Joule Thief

[innovation_station]

well  i let them sit there after being charged ...  for 2 plus hours i looked at the meters  they  say  3.25vdc in 2 0f them and the other 2 i had 2.01vdc    the reason for this would be i had previously charged the first group a cupple times   so yes over time it does drop down  a  bit but after a few charges i expect it will even out ...

ist!!


here is a picture of the finished unit all mounted tested and working properly ... 

[nievesoliveras]

well  i let them sit there after being charged ...  for 2 plus hours i looked at the meters  they  say  3.25vdc in 2 0f them and the other 2 i had 2.01vdc    the reason for this would be i had previously charged the first group a cupple times   so yes over time it does drop down  a  bit but after a few charges i expect it will even out ...

ist!!

here is a picture of the finished unit all mounted tested and working properly ... 

@ist you are a hard worker! It seems that you never rest.

Jesus

[electricme]

@RAF,
Never mind about making mistakes, we all do, and I have made some biggies.
Better to point out that you did something wrong and provide the correct solution rather than trying to think they will never figure it out lol.

@ Bill
Thanks for your kind words to me just before.

Now wouldn't it be something to power a lawn mower via a JT, that would save some liquid juice.

General Jim

[hazens1]

Took back my super cheap $30 Radio Shack DMM and bought a somewhat cheap $70 one that has PC interface, Pulse Width, Duty Cycle and Pulse Frequency. Wow, so much easier to determine what is going on when you can analyze the frequency stuff the transistor is doing!

Wish I could justify $250-$350 to get a good Fluke, but the wife would kill me if she found out I spent that much on one   She already thinks I have to many hobbies already.. Stunt Kites, Traction Kites, Kite Buggying, RC Helis and Airplanes, Video Game playing and programming...

Also searching the net, I came across a post about 555 timers and the JT and this guy has some pretty awesome circuits. My appoligies if this particular souce of info has been posted already, but here it is..
http://forum.allaboutcircuits.com/showthread.php?t=19075

I have 2 JTs running Since last Friday/Saturday. The battery on the one with the 3 led push light circuit is down to 386mv loaded and still going! Amazing! I measured the transistor and it is currently oscillating at 320khz with a pulse duty of 15.5% and a pulse width of 0.485 microseconds or 0.000485ms. The other one is at 1.282v loaded and is running 3, 4v 28,500mcd ultrabright white leds in parallel. That one is running 24khz, pulse duty 63%, pulse width of 26 microseconds or 0.026ms.

I also picked up a few tlc555 timers. I can't wait to expiriment with them!!

[jadaro2600]

Strange observation:  I was attempting to measure voltage across different components in the circuit and noticed that the voltage across the LED is the same as the battery but the voltage across the primary resistor -> toroid -> base connection via the positive terminal across the resistor is infact higher than the voltage of the battery.  Increasing the resistance  also increased the voltage.

Is this a product of the action of the  field collapse?  And why would the voltage across this resistor be higher than the battery while the voltage across the LED is the same as the battery?  Here is the circuit I am using - I am using a special coil in place of the ferrite cored normal, but it has the same effect.  I'll have to wait a bit for antialiasing in the dia program.