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#2920
by
Monomorphic
on 01 Mar, 2017 14:47
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I agree, the balance is very good for testing the EM Drive ! (noise and drift are minimal)
What duration of test would be best with a period of ~40 seconds? 40 seconds, 60 seconds?
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#2921
by
Rodal
on 01 Mar, 2017 16:06
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I agree, the balance is very good for testing the EM Drive ! (noise and drift are minimal)
What duration of test would be best with a period of ~40 seconds? 40 seconds, 60 seconds?
It really depends on whether there is any delay on the EM Drive force.
Using a period of 41 seconds, then any of these:
fraction
of
period Duration (sec)
1/4 10.25
1/2 20.5
3/4 30.75
1 41
1.25 51.25
1.5 61.5
1.75 71.75
2 82
2.25 92.25Since the last time you run the EM Drive for a minute and a half (90 seconds), if my memory is correct (please check), for comparison purposes, this time I would run it for
92.25 seconds (2 1/4 periods)Running for 92.25 accomplishes:
1) A fair
comparison with your previous run for 90 seconds
2) Enough time for the EM Drive to be ON, you had remarked that too small a time (10 sec) would be problematic
to generate enough force to be measured.
3) 2 1/4 periods gives plenty of information as to how the power ON for the EM Drive interacts with the pendulum period (something that Shawyer via TT had remarked on:
the generator vs motor issue)4)
A multiple of 1/4 period of the pendulum ending at 2 1/4 period is nice because it ends at a maximum displacement (if there was no delay. If there is a delay, then any termination is dependent on the delay and the delay is unknown, so this is as good as one can design for at the moment)
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#2922
by
WarpTech
on 01 Mar, 2017 16:48
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I agree, the balance is very good for testing the EM Drive ! (noise and drift are minimal)
What duration of test would be best with a period of ~40 seconds? 40 seconds, 60 seconds?
It really depends on whether there is any delay on the EM Drive force.
Using a period of 41 seconds, then any of these:
fraction
of
period Duration (sec)
1/4 10.25
1/2 20.5
3/4 30.75
1 41
1.25 51.25
1.5 61.5
1.75 71.75
2 82
2.25 92.25
Since the last time you run the EM Drive for a minute and a half (90 seconds), if my memory is correct (please check), for comparison purposes, this time I would run it for
92.25 seconds (2 1/4 periods)
Running for 92.25 accomplishes:
1) A fair comparison with your previous run for 90 seconds
2) Enough time for the EM Drive to be ON, you had remarked that too small a time (10 sec) would be problematic to generate enough force to be measured.
3) 2 1/4 periods gives plenty of information as to how the power ON for the EM Drive interacts with the pendulum period (something that Shawyer via TT had remarked on: the generator vs motor issue)
4) A multiple of 1/4 period of the pendulum ending at 2 1/4 period is nice because it ends at a maximum displacement (if there was no delay. If there is a delay, then any termination is dependent on the delay and the delay is unknown, so this is as good as one can design for at the moment)
I'd like to see a much faster repetition rate. Such as 1 sec ON, 1 sec OFF. It takes < 1 sec to fully charge the frustum, and I would expect the maximum thrust to occur as it's charging and discharging, not steady state. These transient effects should be tested and compared to the longer "steady" powered runs, so see which performs best, IMO.
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#2923
by
Rodal
on 01 Mar, 2017 16:51
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...
I'd like to see a much faster repetition rate. Such as 1 sec ON, 1 sec OFF. It takes < 1 sec to fully charge the frustum, and I would expect the maximum thrust to occur as it's charging and discharging, not steady state. These transient effects should be tested and compared to the longer "steady" powered runs, so see which performs best, IMO.
Agreed, good point, but how about testing that after Monomorphic first gets a 92.25 sec run to compare with his previous 90 sec run ?
That way, if something changed, we have at least the same approximate time ON for the EM Drive ON to compare between runs, rather than running a completely different time ON/OFF for the next test.
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#2924
by
Chrochne
on 01 Mar, 2017 17:40
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I agree, the balance is very good for testing the EM Drive ! (noise and drift are minimal)
What duration of test would be best with a period of ~40 seconds? 40 seconds, 60 seconds?
It really depends on whether there is any delay on the EM Drive force.
Using a period of 41 seconds, then any of these:
fraction
of
period Duration (sec)
1/4 10.25
1/2 20.5
3/4 30.75
1 41
1.25 51.25
1.5 61.5
1.75 71.75
2 82
2.25 92.25
Since the last time you run the EM Drive for a minute and a half (90 seconds), if my memory is correct (please check), for comparison purposes, this time I would run it for
92.25 seconds (2 1/4 periods)
Running for 92.25 accomplishes:
1) A fair comparison with your previous run for 90 seconds
2) Enough time for the EM Drive to be ON, you had remarked that too small a time (10 sec) would be problematic to generate enough force to be measured.
3) 2 1/4 periods gives plenty of information as to how the power ON for the EM Drive interacts with the pendulum period (something that Shawyer via TT had remarked on: the generator vs motor issue)
4) A multiple of 1/4 period of the pendulum ending at 2 1/4 period is nice because it ends at a maximum displacement (if there was no delay. If there is a delay, then any termination is dependent on the delay and the delay is unknown, so this is as good as one can design for at the moment)
I'd like to see a much faster repetition rate. Such as 1 sec ON, 1 sec OFF. It takes < 1 sec to fully charge the frustum, and I would expect the maximum thrust to occur as it's charging and discharging, not steady state. These transient effects should be tested and compared to the longer "steady" powered runs, so see which performs best, IMO.
Like simulating a pulse force right? What can we achive / see by different times of each test? Can it help us to understand if EmDrive can work better with short pulses or longer runs for slowly increasing force over time?
Can this be the case where Mr. Shawyer spoke about the generator and motor mode?
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#2925
by
Rodal
on 01 Mar, 2017 19:05
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...
Like simulating a pulse force right? What can we achive / see by different times of each test? Can it help us to understand if EmDrive can work better with short pulses or longer runs for slowly increasing force over time?
Can this be the case where Mr. Shawyer spoke about the generator and motor mode?
It has to do with Todd's theory of how the EM Drive works, and it would be useful to verify his theory
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#2926
by
InterestedEngineer
on 01 Mar, 2017 19:32
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Which way are you swiping the magnet on the beam? Vertically or horizontally?
Almost all swipes have been mostly horizontal, but it's more like an arcing motion actually. It may be necessary to build a small EM coil that I can energize in pulses. That way I can precisely control the intensity of the taps.
I played around with a mechanical momentary switch eliminating the bounce with a 9 volt battery, voice coil from a old speaker, RC filter ckt and a transistor that worked well, but decided it wasn't good enough as the pulse width would vary and have a 555 timer that I'm putting together as a single shot to get cleaner pulses.
I'm curious why you use a 555 timer instead of a $5 micro controller. Having designed circuits where I've replaced 555s and PLDs with microcontrollers I've found massively more flexibility with microcontrollers. You get A/D conversion, controllable PWM outputs, all sorts of stuff, and most modern controllers (e.g. PIC) have really quick get-started kits. Would be happy to help in this area.
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#2927
by
SeeShells
on 01 Mar, 2017 20:16
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Which way are you swiping the magnet on the beam? Vertically or horizontally?
Almost all swipes have been mostly horizontal, but it's more like an arcing motion actually. It may be necessary to build a small EM coil that I can energize in pulses. That way I can precisely control the intensity of the taps.
I played around with a mechanical momentary switch eliminating the bounce with a 9 volt battery, voice coil from a old speaker, RC filter ckt and a transistor that worked well, but decided it wasn't good enough as the pulse width would vary and have a 555 timer that I'm putting together as a single shot to get cleaner pulses.
I'm curious why you use a 555 timer instead of a $5 micro controller. Having designed circuits where I've replaced 555s and PLDs with microcontrollers I've found massively more flexibility with microcontrollers. You get A/D conversion, controllable PWM outputs, all sorts of stuff, and most modern controllers (e.g. PIC) have really quick get-started kits. Would be happy to help in this area.
Good question and I have an answer. I have all the parts on hand in my parts bins. Have you ever known an engineer that didn't have a pile-o-doodads and extra hardware?
Thanks for your offer to help, that's very nice, I may have a couple questions on microcontrollers a little later.
My Very Brst,
Shell
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#2928
by
PotomacNeuron
on 01 Mar, 2017 21:03
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Which way are you swiping the magnet on the beam? Vertically or horizontally?
Almost all swipes have been mostly horizontal, but it's more like an arcing motion actually. It may be necessary to build a small EM coil that I can energize in pulses. That way I can precisely control the intensity of the taps.
I played around with a mechanical momentary switch eliminating the bounce with a 9 volt battery, voice coil from a old speaker, RC filter ckt and a transistor that worked well, but decided it wasn't good enough as the pulse width would vary and have a 555 timer that I'm putting together as a single shot to get cleaner pulses.
I'm curious why you use a 555 timer instead of a $5 micro controller. Having designed circuits where I've replaced 555s and PLDs with microcontrollers I've found massively more flexibility with microcontrollers. You get A/D conversion, controllable PWM outputs, all sorts of stuff, and most modern controllers (e.g. PIC) have really quick get-started kits. Would be happy to help in this area.
Good question and I have an answer. I have all the parts on hand in my parts bins. Have you ever known an engineer that didn't have a pile-o-doodads and extra hardware?
Thanks for your offer to help, that's very nice, I may have a couple questions on microcontrollers a little later.
My Very Brst,
Shell
There is another reason to use 555: their is no RF, no RF radiation or EMF that people have criticized for the EmDrive experiments. After the transient settles down, there is only small amount of DC which is much easier to quantify. I myself used light controlled switch, which is built upon transistors, op amps with the same benefit.
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#2929
by
Monomorphic
on 01 Mar, 2017 21:51
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I decided to brush up on my illustrator skills while the 14 nickle-metal hydride batteries are charging. I've named my workshop "Star Lab," and here is the official mission patch for this testing campaign.
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#2930
by
TheTraveller
on 01 Mar, 2017 22:54
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#2931
by
Monomorphic
on 01 Mar, 2017 23:34
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I'm under a severe weather watch until 10:00 pm. Lots of thunder and lightning. I think it best if I wait until tomorrow for powered tests.
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#2932
by
PotomacNeuron
on 01 Mar, 2017 23:49
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#2933
by
Rodal
on 01 Mar, 2017 23:57
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#2934
by
SeeShells
on 02 Mar, 2017 00:09
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All,
After being a little down this Winter because I wasn't able to get my new lab up (8700 foot in the Rocky Mountains), winters are normally tough and cold. This year not as much.
I spent the afternoon chatting with my building supplier and we just might be able to get it going sooner than I thought. YEA! Several hurdles are still there... I needed this boost and I'm tired of chomping at the bit.
BTW My lab is going to be called High Frontier Labs
My Very Best,
Shell
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#2935
by
Left Field
on 02 Mar, 2017 03:48
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#2936
by
demofsky
on 02 Mar, 2017 04:28
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#2937
by
A_M_Swallow
on 02 Mar, 2017 08:20
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#2938
by
RERT
on 02 Mar, 2017 09:03
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Monomorphic Re: test duration
With this test rig having taken many months to perfect, I expect you plan a reasonably extensive test program, and will be able to try many if not all of the good suggestions above.
My 2 Cents is that results will be much easier to interpret when a force from the frustum has been applied for long enough for the balance to settle (around) a non-central position. Only when the balance velocity and acceleration are zero is the displacement approximately proportional to the applied force.
With the balance having a number of fundamental frequencies of several seconds, short tests where the balance does not settle will be somewhat harder to analyse to extract the applied force. With pulsed tests, you might even run into resonances with the fundamentals of the balance.
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#2939
by
TheTraveller
on 02 Mar, 2017 09:38
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Only when the balance velocity and acceleration are zero is the displacement approximately proportional to the applied force.
When Jamie's EmDrive thruster stops accelerating, there will be no accelerative Reaction force generated.
Previously shared email from Roger:
Remember there are two forces at work simultaneously, one that I call thrust (small end to big end) and the opposite which I refer to as the reaction force.
When the cavity is free to move, acceleration occurs in the direction of the reaction force. When the cavity stops, both forces cancel out.
This is the only way Newtons laws are satisfied, and has been verified many times.
Careful analysis of the time varying response of your torsional balance will also demonstrate this, which I am sure will help to educate your forum.
