A possible solution Was:: Triac instead of relay ?
I've been thinking about this all day at work (LOL ......!!) And I think I
know why all this is so.
It's because the triac does NOT function as a wave-modifying device ....
rather as a wave-destroying-then-wave-reconstruction device. Kinda like
having a function generator, precisely tuned to 50/60Hz.... then having the
generator's sync input ... triggered by the incoming AC line input through a
comparator. Notice that as you vary the trigger point of the comparator,
the trigger point ... RELATIVE TO THE INCOMING AC LINE INPUT ... will
lag -n- lead in step. This will result with the function generator's
output .... still 50/60Hz, yes .... but shifting left and right (on a AC
line triggered Oscilloscope). A resistor, mounted on the function
generator's output .... will flow CURRENT ... lagging and leading with
respect to the input AC line as well.
What's not in this whole debate ... is the VOLTAGE output of the triac
circuit ... Fourier Transformed. I'd bet you'd find this waveform ...
"lagging" and "leading" with respect to the "input" AC line waveform as
well. THEN ... with the resulting voltage flowing through a resistive
load ... produce that "red waveform" ... IN PHASE ...with the Fourier'd
VOLTAGE OUTPUT of the triac circuit. In-phase .... therefore no reactive
component.
I can picture what I'm saying ... just having difficulty putting it into
words. Hope it made sense.
Curtis
Dazzle Mom this coming Mother's Day season with flowers!
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----- Original Message -----
From: Stefan Trethan <stefan_trethan@...>
The power company meters have a aluminium disk and 2 coils, one for voltage
and one for current.(i reckon a 3 phase unit has 6 coils).this ensures that
really the power is measured. the fields somehow multiply to generate the
torque. I don't know the details just now but there are coils for voltage
and current but.at least this is how the European power meters work.
I thought the definition of reactive power only requires the phase shift.
The problem is if you imagine the first sine approx. of the current it would
still be positive after the voltage is already negative (around the zero
crossing);. This is the part where energy is delivered back normally. Well,
this is only showing at the first sine approximation, not the real current,
the real current always is same polarity as voltage.
I think around this point it the problem, maybe you can not use the sine
approximation. In hardware it would mean to add a filter, containing a
capacitor. then it is explained, the capacitor takes energy during the off
state of the triac and gives it back to the source during the little
opposite polarity time.
This is the only explanation i have, there is phase offset but no reactive
power.
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Re: Triac instead of relay ?
On Tuesday 20 April 2004 02:06 pm, Stefan Trethan wrote: the power company meters have a aluminium disk and 2 coils, one for
voltage and one for current. (i reckon a 3 phase unit has 6 coils).
this ensures that really the power is measured. the fields somehow
multiply to generate the torque. (i don't know the details just now but
there are coils for voltage and current). at least this is how the european
power meters work. The one we have here now is like that. The one where we used to live was electronic, sort of. The display, instead of being the usual mechanical stuff, was a small LCD panel which would sequence through a number of different things, cumulative and otherwise. That gave that particular power company the ability to nail us for more money during "peak" hours vs. "off-peak" hours and similar nonsense. I wasn't real happy about that.
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Re: Sound card as digital Oscope
On Tuesday 20 April 2004 01:46 pm, Steve wrote: --- In Electronics_101@..., "Roy J. Tellason"
<rtellason@b...> wrote:
On Tuesday 20 April 2004 11:17 am, Steve wrote:
I figured a tradeoff would be a PIC or other microcontroller with some
fast external RAM. Do a fast blind transfer of the output of a
parallel ADC into RAM, then a slower transfer from the RAM to the PC Hehe...
Then we add some input conditioning circuitry and attentuators and
such, and when we're done we'll have built ourselves our own digital
storage scope.
You that ambitious? I'm not, these days. Not everyone feels that way. Or we'd still be at the "bang two rocks
together" instead of "surround sound that makes you dump in your
pants" sound system. ;') Not necessarily. I have some other (rather ambitious) plans for my sound card that don't involve making it into a scope... For an audio Oscope, something from 10mV/cm to 50V/cm should cover
things nicely. Sounds about right, though I think my Tek scope will go a little lower. 5MHz doesn't require too terribly much RF design knowledge, especially if
it's only over short distances. My Tek goes out rather a bit further. :-) Microstripline so impedances match in circuit. Heard of that stuff, never saw any (that I know of) or worked with it. What can you tell me about it? People build more complex things in their workshops regularly. Sure. And I don't want to give the impression that I was putting down somebody who would. I tend to like web sites that feature lots of details about projects that people have done (so if you guys know of any feel free to pass the info along). But I also think that at least *some* of those people are nuts! :-) For me it's not ambitiousness that lacks- it's time and money. And an
inability to focus on one task. Only one? That'd be boring. <g> I too never seem to have enough time and money at the same time. When I've got plenty of time, it's usually when I'm between jobs so the funding can be a little short. And when I'm working, there's never enough time. Even now (when I have bunches of time) there still isn't enough time to get to everything I want to accomplish, no way. Which ain't gonna stop me from trying, though.
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Thanks dave for good response
Thanks dave for the valid answer.i got all the answers for the posted questions. Dave Mucha wrote:
--- In Electronics_101@..., rgsparber@a... wrote:
> This is a great subject to try out critical thinking.
>
> I used to work for a man named Dennis Hanson. He was an
exceptionally clear
> thinker and we often referred to the "Dennis Hanson Reasonableness
Check".
> Dennis would take each rumor that came by, and talk about it at the
department
> meeting. He would never say the rumor was impossible but rather
consider how
> reasonable it was plus its consequences.
>
> In the case of a technology that could make a person or thing
invisible, I
> think it is reasonable to assume that if true, it would be
impossible to hide it
> for long.
>
> There would be too much money to be made from its use. If it did
exist,
> people would likely want to use it. As
they found how valuable it
was, they would
> use it more. It would quickly become "visible".
>
>
> Rick Sparber
This is a philosophical approach and is based on the idea that all
parties are interested in TRUTH above all.
That all parties are honest at all times
and that there is no hidden agenda.
and tat science presides over superstition.
In the 1950's there was a push on airframe technology and it came to
be realized that the 'lifting body' concept, the idea that the
fuselage itself contributed to lift, was a better idea than the hot-
dog with wings air frames.
A Pentagon report classified anything remotely like a lifting body is
inherently dangerous and it took over 30 years for actual engineering
AND lots and lots of proven results before the military would even
consider such an airframe. Now, it is hard to find a military jet
WITHOUT lifting body technology.
The possibility,
however remote that both Tesla and Einstein were
completely wrong in this one area is probably more silly than the
idea of a ship that can be hidden from radar.
After the fall of the USSR, the US was able to take possession of a
ship that had been crisscrossed with massive coils.? Depending on the
orientation of the ship to the earth's core, and the charge in the
coils, the ship was able to have a zero net effect on the magnetic
fields around the ship.? This would offer a zero profile to detecting
the magnetic mass of the ship.
The idea that one can take a 'thing' and make it out of phase with
it's environment and render it invisible in the visible light
spectrum is no more ridiculous than one being able to make it
invisible on the infrared or even on radar or magnetism.
The
technology may not exist, but how certain can one be that it will
never exist ?? or that some group did not cross that threshold at one
time ?
I'm not saying it did or did not happen.? But I am saying that the
possibility of it EVER happening, either in the past or the future
would tend to lead to the possibility of such an occurrence.
Review the laughable idea that the Earth was round, or that the sun
did not revolve around the earth, or that the Earth is the only
planet in all the Galaxies.
I don't mind hearing people's opnions when stated as such, but to
have no persoanl research and formal experiance in an area and then
proclaiming something as either impossible or rediculous is a
disservice to those who have the power of creative thought and
scientific imagination.
In other words, those that believe something cannot be done should
get out of the way of those doing them.
Personally, I loathe
the current superstitions that claim to be based
in sciences.
Dave
self moderation in progress.....
....end of rant, end of participaton on topic...
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very very thanks for the valid and proper response.it is real that it is a boon as well as bane for the science and technology.i got a good response from you once again thanks signal snatcher. signal snatcher wrote:
During World War II the Germans invented an anti-shipping mine that exploded when it detected the natural magnetic field of a ship's hull overhead.? This mine could?sit on the sea floor so that it could not be?swept by normal methods?and posed a serious threat to Allied naval and merchant vessels.
?
British scientists discovered that if?a ship's hull was demagnetised by passing a large coil with an AC current over the hull, the ship would not explode these "magnetic mines".? This process, called "degaussing" was experimented with on US?and UK warships but soon applied to all Allied ships.? US sailors were told that degaussing made a ship "invisible to magenetic mines", according to my great-uncle Ed who, though an Aussie, served in the US merchant marine and now lives in California.
?
I think this is where the story came from.? Remember most people who served in the navies of that time had an education equivalent to primary (elementary) school Year 5 by today's standard.? It was war, there was a great deal of secrecy and, of course, this is when the rumour mill gets to work.
?
At that time Einstein was busy at Princeton making contributions to the Manhatten Project (the Atom Bomb), but Tesla, great man though he had been, was in his declining years and had done little scientific work for years.? He had suffered a serious mental collapse some time before and was living on his friends' charity and seems to have had occasional delusional episodes.?
?
Telsa still read the scientific literature and gave regular newspaper interviews during which he often?leaked more secrets than he should have.? Since his homeland was under German occupation he was technically an enemy alien.? In the UK he would have been placed, at least, under house arrest.? When he died the FBI seized his papers, not because he had invented some secret weapon, but because he was a nuisance to a nation at war.? His indiscretions seem to have been the source of many rumours, like this one.
?
There was a reunion of the salors who had served in the USS Philadelphia in 2002.? A journalist from the Fortean Times asked them about the Philadelphia incident but they all agreed that the story was untrue.? I understand it wasn't much of a party.? They were all older guys and they faded early...
Stefan Trethan wrote:
I would say if there was something done it is gone wrong i expect.
You can't make money with something not working (and possibly being
dangerous).
They wouldn't tell us i reckon.
I really see not much positive use for this technology, we shouldn't need
to hide things, should we?
ST
>
> There would be too much money to be made from its use. If it did exist,
> people would likely want to use it. As they found how valuable it was,
> they would
> use it more. It would quickly become "visible".
>
>
> Rick Sparber
>
> rgsparber@...
>
> My Web Site:
> rgsparber.fifthprime.com
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Logic Analyzer using PC Parallel Port
You should start a separate thread for this or someone's going to get
confused (like me).
I'd strongly suggest opto-isolators.
Alien Steve
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--- In Electronics_101@..., John Johnson <johnatl@m...> wrote: If you need an 8 channel logic analyzer (like an o'scope for digital
signals),
have a look at this:
It's been VERY helpful to me working on I2C and AT keyboard I/O.
Regards,
JJ
...snip....
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Re: Sound card as digital Oscope (Logic Analyzer)
If you need an 8 channel logic analyzer (like an o'scope for digital signals),
have a look at this:
It's been VERY helpful to me working on I2C and AT keyboard I/O.
Regards,
JJ
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On Tuesday, Apr 20, 2004, at 14:59 US/Eastern, Steve wrote: --- In Electronics_101@..., "Steve" <alienrelics@y...> wrote:
...
Fast sampler project using the MAX153 which is capable of 1Msps. Of
course the Amiga can't go -that- fast through the parallel port:
Schematic of MaxSampler:
Data page for MAX153:
...
Website for MaxSampler moved and changed. He has a ready to print PCB
pattern in a PDF file there for the SMT version of the IC.
The Wintel computers have much faster parallel ports (I'm told) so
should be possible for someone to write a much faster access.
Alien Steve
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In a message dated 4/20/2004 12:57:45 AM Central Standard Time, dave_mucha@... writes:
funny how Google offers 21,000 hits on Manhatten Project.
funny how it hits? 1,390,000 for Manhattan Project....
?
As they say in Maine, "a-YEP!"
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Re: Sound card as digital Oscope
--- In Electronics_101@..., "Steve" <alienrelics@y...> wrote: ... Fast sampler project using the MAX153 which is capable of 1Msps. Of
course the Amiga can't go -that- fast through the parallel port:
Schematic of MaxSampler:
Data page for MAX153:
... Website for MaxSampler moved and changed. He has a ready to print PCB pattern in a PDF file there for the SMT version of the IC. The Wintel computers have much faster parallel ports (I'm told) so should be possible for someone to write a much faster access. Alien Steve
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Re: home-made signal generator question
What do you mean? If you want to see the phase shift of an amp from
input to output, you need to compare input to output and look at the
zero crossing.
Hmm... how about a dual zero crossing detector, one from the output of
the sig gen, other from the output of the amp. The two zero crossing
signals into a phase shift to voltage converter. Sweep the frequency
(not too fast) with the sweep voltage on the X (horiz) input of the
Oscope. Output of the PS2V into the Y (vert) input of the scope. tada!
A rough graph of phase shift vs frequency.
So why am I not a millionaire? Oh, that's right, it's the salesmen and
management who make the big bucks.
Alien Steve
thought about that... but was looking for a really simple thing using existing components. building a PS2V circuit takes me at least as long as measuring the phase shift point by point. of course if you measure 100 units things are different. If the scope is able to do add/subtract, what would one get? i mean the signals are obviously in sync and same frequency. You would of course need to normalize the amplitude on each channel, i think easy enough to do in any lab with a series resistor and 2 diodes (or a shorted rectifier). now switch to add on your scope and get 0 to 2*dide clamp voltage for 180 to 0 degree phase shift. No opamp, no complicated circuit, no thinking required. Most scopes can add/subtract (even my tek 7633 which i think is older than myself.) Now, why am i no millionaire? guess you are right, simple solutions are no good for making money nowadays... You need bad ideas, and loads of people annoying other people to make money. ST
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Re: Triac instead of relay ?
What kind of wattmeter? A digital meter expecting pure sine will
almost certainly be fooled. And don't the circulating current
wattmeters installed by the power company only measure current?
Alien Steve
the power company meters have a aluminium disk and 2 coils, one for voltage and one for current. (i reckon a 3 phase unit has 6 coils). this ensures that really the power is measured. the fields somehow multiply to generate the torque. (i don't know the details just now but there are coils for voltage and current). at least this is how the european power meters work. There certainly can't be any power returned to the supply as there
would be with a capacitive lead or inductive lag load. exactly what puzzles me. I thought the definition of reactive power only requires the phase shift. the problem is if you imagine the first sine approx. of the current it would still be positive after the voltage is already negative (around the zero crossing). this is the part where energy is delivered back normally. well, this is only showing at the first sine approximation, not the real current, the real current always is same polarity as voltage. I think around this point it the problem, maybe you can not use the sine approximation. In hardware it would mean to add a filter, containing a capacitor. then it is explained, the capacitor takes energy during the off state of the triac and gives it back to the source during the little opposite polarity time. This is the only explanation i have, there is phase offset but no reactive power. ST
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Re: home-made signal generator question
--- In Electronics_101@..., Stefan Trethan <stefan_trethan@g...> wrote:
The VCO capabilities of it mean you could also use it as a sweep
generator. Send a ramp wave into the VCO input of either of those
chips, the same ramp into the Horizontal (X) input of your scope,
output of the sign gen into the amp under test, and the output of the
amp into the vertical input of your scope.
Alien Steve
That's how i did it.. but do you have any ideas on how one can get the
phase
shift on the screen? (If the scope can't calculate it of course)
ST
What do you mean? If you want to see the phase shift of an amp from input to output, you need to compare input to output and look at the zero crossing. Hmm... how about a dual zero crossing detector, one from the output of the sig gen, other from the output of the amp. The two zero crossing signals into a phase shift to voltage converter. Sweep the frequency (not too fast) with the sweep voltage on the X (horiz) input of the Oscope. Output of the PS2V into the Y (vert) input of the scope. tada! A rough graph of phase shift vs frequency. So why am I not a millionaire? Oh, that's right, it's the salesmen and management who make the big bucks. Alien Steve
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Re: Triac instead of relay ?
--- In Electronics_101@..., Stefan Trethan <stefan_trethan@g...> wrote: On Tue, 20 Apr 2004 14:21:18 -0000, Steve <alienrelics@y...> wrote:
And that is what makes me say the current lags.
Alien Steve
I too say that, but i say there can't be reactive power.
now, a phase shift in current and voltage, and no reactive power, can't
be, can it?
i bet a wattmeter would measure none, if it works as a multiplier....
Please anyone having a wattmeter try it, i have none and they are rare
(read expensive) at ebay. There certainly can't be any power returned to the supply as there would be with a capacitive lead or inductive lag load. What kind of wattmeter? A digital meter expecting pure sine will almost certainly be fooled. And don't the circulating current wattmeters installed by the power company only measure current? Alien Steve
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Re: Sound card as digital Oscope
--- In Electronics_101@..., "Roy J. Tellason" <rtellason@b...> wrote: On Tuesday 20 April 2004 11:17 am, Steve wrote:
I figured a tradeoff would be a PIC or other microcontroller with some
fast external RAM. Do a fast blind transfer of the output of a
parallel ADC into RAM, then a slower transfer from the RAM to the PC Hehe...
Then we add some input conditioning circuitry and attentuators and such, and when we're done we'll have built ourselves our own digital storage scope. You that ambitious? I'm not, these days. Not everyone feels that way. Or we'd still be at the "bang two rocks together" instead of "surround sound that makes you dump in your pants" sound system. ;') For an audio Oscope, something from 10mV/cm to 50V/cm should cover things nicely. 5MHz doesn't require too terribly much RF design knowledge, especially if it's only over short distances. Microstripline so impedances match in circuit. People build more complex things in their workshops regularly. For me it's not ambitiousness that lacks- it's time and money. And an inability to focus on one task. Alien Steve
|
Re: home-made signal generator question
The VCO capabilities of it mean you could also use it as a sweep
generator. Send a ramp wave into the VCO input of either of those
chips, the same ramp into the Horizontal (X) input of your scope,
output of the sign gen into the amp under test, and the output of the
amp into the vertical input of your scope.
Alien Steve
That's how i did it.. but do you have any ideas on how one can get the phase shift on the screen? (If the scope can't calculate it of course) ST
|
Re: Triac instead of relay ?
On Tue, 20 Apr 2004 14:21:18 -0000, Steve <alienrelics@...> wrote: And that is what makes me say the current lags.
Alien Steve
I too say that, but i say there can't be reactive power. now, a phase shift in current and voltage, and no reactive power, can't be, can it? i bet a wattmeter would measure none, if it works as a multiplier.... Please anyone having a wattmeter try it, i have none and they are rare (read expensive) at ebay. ST
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On Tue, 20 Apr 2004 14:04:42 -0000, goforitxx <rickward@...> wrote: Does anyone know of a supplier for SMD lqfp smd to .1 pad boards?
in europe you can get them at all major distributors like RS components and such. guess it is similar where you are. ST
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Re: Variable Resistor Using FETs
Hi, The current design is in the group files folder "Filter with DC adjust.jpg" AD8400s tends to roll off around 600KHz, this is a common problem with all digital potentiometers. Using a FET as a vairable resistor might help in extending the range of programmable filter poles. The design requirements are 10KHz to 10MHz second order butterworth filter with gain 2. The input signal might have an offset voltage that could vary from 0.4 Volts to 2.0 Volts DC. The peak to peak signal can never go beyond 0 ~ 3.3 Volts DC range. Regards, Syed Rizvi --- In Electronics_101@..., Ritesh Waghray <ritesh_raj_waghray@y...> wrote: Send me the file first.
and discuss what is Ur project let me see where I can
help.
--- Syed Hasan Rizvi <engrHasanRizvi@H...>
wrote: > Hi All,
I am trying to search for a better way to design a
programmable analog
filter. I implemented a 2nd order Sallen&key filter
with DC adjust a while
back using AD8400 digital potentiometers.
I am looking for ideas to use a FET as a variable
resistor.
I am uploading the existing design "Filter with DC
adjust.jpg" in group
files.
Any suggestions or ideas..............
Regards,
Syed Rizvi
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--- In Electronics_101@..., "goforitxx" <rickward@v...> wrote: Does anyone know of a supplier for SMD lqfp smd to .1 pad boards?
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Re: Sound card as digital Oscope
On Tuesday 20 April 2004 11:17 am, Steve wrote: I figured a tradeoff would be a PIC or other microcontroller with some
fast external RAM. Do a fast blind transfer of the output of a
parallel ADC into RAM, then a slower transfer from the RAM to the PC Hehe... Then we add some input conditioning circuitry and attentuators and such, and when we're done we'll have built ourselves our own digital storage scope. You that ambitious? I'm not, these days.
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Steven AE7HD