Joule Thief

[gadgetmall]

@timmy1729
      I posted this schematic several pages back but no paid attention to it so i thought id post it again . It requires you make your toroid with another output winding and it does feed back to the battery and it does prolong the life of a dead battery on this Joule thief . It works . Not ou but you can see it boost the voltage when you feed it back .

[TheNOP]

Try something like this.
You have to find the way to connect the negative and the positive output of the bridge back to the battery or the negative and positive of the LED. Also you can connect a second battery to the bridge output and it will be recharged. The LED will turn off while charging another battery.

Jesus

did you tested that ?

what is after the first diode that is not before it ?
the answare is : nothing

the part of the ac cycle before and after the first diode are the same.
you simply have rectified the ac, removed a half of the ac cycle, and reduce the volts a bit by .707

and why should the led turn off while charging ?
the led is in parallel with the bridge.
unless the battery being charge use all the available current(short circuit), the led will still light.


the schematic timmy1729 posted show 2 rectifying circuits.
the first diode + the cap is one
the bridge is the second.

the first diode rectify half of the ac cycle,  the bridge..., only a half too.
since it is connected after the first diode, only half of the cycle reach the bridge.

note that the bridge rectifier also drop the voltage by 1.424 volt
think about before trying to charge a second battery.

as it is, i would not try to charge a second battery, the joule thief is not a OU device yet.
hooking the output of the bridge to the input will do nothing else then change the frequency at witch the circuit work.

[TheNOP]

@gadgetmall
more feedback..., i must test this.
thanks

[gadgetmall]

@TheNOP
     Hi . What do you need to know . i posted this 10 20 3050 pages ago . This thread is so full of different experiments it took me two days to read thou them all just to catch up . I posted this experiment with a picture i think . I still have this one . make a regular Jt bi with 40 turns . i used a computer toroid not the large one the next size down maybe 3/4 inch . copper wire . then i took the real thin 32 which is a pain to wind cause you have to string it out first and make sure it does not  tangle .. I wrapped this in between the the regular windings 100 times . it didn't go around all the way . i think if i had the patients you can wrap 500 or more times but i did 100 .. then i wrapped another unused winding that lights an led but it dims the other one .. I used the pots to adjust the bias and frequency to obtain light and positive feedback . you will see that the battery voltage will increase when you connect the feedback up.. Edit .. Dang W"W" Key is sticky . I know how to spell rapped 

[nievesoliveras]

did you tested that ?

what is after the first diode that is not before it ?
the answare is : nothing

the part of the ac cycle before and after the first diode are the same.
you simply have rectified the ac, removed a half of the ac cycle, and reduce the volts a bit by .707

and why should the led turn off while charging ?
the led is in parallel with the bridge.
unless the battery being charge use all the available current(short circuit), the led will still light.


the schematic timmy1729 posted show 2 rectifying circuits.
the first diode + the cap is one
the bridge is the second.

the first diode rectify half of the ac cycle,  the bridge..., only a half too.
since it is connected after the first diode, only half of the cycle reach the bridge.

note that the bridge rectifier also drop the voltage by 1.424 volt
think about before trying to charge a second battery.

as it is, i would not try to charge a second battery, the joule thief is not a OU device yet.
hooking the output of the bridge to the input will do nothing else then change the frequency at witch the circuit work.

I was trying to help the guy with the modification he made.
Yes I tested it and it charged a battery in fifteen minutes to a charge that it was used to run the same joule thief with it.
The way I did it is as depicted on the circuit included here.

Edit:
The only change was that instead of 1k resistor I used 220ohm. With it the light is brighter and charges a battey in fifteen minutes. If you use a power supply set at 1.5 volts as input the battery is charged fully in a couple of hours. Do not let it overnight or the battery will leak everithing that has inside and make a mess.
Jesus