Joule Thief

[Mk1]

@jeanna

My point is  to get a higher voltage you may need to make some improvement on your design, using a pot will help determine if you are really going the right way quickly. Every time you change the coil ratio you retune the pot , monitoring the voltage out with the meter and bridge and the scope , then you will have total control over the variables, any and every changes you make to the toroid primary or secondary can change the freq ,
of the jt , changing the freq changes also the power out.

Mark 

[TheNOP]

If I understand this right, if I wind a single secondary coil on a JT, and the more turns I put on the coil, then the higher the voltage will rise, up to a point.

yes.

there is a case that will not have the same effect.
if the primaries are inbetween the pickups coils and they are not a mirror of each other.
in that case, there are 2 different current flow, one fighting the other.
same goes for the pickups if not connected correctly.
but those are not a problem with a single pickup coil.

So if the JT battery had a higher current supplied to the Bifilar windings, then there would be even more HV output? Could I switch higher pulses by paralleling the JT transistor?

the current supply is not a problem, the voltage of the supply and/or the circuit's resistance are.

i mean, what prevent current to pass through a circuit ?
it is resistance.

there are 2 ways to work around that, either make the source voltage higher and/or lower the resistance of the circuit.

So, if I wind, say 32 secondaries using, say 12turns each, then each output will be 12v but at a higher milliamp?

see above comment.

the coils are in series on a toroid.
but putting them all on the same load is as if you were putting them in parallel to the load.

if the load is, let say 32 Ohms, and all coils are connected to it in parallel.
what will be the total impedence of all coils is the question you must ask yourself.
same question, if you connect them in series.
that total impedence is what limit the amount of the current passing through your circuit.

ex:
if you put leds in series you are increasing the resistance of the load.
by putting the leds in parallel you are lowering the resistance of the load.
the total impedence is really load sensitive.
the way you connect your coils and the load(s) only depend on what you want to achive.
amps = volts / ohms

http://en.wikipedia.org/wiki/Electrical_load

this is far from being the whole thing about impedance.
unless you are very familiar with every aspect of Ohm's law, understanding impedance can prove to be chalenging, as it include a time constant.
http://en.wikipedia.org/wiki/Electrical_impedance

I wonder what will occur, if I drive 4 extra toroids off each of my outputs?

you mean 4 toroids with only one coil of each connect in parallel to the jt's collector coils + theirs pickup(s) ?

i think you should get more current from the battery that way.
but i am not sure for one reason.
since they will be sharing their fields colapses, the impedance of each toroid, if different, might cause unexpected results.

also, due to induction, those toroid should not be near each other.

[resonanceman]

I think 275V is pretty strong for one half of the secondary winding.
I have 2 halves like that if I use a certain resistor, so I am not concerned about getting the biggest output. I am concerned about what happens when they are added together?

Jeanna

This is why  I  put  my  feedback  in paralleled  rather  than trying  to make them add in series .



If  you look  at your scope and think about  time ............I think you will have your answer .
They  do not add up right because they are out of  phase with each other .
Part of them adds .....part of them subtracts from each other .



gary

[jeanna]

Jeanna

This is why  I  put  my  feedback  in paralleled  rather  than trying  to make them add in series .

....part of them subtracts from each other .
gary

Thank you Gary, I was afraid that was the answer.

I think there is more to the parallel thing. I may start the ac joule thief thread soon. I want to explore all this jt and secondary/pickups in parallel circuits and maybe more, and see where it can go.

thank you,

jeanna

[electricme]

@TheNOP,

Thank you for this answers to my question.
They are the reasons why I wound my last parallel secondary.

Now there is only one more question from me, but first I want to say how I think how the magnetic field in the toroid goes like.

If we put a tiny current pulse into the toroid, via the JT circuit, then we will only get a small magnetic field to work with.

If the same toroid was hit with a more intense jolt of current, I would expect a more intense magnetic would circulate inside the toroid.



I am asking this, as I see many of the toroid's which I get from printed circuit boards are already wound with very much heaver wire, input and output.

This tells me that the toroid is capable of working with a very more intense magnetic field, and or is capable of soaking up a more dense magnetic field.

So I think if the toroid is pulsed with a higher amperage, it should put out a higher output from the more dense magnetic field/s in the toroid.

I am wondering if I should put another NiCad in series (1.2v+1.2v =2.4v) to achieve this, but keep the JT running from the 1st 1.2v battery.

jim

@all,

I know if I connect in series, any 1.2v or 1.5v, or 12v batteries, I can raise the voltage of the battery set.

Has anyone got any knowledge on how to do the same using a EB?
To my way of thinking it should be [possible, but has anyone ever done/achieved this?

jim


Lastly
My new round EB is as follows.
9/6/2009  at  5.00pm = .771v
9/6/2009  at  9.00pm = .760v
10/6/2009 at Midnight = .780v
10/6/2009 at  6.30am = .800v
10/6/2009 at  8.00am = .802v
10/6/2009 at  9.00am = .803v
10/6/2009 at 10.00am = .804v
10/6/2009 at 11.00am = .805v

jim