Joule Thief

[freepow]

@ Markdansie

I will post some results that I posted some pages back!

I think I may have come on to something, not sure yet, but my low draw joulethief has 1x AA rechareable
battery
for the run battery, and I have my 50F supercap for the charge cap, and I have it running back into the AA battery, my interesting results so far is this...

When I adjusted the Var-res at just the right spot, the results were strange...

                                                                       RUN BATTERY     SUPER-CAP

                                                                            1.229v             .910v
                                                                            1.239v             .920v
                                                                            1.241v             .925v




By adjusting my var-resistor to the  spot with where LED lit at the lowest light level (still bright)

results so far over a short interval of time...            RUN BATTERY     SUPER-CAP
                               
                                                                            1.252v              .805v
                                                                            1.255v              .804v
                                                                            1.257v              .803v

Then I adjusted the Var-res to the spot where the LED lit the brightest (very bright)

results so far over a short interval of time...            RUN BATTERY     SUPER-CAP

                                                                            1.128v              .870v

But now I have found the spot where this is happening...
                                                                            1.238v             1.010v
                                                                            1.238v             1.040v
                                                                            1.238v             1.044v
                                                                            1.238v             1.052v

I can literally charge either one up by simply adjusting the Var-res or charge both up at the same time !
I may be onto something, and the LED is lit bright or super bright while I am running this joulethief and charging at the same time.

[markdansie]

Thanks freepow,
would be interesting to run it again...perhaps use a battery that was slightly down to begin with.
Many thanks
Mark

[markdansie]

@freepower,
many thanks for posting the results again..saved some work here going back. What time frame were those results taken over?
Might I make a suggestion.....put a larger cap on and see how long it takes to charge that up an either maintain the batery voltage or have both charge up together. If you can achieve what you have already there is no reason it will not sustain itself.
Jut one other question...how long wa this able to run for maintaining the batery voltage, charging the cap and powering the led?
Definately worth investigating further.
Kind Regards
Mark

[dasimpson]

   Guys:
   I had at one time thought the same thing about a step up, and the step down transformer, for more current.  Jeanna mentioned that she had tried it, and that she did not have much luck with it, as a bulb lit for a very short time, only.  There still may be a way though...
  Leds bulbs do like a certain amount of mA also to light all the way,  on not just voltage. I think there are Jtc that do output more current,  like my one inch toroid (shown) that uses a  76 - 76 turn primary,  only.
  The picture is of one of my Captret- Jtc that I'm working with now. Tonight it is lighting a dozen Leds so bright that I'll probably have to toss them in the trash like so many others that I've burnt out, due to the cap surges.  I'm still unable to locate any pots to control the voltage going to the bulbs.
  I've been  trying to find a balance point so that the batteries which are now several days old (and only dropped a volt) will keep up with the load without going down, down, well,  you know...   With one led its a lot easier to do, than when adding a dozen or more.

best way to control the voltage would be put a pick up coil on and find the amount of turns needed for the voltage you wont

[NickZ]

   All:
   I already have the Captret- Joule Thief selfcharging, but only using one or two leds on it.  If I add more leds like last night it was running on 12 leds very bright, it may not be able to keep up that many. This is what I'm working on now, since the draw has to equal the charging ability of the Captret part of the circuit, or it will run down.
  I also have several other Jtc that are running and charging one or two AAs, off of a single AA, and I can also swap them back and forth.    But the Captret-Jt was lighting the leds all week on the same batteries without discharging them by more than one volt.  I still don't know if the Jt part is actually needed at all, as it may be that it is only hanging up the Captret circuit, or a custom made Jtc needs to be made just for that purpose, possibly with no resistor. More tests are needed, but so far I can say that my Captret-Jt will run without discharging, on one or two leds, for at least severals days.  A small solar panel will take care of any further voltage drops, and bump up the charge when needed.
  I'll upload some more pics, soon, but the one shown is of my tiny Bumble Bee Solar Jtc, still self running after 6 months.
               NZ