as a series of sinewaves.
a pure sinewave cant be split into other sinewaves. you can probably tell on
the scope if its say a 90% pure sinewave or more.
if you feed a squarewave into a circuit with a non flat frequeucny response
you can think of it by seperating it into the harmonics, then seeing how big
each harmonic is afterwards but also what phase, and then try and
reconstruct the waveform.
it all depends what you want to do with the reactive circuit, sometimes you
want to filter out the fundemental so you would chose that as the frequency,
but you might also want to use one of the other harmonics instead and filter
out one of those and you have a frequency multiplier. unless of course its
an inductor for a power supply in wich case you would want to filter out as
much as posible.
Colin =^.^=
J
John Popelish
Guest
Charles Jean wrote:
8<
pass any other periodic waveform through a good low pass filter that
passes the periodic fundamental but greatly attenuates the second and
higher harmonics, you always get very nearly the same sine wave out of
the filter.
Assume a linear circuit, calculate the effect of each component
frequency, individually, and using the assumption of linearity, add
the various component frequency effects together to get the overall
effect or just deal with what happens to each harmonic, separately.
Use the instantaneous (differential) descriptions of all the
components and integrate the result (usually using numerical
approximations).
Most Spice programs allow both the amplitude and phase versus
frequencies that you specify (the first method) or the time response
to an arbitrarily stimulus (the second method) that simulates what you
would see on a scope.
because the amplitudes become insignificant, or because you have some
reason to suspect that frequencies above some point are so attenuated
or ignored by other parts of the system that they ate moot.
pretty good approximation of what is going on. If the waveform is a
pulse with an on time 1% of the period, you will learn almost nothing
useful.
8<
Yes, you can infer that. Another way to this conclusion is if you
pass any other periodic waveform through a good low pass filter that
passes the periodic fundamental but greatly attenuates the second and
higher harmonics, you always get very nearly the same sine wave out of
the filter.
For analysis of what happens, either you:
Assume a linear circuit, calculate the effect of each component
frequency, individually, and using the assumption of linearity, add
the various component frequency effects together to get the overall
effect or just deal with what happens to each harmonic, separately.
Use the instantaneous (differential) descriptions of all the
components and integrate the result (usually using numerical
approximations).
Most Spice programs allow both the amplitude and phase versus
frequencies that you specify (the first method) or the time response
to an arbitrarily stimulus (the second method) that simulates what you
would see on a scope.
As many of them as you are interested in. Your interest may fade
because the amplitudes become insignificant, or because you have some
reason to suspect that frequencies above some point are so attenuated
or ignored by other parts of the system that they ate moot.
If the waveform is a pretty clean sinusoid, that will give you a
pretty good approximation of what is going on. If the waveform is a
pulse with an on time 1% of the period, you will learn almost nothing
useful.
M
Michael A. Terrell
Guest
"thomson.eric@gmail.com" wrote:
Any books to suggest? I am willing to write and maintain a FAQ, but
no one can seem to agree on what they want in it.
--
Former professional electron wrangler.
Michael A. Terrell
Central Florida
Any books to suggest? I am willing to write and maintain a FAQ, but
no one can seem to agree on what they want in it.
--
Former professional electron wrangler.
Michael A. Terrell
Central Florida
B
Ban
Guest
billcalley wrote:
http://focus.ti.com/docs/prod/folders/print/opa692.html
Or this specialized audio circuit
http://focus.ti.com/docs/prod/folders/print/ina134.html
These buffers have the gain setting resistors built-in and usually are
trimmed for accuracy. Otherwise any opamp which is stable at the gain of 1
can be used, as you wrote.
Stability depends on the opamp design and on the load characteristic. Here
are a few remedies:
1) Capacitive loads can be isolated with a 220 ohms series resistor on the
output.
2) You can increase the phase margin by throwing away some bandwidth with a
R-C series combination between +in and -in.
3) Instead of connecting directly the -in to the output, you can use a
resistor with a parallel capacitor (1k + 100p).
4) A Zobel network on the output.
A buffer is actually the most demanding application, stability wise. Keep
away from certain opamps, especially high-speed parts, that exhibit a bag of
stability problems if the trace on the circuit board is longer than an
inch...
--
ciao Ban
Bordighera, Italy
gain(1 or 2) and with a lot of current output capability.
http://focus.ti.com/docs/prod/folders/print/opa692.html
Or this specialized audio circuit
http://focus.ti.com/docs/prod/folders/print/ina134.html
These buffers have the gain setting resistors built-in and usually are
trimmed for accuracy. Otherwise any opamp which is stable at the gain of 1
can be used, as you wrote.
Stability depends on the opamp design and on the load characteristic. Here
are a few remedies:
1) Capacitive loads can be isolated with a 220 ohms series resistor on the
output.
2) You can increase the phase margin by throwing away some bandwidth with a
R-C series combination between +in and -in.
3) Instead of connecting directly the -in to the output, you can use a
resistor with a parallel capacitor (1k + 100p).
4) A Zobel network on the output.
A buffer is actually the most demanding application, stability wise. Keep
away from certain opamps, especially high-speed parts, that exhibit a bag of
stability problems if the trace on the circuit board is longer than an
inch...
--
ciao Ban
Bordighera, Italy
M
me
Guest
"Kruminilius W." <anonymous@a.com> wrote in
news:kJTue.69$vX1.64@newsreader1.level3.com:
used to adjust the display on some computer monitors. There are variable
capacitors. Also popular is the metal shaft with a knob on it, which moves
a dial string.
What exactly are you wanting to use this dial you are looking for for...
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news:kJTue.69$vX1.64@newsreader1.level3.com:
There are optical shaft encoders, or cheaper mechanical encoders like are
used to adjust the display on some computer monitors. There are variable
capacitors. Also popular is the metal shaft with a knob on it, which moves
a dial string.
What exactly are you wanting to use this dial you are looking for for...
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B
Bob Myers
Guest
"colin" <no.spam.for.me@ntlworld.com> wrote in message
news:2_2ve.2400$5D4.1641@newsfe4-win.ntli.net...
"perfect" square waves in practice, since finite limits on bandwidth
always mean that you can never get to zero rise/fall time.
components; the frequency domain (i.e., what you see on the screen of
a spectrum analyzer) is just as valid as the time domain (which is what you
see on the screen of an oscilloscope).
Bob M.
news:2_2ve.2400$5D4.1641@newsfe4-win.ntli.net...
True, but that's just another way of saying that there are no truly
"perfect" square waves in practice, since finite limits on bandwidth
always mean that you can never get to zero rise/fall time.
No, it really, really is. Any periodic signal IS composed of sinusoidal
components; the frequency domain (i.e., what you see on the screen of
a spectrum analyzer) is just as valid as the time domain (which is what you
see on the screen of an oscilloscope).
Bob M.
J
John Popelish
Guest
billcalley wrote:
show tweaks to make the amp handle more capacitive load without ringing.
Such simple buffers are used by the millions. Most opamp data sheets
show tweaks to make the amp handle more capacitive load without ringing.
T
Tom Biasi
Guest
<junk1@davidbevan.co.uk> wrote in message
news:1119688798.653100.296920@o13g2000cwo.googlegroups.com...
The charger you have will charge the larger battery but will take longer.
Car batteries are pretty heavy to be lugging around.
Regards,
Tom
news:1119688798.653100.296920@o13g2000cwo.googlegroups.com...
Hi David,
The charger you have will charge the larger battery but will take longer.
Car batteries are pretty heavy to be lugging around.
Regards,
Tom
T
Terry Pinnell
Guest
"biltu" <suman_25biltu@yahoo.co.in> wrote:
--
Terry Pinnell
Hobbyist, West Sussex, UK
Try again - that makes no sense!
--
Terry Pinnell
Hobbyist, West Sussex, UK