Joule Thief 101

[EMJunkie]

PW, lost for words? Or just lost?

I have already answered all your questions in Image form previously.

Would you be so courteous?

   Chris Sykes
       hyiq.org

[picowatt]

Do you agree that the Only things that Faradays Law Predicts:

   1: The E.M.F
   2: The Sign of the E.M.F

As stated many hundreds of times now, the Sign is Anti Phase. 180 Degrees out of phase from the Source.

   Chris Sykes

All that is required as per TK and Tinman's responses is whether or not the induced
voltage is proportional to the rate of change of the magnetic flux.  All other discussion is moot.

I believe you now realize that Tinman was measuring primary current, not voltage, so
you also now agree that the correct capture is the 90 degree phase difference capture.

You also surely agree that the induced voltage is indeed proportional to the rate of change of
the magnetic flux, so it is therefore reasonable to predict that the induced voltage will be at
a minimum when the rate of change of the magnetic flux is also at a minimum.

Perhaps you are unhappy with the semantics of the word "predicts" and would have rather
had TK and Tinman use something more like "as further supported by" or "as can be deduced from". 

[tinman]

Let's recap...

Tinman posts a schematic and two scope captures.

One capture shows a 90 degree phase difference between primary CURRENT and the open circuit secondary VOLTAGE.

The second capture shows a difference of 180 degrees between primary CURRENT and open circuit secondary VOLTAGE.

Tinman asks "which capture is correct?"

TK responds that the capture showing the 90 degree phase difference is correct, as determined by his empirical study (replication) and by his very lucid argument invoking Faraday by stating that the primary current is a fairly accurate proxy for the magnetic flux and that when the rate of change of that flux is at its minimum so will the secondary voltage be at its minimum.

Tinman also states that his empirical study demonstrated that the 90 degree phase shift was indeed correct  and, as well, also invokes Faraday in further support of his empirical results.

EMJ apparently disagrees with TK and Tinman and claims that the capture showing the 180 degree phase shift is correct, making one wonder if EMJ actually understands the question as presented.  It seems more likely he is arguing about the primary VOLTAGE instead of primary CURRENT, but perhaps not...

In EMJ's post 1585, he presents an ideal transformer graphic supposedly in support of his 180 degree phase shift assertion regarding Tinman's question that only further causes one to wonder if he actually understood Tinman's question, his schematic, his scope captures, or none at all.  The ideal transformer graphic presented appears to be discussing primary voltage (not current) and does not indicate an open secondary.

EMJ in his post #1562 appears to argue in support of both TK and Tinman via presentation of a graphic clearly stating that Faraday does indeed state that the induced voltage is directly proportional to the time rate of change of the magnetic flux.  Which, reasonably, also indicates that the induced voltage will be at its minimum when the time rate of change is also at its minimum (as both TK and Tinman reasoned in further support of their empirical data).

EMJ again appears to argue in support of both TK and Tinman by presenting the copy/paste of a textbook page several times now similar to his post #1658.  In that copy pasta is a "Figure 10.14".  The caption to that figure clearly states that the open circuit primary current lags the primary voltage by 90 degrees and that the primary current is mainly responsible for the magnetic flux which, therefore, also lags the primary voltage by 90 degrees.  This clearly supports TK's original response to Tinman's question. 

So, at this point I have no idea what it is EMJ is arguing for or against.

EMJ seems to argue that the empirical data both TK and Tinman presented is incorrect and that instead, the open circuit secondary voltage should differ from the primary current by 180 degrees.  But EMJ also presents data clearly stating that the correct answer is 90 degrees.

EMJ also apparently disagrees with both TK and Tinman's assertion that, from Faraday, it can be deduced that the secondary voltage will be at its minimum when the rate of change of the magnetic flux (as indicated by the primary current) is also at is minimum.  But again, EMJ posts material also agreeing with TK and Tinman's assertion that Faraday does indeed indicate the induced voltage is proportional to magnetic flux and that the primary current is indeed a fairly accurate proxy representative of magnetic flux.

Perhaps someone else can sort this out...

PW

Tinman posts a schematic and two scope captures.
TK responds that the capture showing the 90 degree phase difference is correct

I will clear this bit up.
I posted only one schematic with one scope shot,and asked minnie if the wave form was correct for the schematic.(he did not answer of course),but TK did,and said it was correct.
The second wave form was added only after EMJ said it should be 180* out of phase-not 90* as the first scope shot showed,and only after TK had already answered the question,and performed his experiments--so i added the wave form with the magnetic oscillator in play with the supplied schematic to give a wave form that represented what EMJ said it should be.. As seen in my video,both wave forms came from the same electrical circuit,but the one that shows the secondaries EMF 180* out from the primaries current,is with the magnetic oscillator in play--the mechanical side of the device is now in play. But a note on that. The secondaries EMF is not 180* out of phase with the primaries current,it is actually in phase now,as the external magnetic field(the PM) rises before current starts to flow through the primary coil-->this is the odd thing i am asking others to consider,as it is the primary coils current/magnetic field that is the source that oscillates the PM and stand.

Anyway-just wanted to clear up the fact that the question was asked and answered before the second scope shot was in play. MH added to the confusion by insisting that the second scope shot was of importance--some sort of loaded question-,but as it was not anything to do with the original question,it was of no importance at all.


Brad

[tinman]

One thing. Not sure.  Does it matter if the secondary is wound first under the primary or as you have it. Just wondering if the effects would be any different.

Mags

Not sure yet Mag's, but i have started building a more powerful unit,and the primary and seconary will be wound on the former together.

Brad

[EMJunkie]

I will clear this bit up.
I posted only one schematic with one scope shot,and asked minnie if the wave form was correct for the schematic.(he did not answer of course),but TK did,and said it was correct.
The second wave form was added only after EMJ said it should be 180* out of phase-not 90* as the first scope shot showed,and only after TK had already answered the question,and performed his experiments--so i added the wave form with the magnetic oscillator in play with the supplied schematic to give a wave form that represented what EMJ said it should be.. As seen in my video,both wave forms came from the same electrical circuit,but the one that shows the secondaries EMF 180* out from the primaries current,is with the magnetic oscillator in play--the mechanical side of the device is now in play. But a note on that. The secondaries EMF is not 180* out of phase with the primaries current,it is actually in phase now,as the external magnetic field(the PM) rises before current starts to flow through the primary coil-->this is the odd thing i am asking others to consider,as it is the primary coils current/magnetic field that is the source that oscillates the PM and stand.

Anyway-just wanted to clear up the fact that the question was asked and answered before the second scope shot was in play. MH added to the confusion by insisting that the second scope shot was of importance--some sort of loaded question-,but as it was not anything to do with the original question,it was of no importance at all.


Brad

Brad, this is not true: