Joule Thief

[innovation_station]

hello everyone here is what i was building yesterday it is a voltage divider

this will be charged from 1 ring and a aa battery and then it splits into 6 switched feeds of 1.2vdc x6 from 4 3.6v cordless fone batteries ..

i would have used super caps but the last investor was too cheep to buy them ...  so i walked ...  lol

and here we are ... 

but yep i will wind the ring todoay that will drive this divider   

this powers the 6 pac from 1 aa or crank or solar or closed loop i dont care ...  it dosent matter ...

i hear they like solar .....as they say it comes from the sun     it is not ou .... lol

solar the world understands ...   perpetual engery .... well   the world aint there yet ...



ist!!

[gyulasun]

@ jadaro2600
you are having trouble in working out how come the current passes through the transister? is this right, relating to the JT?

Well I don't know if I could help you on this, as I am not sure how it works, but some how hi frequencies are involved in this process.

The JT steps up the voltage big time, in the process  the current falls to amounts that we carnt measure accuratly.
Some of us have got small voltage in our torids, some of us have got hundreds of volts.

The higher the voltages and frequencies and 1.5v turns into stuff that we don't know about, its almost like smoke or a mist but it can light up LEDs left right and center.
Example is Bills (Pirate88179s) work he pioneed on lighting up literally hundreds and hundreds of LEDs, all on a simple 1.5v AA battery cell, actually I take my hat off to him because he deserves recognition for this, he is the first person in the world who has successfully done this.
That is why this thread seems to have 2 or more seeminly different topics all going at the same time, they are all related and find their roots here on the working of the JT circuit.
When I built my first joule thief, (in the early days) I also made a test LED, it had 2 wires connections, the LED would not light from a 1.5v aa cell fully charged.
But put the same LED on a joule thief, and viola, light shone out of it, using the same test battery.
Anyway, mabe there would be others who would have a better explination than mine, if you do, please hop on and tell.

Hooroo
General Jim 

Hi Jim and All,

jadaro2600 opened a new thread for his question and I tried to answer his LED/collector current question there, see this link:
http://www.overunity.com/index.php?topic=6905.0

Now let me briefly discuss how the JouleThief circuit operates and how may you improve it. If the principle was already explained I apologize I did not search for it in these long threads.
So it all boils down to induced voltage in a coil when you interrupt the current flowing in it. The collapsing magnetic field induces a voltage pulse across the coil, the polarity of this pulse is just the opposite of the DC voltage you switch across the coil to make the current flow in it.  The formula for the induced voltage is V_induced=L(dI/dt)  where L is the coil's self inductance in Henry, dI is the current change in the coil in Amper and dt is time in seconds under which the current changes.
So you see the higher the current change and the shorter the time, also the higher the coil's self inductance, the higher the induced voltage you receive across the coil.
This means you can get higher flyback pulse by using a fast switch. A higher amplitude pulse can lite up more LEDs in series  because the LED forward voltages add up and you have to defeat their series resultant voltages. 10 white LEDs in series needs at least a 35-40V peak pulse to create and also get some light with certain intensity. You can combine LEDs in parallel from the series chains.
Let's make a small calculation with the formula above, say you switch on 50mA via your 1mH coil in 1usec.  Then the induced voltage will be:  (0.001H*0.05A) / 0.000001sec=50V  If you are able to switch faster than 1usec in a JT circuit then you get a higher pulse in the calculated example. 
An extreme example is the spark transformer in cars where you switch a 12V battery to the tapped coil and receive 30-50kV peak pulses. (It is a heavy duty JT if you like, inputting some Ampers at 12V.)

Here is link on using a transformer (basically two coils instead of one or one coil with a tap if you like): http://www.maxim-ic.com/appnotes.cfm/an_pk/1109/

No need for using the Maxim specific ICs for the job, a JT can be adapted for the transformer circuit,  basically also an autotransformer with 1:5 or higher up-transformation ratio.  You simply connect the collector to the tap of the coil and instead of the D1 fast diode you connect the series of LEDs towards the negative pole of the battery like in the JT.

rgds, Gyula

[RAF]

Oh good lord !!!!! I am soooo sorry to all

Some times one should get some sleep then try again before posting
Got up this morning caught up on the thread grabbed my JT and drew up the circuit
post it.
Tore apart an old power supply to get the fan to see if the same thing would happen.
All of the voltages where wrong Dazed and confused (a normal state of mind for me)
tried to get the voltages back.
Suddenly remembered i was working with the fugi camera transformer   
I have run out of time but will post the Fugi circuit latter tonight

Again i am sorry to start a confusion with the toroid and the fugi transformer

[innovation_station]

well this unit works awsome .... 

i now have 4 fully charged fone batteries in less than 15 min from a aa battery ....

they do drop off a wee bit after i stop chargeing them  but not below 3.4 v dc    all 4 were verry low b4 i hooked them up ... 

i have not powered anything from this unit yet but i will do that soon



ist!

btw im only useing 2 feeds from the mk2 to test it ...  there is still 2 free coils on the toroide wich i will add to the unit    i think charge time will be cut in half ... 

[nievesoliveras]

well this unit works awsome .... 

i now have 4 fully charged fone batteries in less than 15 min from a aa battery ....

they do drop off a wee bit after i stop chargeing them  but not below 3.4 v dc    all 4 were verry low b4 i hooked them up ... 

i have not powered anything from this unit yet but i will do that soon



ist!

btw im only useing 2 feeds from the mk2 to test it ...  there is still 2 free coils on the toroide wich i will add to the unit    i think charge time will be cut in half ... 

Did you tried to power something with the charged batteries to see if the charge is not illusional?

Jesus