Go Back   Physics Help Forum > High School and Pre-University Physics Help > Electricity and Magnetism

Electricity and Magnetism Electricity and Magnetism Physics Help Forum

Like Tree2Likes
Reply
 
LinkBack Thread Tools Display Modes
Old Apr 16th 2018, 12:37 PM   #31
Senior Member
 
Woody's Avatar
 
Join Date: Jun 2016
Location: England
Posts: 515
You are asking for a sensor that detects the electric field around the plasma globe
It strikes me that the plasma globe itself is such a sensor.
When the field around the globe is essentially uniform,
the plasma discharges seemingly at random around the globe in response to tiny natural variations due to air currents, dust particles, etc...
When there is a definite non-uniform field near the globe, the discharge direction will indicate the direction of non-uniformity.
The intensity and compactness of the discharge will indicate the degree of the fields non-uniformity.
__________________
~\o/~
Woody is offline   Reply With Quote
Old Apr 16th 2018, 07:44 PM   #32
Senior Member
 
Join Date: Apr 2017
Posts: 312
Another and easier approach is to measure the input to the globe itself ...

I believe most globes run on an input supply of 12V DC , you can measure current under different conditions , and see the change in power when a load is applied ....

you could also tap into the electronics inside measure the output voltage and frequency and current
studiot likes this.
oz93666 is offline   Reply With Quote
Old Apr 16th 2018, 08:29 PM   #33
Junior Member
 
Join Date: Mar 2018
Posts: 29
Originally Posted by Woody View Post
You are asking for a sensor that detects the electric field around the plasma globe
It strikes me that the plasma globe itself is such a sensor.
When the field around the globe is essentially uniform,
the plasma discharges seemingly at random around the globe in response to tiny natural variations due to air currents, dust particles, etc...
When there is a definite non-uniform field near the globe, the discharge direction will indicate the direction of non-uniformity.
The intensity and compactness of the discharge will indicate the degree of the fields non-uniformity.
yes woody thanks for the input, I do agree that the globe appears to react to stimulus, unfortunately I do not know how to electronically monitor the uniformity of the field around the globe. would you have any suggestions upon how to do that? what type of circuit would I need?

thanks,
QP
QuestionablePhysics is offline   Reply With Quote
Old Apr 17th 2018, 12:52 AM   #34
Senior Member
 
Join Date: Apr 2015
Location: Somerset, England
Posts: 959
Originally Posted by oz93666 View Post
Another and easier approach is to measure the input to the globe itself ...

I believe most globes run on an input supply of 12V DC , you can measure current under different conditions , and see the change in power when a load is applied ....

you could also tap into the electronics inside measure the output voltage and frequency and current
Exactly. That's what the sensitive wattmeter I proposed was for.

All that is then needed is to correctly set up the rest of the experiment.

Last edited by studiot; Apr 17th 2018 at 01:12 AM.
studiot is offline   Reply With Quote
Old Apr 17th 2018, 02:04 AM   #35
Senior Member
 
Woody's Avatar
 
Join Date: Jun 2016
Location: England
Posts: 515
So you are looking for equipment with which you can calibrate the response of the plasma globe.
I guess such equipment must exist, but I don't know about it...

Another approach might be to construct a structure for which the resultant electrical field can be calculated.
(is that even possible?)

Measuring the current demand of the globe itself (as suggested by OZ) might give useful information.
studiot likes this.
__________________
~\o/~
Woody is offline   Reply With Quote
Old Apr 17th 2018, 02:20 AM   #36
Senior Member
 
Join Date: Apr 2015
Location: Somerset, England
Posts: 959
Originally Posted by Woody View Post
So you are looking for equipment with which you can calibrate the response of the plasma globe.
I guess such equipment must exist, but I don't know about it...

Another approach might be to construct a structure for which the resultant electrical field can be calculated.
(is that even possible?)

Measuring the current demand of the globe itself (as suggested by OZ) might give useful information.
Yes, Woody, that is the second part of my proposal. +1
studiot is offline   Reply With Quote
Old Apr 25th 2018, 01:27 AM   #37
Junior Member
 
Join Date: Mar 2018
Posts: 29
Originally Posted by Woody View Post
Another approach might be to construct a structure for which the resultant electrical field can be calculated.
(is that even possible?)
what would you suggest for constructing such a structure?

Thanks in advance
QP
QuestionablePhysics is offline   Reply With Quote
Old Apr 25th 2018, 05:32 AM   #38
Senior Member
 
Woody's Avatar
 
Join Date: Jun 2016
Location: England
Posts: 515
I don't know

The main thing you will need to determine is the potential difference between the globe and the approaching object.
How that is achieved, I don't know.
__________________
~\o/~
Woody is offline   Reply With Quote
Old Apr 27th 2018, 04:11 PM   #39
Junior Member
 
Join Date: Mar 2018
Posts: 29
Originally Posted by Woody View Post
The main thing you will need to determine is the potential difference between the globe and the approaching object.
How that is achieved, I don't know.
Originally Posted by oz93666 View Post
Another and easier approach is to measure the input to the globe itself ...
woody had suggested a structure to calculate the results, and everybody agrees upon measurements are needed.

but ideally I had already imagined a structure as follows:
the globe is basically the same thing as a Jacob's Ladder with one big exception, its effectively using a monopole antenna where the Jacob's ladder uses (either 2 monopole antennas in proximity) or effectively a dipole antenna.

the globe then is surrounded by monopole virtual receiving antennas each individually connected in series to a variable inductor all connected in parallel to the ground plane which feeds back thru the power supply's ground.

When an object comes into proximity to the globe it has a lower inductance so hypothetically this object acts as the monopole antenna at that location of the globe and is inductance compared to the parallel antenna surrounding the globe is virtually zero compared to infinite. causing the spark to jump accordingly.

however, if you measure the input current to the device as suggested you are measuring the current thru all parallel paths which includes all Inductive paths at infinite and the one which is effectively zero in perspective to the others but still high enough to not actually short out the device, kirchoff's law basically tells us that the sum of the branch currents totals to the input current.

so we are talking a structure of virtual paths of inductance to monopoles all in parallel to the ground plane. so yes Woody I agree when you ask the question is this even possible!

so here again we have restated the question in yet an even more meaningful way... How do we differentiate the parallel paths of virtual inductances for individual measurement?

Thanks In Advance,
QP
QuestionablePhysics is offline   Reply With Quote
Old Apr 27th 2018, 05:30 PM   #40
Junior Member
 
Join Date: Mar 2018
Posts: 29
Originally Posted by QuestionablePhysics View Post
How do we differentiate the parallel paths of virtual inductances for individual measurement?
also note these are virtual, meaning they are only effectively in place and don't physically exist, so you cannot put a meter across them directly.
QuestionablePhysics is offline   Reply With Quote
Reply

  Physics Help Forum > High School and Pre-University Physics Help > Electricity and Magnetism

Tags
globe, plasma, question



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
PLASMA BALL and Concave Mirror Trick QuestionablePhysics Electricity and Magnetism 0 Mar 26th 2018 03:18 AM
Plasma Spectroscopy jagadeeshr Physics 0 May 4th 2017 07:30 AM
What is the approximate impedance of an RF plasma "antenna"? adamjohnson Physics 0 Oct 21st 2016 12:21 AM
Plasma and Gravity neil Energy and Work 6 Nov 27th 2013 02:50 PM
plasma gun arezo Nuclear and Particle Physics 3 Mar 24th 2011 02:50 PM


Facebook Twitter Google+ RSS Feed