Joule Thief 101

[tinman]

 author=poynt99 link=topic=8341.msg480910#msg480910 date=1460809484]

The scope capture and schematic would be 100% correct if it was denoted with either dot convention on the transformer, OR stated that CH2 is inverted. What part of that are you having difficulty understanding?

I nor PW and TK any any difficulty using the associated scope shot to answer the question asked. The scope shot presented was correct in that it provided the needed information to answer the question. The question was presented to minnie,in order to determine if he had the smarts to make judgement on me,and my induction skills. CH2 was inverted for this very reason--so once again,the scope shot is correct for the question asked.

How is it that I am adding confusion? Tell us then,

Because the question was aimed to determine whether minnie had the skill set to pass judgement on mine. It was not suppose to show a correct or incorrect polarity of channel inversion. It was set like that as a test,and a question was provided in regards to that test.

if someone built your circuit and placed the probes precisely as you have, and did not invert their scope channel nor flip the transformer leads, would they produce the same wave form as you showed?

No they would not. But  if the same question i asked was associated with there wave form,then the very same answer would be correct.

Will they not be confused when they see the secondary voltage leading the primary
current?

Not if they know what they are looking at,which was the very reason i asked minnie the question--to find out if he had the skill set/the right to say i needed to learn basic induction.

This is exactly what i mean by !!adding confusion!! to add something that is not related to the question asked in regards to the scope shot.


Brad

[poynt99]

Good, thank you for acknowledging that.

For future reference, I strongly encourage you to note scope channel inversions or coil lead flips on your diagrams and/or descriptions, regardless of the purpose of the post.

[tinman]

Good, thank you for acknowledging that.

For future reference, I strongly encourage you to note scope channel inversions or coil lead flips on your diagrams and/or descriptions, regardless of the purpose of the post.

As you will see(in most cases),i do exactly that. But if i had done that in this case,then the question is already half answered for the person asked.

Anyway,have you had any more thought toward the effect being seen in my little experiment?.

I in no way can see the change in impedance being the cause for the drop in current(power-as voltage to primary is fixed)to the primary coil. I have used what i know to determine this,and so that is why i asked you the question regarding-what can change the impedance of a transformer,as there may be something i have over looked,or do not know about.
I do not count a CEMF from the secondary reducing primary current as an impedance change,as in most cases,an increase in secondary current would result in an increase in primary current.

Due to the fact that we have a decrease in primary current as we get an increase in secondary current,then a change in transformer impedance would mean some sort of positive outcome impedance increase on the primary,where it has the opposite effect we would think it should have.--what ever that means?,and hence my request for some information.


Brad

[minnie]

   I haven't got much interest in the circuit, the point I was trying to make was
   understanding the very basics of magnetism and induction. Lorentz and Einstein
   and that sort of stuff.
      You have to accept a lot of that to be right,study "The Moving Magnet and Conductor Problem"
   can be found on Wiki.
      It's got to be a bit of a joke all this argumentation over a transformer where you
   have dots to show the way
       Otherwise fritter and waste your life away sniping at MH.
               John.

[poynt99]

Anyway,have you had any more thought toward the effect being seen in my little experiment?.

I would be seeing what polarity emf is induced in both the secondary and primary from the magnet motion alone (you've probably already done that). I'd also be attempting to determine all the phasing and timing, as MH suggested, in order to try and piece together what is happening throughout the process.

Do you think the same effect would be present if your air transformer was just a simple 1:1 ratio? Have you tried it?