Single AA battery to light WHITE LED for long-long time

[Yucca]

@All,

If you need a home made mini flash light then this is one way to make it.
The few components is soldered together inside the plastic top and bottom
from a used Duracell 9V battery. Use a side cutter to get the top plastic
with the battery connectors off, and also take out the bottom plastic. The
bottom plastic is drilled (5,5mm) for two ultra bright white LEDs. The
regulator need a little heat sink and the way to do that is by placing
the regulator at the + connector metal. I use a little heat sink silicone
compond between the regulator and the metal. The heat from the regulator
is then transferred down to the battery and dissipated to the environment.
The ultra bright LEDs has a full light output and a Duracell Ultra 9V battery
will light the LEDs for approx. 14 - 15 hours. This is not a free energy light,
just a fun project when you are bored and have nothing to do.

Groundloop.

Wow, that's a cool little flashlight you've designed! You could take any old flattish 9V battery and just clip this on. In my local DIY store there's a big bin for people to throw their used batteries in, I'll bet there's plenty of Joules still in most of them, next time I'm in I might fish around in it like some battery hobo.

[Groundloop]

@Yucca,

My little clip on flash light will not light on dead 9 volt batteries.
It must be some charge in the battery. That said, most people
trow away their batteries long before the battery are empty, so the answer
is yes, you will probably find batteries in the bin that still are usefull
for some few hours of light.

@All,

Did anybody replicate the Sweet DTO circuit?

Groundloop.

[zon]

@all
Here is my design favorite for highly efficient of led driver.
Easy to build and will run a couple of weeks with 24 hours lit on.

Coil setup:

Take 1.2 metres  of two wire the SWG 38 and SWG 35.
Wound together (bifilar).
Fill surrounded of toroid
At my toroid size will fill at 50 turns

After we make one layer coil, take 3.4 metres of the SWG 35
Wound on top of bifilar layer, same direction.
Make 2 layers,  at my toroid size will fill at 150 turns.

Now, we have coil with three layer, one layer of bifilar coil and two layers of feedback coil.
Covering the hole toroid with 2 magnets, configuration from bottom is   
     South-North  ?   Coil  ?   South-North

Current measurement at + battery  is 14 mA.
But running time not same with capacity battery mAH / 14 ma = xxx Hours.
It's longer than xxx hours
I don't know why ?

zon

[gyulasun]

Current measurement at + battery  is 14 mA.
But running time not same with capacity battery mAH / 14 ma = xxx Hours.
It's longer than xxx hours
I don't know why ?

zon

Hi Zon,

Thanks for these interesting infos.  For the time being I think the only possible answer for your 'why' question is that you found/experimented a good practical circuit for feeding back the flyback pulse energy of the coil to the battery so that the load on the battery is eased, its mAh capacity is extended out for a longer time periode.
Because if I am mistaken and you get any extra energy, then your battery at least would stay on a charged up state for several months due to the continuos trickle charge it receives back from the circuit.
OR if you could replace the battery for a few seconds with a 1F or 3.3F supercapacitor charged up in advance to around 1.274V and see how long the LED stays on with the same or similar brightness and measure the supercap voltage if it starts decreasing or increasing or just does not change:  This would prove for yourself if you have any extra output or not?

Would you measure the current that flows through your LED?  I am curious because its brightness seems stronger on your photo with respect to the total current of 14mA consumed (I know the angle of view can also be decisive on the brightness).

thanks,  Gyula

[zon]

@all
sorry, i make mistake on  schematic drawing. See attachment for correction.


@Gyula
I will measure the current that flows through LED and disconnect LED with capacitor together, because if i disconnect without capacitor, the LED will burn. Output voltage without load is 20 VDC


zon