Joule Thief

[timmy1729]

For those of us who are inexperienced and/or learning this as we go along(i.e. myself), here is a great visual interactive diagram on how BEMF works.
http://www.magnet.fsu.edu/education/tutorials/java/backemf/index.html

I am going to try this simple setup when I get home this afternoon! That totally makes sense now! 
My question to you experienced guys is where would I put a diode in this setup(a la Bedini) to redirect the BEMF

[innovation_station]

http://www.magnet.fsu.edu/education/tutorials/java/ignitioncoil/index.html

Speaking of BEMF, this is a very simple introduction to the induction in Tesla coils and ignition coils. Even I understand what it shows 

nice TIMMY ...


i have a few mods for that unit too!!!

sheesh ...... tho ....   can you repost it in 1 week so i can then get to it     

im just trying to finish that little green thing ... lol   yea ... well that and everything else i have started then imagine the carpet RIPPED OUT FROM UNDER YOUR FEET!!! 

but i move along as time stops for no man YET !!  lol 

ist!

so i hooked up the super cap it charges to 2.1 v off of the bridge ...  so i was thinking of hooking up all the - to the super cap and the neg from the bridge    then the pos from the bridge into the super cap then 2 resistors off the pos of the supercap to each battery ... 


but what value resistor ??   will this work ??  i want the cap to fill first then i want to slowly drain in to both batteries ....


IDEAS ...  ?!?!?!?!?!

[xee2]

@ timmy1729

The voltage across an LED is a function of the diode current, not the voltage put across it. The voltage usually goes up with current, but in your case it seems that the LED voltage is decreasing with increased current. Increasing the current should always make the LED brighter, although this may not always be noticeable.  LEDs do not obey Ohms law.

Your links are good learning places. When you try the second demo, use a current meter in place of the light and note which way the current goes when the switch is closed and when it is opened. That is not clearly shown in the demo.

[innovation_station]

been playing round trying to choke back the flow from the super cap to the recharge batteries ... lol

i discover i need a LOT OF RESISTANCE ...  i ended up with 2 1 meg pots hooked togather and it slows it down a bit ....


the answer would be 2 HIGH RESISTANCE DIODES ....     where do i find them ??   i think 2 mega ohm should work great ...  if not im on

the search  for high value resistors ...  if not  i will stick to the post all works as planned .... 

it allows me a BUFFER TIME .... lol in my cap to charge to a higher voltage ...  this is required as i see it ...

ist!

[Pirate88179]

@ All:

I have been approached by someone that wants us to develop a lighting system for them consisting of the earth battery, supercaps and the JT circuit driving leds.  They have looked over our topic here and evidently like what they have seen. I will let you know more when additional information is available.  In the meantime, keep up the great work everyone.

Bill