Joule Thief

[dasimpson]

you could charge at these ampages but you will need some way to control over charge the 9000 would take 3 hours at 0% loss the aa would be about 1 hour at solar noon that is when you are most lightly get the highest output

@ ALL,     I have seen  rechargeable  "C" batteries rated at  9000 mA's  and  "AA" rated at  3000 mA's

              Does anyone know the maximum current I can charge these at with a solar panel ?

Can I charge the  "C" batteries with a  3 Amp solar panel ??
Can I charge the "AA"batteries with a  3 Amp solar panel ??

What minimum volts do I need to charge  2x AA battery rated at 1.25v each ?

[Bizzy]

Good Morning
When using the standard JT schematic everyone has been using to run LEDS, is there a maximum voltage this circuit can handle? or a Maximum amperage
Thanks
Bizzy

[dasimpson]

yeah it tends to be were you start blowing components not every part is the same so it is hard to tell or give a exact point were something will and will not work
the best goal is to use as low a voltage an ampage as possible this way you save power and can run for longer

i would say max voltage is 2.4v anything higher then that you may as well run the led direct off the battery
ampage i guess is the point were components start to get warm for me i wont longivity so i try for as little ampage and voltage as possible at 1volt my jt will put out 50 volts so i can run about 117 leds in series if i run them in parallel i start to lose brightness i find at full brightness the voltage across the led is about 2.9v

Good Morning
When using the standard JT schematic everyone has been using to run LEDS, is there a maximum voltage this circuit can handle? or a Maximum amperage
Thanks
Bizzy

[Bizzy]

Hi dasimpson
Ok Great. I don't need to know exact just a ball park figure. So what you gave me is perfect. I am in the process of adapting my JT to run a small pulse motor I am working on.
thanks
Bizzy

[NickZ]

    Guys:
    I can't really say how many mA are being drawn from the Jt circuits.  But if they don't last all night, with still some usable light output in the morning, I would say something is wrong.  Most of my Jts will last all night and all day,  plus... It seams that the smaller the toroid coil is, the longer the light lasts, still putting out good usable brightness.  3/4 inch ferrite toroids, like come in pc power supplies, work best, and don't take much space.  I'll show what my units look like in my next post.  Most of my Jtc use 3/4 to one inch toroids, and one or two AAs depending on the resistor. Of course the one with two AAs will last longer,  but all I need them to last is overnight, as they will be charged during the day. 
  To charge any battery you need 1. 5 times the voltage over their normal voltage.  The more time spent to charge the battery the better, as there is no heat or other problems related when charging too fast. If you feel the battery getting hot, you'll know that they are getting to much juice.
   Using ready made multi-led bulbs don't work as well on a Jt, even though the light is strong, but they don't last as long, as they use too many mAs.  If using a solar panel that may not matter. I find that using a secondary coil on the torroid, can help the light output, but not the duration. Using the right resistor on your panel to the battery will control the voltage level.   
   I would make it so the led lights are on 24/7, and the battery is charging all day. You can Balance the power draw from the leds so that no matter what, there is no overload on the battery,  and you won't have to do anything,  it can all be automatic, without any switches, or overlead protection.  Or you can buy a charge controler for $20.  The ones that desulfate the batteries with pulses are best, when going at it in a serious way.
   There is no point in using a Joule Thief when using batteries of 2.5 volts or higher. As the JT is a hog, and the panel-battery circuit can be connected direct to the leds, without the JT.  Thus getting All the light intensity from the leds, as they need the 30 mA or so for each led to light 100%.  In that case an led boast circuit can be used instead.
  Hope this helps...