Electron Reversing Device

[TinselKoala]

.99 said,

My Tonghui TH2821A impedance meter shows a negative capacitance while trying to measure an inductor, and vice versa when trying to measure a capacitor on inductance.

I'm glad to hear that, because my ProsKit cheapo RLC meter, and my Fluke 83 on capacitance setting, also behave pretty much the same way. I wonder what's different about TM's meters that allow them to give readings when ours don't.

[tinman]

Thank you TinselKoala, I get it.

Once an electronics engineer told me that "measurment technique" is the most difficult area in his science. And whenever I try measurements in my experiments and when I see some crude OU claims I am reminded of that.

The claim in connection with tinman's circuit is not crude, it seems to be a subtle measurement problem. Electrodynamics is the high ground.

I recently bought this book about electrodynamics (it is supposed to be a standard book for electronics students in the German language)

http://www.amazon.com/Elektrodynamik-Einf%C3%BChrung-Experiment-Theorie-Springer-Lehrbuch/dp/3540214585/ref=sr_1_3?ie=UTF8&qid=1358202583&sr=8-3&keywords=Brandt+Dahmen

and it scares me. Them swinging things are not as simple as one thinks.

Greetings, Conrad

Im glad you made this point Conrad'Quote: it seems to be a subtle measurement problem

Now this is what im trying to get an answer to--what or where is the error being made?

Is it M1 and M2 that arnt reading the full current being supplied to the system?
If that is the case,then dose that same error occur when useing CVR's?

A quote from TK : OK... with 1n4004 diodes and UV LEDs I can get twice as much indicated current in the M3, M4 positions than in the M1, M2 positions, both with the 1 ohm CVRs (voltage drop) and by disconnecting the CVRs and using milliammeters directly in circuit.-end quote:

I will be the first to admit that DMM's at high frequencies can give incorrect reading's,but do we also have a situation as to where we cannot use CVR's and a scope to read the amount of current being sent to and consumed by a system?

Like TK said,i make no claim's what so ever with this circuit.
I simply came looking for answer's,and to have TK build the system and have the same sort of result's is an added bonus.
That is why i freely gave my system for other's to replicate and test-to find answer's.

If some one can come forward and not only tell me,but show me a system where current cannot be measured in a similar situation useing a scope and CVR's on the input and output-then i guess i have the answer i seek.

I also see it mentioned that the two seperate systems have to be taken into account.
My question would be why?
Im not interested in what the power supply uses under load,im interested in what the system that is showing a current increase is useing.
The reason why i think like this is because every one else dose.
If you have a good bench top power supply,and you want to know how much power your system is useing that you are powering with your bench top power supply-do you take into account all the power being consumed by your power supply?
I think the answer is no-you only take into account what the amp and volt meter on the power supply is telling you what your system is consuming.

The SG is my power supply,and i wish to find out how much power is being consumed on the output by the system.
Im happy to have recieved the ! why it's happening ! explanation's,it gives you reason to go and reserch these thing's and learn.
So now were looking for the ! how to ! measure correctly ?

  Brad

[tinman]

.99 said, I'm glad to hear that, because my ProsKit cheapo RLC meter, and my Fluke 83 on capacitance setting, also behave pretty much the same way. I wonder what's different about TM's meters that allow them to give readings when ours don't.

I think we will have to dismiss the 49.47pf on my coil.
I decided to go and make a short video to show you all how i got that reading.
So upon hooking the DMM to the coil(set on capacitance) i then got a reading of 1.23nf?
So i disconected again and reconected once the meter zero'd out-i got 436.0pf

So i think we had better chuck that one in the bin-i should have tested it more than once(in to much of a hurry)
Useing my analog meter-i get nothing.

So TK-your readings are correct-mine were wrong.

[conradelektro]

@Brad (tinman): you are right, it is intriguing and should be explored. Thank you for the explanation and for showing your circuit. Much can be learned.

Greetings, Conrad

[MileHigh]

Of course a capacitance meter expects an open circuit when it's supposed to measure the capacitance and of course an inductor is a short circuit.  So the capacitance meter is not "happy" when you connect an inductor to it.

The real answer is that the coil can be modeled as an inductor in parallel with a very small capacitor.  This is another form of a filter where frequency comes into play.  To really understand whatever coil you are looking at would be to understand how it looks at all frequencies.  As the frequencies get very high some capacitive effects will come into play.

Tesla pancake coils are designed (I believe) to put coils in contact with other coils that are "far away" in the loops such that they will have a higher voltage gradient between each other.  So that allows the normally minuscule capacitance to get a "voltage boost" to store more capacitive energy.  The two coils are also further away from each other on the coil transmission line, and that gives them more of a chance to act "capacitive" at high frequencies.

To bring this back to reality and also add a disclaimer, these effects are all very minuscule, and for a regular coil you simply ignore the associated high frequency capacitance.  If you want capacitance, you add a capacitor to your circuit.  The disclaimer is that I have no direct experience playing with coils like this, I never had reason to.  Also I am not a high frequency analog expert by any mans but the gist of what I am saying is correct.

This experiment is really all about exploring how an LC resonator works.  There are two types as E2matrix stated, a parallel and a series.  This actually a classic basic electronics experiment.  You first learn how a capacitor works in the time domain and then the frequency domain.  Then you learn how an inductor works in the time domain and then the frequency domain.  Then you move on to understanding things like LC circuits.

As Poynt mentioned, you also need to understand power flow and impedance matching.  When a battery outputs power, where does the power go and how come some components dissipate more power than others?

Try looking up "LR circuit" and "RC circuit" and then "LC circuit" and "LCR circuit."  The Wikipedia entries are too technical and get into the differential equations to solve for the behaviour, although there are some nice plots that show you whats happening.  But for sure there will be other links that come up that give you more friendlier explanations.

Going back to this circuit, it's kind of a somewhat mangled LC circuit with extra diodes in the loop, but in principle the behaviour is the same.

Doing a search on "basic circuit analysis" (the name of a course that strikes fear in the hearts of first-year engineering students) would be helpful also.

MileHigh