Joule Thief

[Koen1]

I just wound a new bar last night it has 21 turns wound first then 7 turns wound on top of that. all wires are wrapped close and tight and insulated between the layers. and centered on the bar. if i take the 7 turns and connect that coil to the collector and the 21 turn coil to the base i get almost all battery voltage going to the trans. plus the led is very bright.  if the coils are reversed i only get half the voltage and the led is dim. i think if i used a fully charged battery it would blow the led it is that bright. it also ran all night with very little battery voltage drop. what i don't understand is that the voltage measured at the led but after the diode

Where is this diode in your circuit? Does the voltage perhaps increase if you use 4 such diodes as a rectifying bridge? 

is a small minus voltage like -.04 volt.

i think i like bars they are so easy to wind and seem to work just as good.

Yeah, apparently all kinds of other coil configs work for a JT, not just the ferrite toroid core type.
I have seen simple air-core coil versions that appear to work quite well too, and of course
there's the braided/entangled iron- and copper wire type which seems to work,
and Jeanna has been using a carbon toroid recently, so yeah I suppose a bar wound
coil will also work, sort of a crossover between air core on the outside and solid core
on the inside...
The fact that air-core and even braided/entwined wire versions seem to work almost
just as well would seem to imply that direct induction either plays a role in the effects
we're seeing...
... right? (If anyone disagrees then please point out why? )

Kind regards,
Koen

[TheNOP]

without a pickup coil(s) there is almost no "transformer action".
the "transformer action" is only to oscilate the transistor.


when we interupt a current flow in a conductor the voltage will temporarely rise in the conductor.
those spike, correspond to the collapse of the mag field that was created by the current flow.
but, when current is interupted, there is no circuit path for the currents anymore, there is no currents flow, it is just rising the potential.

to understand how those voltage spikes are created, one need to add a time constant to the equations.
the voltage measurement we are taking are in reality volts/second, but it does not take a second for a mag field to collapse.

a coil is much like a capacitor in a way, it store energy in the form of a mag field and can release it faster then it take to fill it.

[jeanna]

...
2. Am I ( or am I not ) the only one that's operating the transistor in such a way as to completely turn the transistor on?  ...is there anyone that's NOT using it in this way...because not using it in this way would indeed result in transistor resistance, and thus, there may be less amp drawn from the battery?    ..and the result may be heat on the transistor?

Hi Jadaro,

I am using the transistor as a switch in the way of  xee2's description.
I do not get overheating.

AbbaRue gave me a bit of vital info a while back (350 pages ago, maybe) He pointed out that
fewer primary turns will use more amps, and will make the transistor heat up . He also used the words stress the transistor.
More primary turns will cause heat in the primary wires themselves.
So, the 'art' is to find the medium place.

---
I was hunting down information and found a really good site. It is from New South Wales. The teacher made the site for personal reasons after watching high school teachers be told what to teach or something like that - political reasons. The High schools were being told to teach history of physics and not physics, so he put up this excellent site for high school physics remediation. 

Unfortunately for math deprived americans, at least, understanding AC requires comfort with calculus, because everything is moving in curves every moment. It is easiest to default to DC laws and muddle through. However, I am convinced that while we can muddle through this, it might be easier to face the dragon.

So, I read all the words and watched all the flashes, and it really is very good information.

One piece of information that is very relevant is that at high frequency, the voltage rises in respect to the current.
At first, I thought they both moved away from each other, but it seems more that the voltage rises a lot while the current stays where it is.

This is exactly what we are finding.

This explains how it is that we are not seeing plain transformer proportions. What I do like about this is that it is from nonfringe physics. I like the verification.

http://www.physclips.unsw.edu.au/jw/AC.html

jeanna

[jadaro2600]

Ehm... is transformer action not a great example of logical physics? I think I don't follow your statement... Transfer of current between what? Between source and circuit there should be zero transfer of current when
the transistor, used in this case as an auto-switch, is off. Logically, in that phase any "transfer of current"
between the primary and secondary will not be drawn from the unconnected source. But that "transfer of
current" is still induction, is it not? Be it electromagnetic (via the flux core) or direct (wire to wire)
induction, still induction... Right?
If you think I completely missed the point you were trying to make, please tell me?

I say

there is less

, this is referring to the action of the coil to base on the coil to collector with regard to the voltage produced, ..if there is 'transformer action', induction or otherwise, when the coil to base is on and unimpeeded by the coil to collector, then there will be LESS current transfered via this mechanism to the coil to collector from the coil to base, even if the coil is off via the transistor, than there would be in the inverse situation.  This does cause the oscilation action, this is simply a recitation of something that's already been stated here.

My postulate is that there is energy transfered to the coil to collector via the coil to base even though the coil to base may be turned off.  We both admit that even though a coil is turned off, that energy can be transfered to it, right?  ...this would be minimal, but still present.

I can't assume that one is taking pace and not the other - and I have to account for the degree to which it is taking place, because I can rectify the current off the coil to collector BOTH ways and get readings, and one way is significantly less ( yet larger still, than the source voltage ) than the other, but still measurable.

Without a secondary, there is little transfer of current, because when one is off, the other is on, the currents already in them are more powerful than anything 'to be transfered', ON top of that, the path of resistance on the coil to base is much higher than the path of resistance on the coil to collector.  This means that it only takes a little bit of 'transformer action' to turn the transistor off... we both know that's really the trick here on the oscillations; unless the impedance resistance is so high that it matches or exceeds the resistance of the path from positive to the base of the transistor, then there should be some degree of oscillation in the circuit.

With a secondary, there is little current and more voltage transfered because the collapse of the magnetic field is what's causing the voltage energy in the pickup coils.  Someone here stated that if you let a cap charge long enough on a secondary, then you will get current back..this is true, there is transformer action on the secondaries...but;

I say that it is less, because if we thought of magnetic field collapse causing voltage as transformer action, then we would see voltage gains in transformers even in the 1:1 ratio would we not? ..so I say that the whole effect is less transformer action and more logical physics because ...

Yesterday, I took a crap, and when the turd hit the water, some of that water splashed back up but the turd continued falling in that direction.  ..this is a crude revelation of what I mean, but it's like a drop of water hitting a still body of water, the drop goes in, but water there comes back up...    this is something like a magnetic field collapse, barring any potty humor, because a voltage gain can be realized without a transformer, without more then one coil, all that is needed is a single coil (inductor ) to attain a voltage spike.

We have them, generally speaking, setup in such a way as to create an inductive switch, which in some ways, obscures the beauty of the magnetic field collapse causing the voltage, ..if you venture towards the timer controlled circuit, there is no induction which triggers the oscillation, only a timer.  IN a way, this is more reliable because it becomes less reliant on ambient temperature for oscillation frequency, but in as much as it is reliable, it is costly to run via current.

Obviously, with temperature, the cores would change their dynamics a bit - this is all hinging on the fact that magnetic fields begin to fail at elevated temperatures.

And why did you think that, if I may ask? (yes sorry for the annoying question )
Ehm... perhaps I misunderstand your remark, but yes, there is polarity, it is positive or negative, and yes, that is just a relative difference in
potential between two points. I fail to see the problem... ?

Regards,
Koen

The reason I say that, is the magnetic field collapse causes a voltage - I've apparently been fooled by my own drawings though.  I forget that one of the windings is reversed to the other, so disregard my musings on the polarity of voltage ( or lack thereof ), it's an oversight on my part.

I just wound a new bar last night it has 21 turns wound first then 7 turns wound on top of that. all wires are wrapped close and tight and insulated between the layers. and centered on the bar. if i take the 7 turns and connect that coil to the collector and the 21 turn coil to the base i get almost all battery voltage going to the trans. plus the led is very bright.  if the coils are reversed i only get half the voltage and the led is dim. i think if i used a fully charged battery it would blow the led it is that bright. it also ran all night with very little battery voltage drop. what i don't understand is that the voltage measured at the led but after the diode is a small minus voltage like -.04 volt.

i think i like bars they are so easy to wind and seem to work just as good.

I once did a similar thing with a needle,  I wound many turns of 30 gage wire around it, and then wound about 14 or so winds around that of 26 gage wire, by running the inner coil to the base and the outter coil to the collector, I got a larger collector voltage than I did in the opposite configuration.  This is nearly opposite the effect seen in the toroid setups, I assume that it is because the more winds, the larger the flux..etc.  Maybe things are a bit different without a ferrite core, maybe what we did isn't so similar?

@TheNOP,  This is what I was trying to say, and you quoted me,  but there's nothing showing up in the box? So I assume it had something do do with transformer action?

[jadaro2600]

Hi Jadaro,

I am using the transistor as a switch in the way of  xee2's description.
I do not get overheating.

AbbaRue gave me a bit of vital info a while back (350 pages ago, maybe) He pointed out that
fewer primary turns will use more amps, and will make the transistor heat up . He also used the words stress the transistor.
More primary turns will cause heat in the primary wires themselves.
So, the 'art' is to find the medium place.

...

jeanna

I wouldn't dare make you read my most recent post an reply, so I put it here instead,

I'm not quite sure what you mean by primaries, but I can assume from your latests interest with the MK2 and Hazen's  designs, that putting less turns on the coil to base and the coil to collector is what you mean?  This makes sense, as a strong field is a good thing, so, I can imagine that fewer turns means less flux generated...and more turns mean more heat gnerated.. and you're right, there's a balance here / there.

But wouldn't putting ( interleaving ) the windings create a stronger effect .... I'll post a picture of a toroid I've been working with,

This would lead to less energy spent on creating the desired effects.

The way I have this setup, if for use with two transistors, two joule thief's setup on the same toroid with the same resistor in front of the base, all coils are wound opposite...but this is irrelevant, I got it to work, but with much less voltages produced.

The Idea is as Illustrated, the red wire is the coil to base and the green wire is the coil to collector, the blue wire is the secondary.  In this way, I picked up more voltage from the collector coil than in the secondary, proving, at least, what you've mentioned.

My idea is that putting the coil to base inside the coil to collector would yield a higher voltage across the collector than putting it next to the coil to collector.  Not working with secondaries....  and so, imagine then, the black wire is then wound with the red wire ( moving it ), red and black wire being primaries, and then the green being a secondary ( while for now, disregarding the blue wire ).  This would put the magnetic collapse closest to the secondary.

I'm currently testing many configurations on this toroid.
---
I can understand stressing the transistor, I think, from what I've gathered, that when there's a load available, and the transistor is off, then it will be less effected my the higher voltage - which can just as easily be diverted away with a diode and a load.

*edit, forgot to post the picture. And edited some keywords.