PopularFX
Home Help Search Login Register
Welcome,Guest. Please login or register.
OverUnity Research > Electrical / Electronic Theory and Learning Center > Joule Thief Circuits > Lawrence Tseung sent a Prototype to test... any comments?
2024-11-26, 13:24:16
News: A feature is available which provides a place all members can chat, either publicly or privately.
There is also a "Shout" feature on each page. Only available to members.

Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 [15] 16 17 18 19 20 21 22
Author Topic: Lawrence Tseung sent a Prototype to test... any comments?  (Read 342639 times)
Topic Options img
img  PhysicsProf
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #350 on: 2011-01-22, 15:21:49 »
Group: Professor
Hero Member
*****

Posts: 3017
  I make note of your suggestions, .99 -- makes sense.

My post with 3 attachments appears to have been lost.  It took me about 45 minutes to assemble this post, and I am not inclined to waste time.  Can you recover my post, .99?   The problem evidently occurred when other posts came in while I was trying to post my post with 3 attachments...   It starts thus:

 Preliminary Results -- Tek3032 waveforms for 1.5V AA battery as power source, and 1-ohm resistor as the output resistor.
   
img  PhysicsProf
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #351 on: 2011-01-22, 15:27:32 »
Group: Professor
Hero Member
*****

Posts: 3017
  I cannot recover the lost text, and I have an appointment in 35 minutes. No time to re-do all that text.

 I will provide the text (which walks you through the Tek 3032 outputs) later... irritating to lose the text when other posts came in and the system declined my post...  At least the 3 attachments were posted... have fun.  I'll be back in about 3 hours.

Some of you will be able to figure out the waveforms and the printed RMS values on the scope, without my walking you through it.  I also provided CAVEATS regarding these data -- and I have more data to show later that make me question a naive COP > 1...  not sure at this point!!

I compared the (Vrms X Irms), i.e., Lawrence's suggestion when the scopes lack the fancy-math multiply feature -- with the (V X I)rms calculated by the Tek3032 -- and the results you can read off the screen-captures are: 
input:  4.27 mW versus 4.39 mW
output:  6.05 mW versus 6.48 mW.

I conclude that the "FLEET Index" method  (Vrms X Irms) of Lawrence may provide a reasonable approximation to permit comparisons between DUT's (not as final results).
Gotta run.

 
   
img  poynt99
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #352 on: 2011-01-22, 15:52:53 »

Group: Administrator
Hero Member
*****

Posts: 3217
It's not as complicated as it may seem...
Professor,

I have no explanation for your post getting "lost". That has never happened to me, and no one else has ever reported this happening that I am aware of.

Peter, do you have any suggestions? The only thing I can think of is that perhaps the host server was too busy just as you sent the post, and it could not connect to the database.

If it was lost, it is probably gone for good. Apologies. I would suggest for the future, that you do a ctrl-c ("copy" for MAC users) of your text before you hit the post button. That way if something goes wrong, you simply reply again and ctrl-v ("paste" for MAC users) your text back in. This is an especially good practice when making long posts.

.99


---------------------------
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa
   
img  ltseung888
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #353 on: 2011-01-22, 16:13:14 »
Group: Guest
Quote from: PhysicsProf on 2011-01-22, 15:21:49
  I make note of your suggestions, .99 -- makes sense.

My post with 3 attachments appears to have been lost.  It took me about 45 minutes to assemble this post, and I am not inclined to waste time.  Can you recover my post, .99?   The problem evidently occurred when other posts came in while I was trying to post my post with 3 attachments...   It starts thus:

 Preliminary Results -- Tek3032 waveforms for 1.5V AA battery as power source, and 1-ohm resistor as the output resistor.




Dear PhysicsProf,

Thank you so much for the post with the 3 screen shots.  Prototype A is one with relatively low Tseung FLEET Comparison Index.  It appears that the resultant Output Power over Input Power ratio is greater than 1 with the Tek 3032 DSO.

The apparent COP is 1.48 (6.486/4.388).

The Tseung FLEET Comparison Index I normally use would yield:
3.33 (Vpp*I pp out divided by Vpp * Ipp in with a 10 ohm resistor on the out)

See the original post on
http://www.overunity.com/index.php?topic=8825.msg267627#msg267627

We shall have much discussion with the apparent COP = 1.48 value. 

I shall start posting the screen shots of the various prototypes with much higher Tseung FLEET Comparison Index.  If the shots by PhysicsProf are acceptable, I shall ask the Hong Kong and China teams to post something similar.  I shall try to do the same myself in Irvine.

As the PhysicsProf said, “You can try it yourself.”  Do not wait for a retired old man to beg his friends to do a favor.

@PhysicsProf, I usually do my typing in Word and then paste for posting.  I experienced your same happening once in the overunity.com forum when I stupidly typed a long post.  I never did that again.

May God guide us all.  Amen.
   
img  poynt99
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #354 on: 2011-01-22, 16:19:48 »

Group: Administrator
Hero Member
*****

Posts: 3217
It's not as complicated as it may seem...
Professor,

May I suggest that you take the battery voltage measurement as I previously described.

And may I suggest that you not apply any math at all to the voltage and current traces before applying a math function to multiply them together.

To do it properly, take the voltage and current measurements and leave them in their "native" form. Apply a math function to multiply the two channels together to get instantaneous power. Then use the "mean" function (as I described before and referenced in the manual) to average the resulting power trace. Note what the final value is and perform the same measurement on the output.

Then compare these two numbers.

Multiplying  Vrms x Irms is most likely providing misleading data. Do you understand why that is?

.99


---------------------------
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa
   
img  poynt99
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #355 on: 2011-01-22, 16:33:23 »

Group: Administrator
Hero Member
*****

Posts: 3217
It's not as complicated as it may seem...
Lawrence,

Your post above is noted, however as I mentioned above, the numbers produced by the professor's measurements are most likely misleading and should not carry much weight. The method is flawed, as I have pointed out a number of times.

I am trying to encourage the professor to make the measurements properly. Using RMS functions totally precludes the possibility of obtaining correct results with this circuit.

I would insist that anyone serious about making proper measurements (including your China team), perform the measurements as I just outlined above. Any use of math functions applied before the channel multiplication, is to be considered unscientific.

.99


---------------------------
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa
   
img  MileHigh
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #356 on: 2011-01-22, 16:43:22 »
Group: Guest
Just a few preliminary comments on the traces themselves.  There is a lot of noise across the current sensing resistors.  I really can't be sure where it is coming from.  Note of course that resistors themselves actually generate noise, but I doubt that it is at the levels seen in the graphs.  Note also that the scope's vertical gain is very high, and that means that noise inherent in the circuitry of the scope itself is being amplified.  As a general comment, the lower the amplification of anything, the better off you are.

So when the noisy current sensing signal gets multiplied by the voltage waveform, you get the red trace as the resultant.  It's important to state that the displayed red trace does not even resemble the actual real-world red trace.  That's because it gets washed through the display filter/algorithm for the scope itself, which tries desperately to fit the waveform onto the appropriate display pixel on the LCD screen.  When the bandwidth in the waveform is much higher than the number of horizontal pixels on the display, and you are dealing with a signal that has random noise in it, all hell breaks loose and the algorithm has a really hard time deciding what to display.

The noise in the current sensing resistor waveform needs to be filtered out.  There is a decent chance that the scope can do it itself if it has built-in signal processing functions.  Alternatively, this is a job for a good old-fashioned operational amplifier.  The op-amp can take a nice differential input across the current sensing resistor and generate a nice clean output waveform provided you implement the right low-pass filter and build it properly.  That would take some effort.

I will defer to Poynt and Ion and Humbugger and others here for their expertise on what to really do.  Here is where I feel the limitations of being in my armchair.  If I was on the bench the first thing I would have done would have been to solder a small 0.1 uF ceramic cap across the current sensing resistor(s) just to see what that would have done to the noise.  I would also have checked the scope itself, and shorted the probe leads together to see how much noise is displayed when the scope's vertical gain is set very high.

MileHigh
   
img  wattsup
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #357 on: 2011-01-22, 16:51:16 »
Hero Member
*****

Posts: 520
@PhysicsProf

In all forums, while you are opening a post window and preparing your post, others may have posted some posts. So when you click to post yours, the software will come back saying something like "others have posted while you are posting". Just ignore it and click again on the post button.

Most of my posts are prepared in Ulraedit then copied and pasted on the post window. This enables me to keep a copy of my posts.

@ltseung888

This has nothing to do with your device but simply a recommendation when you are referring wishes to your GOD.
Such as;
"May God guide us all.  Amen."

You have to be very very very careful on how you formulate such statements because they do have power but people do not know how to use that power. In essence, your use of the word "May" is the worst word to use in such cases.

When you say May God Guide Us, you are in fact saying "right now God is not guiding us but hopefully in the future he will".

What God does in such cases is simply keeps you in the same state you are asking him. You are asking him to keep you in a stake of "wishing he will guide you". Very bad for you and very very bad for others for whom you are wishing this also.

Instead, always say such things with the perspective that you already have it in hand, you already live it, you already experience it. Instead of May God Guide Us, it is better to say "God is guiding us". That removes all chances for misinterpretation because he will really really do what you literally say and keep you in that state.

So you have a choice. Do you want to be kept in a state of wishing he guides you or do you want him to keep guiding you.

Don't ever wish anything. Always state it like it is already in hand, already materialized.

When I do this I have a special method and always the same way.

Example;

Thank you all powerful for the great life you give me filled with love, success and happiness, all in a just and perfect manner".

You always finish with "in a just and perfect manner". This is your insurance coverage. If you simply thank him for your new heart transplant, he will give it to you, but it could be the heart of your son. Saying in a just and perfect manner makes the heart come to you from an honorable method that will not hurt anyone.

Playing with such statements is like playing with slow acting dynamite. You always have to make sure it explodes in the right way.

Off topic, but if you are going to make such statements in the future using the word "us", meaning everyone here, I think you should use the proper method.

All the best.

wattsup  

PS: When you  understand the above, you quickly realize why your should never say the standard prayers that are designed to keep you in the same state you are in. Well I am an atheist that recognizes only the power of the all mighty and not in the pseudo power of all religions. But I respect them all for what they are.
« Last Edit: 2011-01-22, 17:18:39 by wattsup »


---------------------------
http://etherimpress.com
   
img  poynt99
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #358 on: 2011-01-22, 17:06:28 »

Group: Administrator
Hero Member
*****

Posts: 3217
It's not as complicated as it may seem...
MH, et al:

Yes, the vertical gain is set to 10mV/DIV.

The cap shunting the CSR is not going to help this, because the resistor is not the source of the "noise". It is the scope. The "hair" seen on digital scope traces is due to sampling limits, and is inherent in every digital scope.

Even an analog scope will begin to show noise at this setting, but let's be real for a moment here folks, digital scopes as far as I am concerned, are still in their "infant" stage, and albeit they are extremely useful, they are basically 'crap' when it comes to making low level measurements, and measurements of signals that posses a high dynamic range.

Remember, they are STILL only 8-bit devices. 8 bits is an absolutely horrible resolution by today's standards, but unfortunately, this is a limit we will have to live with until the physicists and electronics geniuses can figure out how to make affordable high speed 16-bit A/D converters. By high speed, I mean at least 20Gb/s. Today, they simply don't exist.

So, this is one of the artifacts, pitfalls, subtleties, nuances, that one must be aware of when using these scopes. They are great tools, but they have their limits and we must know how to work around them to get useful data from them.

.99


---------------------------
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa
   
img  MileHigh
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #359 on: 2011-01-22, 17:27:23 »
Group: Guest
When I was last on the bench the fist generation of "digitally assisted" analog scopes had just come out.  They were great analog scopes that had a second electron beam(?) or they were multiplexing the single electron beam to display alphanumeric data on the scope display.  There were cursors on the display that you could line up with your waveform to display period or equivalent frequency.  There were horizontal cursors that displayed voltage.  Awesome!!!  If my memory serves me correctly I think they were the first generation of scopes to have built-in 3.5" floppy drives.  If the scopes didn't have floppy drives then the latest generation of logic analyzers did.  Cutting edge stuff at the time!  lol

But back to those late-Eighties "digitally assisted" analog scopes.  I loved them, they were really nice!!!

I am surprised that the DSO PhysicsProf is working with has only 8-bit sampling!  On the other hand, it's not surprising because I think the scope is about 15 years old.  10-bit gives me a better feeling and 12-bit would be awesome!

Nonetheless, the scope should be able to do the job but like Poynt said it does require that you understand how to use your instrument properly.

MileHigh
   
img  ltseung888
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #360 on: 2011-01-22, 18:12:59 »
Group: Guest
Quote from: poynt99 on 2011-01-22, 16:19:48
Professor,

May I suggest that you take the battery voltage measurement as I previously described.

And may I suggest that you not apply any math at all to the voltage and current traces before applying a math function to multiply them together.

To do it properly, take the voltage and current measurements and leave them in their "native" form. Apply a math function to multiply the two channels together to get instantaneous power. Then use the "mean" function (as I described before and referenced in the manual) to average the resulting power trace. Note what the final value is and perform the same measurement on the output.

Then compare these two numbers.

Multiplying  Vrms x Irms is most likely providing misleading data. Do you understand why that is?

.99

Dear poynt99,

Are you sure that the PhysicsProf did the math function to voltage and current traces incorrectly?

If I use the figures as shown on the scope:
Input
Ch1 rms  = 1.52V
Ch2 rms  =  2.81mV
The product would be = 4.2712mVV and not 4.388mVV as shown on the screen.

Output
Ch1 rms = 2.91V
Ch2 rms = 2.08mV
The product would be = 6.0528mVV and not 6.486mVV as shown on the screen.

It is getting exciting.

Lawrence
   
img  poynt99
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #361 on: 2011-01-22, 18:13:17 »

Group: Administrator
Hero Member
*****

Posts: 3217
It's not as complicated as it may seem...
The DPO3032 is an 8-bit scope.

It has an 11-bit mode using "Hi-Res", but this is only a processing trick to make it appear to have a better vertical resolution.

btw, please use the full model name when mentioning the Tektronix scopes. They use DPO, MSO and TDS as prefixes, so it can be any one of them, and they are different. The suffix can be A, B, C, or D, but they are not quite as important to note.

The Professor uses a DPO3032, and there is no such model as a "Tek3032".

I doubt the DPO3032 model is much older than a few years. Maybe you were looking at the "TDS3032" ?

.99


---------------------------
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa
   
img  poynt99
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #362 on: 2011-01-22, 18:34:06 »

Group: Administrator
Hero Member
*****

Posts: 3217
It's not as complicated as it may seem...
Quote from: ltseung888 on 2011-01-22, 18:12:59
Dear poynt99,

Are you sure that the PhysicsProf did the math function to voltage and current traces incorrectly?

If I use the figures as shown on the scope:
Input
Ch1 rms  = 1.52V
Ch2 rms  =  2.81mV
The product would be = 4.2712mVV and not 4.388mVV as shown on the screen.

Output
Ch1 rms = 2.91V
Ch2 rms = 2.08mV
The product would be = 6.0528mVV and not 6.486mVV as shown on the screen.

It is getting exciting.

Lawrence


Looking at it again, I jumped the gun a little in saying the math should not be applied to the voltage and current wave forms, it does not matter because I remember now that this only computes and displays the RMS on the wave form, it does not change the wave form. The two channels are still being multiplied in their raw format. The resulting red wave form then is indeed the instantaneous power, but using the RMS computation on this is incorrect. The "MEAN" computation is the one that should be used. Alternatively, an "averaging" function can be applied to the actual wave form, which in theory should provide the same result. Let's keep it simple for now though and just try the "MEAN" computation.

Is this relatively clear?

.99


---------------------------
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa
   
img  poynt99
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #363 on: 2011-01-22, 18:45:11 »

Group: Administrator
Hero Member
*****

Posts: 3217
It's not as complicated as it may seem...
What we require is the average of the instantaneous power, not the RMS.

.99


---------------------------
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa
   
img  PhysicsProf
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #364 on: 2011-01-22, 19:08:52 »
Group: Professor
Hero Member
*****

Posts: 3017
Quote from: poynt99 on 2011-01-22, 18:45:11
What we require is the average of the instantaneous power, not the RMS.

.99

Returned -- Thanks for the comments.   Won't loose another long post, I think.   Seems you fellows are reading the screen-print-out just fine, without my having to walk you through it.

The scope is: Tektronix TDS3032B 300 MHz 2 Channel Digital Phosphor Oscilloscope.

.99 -- would you kindly save me some time in the manual -- how does one get the 3032 to provide the average power, rather than the RMS?  I would like to try it (next time at the university).
 
So let me proceed to the next data set.  Realizing that the 1 ohm resistor on the output circuit provided a signal too small for reliability, we replaced it with a 100 ohm resistor.  Now we have significant signal above noise, as you will see.  Big caveat -- if Lawrence is right about the circuit resonating, then changing the output resistor in this way will also change the performance...

Below are the data, displayed much as i did earlier.   Note that to get the output current, one must divide the voltage drop on the 100-ohm resistor by 100, and the power needs to be so divided also.

I should say that John and I felt this was a learning exercise, not a final judgement in any way.   Taking "average power" values will have to wait for next time.  Meanwhile, perhaps we can learn something from the waveforms -- and more tests from yesterday will follow.
   
img  poynt99
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #365 on: 2011-01-22, 19:14:45 »

Group: Administrator
Hero Member
*****

Posts: 3217
It's not as complicated as it may seem...
Professor,

I stand corrected, TDS3032 it is. Not sure where I got that it was the DPO3032.

Anyway, here is the manual for the TDS3032B.

I'll look into it and let you know what page to see. Essentially, it will be available through the same menu you accessed to get the RMS computation. Simply select "MEAN" rather than "RMS".

.99


---------------------------
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa
   
img  poynt99
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #366 on: 2011-01-22, 19:31:06 »

Group: Administrator
Hero Member
*****

Posts: 3217
It's not as complicated as it may seem...
This TDS3032B manual is not as good as the one for the DPO3032, unfortunately.

However, if you go to page 3-45, you will see the listing for the "Mean" computation. As I mentioned, choose this the same way you chose RMS. It's just a simple change.

.99


---------------------------
"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa
   
img  PhysicsProf
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #367 on: 2011-01-22, 19:44:03 »
Group: Professor
Hero Member
*****

Posts: 3017
  Thanks, .99 -- I appreciate your finding out these things.  It's really fun for me learning/reviewing all these things.

OK -- our next test, now that we have a decent signal-above-noise on the 100 ohm output resistor, was to drop cut the input voltage by half.  (No other changes to the circuit.)  Just wanted to see what would happen.  Here we went to a power supply, set at 0.754 volts DC (as read by an external multimeter, agrees with the Vrms value, see data below).

We also decided to take the RMS values over one second -- this cuts the jitter way down.  You can also see some interesting variations in both the input and output voltages at the longer time scale -- I provide the observed data below.

Now here's the question -- the input LED is noticeably dimmer with 0.75V in, but the output LED remains VERY bright.  Now, the input power RMS according to the scope analysis is 160 micro-watts...  that's 0.16 mW.  And the current in the output circuit determined by the output resistor (100 ohms) is something like
1.33mV/100ohms =13.3 microamps, which is not much at all for lighting the LED.  

Now that bright output LED is running at less than 2.3 volts (2.3 V rms across the output including LED and 100-ohm R) with a current of about 13 MICROamps.   How in the world does it light up so brightly??

OK -- I realize that the LED is blinking at about 100 Hz -- and that there are voltage spikes that will get the LED to light up, but BRIGHTLy at this low current and power?  How is that done?
   
img  ltseung888
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #368 on: 2011-01-22, 20:38:25 »
Group: Guest
Quote from: PhysicsProf on 2011-01-22, 19:44:03
  Thanks, .99 -- I appreciate your finding out these things.  It's really fun for me learning/reviewing all these things.

OK -- our next test, now that we have a decent signal-above-noise on the 100 ohm output resistor, was to drop cut the input voltage by half.  (No other changes to the circuit.)  Just wanted to see what would happen.  Here we went to a power supply, set at 0.754 volts DC (as read by an external multimeter, agrees with the Vrms value, see data below).

We also decided to take the RMS values over one second -- this cuts the jitter way down.  You can also see some interesting variations in both the input and output voltages at the longer time scale -- I provide the observed data below.

Now here's the question -- the input LED is noticeably dimmer with 0.75V in, but the output LED remains VERY bright.  Now, the input power RMS according to the scope analysis is 160 micro-watts...  that's 0.16 mW.  And the current in the output circuit determined by the output resistor (100 ohms) is something like
1.33mV/100ohms =13.3 microamps, which is not much at all for lighting the LED. 

Now that bright output LED is running at less than 2.3 volts (2.3 V rms across the output including LED and 100-ohm R) with a current of about 13 MICROamps.   How in the world does it light up so brightly??

OK -- I realize that the LED is blinking at about 100 Hz -- and that there are voltage spikes that will get the LED to light up, but BRIGHTLy at this low current and power?  How is that done?


If I use the rms Power Values (the best we have now until PhysicsProf’s next trip), the apparent COP is:

Apparent COP = Output Power/Input Power (rms value)
                         = 4.687 *1000/160.0
                         = 29.29375

This is getting even more interesting.  I do not think noise is a big factor.  The use of mean, average or rms values are unlikely to make a huge difference.  This is worthy of further research (and replication).  Any one agree?

Thank you for the wonderful job.  My dear PhysicsProf.

Edit: I have not taken into account the 100 ohm resistor on the output.  Should I???
« Last Edit: 2011-01-22, 21:46:37 by ltseung888 »
   
img  hartiberlin
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #369 on: 2011-01-22, 20:48:33 »
Group: Guest
Quote from: FuzzyTomCat on 2011-01-21, 20:19:55
Hi Stefan,

IMHO ..... you should know there are differences in the type of electrical power supplied from Utilities to consumers around the World ( please find attachments ) which have characteristics and permanent installations that are "NOT" the same and must be treated that way. The only way to elevate any potential "ground loop" problems a Isolated grounding system must me invoked and permanently installed to all applicable electrical codes that may apply, this is the same system all reputable testing laboratories and facility's use to isolate the equipment ground to a clean electrical ground. The use of any equipment that has a grounded power outlet is for equipment and personal life protection and as a professional in the industry for over 30 years I would never recommend not to user this mandatory safety feature delegated from electrical installers, engineers and insurance company's around the globe to "INSURE" proper grounding.

As for Musicians and "ground loop" audio feed back in LIVE presentations 99% of the time are from the XLR 3-wire audio patch cord cables used between mixers, snakes and other audio equipment such as mixers, amplifiers and microphones seen first hand from my volunteer MCTV Staff experience recording several times at the famous Portland, Oregon "Waterfront Blues Festival" years ago ..... stomp and walk on XLR patch cord .... twirl a microphone by the XLR patch cord ...... drop a microphone stand on a patch cord ..... just to name a few things, none that are a permanent wiring system with equipment grounding protections in place. 

Regards,
Glen

Hi Glen,
I am commenting only on the measurementdone  in the new Rosemary circuit,
that she has already shown me privately , which is   not yet public.

So this is offtopic to this Lawrence Tseng topic here, sorry..

Well, I have a Hameg 312 scope and that is also grounded and there is
a connection between the scope ground and the case and the earth ground
of the grid plug.

I measured 2 years ago the voltage of a cap bank of 10 x 100 nF ceramic caps in parallel,
so it was basically a 1 uF ceramic cap and wondered,
why the capbank always charged up on the scope.

It was only, because the scope connected to the capbank was earth grounded via the scopehead.

So you see, this is just one problem.
If you additionally use another earth grounded function generator that
might also be connected to a different plug in the room,
you will get all kinds of measurement problems and probably groundloop current problems.

The only thing what the earth ground connection is good for is for security.
But if you had made sure that all the internal connections of the scope
are okay, you can surely disconnect the earth ground for just a measurement.

So it is much better to use battery operated measurement scopes and function
generators in this area, so you will not have these earthground current looping problems.


Regards, Stefan.
   
img  humbugger
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #370 on: 2011-01-22, 21:06:20 »
Group: Guest
Hello Stefan,

Remember me?  How have you been?  I have two comments on your post above.

1)  What would be the problem if all the bench gear was plugged into a common outlet striip on the bench?  With critical items plugged into adjacent outlets.

2)  Are measurements made by OU folks really that special?  How in the world could all the rest of the world manage to do just fine with our AC-powered bench equipment?  If AC line connected test equipment was as problem-plagued by "ground loops" as you say, wouldn't all test gear have been battery-powered by now?

I am not saying that problems cannot arise; just that there are usually other, better solutions than cutting off the thrid prong ground in the great majority of cases. 

Just my 2 cents.

Cheers!

Humbugger
   
img  muDped
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #371 on: 2011-01-22, 21:12:26 »

Group: Tinkerer
Hero Member
*****

Posts: 3055
Quote from: humbugger on 2011-01-22, 10:50:06
By the way, Poynt, we (apparently all males, but she specifically mentions you and I and MileHigh) have been publicly accused of being ignorant sexist chauvinist pigs today in Rosemary Ainslee's blog here:

http://www.newlightondarkenergy.blogspot.com/

"Humbugger (TK's new (and much needed) forum identity) can advise all and sundry that we may ignore the effect of a junction on a 'line' when making a voltage measurement."

She is saying that I am Tinsel Koala and he is me, which is true only in her paranoid imagination.  Quite laughable if it were not so sad.

These accusations are unfounded and slanderous to us as people and to this forum.  I consider these irresponsible statements to be quite offensive.  She is trying to come off as a martyr to the "old boys club", it seems.  I guess it's easier for her to do this than to work on her "invention" or learn at least the proper semantics for technical discussions (if not the physics and electronics).

This is not a "call for banning" on my part; only a heads up in case you were unaware that she tippy-toes away from here and splatters falsehoods and ugly reports about members here on her public blog.


Quote from: poynt99 on 2011-01-22, 14:49:24
humbugger,

I was made aware of her latest entry, but thanks again for the headsup. She didn't quite use all those adjectives, but the message is basically the same, I agree.

I am not too concerned about her rant at this point, as it's quite tame relative to the formidable wrath of Rose that she is capable of unleashing. And she is entitled to her opinion, even though it is borne of frustration.

She claims to have "deregistered" herself, but it's not so.

.99

Is this sort of "DRAMA" truly necessary (or even desirable)
within a forum principally composed of MEN?

That Women can be challenging (even threatening) to the Male
comfort zone level is ancient history.

Sometimes MEN are guilty of saying too much.  Especially the
new phenomenon "Forum Man."

Too Much DRAMA.


---------------------------
For there is nothing hidden that will not be disclosed, and nothing concealed that will not be known or brought out into the open.
   
img  humbugger
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #372 on: 2011-01-22, 21:17:21 »
Group: Guest
I agree.  My post should have been sent via PM rather than posted here.

But to claim all men and especially "Forum men" (whatever that is) are threatened by the female species is too vast a generalization for me.  My remarks to Rosemary and comments about measuring her circuit would have been exactly the same were she a male.

Humbugger
   
img  FuzzyTomCat
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #373 on: 2011-01-22, 21:52:13 »
Group: Guest
Quote from: hartiberlin on 2011-01-22, 20:48:33
Hi Glen,
I am commenting only on the measurementdone  in the new Rosemary circuit,
that she has already shown me privately , which is   not yet public.

So this is offtopic to this Lawrence Tseng topic here, sorry..

Well, I have a Hameg 312 scope and that is also grounded and there is
a connection between the scope ground and the case and the earth ground
of the grid plug.

I measured 2 years ago the voltage of a cap bank of 10 x 100 nF ceramic caps in parallel,
so it was basically a 1 uF ceramic cap and wondered,
why the capbank always charged up on the scope.

It was only, because the scope connected to the capbank was earth grounded via the scopehead.

So you see, this is just one problem.
If you additionally use another earth grounded function generator that
might also be connected to a different plug in the room,
you will get all kinds of measurement problems and probably groundloop current problems.

The only thing what the earth ground connection is good for is for security.
But if you had made sure that all the internal connections of the scope
are okay, you can surely disconnect the earth ground for just a measurement.

So it is much better to use battery operated measurement scopes and function
generators in this area, so you will not have these earthground current looping problems.


Regards, Stefan.

Hi Stefan,

Yes your correct that sometimes battery powered electronic measurement devices have there places of use and most of us don't have access to such equipment ... but there is alternative device that can be used for short durations of circuit measurements that give some types of electrical protections.

I use a Uninterruptible Power Supply or "UPS" ( http://en.wikipedia.org/wiki/Uninterruptible_power_supply ) one sized with large enough back up batteries for all the electronic measurement devices plus any external power supplies needed plugged into it, using a plug strip for enough outlets for everything being used if required.  I just disconnect the "UPS" from the incoming utility power to quickly take any measurements keeping all the testing equipment grounded on the same ground plane and powered by the "UPS" batteries, this effectively removes all connections to a earth ground and utility power stray voltages or harmonics although extreme care should be taken a electrical short circuit is still a electrical short circuit.

Regards,
Glen
   
img  hartiberlin
Re: Lawrence Tseung sent a Prototype to test... any comments? « Reply #374 on: 2011-01-22, 22:01:13 »
Group: Guest
Quote from: FuzzyTomCat on 2011-01-22, 21:52:13
Hi Stefan,

Yes your correct that sometimes battery powered electronic measurement devices have there places of use and most of us don't have access to such equipment ... but there is alternative device that can be used for short durations of circuit measurements that give some types of electrical protections.

I use a Uninterruptible Power Supply or "UPS" ( http://en.wikipedia.org/wiki/Uninterruptible_power_supply ) one sized with large enough back up batteries for all the electronic measurement devices plus any external power supplies needed plugged into it, using a plug strip for enough outlets for everything being used if required.  I just disconnect the "UPS" from the incoming utility power to quickly take any measurements keeping all the testing equipment grounded on the same ground plane and powered by the "UPS" batteries, this effectively removes all connections to a earth ground and utility power stray voltages or harmonics although extreme care should be taken a electrical short circuit is still a electrical short circuit.

Regards,
Glen


Yes, this makes sense, but you have to watch out that you also don´t have any ground loops
inside this setup.
Just one meter with double grounding can generate a ground loop current in special cases...
So better just disconnect the earth ground from all your measurement euipment
and put and tie all groundcables from your scopeheads just to one place in your circuit.

I am not sure , if that is why Rose might have these mysterious bursts at her heating load resistor,
because maybe the transistor goes into oscillation due to induced ground currents.

You really have to take care how you do the measurements and how you set it all up.

Regards, Stefan.
   
Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 [15] 16 17 18 19 20 21 22
« previous next »


 

Home Help Search Login Register
Theme © PopularFX | Based on PFX Ideas! | Scripts from iScript4u 2024-11-26, 13:24:16